Fairey P24 engine

[PMN1]

Found some information on the Fairey P24 in one of Bill Gunston’s books (World Encyclopaedia of Aero Engines)

‘Forsyth went ahead in October 1935 with the totally new P.24, aimed at carrier-based aircraft. Twin-engine reliability was to be gained (for the first time in any engine) by having two halves each comprising a vertically opposed 12-cyclinder unit with a side supercharger, with pressure-glycol cooling. Each crankshaft was geared to its own coaxial propeller of Fairey constant speed type. Each half engine was tested throughout 1938 (the test bed could not handle the 2,200 total horsepower), and on 30th June 1939 the P.24 was flown in a Battle (K9370). With a potential for 3,000hp, the P.24 was considered for the Hawker Tornado and then the P-47 Thunderbolt, the Battle flying some 250hrs at Wright Field in 1942, but wartime pressures forced the termination of what was a very promising engine.’

Janes also mentions it flying between June 13th 1939 and December 5th 1941 in the UK with about 86 flying hours being made.

Anybody know what the results of this testing in a Battle were?

Given the fact that it was tested in a Battle suggests it could have gone into a Fulmar, Firefly or a Barrcuda – anybody want to hazard a guess of these aircraft’s performance with this engine had it been successfully introduced?

[PMN1]

I've been sent some information on this,

With the P24 design - there was no "coupling" of its two component halfs - They were two entirely separate engines - one of which drove its propeller through the hollow driveshaft of the other. Other than that there was absolutely no mechanical linkage between the two "halves" at all – So very little to go wrong.

The P24 Monarch was a very advanced engine if the surviving details are true...

Compressed Glycol /Water Cooling - As first used in Rolls Royce production engines (Merlin XII) from the end of 1940. RPM of 3,000 (same as wartime Merlins) 2 Stage, 4 Speed supercharger (Rolls Royce only ever managed a 2 speed Supercharger on the Merlin and only managed a 3-speed supercharger on post-war Griffons).

With a 2-stage, 4 speed supercharger you would expect the Monarch to have had a very impressive performance at height.

There were two designs - The 16 Cylinder H-16 "Prince" of 1.540 hp and the 24 cylinder P-24 "Monarch" of 2,240hp (perhaps more). The H-16 had only a two-speed single stage supercharger.

The H-16 could well have boosted a Battle Bomber to close to 300 mph - who knows with a Monarch - 350 mph + ???

The Fulmar and Barracuda could have had similar boosts in performance – along with "Twin-engine" reliability.

Both the H-16 and P-24 used essentially the same cylinders as the earlier P12 Prince - Which had first flown in 1934, and it used poppet-valves, and so would have had none of the problems Bristol + Napier had with sleeve-Valves, so it is by no means unreasonable to think that with a bit of government backing the H-16 and P-24 could have been in production as early as 1938, and certainly by 1940. As it was CR Fairey said to have spent at least 1 million pounds (at today’s prices) out of his own pocket on the project.

[Groggy]

quote:Originally posted by PMN1

I've been sent some information on this,

With the P24 design - there was no "coupling" of its two component halfs - They were two entirely separate engines - one of which drove its propeller through the hollow driveshaft of the other. Other than that there was absolutely no mechanical linkage between the two "halves" at all ?So very little to go wrong.

The P24 Monarch was a very advanced engine if the surviving details are true...

Compressed Glycol /Water Cooling - As first used in Rolls Royce production engines (Merlin XII) from the end of 1940. RPM of 3,000 (same as wartime Merlins) 2 Stage, 4 Speed supercharger (Rolls Royce only ever managed a 2 speed Supercharger on the Merlin and only managed a 3-speed supercharger on post-war Griffons).

With a 2-stage, 4 speed supercharger you would expect the Monarch to have had a very impressive performance at height.

There were two designs - The 16 Cylinder H-16 "Prince" of 1.540 hp and the 24 cylinder P-24 "Monarch" of 2,240hp (perhaps more). The H-16 had only a two-speed single stage supercharger.

The H-16 could well have boosted a Battle Bomber to close to 300 mph - who knows with a Monarch - 350 mph + ???

The Fulmar and Barracuda could have had similar boosts in performance ?along with "Twin-engine" reliability.

Both the H-16 and P-24 used essentially the same cylinders as the earlier P12 Prince - Which had first flown in 1934, and it used poppet-valves, and so would have had none of the problems Bristol + Napier had with sleeve-Valves, so it is by no means unreasonable to think that with a bit of government backing the H-16 and P-24 could have been in production as early as 1938, and certainly by 1940. As it was CR Fairey said to have spent at least 1 million pounds (at today’s prices) out of his own pocket on the project.




I agree the Fairey P.24 was a very advanced engine. I have seen a drawing of a Fairey Project for a Naval aircraft With a Fairey Queen engine, that from the drawing must have been the P.16. I believe the Monarch was intended for the Fairey Heavy Bomber project hence the advanced supercharger. The Bomber was to have used two Monarchs and would have had a tricycle undercarraige. the 100+feet
wingspan was greater than the Avro Manchester which was similar in looks. Rolls Royce considered producing a much altered version of the Merlin with Two Merlins configured like the Monarch. There is a wonderful cutaway drawing of the project in a picture history of Rolls Royce engines. I would be very interested in drawings of the Heavy Bomber.

Some fifty years ago I recall a former Westland employee saing that Petter wanted to install a pair of Merlins in the Whirlwind before the start of the 2nd WW.

[Wuzak]

This is the sort of engine that I was looking for earlier.

Anyone got any physical dimensions?


Since the Battle was equipped with a Merlin, could we assume that any Merlin powered aircraft could have been converted to use this powerplant?

Imagine that, a twin engined Spitfire in 1940 with 2000hp! Or a 4 engined Mosquito.....

A quick google search came up with this http://forum.keypublishing.co.uk/showthread.php?t=33404 which contains a couple of photos of the engine.

[Nick Sumner]

Since the Battle was equipped with a Merlin, could we assume that any Merlin powered aircraft could have been converted to use this powerplant?

No I don't think that's a safe assumption at all. Weight and frontal area would increase sharply with a double merlin. the Germans had many problems perfecting coupled V-block engines, note that the monarch is two horizontally opposed types, ie two 'I' block engines not 'V' blocks.

Is there any evidence that the afore mentioned P24 powered Battle flew with both 'halves' of the engine installed? Fairey aircraft since 1915 implies that it flew with half the engine but doesn't state catagorically that it flew with both.

What may have killed the project was that 4 'hyper' engines (ie 2000 + HP, Vulture, Griffon, Sabre and Centaurus) were already flying in prototypes in 1940. It wasn't then clear how problematic their development would be.

[Groggy]

quote:Originally posted by Nick Sumner

Since the Battle was equipped with a Merlin, could we assume that any Merlin powered aircraft could have been converted to use this powerplant?

No I don't think that's a safe assumption at all. Weight and frontal area would increase sharply with a double merlin. the Germans had many problems perfecting coupled V-block engines, note that the monarch is two horizontally opposed types, ie two 'I' block engines not 'V' blocks.

Is there any evidence that the afore mentioned P24 powered Battle flew with both 'halves' of the engine installed? Fairey aircraft

since 1915 implies that it flew with half the engine but doesn't state catagorically that it flew with both.

What may have killed the project was that 4 'hyper' engines (ie 2000 + HP, Vulture, Griffon, Sabre and Centaurus) were already flying in prototypes in 1940. It wasn't then clear how problematic their development would be.


Yes, the P.24 flew with both halves, both in the UK and the USA where I believe That the Spec. and flight test results still exist, can any one help locate them? As I understand it The combined unit was tested halve at a time by Fairey. The Merlin V block was changed to a verticaly opposed I for the RR design study. From memory the P.24 was about 84 x 53 x 43 inches which is compact for such a big beast,which is about double the frontal area of the Merlin, they have an original engine at the FAA Museum in the reserve collection but I understand they will charge £18 to look at it!!! Testing started in 1938 and flight testing in 1939 and was trouble free as far as I am aware. The American test results would be interesting if any one can locate them.

[PMN1]

quote:Originally posted by Wuzak

Or a 4 engined Mosquito.....





Tony Has this in his book - he's called it the Manchester......

:)

[PMN1]

quote:Originally posted by Nick Sumner

Is there any evidence that the afore mentioned P24 powered Battle flew with both 'halves' of the engine installed? Fairey aircraft since 1915 implies that it flew with half the engine but doesn't state catagorically that it flew with both.

What may have killed the project was that 4 'hyper' engines (ie 2000 + HP, Vulture, Griffon, Sabre and Centaurus) were already flying in prototypes in 1940. It wasn't then clear how problematic their development would be.


Doesn't say that it didn't either...

:D

My guess is you are correct on why it didn't get far, John Dell has written a book that includes the Fairey engines, he is currently looking for a publisher.

[ChrisMcD]

Gents,

I suspect that the main problem with the P24 was that it was sponsored by Richard Fairey.

Fairy had monumental battles with the Air Ministry and they did not forgive him for building a private venture bomber - with an American engine - that was faster than all the UK's fighters. They bought a squadron but not with good grace and mucked him about royally over the Fairey Night Bomber monoplane.

It is widely believed that the Curtis D12 in the Fairey Fox was the main reason Rolls were cajoled/coerced into building the Kestrel - which powered the Fox II!

So it is highly probable that the Air Ministry were determined not to have anything to do with another Fairey engine however good it was! Which might also explain the Admiralty interest as well.

[Groggy]

quote:Originally posted by ChrisMcD

Gents,

I suspect that the main problem with the P24 was that it was sponsored by Richard Fairey.

Fairy had monumental battles with the Air Ministry and they did not forgive him for building a private venture bomber - with an American engine - that was faster than all the UK's fighters. They bought a squadron but not with good grace and mucked him about royally over the Fairey Night Bomber monoplane.
It is widely believed that the Curtis D12 in the Fairey Fox was the main reason Rolls were cajoled/coerced into building the Kestrel - which powered the Fox II!
So it is highly probable that the Air Ministry were determined not to have anything to do with another Fairey engine however good it was! Which might also explain the Admiralty interest as well.


Good point, At the time as I understand it there was a airframe manufactures cartel and engine cartel. poor old Fairey was not a member of either and had to smile when one of the Curtis D.12 was loaned to Rolls Royce for a look see.

Richard Fairey must have lived in hope because the primary reason for the P.12 was for the large Bomber proposal, I only recall seeing two references to it in print, the last was some twenty plus years ago, It woud be interesting if any one can find details about it.

The developed engine was expected to give about 3200 hp so the large mossie should have moved, any one care to hazard a guess how fast?
The photos of the Monarch are great, its a pity the engine is not on public veiw

[Wuzak]

I did a rough calc for a Mosquito using a pair of RR Eagle 22s. That was also to be rated at about 3200hp.

The number that it spat out was 481mph (775km/h)!

Which is fair moving for a bomber! So the larger Mossie would have easily done the projected 430mph.


Just remembered that the Sabre Mosquito was to do 430mph on 2 Sabres rated around 2500hp. Assuming this, the simple estimate gives 466mph (752km/h) top speed for teh Super Mossie. Considering it was to carry up to 16000lb (or 6000lb depending on who you speak to) that speed is impressive.

[Groggy]

quote:Originally posted by Wuzak

I did a rough calc for a Mosquito using a pair of RR Eagle 22s. That was also to be rated at about 3200hp.

The number that it spat out was 481mph (775km/h)!

Which is fair moving for a bomber! So the larger Mossie would have easily done the projected 430mph.


Just remembered that the Sabre Mosquito was to do 430mph on 2 Sabres rated around 2500hp. Assuming this, the simple estimate gives 466mph (752km/h) top speed for teh Super Mossie. Considering it was to carry up to 16000lb (or 6000lb depending on who you speak to) that speed is impressive.


That is a fair mover, thinks! The Monarch could have benn in production about six years befoe the Eagle,would it have benn a major influence???

[Wuzak]

quote:Originally posted by Groggy
[brThat is a fair mover, thinks! The Monarch could have benn in production about six years befoe the Eagle,would it have benn a major influence???


I think so. Consider that the Lancaster could have used two Monarchs instead of 4 Merlins for similar, or better, performance. Fighter aircraft designed around it would have had a significant power and speed advantage over the enemy early in the war. Could have tipped the airwar balance to the allies earlier.

[Mark J]

The P-47 nearly had the Fairey engine.........
cheers

[Groggy]

quote:Originally posted by Mark J

The P-47 nearly had the Fairey engine.........
cheers


It would have been a good combination, potentialy 500mph, any thoughts?

The only drawings of the P16 in the public domain are to found in Fairey Firefly by W. Harrison,Airlife, ISBN 1 85310 196 6, PAGES 2+3
They show two designs by Marcel Lobelle. To Spec. N8/39 and N9/39 that appear to have some better design points than the latter Firefly.
as some one has already pointed out, The Fulmar would have been a could candidate for the Monarch or Queen. Given that Monarch would have given about 3000hp and the Queen about 1800hp what sort of preformance would that have given?

[Wuzak]

quote:Originally posted by Groggy

quote:Originally posted by Mark J

The P-47 nearly had the Fairey engine.........
cheers


It would have been a good combination, potentialy 500mph, any thoughts?

The only drawings of the P16 in the public domain are to found in Fairey Firefly by W. Harrison,Airlife, ISBN 1 85310 196 6, PAGES 2+3
They show two designs by Marcel Lobelle. To Spec. N8/39 and N9/39 that appear to have some better design points than the latter Firefly.
as some one has already pointed out, The Fulmar would have been a could candidate for the Monarch or Queen. Given that Monarch would have given about 3000hp and the Queen about 1800hp what sort of preformance would that have given?


Give us some base numbers - power and speed - for the model you want checked, and I'll put it into the magic fomula for estimating speed.

[Groggy]

quote:Originally posted by Wuzak

quote:Originally posted by Groggy

quote:Originally posted by Mark J

The P-47 nearly had the Fairey engine.........
cheers


It would have been a good combination, potentialy 500mph, any thoughts?

The only drawings of the P16 in the public domain are to found in Fairey Firefly by W. Harrison,Airlife, ISBN 1 85310 196 6, PAGES 2+3
They show two designs by Marcel Lobelle. To Spec. N8/39 and N9/39 that appear to have some better design points than the latter Firefly.
as some one has already pointed out, The Fulmar would have been a could candidate for the Monarch or Queen. Given that Monarch would have given about 3000hp and the Queen about 1800hp what sort of preformance would that have given?


Give us some base numbers - power and speed - for the model you want checked, and I'll put it into the magic fomula for estimating speed.


Many Thanks,
The Fulmar Mk1 with 1080hp Merlin VIII about 250 to 260mph on a good day

[Red Admiral]

3#8730;1080=10.26

255/10.26=24.85

3#8730;1800=12.16

24.85*12.16=302mph or 358mph with 3000hp.

[PMN1]

Fairey P13/36 - to be powered by 2 P24's though Vulture and Sabre engine options were avaialble.

Based on the P4/34 light bomber, with 2 P24 engines it would have a top speed of 327mph at 17,000ft though Tony Butler's book only says 4,000lb bombload rather than the 8,000lb that the spec called for.

Span 85ft, length 55ft, WA ?, Max TO 38,678lb, twin 0.303" MG in nose and quad 0.303" MG in tail.

This to me looks the most 'right' of the P13/36 submissions, to me the rest look like dogs or look out of proportion (Manchester).

http://img.photobucket.com/albums/v136/paul1/FaireyP1336.jpg

[dannycarroll]

Give us some base numbers - power and speed - for the model you want checked, and I'll put it into the magic fomula for estimating speed.
[/quote]

Kutcha and others, can you post those formulae you guys make the comparisons with please? I am keen to do some of my own.

Cheers

[Groggy]

quote:Originally posted by dannycarroll

Give us some base numbers - power and speed - for the model you want checked, and I'll put it into the magic fomula for estimating speed.


Kutcha and others, can you post those formulae you guys make the comparisons with please? I am keen to do some of my own.

Cheers
[/quote]

The 1936 figures would have been for 87oct by 1941 it would have been 100oct.
.........................
Fairey H-16 Prince, Queen. fuel spec. not known; as tested 1938/39?.

Take-Off,S/L
1,580BHP; 2,800RPM; Max Boost +3.
Normal Continuous Climb (Rated) Power.
1,540BHP; 2,000RPM; Max Boost +2; Rated Alt. 8,500feet.
Maximum Power (Emergency, Combat, 5 Minutes)
1,600BHP; 3,000RPM; Max Boost +3; Altitude 10,000feet.

DRY WT 2,180LB
.............................
Fairey H-24 Prince, Monarch. fuel spec. not known, as tested.

Take-Off,S/L
2,240BHP; 3,000RPM; Max Boost +???.
Normal Continuous Climb (Rated) Power.
2,240BHP; 3,000RPM; Max Boost +???; Rated Alt. 9,000feet.
Maximum Power (Emergency, Combat, 5 Minutes)
2,2040BHP; 3,000RPM; Max Boost +???; Altitude ????feet.
DRY WT ????LB.
One could ask the FAA Museum to put it on the scales.

Note Fairey were expecting to eventually get 3,200BHP from the Monarch
: Rough estimate (needs checking) Frontal area about 1.5x Merlin
.............................

I agree the Fairey P13/36 looks good. So there was Two fairey Propsals with twin Monarchs?? Many years ago I remember reading about a Fairey proposal with twin Monarchs which I thought said that it had 100+ foot wingspan, can any one help.

[Wuzak]

quote:Originally posted by dannycarroll

Kutcha and others, can you post those formulae you guys make the comparisons with please? I am keen to do some of my own.

Cheers


It is a simple formula, but is by no means very accurate. For a start the top speeds of aircraft are not always at the maximum power figure. Consider that a Mosquito's top speed is recorded about 20,000ft, but its engines produce maximum power at lower altitude. It also assumes 100% efficiency of translating the power into thrust, which is not the case, and most probably varies with speed.

That being said it can be a good indicator.

The basis of the formula is that drag is roughly proportional to the square of the speed.

Mathematically, F (drag) = k * V².

Also, power is defined as the work done per unit time. Work is expressed as force times distance ie W = F * d, so power is work divided by time ie P = W/t, or P = (F * d) / t.

Rearranging that we get P = F * (d/t), where d/t = V or speed.

Hence P = F * V

In our case the force is drag. So substituting the drag formula we qet:

P = k * V² * V

=> P = k * V³

To get the original value of k we rearrange the formula to get

k = P/V³

Once we have that we can plug the new power number back into the formula and rearrane to solve for V, we have

V = (P/k)^(1/3) [ie the cube root of P/k].

So long as the units used in all the calculations are consistent, the units used doesn't matter.

It is assumed that k is constant. k is equivalent to the coeffcient of drag multiplied by the cross sectional area, or CdA.

Sometimes an engine swap may cause an increase (or reduction) of drag for the installation. That can be compensated for by a guess of a percentage change, and applied to the k value.

[Wuzak]

quote:Originally posted by Groggy

The 1936 figures would have been for 87oct by 1941 it would have been 100oct.
.........................
Fairey H-16 Prince, Queen. fuel spec. not known; as tested 1938/39?.

Take-Off,S/L
1,580BHP; 2,800RPM; Max Boost +3.
Normal Continuous Climb (Rated) Power.
1,540BHP; 2,000RPM; Max Boost +2; Rated Alt. 8,500feet.
Maximum Power (Emergency, Combat, 5 Minutes)
1,600BHP; 3,000RPM; Max Boost +3; Altitude 10,000feet.

DRY WT 2,180LB
.............................
Fairey H-24 Prince, Monarch. fuel spec. not known, as tested.

Take-Off,S/L
2,240BHP; 3,000RPM; Max Boost +???.
Normal Continuous Climb (Rated) Power.
2,240BHP; 3,000RPM; Max Boost +???; Rated Alt. 9,000feet.
Maximum Power (Emergency, Combat, 5 Minutes)
2,2040BHP; 3,000RPM; Max Boost +???; Altitude ????feet.
DRY WT ????LB.
One could ask the FAA Museum to put it on the scales.

Note Fairey were expecting to eventually get 3,200BHP from the Monarch
: Rough estimate (needs checking) Frontal area about 1.5x Merlin
.............................

I agree the Fairey P13/36 looks good. So there was Two fairey Propsals with twin Monarchs?? Many years ago I remember reading about a Fairey proposal with twin Monarchs which I thought said that it had 100+ foot wingspan, can any one help.


Let's assume the rated speed (say 260mph) came at 8-9,000ft, and the Merlin's rated horsepower (1080hp) was also at that altitude.

we have k = P/V³

So k = 1080/(260^3)

k = 0.000061447

Since the frontal area of the engine has increased the frontal area of the plane has increased. But the frontal area is the whole frontal area, which includes wing, tail, etc. So let's say 25% increase in area. The actual coeffcient of drag could probably have been made to be very similar, as that depends on the shape, the rear end as much as the front. So an overall increase in the CdA of 25%.

This makes k = 1.25 * 0.000061447
k = 0.0000768093

Now let's assume that the rated power at 8500ft for the H16 is the same at 10,000ft. ie 1540hp.

Putting that into the power equation, V = (P/k)^(1/3)

V = (1540/0.0000768093)^(1/3)

which gives V = 272mph. Which doesn't sound much of an increase, but the original engine with the increased drag would have given 241mph.

At war emergency power (1600hp), V = 275mph.

For the H24 at normal rated power (2240hp) the speed goes up to V = 308mph.

Emergency power is less for some reason (higher altitude).

[Wuzak]

If the later Mosquitos were equipped with the projected Monarch (3200hp, say), and the fitment increased drag by 25%, the Mosquito's top speed would increase to about 472mph.

[Wuzak]

Just another thought on the speed issue.

As I said earlier, our estimates are based on the assumption that the propellor is 100% efficient in converting power to thrust.

This is not the case. The use of the Fairey engines would necessarily mean the use of a pair of coaxial propellors, which possibly would have increased the efficiency. It is doubtful that it would be as significant a change as the drag increase.

So there is just another variable to look at.

[Groggy]

quote:Originally posted by Wuzak

Just another thought on the speed issue.

As I said earlier, our estimates are based on the assumption that the propellor is 100% efficient in converting power to thrust.

This is not the case. The use of the Fairey engines would necessarily mean the use of a pair of coaxial propellors, which possibly would have increased the efficiency. It is doubtful that it would be as significant a change as the drag increase.

So there is just another variable to look at.

I think this is the same book, but later edition in which the RR H-24 Merlin proposed varaint just like the Monarch is shown: plus Pennine possible Crecy as well if memory serves me.

Sectioned Drawings of Piston Aero Engines
L Jones 1995 - Reprinted 2002 (80 pages, 36 illustrations)

'This A3 size book contains detailed section drawings of piston aero engines from Rolls-Royce, Bristol, Napier, de Havilland, Germany and America, together with views of aircraft.'

Price for Members: £14.00
Price for Non Members: £20.00

[Groggy]

quote:Originally posted by Groggy

quote:Originally posted by Wuzak

Just another thought on the speed issue.

As I said earlier, our estimates are based on the assumption that the propellor is 100% efficient in converting power to thrust.

This is not the case. The use of the Fairey engines would necessarily mean the use of a pair of coaxial propellors, which possibly would have increased the efficiency. It is doubtful that it would be as significant a change as the drag increase.

So there is just another variable to look at.

I think this is the same book, but later edition in which the RR H-24 Merlin proposed varaint just like the Monarch is shown: plus Pennine possible Crecy as well if memory serves me.

Sectioned Drawings of Piston Aero Engines
L Jones 1995 - Reprinted 2002 (80 pages, 36 illustrations)

'This A3 size book contains detailed section drawings of piston aero engines from Rolls-Royce, Bristol, Napier, de Havilland, Germany and America, together with views of aircraft.'

Price for Members: ?4.00
Price for Non Members: ?0.00



Hi, PMN1,

What are the details of the Tony Butler book please???

[Nick Sumner]

I think this is the same book, but later edition in which the RR H-24 Merlin proposed varaint just like the Monarch is shown: plus Pennine possible Crecy as well if memory serves me.

Sectioned Drawings of Piston Aero Engines
L Jones 1995 - Reprinted 2002 (80 pages, 36 illustrations)

'This A3 size book contains detailed section drawings of piston aero engines from Rolls-Royce, Bristol, Napier, de Havilland, Germany and America, together with views of aircraft.'

Can anyone confirm that this book has drawings of the Merlin H block engine? If not is there another source for info?

[PMN1]

quote:[i]Originally posted by Groggy

Hi, PMN1,

What are the details of the Tony Butler book please???


British Secret Projects - Fighters and Bomber 1935 - 1950

ISBN 1 85780 179 2

Price £30 (I think) unless you have a book voucher and then its free, which I did so it was.

:D

[Nick Sumner]

Speculating on why the Monarch wasn't proceeded with.

It would have been ideal for naval aircraft but until the angled deck it wasn't possible to use contraprops on carriers. The problem was that if an aircraft missed the wire and ran into a crash barrier the blades of the props would strike each other, shatter, and spread fragments like shrapnel. There were tests with contra prop spitfires in 1942. This is the same reason why there was no quick fix for the Seafire XVIIs problems.

[Groggy]

quote:Originally posted by Nick Sumner

Speculating on why the Monarch wasn't proceeded with.

It would have been ideal for naval aircraft but until the angled deck it wasn't possible to use contraprops on carriers. The problem was that if an aircraft missed the wire and ran into a crash barrier the blades of the props would strike each other, shatter, and spread fragments like shrapnel. There were tests with contra prop spitfires in 1942. This is the same reason why there was no quick fix for the Seafire XVIIs problems.


At the time the Navy would have liked contra props. The problem with the Seafire was that it was front heavy; the RAF had priority on development needs at the time. And one of the seafire screws could experience a judder of some sort.
With the Griffon difficulties were made worse the Engine turned the opposite way: the torque could send the plane to the right and into the Island.
Also Martin baker solved an oil problem with the contra prop mechanism that I think was used on the Shackelton

[Groggy]

quote:Originally posted by PMN1

Found some information on the Fairey P24 in one of Bill Gunston’s books (World Encyclopaedia of Aero Engines)

‘Forsyth went ahead in October 1935 with the totally new P.24, aimed at carrier-based aircraft. Twin-engine reliability was to be gained (for the first time in any engine) by having two halves each comprising a vertically opposed 12-cyclinder unit with a side supercharger, with pressure-glycol cooling. Each crankshaft was geared to its own coaxial propeller of Fairey constant speed type. Each half engine was tested throughout 1938 (the test bed could not handle the 2,200 total horsepower), and on 30th June 1939 the P.24 was flown in a Battle (K9370). With a potential for 3,000hp, the P.24 was considered for the Hawker Tornado and then the P-47 Thunderbolt, the Battle flying some 250hrs at Wright Field in 1942, but wartime pressures forced the termination of what was a very promising engine.’

Janes also mentions it flying between June 13th 1939 and December 5th 1941 in the UK with about 86 flying hours being made.

Anybody know what the results of this testing in a Battle were?

Given the fact that it was tested in a Battle suggests it could have gone into a Fulmar, Firefly or a Barrcuda – anybody want to hazard a guess of these aircraft’s performance with this engine had it been successfully introduced?


Some of the Merlin "Monarch clone" presentation cutaway drawings are dated 1940.I guess this means that RR were looking at the layout at an earlier period, I wonder if Fairey patented the idea???

[Wuzak]

quote:Originally posted by Groggy

Some of the Merlin "Monarch clone" presentation cutaway drawings are dated 1940.I guess this means that RR were looking at the layout at an earlier period, I wonder if Fairey patented the idea???


Did RR do some work with paired Merlins?

Or is the RR H24 referred to earlier actually the Eagle 22?

[Groggy]

quote:Originally posted by Wuzak

quote:Originally posted by Groggy

Some of the Merlin "Monarch clone" presentation cutaway drawings are dated 1940.I guess this means that RR were looking at the layout at an earlier period, I wonder if Fairey patented the idea???


Did RR do some work with paired Merlins?

Or is the RR H24 referred to earlier actually the Eagle 22?

Sorry you are right Rolls used the designation H24 to refer to the horizontal H24Eagle.
But I Meant it in the sense of a Vertical H24 Merlin Variant. They actually investigated swinging one bank of cylinders around to make a vertically opposed Merlin engine. Made the pair drive separate counter rotating airscrews Monarch style. Not much survives other than some superb section drawings which took some one at RR a lot of time and must have been based on original plans. The Eagle was more of a Sabre clone with each bank Horizontal with sleeves.

[Nick Sumner]

quote:

Sorry you are right Rolls used the designation H24 to refer to the horizontal H24Eagle.
But I Meant it in the sense of a Vertical H24 Merlin Variant. They actually investigated swinging one bank of cylinders around to make a vertically opposed Merlin engine. Made the pair drive separate counter rotating airscrews Monarch style. Not much survives other than some superb section drawings which took some one at RR a lot of time and must have been based on original plans. The Eagle was more of a Sabre clone with each bank Horizontal with sleeves.



I don't suppose you could post the drawings?

If not where are they available?

Thanks in advance.

[Groggy]

quote:Originally posted by Nick Sumner

quote:

Sorry you are right Rolls used the designation H24 to refer to the horizontal H24Eagle.
But I Meant it in the sense of a Vertical H24 Merlin Variant. They actually investigated swinging one bank of cylinders around to make a vertically opposed Merlin engine. Made the pair drive separate counter rotating airscrews Monarch style. Not much survives other than some superb section drawings which took some one at RR a lot of time and must have been based on original plans. The Eagle was more of a Sabre clone with each bank Horizontal with sleeves.



I don't suppose you could post the drawings?

If not where are they available?

Thanks in advance.



Hi Nick,
I use the local library for access to the Net and they do not have a scanner. I do have a digital camera so that might be a route or they could be photocopied and forwarded to any one who wants to post them to the site.
They are still imprint and to be found in the Rolls Royce Heritage series. Sectioned Drawings of Piston Aero Engines
L Jones 1995 - Reprinted 2002 (80 pages, 36illustrations) Rolls-Royce Heritage Trust
PO Box 31
Moor Lane
Derby DE24 8BJ
England
This assumes the second is the same as the first edition
………………………………………………………………………………………………….

I have not forgotten your question about the Merlin and Fairey. It was not the sort of thing that RR people would commit to print; it was what came up in conversation on the odd occasion over the years with people who were in the know. Both RR and others, the last person with direct knowledge that I am aware of died about four years ago. We had several very interesting conversations about the subject even when he was very ill indeed.
There is only one reference in print that I have seen and that was many years ago by a non RR or Fairey engineer person and stated what he had heard from RR engineers. I am still looking for it.
What I will do is give some dates for key events that will cast an interesting light on the subject of why I think RR developed the PV12/Merlin. I would be interested to see what you and the other members make of it.

[Nick Sumner]

Many thanks Groggy

[Groggy]

quote:Originally posted by PMN1

Found some information on the Fairey P24 in one of Bill Gunston’s books (World Encyclopaedia of Aero Engines)

‘Forsyth went ahead in October 1935 with the totally new P.24, aimed at carrier-based aircraft. Twin-engine reliability was to be gained (for the first time in any engine) by having two halves each comprising a vertically opposed 12-cyclinder unit with a side supercharger, with pressure-glycol cooling. Each crankshaft was geared to its own coaxial propeller of Fairey constant speed type. Each half engine was tested throughout 1938 (the test bed could not handle the 2,200 total horsepower), and on 30th June 1939 the P.24 was flown in a Battle (K9370). With a potential for 3,000hp, the P.24 was considered for the Hawker Tornado and then the P-47 Thunderbolt, the Battle flying some 250hrs at Wright Field in 1942, but wartime pressures forced the termination of what was a very promising engine.’

Janes also mentions it flying between June 13th 1939 and December 5th 1941 in the UK with about 86 flying hours being made.

Anybody know what the results of this testing in a Battle were?

Given the fact that it was tested in a Battle suggests it could have gone into a Fulmar, Firefly or a Barrcuda – anybody want to hazard a guess of these aircraft’s performance with this engine had it been successfully introduced?


Have just seen photograph of what is supposed to be a installed Fairey Prince P12 under test with what appears to be 16 exhaust pipes per Side???Why 16 pipes ???

[Wuzak]

If it was the H16 you were talking about, I'd suggest that one stack for each of the exhaust valve ports (32 in a 4V 16 cylinder engine).

For a 12 cylinder engine it could only be done by having extra stacks from a common manifold.

[Groggy]

quote:Originally posted by Wuzak

If it was the H16 you were talking about, I'd suggest that one stack for each of the exhaust valve ports (32 in a 4V 16 cylinder engine).

For a 12 cylinder engine it could only be done by having extra stacks from a common manifold.

Yes I agree what you post is logical. but this was a Vertical V
with 16 exhausts on one side which does not make sense to me from a 6 cylinder bank. Should have made it clear it was a Fairey biplane in which I thought they only tested the Fairey V P12. The H16 was double the weight of the P12

[Wuzak]

Much weirdness on Fairey's part!

[Groggy]

quote:Originally posted by Wuzak

Much weirdness on Fairey's part!


Yes !! and they must have done it for a reason???

[Wuzak]

quote:Originally posted by Groggy

quote:Originally posted by Wuzak

Much weirdness on Fairey's part!


Yes !! and they must have done it for a reason???


To confuse the opposition (Rolls Royce?)?

[Ricky]

An experiment, to see if splitting up the exhaust flow acheived anything? After all, the number of exhaust pipes used on the Marlin varied throughout the war.

[Wuzak]

quote:Originally posted by Ricky

An experiment, to see if splitting up the exhaust flow acheived anything? After all, the number of exhaust pipes used on the Marlin varied throughout the war.


Yes, but in a direct relationship with the number of cylinders.

The ones I am familiar with are 6 pipes per side, and 3 pipes (combining exhausts from 2 cylinders) perside.

[ChrisMcD]

It sounds like the RR Eagle was not one of Rolls Royce's better designs!

this is a quote from Mike Crosley's "Up in Harms Way"

By the way - he obvioulsy has first hand experience of Eagles, but not Vultures!!

The Navy had persisted in its desire for a dual-purpose - or multi-role -
prop-driven 'fighter/torpedo aircraft' capable of dropping a torpedo at enemy battleships into the bargain! This impossible dream - that of being able to design an aircraft for the strike role with it able to turn itself magically into a fighter once it had dropped its load on the enemy - may have had its origin when most of the brave Swordfish led by Lt/Cdr Eugene Esmonde VC had been shot down by Me 1O9s when attempting to torpedo the Scharnhorst, Gneisenau and Prinz Eugen before they could get into firing range. The remainder were then shot down by the same Me 109s on their way home as most of their Spitfire fighter escort had failed to find them as they had no radar direction.
So the first Wyvern Mark 1 piston-engined prototype with the 3,500 hp Eagle engine had been completed at Yeovil and flown from Boscombe Down by Harald Penrose - Westland's Chief Test Pilot - on 12 December 1946 -seven years before its final version arrived at Manby.
The Eagle-engined prototype's first flight was on 12 December 1946 from Boscombe Down with Pete Gamer at the controls - seven years before the Python-engined version eventually arrived with us at Manby. Initial carrier trials were carried out in May 1948 in Implacable using TS 378, one of six Eagle-engined prototypes then flying. A prop-jet engine - the 4,300 hp Rolls-Royce RB-39 Clyde - was substituted for a short time, before the Python became available. This Admiralty decision was a wise move, for, like the Manchester bomber's Vulture engine (which was virtually a couple of Merlins placed one under the other and driving the same propeller shaft), the Eagle piston engine had already shown itself to be unreliable and had some poor design features. For instance, when Harald Penrose was flying the second prototype Mark l one day, both magnetos failed in the Rolls-Royce Eagle and the engine stopped dead. He made an exceedingly skilful forced landing - having no ejector seat fitted - and inspection of the engine revealed that Rolls-Royce had designed it with a single shaft drive to the duplicated magnetos and this had fractured, so nullifying the duplication-for-safety reasons inherent in having two independently-driven magnetos and twin sets of spark plugs for each engine in all aircraft from the time of Wilbur Wright. This design error had therefore caused the loss of another aircraft, a single one of which cost the Navy its weight in solid silver to build.

Although we knew little of the Rolls-Royce Eagle engine's history at that time - for everything was secret and fatalities were seldom discussed - we were not surprised at the Eagle's cancellation for we knew that the piston engine was becoming obsolete where very high powers were needed. Moreover, the Eagle's rpm had to be kept high when taxying to prevent oiling up the lower cylinders in this 24-cylinder engine. A plug change would then be necessary - all 48 of them - and this usually took the entire day by the time things had cooled down sufficiently for work to start. The over-worked but very patient Rolls-Royce 'rep' had also warned us that when taxying down wind, the overheating that this caused could also damage a few of its 24 'sleeve' exhaust valves - due to lack of lubrication. The engine would then seize up and one or two connecting rods might appear through the crankcase and the whole aircraft could become shrouded in blue and black smoke.

After the cancellation of the Eagle-engined Mark 1 it took until late 1951 before the Python prop-jet version was sufficiently developed for it to begin its Naval clearance trials. Even then it was still suffering fatally from power and/or prop failures, a subject still of some interest to us at Manby in May 1953.

[Nick Sumner]

It sounds like the RR Eagle was not one of Rolls Royce's better designs!

But it wasn't fully developed, is it really surprising that there were problems onits first flight? Isn't finding problems the function of first flights? Look at the development cycle of the Sabre, Griffon or Centaurus, there are always difficulties to be overcome. The Eagle was dropped because it couldn't compete with gas turbines, not because it was incapable of further development or becoming a reliable engine with that development.

[Groggy]

quote:Originally posted by Nick Sumner

It sounds like the RR Eagle was not one of Rolls Royce's better designs!

But it wasn't fully developed, is it really surprising that there were problems onits first flight? Isn't finding problems the function of first flights? Look at the development cycle of the Sabre, Griffon or Centaurus, there are always difficulties to be overcome. The Eagle was dropped because it couldn't compete with gas turbines, not because it was incapable of further development or becoming a reliable engine with that development.


The Eagle was probably to complex with to small a capacity to have been useful. RR made another big mistake with the cancellation of the Clyde; They had a potential winner; it had already been tested at a power setting that would have guaranteed 500mph at sea level for the Wyvern. The layout was based on Whittles turboprop and the axial compressor was derived from Metro-Vicks work (F3?). The Wyvern did eventually have an ejector seat fitted. I remember reading about a pilot banging out underwater after ending up in the drink and he lived!!! The scary bit was the carrier’s propellers.
My gut feeling is that the RR Pennine would have been the better/ best piston engine ever but again it was too late.

[Groggy]

quote:Originally posted by Wuzak

quote:Originally posted by Ricky

An experiment, to see if splitting up the exhaust flow acheived anything? After all, the number of exhaust pipes used on the Marlin varied throughout the war.


Yes, but in a direct relationship with the number of cylinders.

The ones I am familiar with are 6 pipes per side, and 3 pipes (combining exhausts from 2 cylinders) perside.


What you say makes sense so after some thought I have now measured up the Fairey Fox 2 picture with the alleged P12 installation and the 16 exhaust stack and compared it to the standard Fairey Fox 2 with the Kestrel.
It is almost/about 40% longer across the bank than the Kestrel. The P12 was known to be a much lighter engine than the Merlin so I doubt that it was that large. Could it be Fairey’s P16 vertical V with two exhaust ports per Cylinder? Would this also account for the proportionate size increase? Many years ago it was said that the P16 was built however most recent works say it was only planned. The one thing that seems to be consistent in the Fairey engine saga is that every one said they were brilliant engines the big puzzle is just how many different engines did Fairey build in the Thirties???

[ChrisMcD]

Originally posted by Nick Sumner
_____________________________________

But it wasn't fully developed
_____________________________________

having a single magneto drive is a design flaw of the first magnitude!

Rolls were late into sleeve valves. Groggy is right they should have moved right on to turbojets and props where their compressor expertise would have been a real asset.

[Nick Sumner]

quote:Originally posted by ChrisMcD

having a single magneto drive is a design flaw of the first magnitude!



I'll take your word for it, but what I'd like to know is why they did it? As a general rule smart people make errors for good reasons, what was the reason RR did this?

[Nick Sumner]

quote:Originally posted by Groggy

My gut feeling is that the RR Pennine would have been the better/ best piston engine ever but again it was too late.



Why do you say this? - I'm not looking to pick holes in your view I'm just interested.

The Pennine was a developed Exe?

[ChrisMcD]

Hi Nick

Re: single magneto drive.

I was quoting Mike Crosley, in his book. But as a test pilot on the Wyvern, I would trust him to get 'life and death' facts right.

If you want an opinion, I think that Rolls were too prone to designing engines intended to be 'spoilers' against other companies designs. In the case of the Eagle, I think they were trying to compete with the Sabre.

JK Setright alway felt that Rolls were much better developers than designers and I think that a single magneto drive would come into this category.

But bear in mind that the auxillary drives on the Griffon were held to be a superb example of how a big capacity engine could be made so compact that it easily fitted into engine bays designed for the Merlin.

Rolls got it right more often than most, but they did make some lemons!

[Wuzak]

Having seen pics of a model Eagle 22, I have to say it was a very complicated piece of equipment.

Maybe someone was conciously trying to reduce the complexity, but chose the wrong component to do it with!

[Groggy]

quote:Originally posted by Wuzak

Having seen pics of a model Eagle 22, I have to say it was a very complicated piece of equipment.

Maybe someone was conciously trying to reduce the complexity, but chose the wrong component to do it with!

Hi Folks!!
Sorry pardon, eating humble pie. New prescription spectacles and a big magnifying glass and the 16 exhaust ports become 12 exhaust ports. Wuzak, your logic is good 3 or 6 per bank makes sense, but we now know that the P12 does have two exhaust ports per cylinder. Looks a bit like truncated mutant bagpipes. I am still puzzled by the overall length increase so have asked some retired RR people when they have the chance to measure up the Kestrel and Merlin banks across the exhaust ports. Will double check before posting next time, my memory is still good and my vision now excellent with the new glasses!! MERRY XMAS

[Groggy]

[/quote]
Hi Folks.
Sixty-three years ago in 1943 Metrovik tested very successfully a counter-rotating open rotor motor. This week’s Flight reports renewed interest by Rolls Royce in open rotors— ..... “perhaps even with the two rotors spinning in opposite directions” ....No doubt much refined, but with out the old manufacturing cartel retarding progress one wonders where we could have been today. I have been promised some very interesting material relating to the Fairey P.24 Monarch but it could be September before I see it.

[ChrisMcD]

Hi Groggy,

Have you seen this link

http://forum.keypublishing.co.uk/showpost.php?p=495538&postcount=4

P 24 Photos, albeit not very clear ones. from the FAA Museum

[Red Admiral]

Groggy, do you happen to have any details on the R-R Pennine? I can't find mention of anything apart from it's existance.

[Groggy]

quote:Originally posted by Red Admiral

Groggy, do you happen to have any details on the R-R Pennine? I can't find mention of anything apart from it's existance.


Hi ChrisMcD
Many thanks, it look s very clean to be in a store.
------------------------
Hi Red Admiral,

The Pennine design 1942, aircooled, sleeve valve, 24 cylinders, four rows six cylinder set at 90 degrees X configuration, 5.4 inch bore, 5 inch stroke, 44 litres, epicycle gears allows airscrew on centre line/ inline with crankshaft, Civil rating 3,000+hp.
Rolls Royce Heritage Trust Book of Cutaway Drawings excellent, also shows 16X double engine, but can not find my copy—
Personal opinion it looks a superb engine possible the best large aero piston engine ever.

[Groggy]

Hi Folks,

Nick, PMN1 I promised to keep you aware as far as I can of Fairey developments but had to sign a form about copy right; hope this is OK, this was from a letter buried amongst a welter of other papers and only the very shortest of looks before they were whisked away. Tantalising glimpse from private correspondence of what the thoughts were about the P24 in the States. There was another fighter that was thought a better candidate than the P47 for the P24. No details given; what could that have been? The P24 was about half a ton lighter? than the best American large liquid cooled engine for similar power out put. What were these large engines in the 2500 to 3000hp range? They wanted clearance to tell the Americans about a 4000hp Fairey engine or design as well as yet another Fairey engine development? Not the helicopter engine. I am told there is no references to the proposed large bomber projects known to have survived in this archive. Although some material was apparently saved from a giant bonfire of Fairey drawings etc, but I do not have a clue as to what or were that material is . . It is just so sad and frustrating.

[Kutscha]

Ok, only a scale model (1/5 scale) of the Eagle

http://www.enginehistory.org/eagle_22.htm

And for those interested in the Merlin, http://www.enginehistory.org/merlin_xx.htm

If one wants their own Merlin (1/4 scale), http://dynamotive.netfirms.com/merlin/

Looks like a good book

Rolls-Royce: Piston Aero Engines
By: A. A. Rubbra
#8116 - 156 Pages Pages
Softcover
210mm x 150mm
£9.00

Rolls-Royce piston engines, components and accessories in detail.

The Kestral, Eagle XVI, Goshawk, Peregrine, Buzzard and 'R' engines.

A large portion of this book is devoted to the Merlin and it's features and components - ramp cylinder head, supercharger and auxiliary drives, two-piece cylinder block, valves and valve gear, auxiliary gearboxes, variable-pitch propeller, two stage supercharger engines, main bearing oil feed, end-to-end crankshaft oil feed, flame traps, engine externals, carburettors and fuel injection equipment, valves and valve gear.

Chapters also cover the Griffon, left and right tractor Merlins, Contra-rotating propellers, the Eagle 22, the Vulture, the Exe and the Crecy engines.

Very well illustrated withy technical drawings and photographs.

Lots of other goods books, http://www.rolls-royce.com/history/publications/historical2.jsp

[Red Admiral]

For those of you who are interested the scale Eagle 22 only runs satisfactoraly on meths. I met a guy who writes for Model Engineer a few months back and apparently the small sleeve vales are real buggers and don't work well with aviation spirit, well yet anyway.

[Nick Sumner]

quote:Originally posted by Groggy

Hi Folks,

Nick, PMN1 I promised to keep you aware as far as I can of Fairey developments but had to sign a form about copy right; hope this is OK, this was from a letter buried amongst a welter of other papers and only the very shortest of looks before they were whisked away. Tantalising glimpse from private correspondence of what the thoughts were about the P24 in the States. There was another fighter that was thought a better candidate than the P47 for the P24. No details given; what could that have been? The P24 was about half a ton lighter? than the best American large liquid cooled engine for similar power out put. What were these large engines in the 2500 to 3000hp range? They wanted clearance to tell the Americans about a 4000hp Fairey engine or design as well as yet another Fairey engine development? Not the helicopter engine. I am told there is no references to the proposed large bomber projects known to have survived in this archive. Although some material was apparently saved from a giant bonfire of Fairey drawings etc, but I do not have a clue as to what or were that material is . . It is just so sad and frustrating.




Groggy, thanks for keeping us posted.

[PMN1]

Someone I know has heard on the grapevine that plans for the Monarch to go into production were much more advanced than had previously been thought - By Wolsey in the UK and more particularly by Ford in the US (this was apparently pre Pearl Harbour) with the engines destined to be fitted in British airframes.

He is hoping to shortly track down proof - does anyone have info on the subject?

[PMN1]

quote:Originally posted by Groggy

Hi Folks,

Nick, PMN1 I promised to keep you aware as far as I can of Fairey developments but had to sign a form about copy right; hope this is OK, this was from a letter buried amongst a welter of other papers and only the very shortest of looks before they were whisked away. Tantalising glimpse from private correspondence of what the thoughts were about the P24 in the States. There was another fighter that was thought a better candidate than the P47 for the P24. No details given; what could that have been? The P24 was about half a ton lighter? than the best American large liquid cooled engine for similar power out put. What were these large engines in the 2500 to 3000hp range? They wanted clearance to tell the Americans about a 4000hp Fairey engine or design as well as yet another Fairey engine development? Not the helicopter engine. I am told there is no references to the proposed large bomber projects known to have survived in this archive. Although some material was apparently saved from a giant bonfire of Fairey drawings etc, but I do not have a clue as to what or were that material is . . It is just so sad and frustrating.




A thought on that other fighter, when was this proposed as an engine that you could shut down half the engine would presumably be useful for a long range fighter such as the Fisher P75 Eagle. The Monarch isn't developing the power the Eagle's eventual engine did but with development??

[Groggy]

quote:Originally posted by PMN1

quote:Originally posted by Groggy

Hi Folks,

Nick, PMN1 I promised to keep you aware as far as I can of Fairey developments but had to sign a form about copy right; hope this is OK, this was from a letter buried amongst a welter of other papers and only the very shortest of looks before they were whisked away. Tantalising glimpse from private correspondence of what the thoughts were about the P24 in the States. There was another fighter that was thought a better candidate than the P47 for the P24. No details given; what could that have been? The P24 was about half a ton lighter? than the best American large liquid cooled engine for similar power out put. What were these large engines in the 2500 to 3000hp range? They wanted clearance to tell the Americans about a 4000hp Fairey engine or design as well as yet another Fairey engine development? Not the helicopter engine. I am told there is no references to the proposed large bomber projects known to have survived in this archive. Although some material was apparently saved from a giant bonfire of Fairey drawings etc, but I do not have a clue as to what or were that material is . . It is just so sad and frustrating.




A thought on that other fighter, when was this proposed as an engine that you could shut down half the engine would presumably be useful for a long range fighter such as the Fisher P75 Eagle. The Monarch isn't developing the power the Eagle's eventual engine did but with development??

Hi PMN1,
There are two references to this other American fighter, but not a clue as to which one it was. Your suggestion is a good candidate, Power out put 2400 hp is the Fairey figure in a brochure. The US Army Air Corp think 2500 Hp. and the American Navy think 2750 hp, I do not as yet know why the differences. There is a figure of 1500hp quoted for half the P24 on trials in the UK.
The contra-prop is of great interest to the Americans as it works, when combined with the P24 is a 1000lbs lighter than the best inline liquid cooled motor plus contra-prop proposed American combination This from a document. I do not which specific engines are being referred to? Hope this helps? I will look for the date, but have nothing on shutting half the engine down. but from the beginning it was possible for ground running with either RH or LH half for tests.

[Groggy]

A thought on that other fighter, when was this proposed as an engine that you could shut down half the engine would presumably be useful for a long range fighter such as the Fisher P75 Eagle. The Monarch isn't developing the power the Eagle's eventual engine did but with development??
[/quote]

Hi PMN1
What would the Fisher P75 Eagle have done with Two Monarchs in tandem mounted in the fuselage? having now looked at a plan view of the Fisher P75 Eagle . I recall this looks a bit like a sketch view that was amongst the letters and which did not make much sense at the time. But else ware there was a power curve for such an engine giving 4,400hp output so they looking at the possibility of such an 48 cylinder powerpack,that is two coupled Monarchs,engine.

[PMN1]

Anyone want to guestimate the speed, range etc of a 4 Monarch engine B-29?

[Wuzak]

quote:Originally posted by PMN1

Anyone want to guestimate the speed, range etc of a 4 Monarch engine B-29?


The numbers for the Monarch are very similar to that forteh V-3420 which was used in the B-29.

The numbers for the V-3420 equipped XB-39 were:

Maximum speed: 405 mph/648 km/h
Range 6,290 mi/10,060 km
Service ceiling: 35,000 ft/11,000 m
Wing loading: 69.12 lb/ft²/337.5 kg/m²
Power/mass: .073 hp/lb/121 W/kg

[Montana]

quote:Originally posted by Wuzak

quote:Originally posted by PMN1

Anyone want to guestimate the speed, range etc of a 4 Monarch engine B-29?


The numbers for the Monarch are very similar to that forteh V-3420 which was used in the B-29.

The numbers for the V-3420 equipped XB-39 were:

Maximum speed: 405 mph/648 km/h
Range 6,290 mi/10,060 km
Service ceiling: 35,000 ft/11,000 m
Wing loading: 69.12 lb/ft²/337.5 kg/m²
Power/mass: .073 hp/lb/121 W/kg


Hi,

was the Vmax calculated with or without gun-turrets? If it was calculated with full armament - then with the turrets deleted, the XB-39 might have been a 700 km/h-bomber, in fact.

Whoopy!

Montana

[Wuzak]

quote:Originally posted by Montana



Hi,

was the Vmax calculated with or without gun-turrets? If it was calculated with full armament - then with the turrets deleted, the XB-39 might have been a 700 km/h-bomber, in fact.

Whoopy!

Montana


That performance was for an XB-39 with full armamemnt (ie all turets). Couldn't tell you at what weights they did that.

[Groggy]

quote:Originally posted by Wuzak

quote:Originally posted by Montana



Hi,

was the Vmax calculated with or without gun-turrets? If it was calculated with full armament - then with the turrets deleted, the XB-39 might have been a 700 km/h-bomber, in fact.

Whoopy!

Montana


That performance was for an XB-39 with full armamemnt (ie all turets). Couldn't tell you at what weights they did that.


Hi PMN1, Wuzak, Montana, Folks,
A t 36,000 feet the Anglo-American Fairey Ford Monarch would give 2,210 hp total with ejector thrust factored in. does this help?

[Wuzak]

quote:Originally posted by Groggy

quote:Originally posted by Wuzak

quote:Originally posted by Montana



Hi,

was the Vmax calculated with or without gun-turrets? If it was calculated with full armament - then with the turrets deleted, the XB-39 might have been a 700 km/h-bomber, in fact.

Whoopy!

Montana


That performance was for an XB-39 with full armamemnt (ie all turets). Couldn't tell you at what weights they did that.


Hi PMN1, Wuzak, Montana, Folks,
A t 36,000 feet the Anglo-American Fairey Ford Monarch would give 2,210 hp total with ejector thrust factored in. does this help?



The maximum speed of the XB-39 was recorded at 35,000ft, but the quoted power for the V-3420 was 2,100 hp (1,565 kW) at 2,600 rpm at 25,000 ft (7,625 m) maximum continuous power (from http://en.wikipedia.org/wiki/Allison_V-3420).

We need to know what hp the engines were producing at 35,000ft, the point of maximum speed, or what speed the aircraft was doing at point of maximum hp.

If we just use the max horsepower difference the speed difference would not be great.

[Groggy]

quote:Originally posted by Wuzak

quote:Originally posted by Groggy

quote:Originally posted by Wuzak

quote:Originally posted by Montana



Hi,

was the Vmax calculated with or without gun-turrets? If it was calculated with full armament - then with the turrets deleted, the XB-39 might have been a 700 km/h-bomber, in fact.

Whoopy!

Montana


That performance was for an XB-39 with full armamemnt (ie all turets). Couldn't tell you at what weights they did that.


Hi PMN1, Wuzak, Montana, Folks,
A t 36,000 feet the Anglo-American Fairey Ford Monarch would give 2,210 hp total with ejector thrust factored in. does this help?



The maximum speed of the XB-39 was recorded at 35,000ft, but the quoted power for the V-3420 was 2,100 hp (1,565 kW) at 2,600 rpm at 25,000 ft (7,625 m) maximum continuous power (from http://en.wikipedia.org/wiki/Allison_V-3420).

We need to know what hp the engines were producing at 35,000ft, the point of maximum speed, or what speed the aircraft was doing at point of maximum hp.

If we just use the max horsepower difference the speed difference would not be great.



Hi Wuzak,

Thanks, the Monarch plus airscrew would be about 800lb lighter per engine, so a total of 3,200 lb altogether, it helps abit.
The Alison is compact for such a big engine, I will have to measure up next time I am at Derby.

[Wuzak]

quote:Originally posted by Groggy

Thanks, the Monarch plus airscrew would be about 800lb lighter per engine, so a total of 3,200 lb altogether, it helps abit.
The Alison is compact for such a big engine, I will have to measure up next time I am at Derby.


The V-3420 weighed 2600lb dry. http://en.wikipedia.org/wiki/Allison_V-3420

So the weight of the <omarch was comparable.

[Groggy]

quote:Originally posted by Wuzak

quote:Originally posted by Groggy

Thanks, the Monarch plus airscrew would be about 800lb lighter per engine, so a total of 3,200 lb altogether, it helps abit.
The Alison is compact for such a big engine, I will have to measure up next time I am at Derby.


The V-3420 weighed 2600lb dry. http://en.wikipedia.org/wiki/Allison_V-3420

So the weight of the <omarch was comparable.


Hi Wuzak,
Sorry 800 lb estimate from memory, I was thinking of the early Monarch P24 and the very advanced Fairey contra-prop. From rather brief notes, the 51L Monarch coupled to standard exhaust turbo blowers and intercoolers plus estimate for standard American blades in place of Fairey blades would be a conservative 600lbs less than the bigger 56L Alison plus contra-prop, so I agree for the big aircraft it is comparable; that gives a ton less or only about 2% for B39.
The “normal” plus ejector exhaust output at 36,000ft is given as 2,000hp, does normal mean cruise?? The Fairey engine plus contra-prop is stated to be about 1,000 lb lighter than the big liquid cooled Wright, General Motors , and Lycoming engines of similar output so I guess the Alison was the lightest of the big American engines? I have no details of these other engines except the General Motors engine is a bigger capacity than the Fairey.

[Groggy]

[/quote]

Hi Folks,
Fairey monarch; Consumption, fuel cruising .49 PTS (IMP)
no other details, does this mean per second?
is this good? how would it translate in terms of the B39?

[Nick Sumner]

This is an extract from page 206 - 207 of George P. Bulman's 'An account of Partnership: Industry, Government and the Aero Engine' Bulman was the Director of Engine Development and Production at the MAP from 1928 to 1944.

It seems to offer some clues as to why the Monarch wasn't pursued. Whether Bulman's reservations are valid I don't know, evidently Fairey and his engineers didn't think so or they wouldn't have persevered.

The 'Dick' in the extract is Richard Fairey.

In due time, the Prince engine emerged, clean, commendable, a bit larger in capacity than the Rolls Kestrel which it endeavoured in all respects to beat, and it was type-tested and flown by Fairey’s, quite satisfactorily. However, as one had foreseen, it offered no exceptional potential merit nor attracted any interest by aircraft designers, other than Fairey himself, to justify the introduction of another British engine firm with all the immense build up and ramifications involved. The Air Ministry cake of finance and effective support was not big enough to cater for another customer.

With head unbowed, Forsyth persisted and created the Princess, a 24-cylinder H engine, ie with two crankshafts, water-cooled - the crankshafts being unconnected - separately driving co-axial propeller shafts running in contra-rotation. This layout, he argued, provided a pair of 12-cylinder engines within the same crankcase, which by independent throttle control could give the full power of both for take-off and climb, or a variation in speed and power for cruising. One half could be throttled back completely if need be to achieve maximum fuel economy, or cut out altogether if it failed, leaving the pilot with half of his power with which to get home.

It was a plausible claim but hardly sound in reality, because if one half failed the odds were that the common crankcase with its single lubrication system would be affected, and if a connecting rod went on one crankshaft it would pretty surely react on the other shaft. Moreover, at that time, co-axial contra-rotating propellers were not necessary to absorb efficiently the power of the then most powerful engines (around the 1000hp mark) as shown for example in the Schneider contests when 2000hp was absorbed with two bladed designs. Nor were they required for aerodynamic control reasons, contrary to the earlier assumption that a twin or four-engined aircraft would require pairs of opposite rotating engines (this being very fortunate for those concerned with the making and distribution of engines).

So, with the shadow of war creeping up, once again the Air Ministry could not fulfil Fairey's and Forsyth's dreams of production, despite their labours and the very substantial amount of money Dick had spent.

[Nick Sumner]

I can't help wonder if this extract is a reflection of a pro Rolls Royce bias in UK government circles. There is a picture of Bulman in his office at the front of the book. Behind him, on the wall, is a photograph of Henry Royce. For a civil servant who (I would have thought) had an obligation to be impartial this seems a surprising choice.

Rolls Royce were the only UK aero engine firm ever bailed out of bankruptcy by the government (in the 1970s over the RB 211) and by a government that claimed to be staunchly non-interventionist!

I'm not saying RR weren't an exceptional company with a superb track record but I wonder if Rolls Royce fixation didn't help blind men like Bulman to other posibilities?

It is interesting to note that despite Bulman's technical objections RR itself went on to scheme a double Merlin with the same layout as the Prince - including the critiscised two crankshaft arrangement!

[ChrisMcD]

Hi Nick,

I am sure that you are right. The Air Ministry had a deliberate policy of trying to keep sufficient firms going in both the airframe and engine businesses.

Rolls and Bristol were the favourite engine manufacturers.

Napier were too nostalgic for their Lion and then mucked about with the Culverin, Cub, Dagger etc. before coming up with the Sabre - which they still mucked about with rather than developed logicaly.

Armstrong Siddley took forever to make the Tiger as powerful and reliable as it should have been - and AFAIK remember it was always expensive for what it did.

Richard Fairey really put the cat among the pigeons when he got the license for the Curtis D12 - so he was hardly popular with the 'Men from the Minstry"

[PMN1]

quote:Originally posted by Nick Sumner


Rolls Royce were the only UK aero engine firm ever bailed out of bankruptcy by the government (in the 1970s over the RB 211) and by a government that claimed to be staunchly non-interventionist!



Interesting article and there does appear to have been a mafia like organisation within the established industries to protect their own which is not too surprising.

On the RR issue, in one of Bill Gunston's books he suggests that if Hooker had been brought back a year or so earlier then RR wouldn't have needed bailing out.

Also its speculated in 'Stuck on the Drawing Board' that the money used to bail out RR would have been very useful for the BAC2-11.

Shorts also appear to have been a 'favoured company' due to its location more than anything I would imagine.

[PMN1]

One of the options for the cancelled FC.1 airliner was 4 Princes, if the UK had realised earlier that its civil aviation was being outclassed and issued specs 14/38 and 15/38 sooner, does this eventually help the Monarch?

[Groggy]

quote:Originally posted by PMN1

One of the options for the cancelled FC.1 airliner was 4 Princes, if the UK had realised earlier that its civil aviation was being outclassed and issued specs 14/38 and 15/38 sooner, does this eventually help the Monarch?


Hi folks PMN1,
The Fairey FC.1 could have made an excellent Maritime patrol aircraft. One would suggest four Fairey P.16(V) engines with every thing sourced in Canada and a production line in Australia as well.
I do not have the performance figures for the FC1 to hand:
Any one got the estimates please? Then look at the aircraft for bomber purposes.

[PMN1]

quote:Originally posted by Groggy

quote:Originally posted by PMN1

One of the options for the cancelled FC.1 airliner was 4 Princes, if the UK had realised earlier that its civil aviation was being outclassed and issued specs 14/38 and 15/38 sooner, does this eventually help the Monarch?


Hi folks PMN1,
The Fairey FC.1 could have made an excellent Maritime patrol aircraft. One would suggest four Fairey P.16(V) engines with every thing sourced in Canada and a production line in Australia as well.
I do not have the performance figures for the FC1 to hand:
Any one got the estimates please? Then look at the aircraft for bomber purposes.



I think this is from one of the Putnams books

Span: 105ft
Length: 82ft
Wing area: 1,300 sq ft
Wing loading: 32.5lb/sq ft
Interior cabin length: 32ft
Cabin width: 10ft
Cabin height: 7ft
Payload for 500miles: 9,500lb
Payload for 1,700miles: 4,500lb
Loaded weight: Short haul 42,000lb
Maximum speed at 13,000ft: 275mph
Cruising speed at 60% rated power: 225mph
Stalling speed: 70mph
Maximum range in still air at 50% rated power: 1,700miles

[Groggy]

quote:Originally posted by PMN1

quote:Originally posted by Groggy

quote:Originally posted by PMN1

One of the options for the cancelled FC.1 airliner was 4 Princes, if the UK had realised earlier that its civil aviation was being outclassed and issued specs 14/38 and 15/38 sooner, does this eventually help the Monarch?


Hi folks PMN1,
The Fairey FC.1 could have made an excellent Maritime patrol aircraft. One would suggest four Fairey P.16(V) engines with every thing sourced in Canada and a production line in Australia as well.
I do not have the performance figures for the FC1 to hand:
Any one got the estimates please? Then look at the aircraft for bomber purposes.



I think this is from one of the Putnams books

Span: 105ft
Length: 82ft
Wing area: 1,300 sq ft
Wing loading: 32.5lb/sq ft
Interior cabin length: 32ft
Cabin width: 10ft
Cabin height: 7ft
Payload for 500miles: 9,500lb
Payload for 1,700miles: 4,500lb
Loaded weight: Short haul 42,000lb
Maximum speed at 13,000ft: 275mph
Cruising speed at 60% rated power: 225mph
Stalling speed: 70mph
Maximum range in still air at 50% rated power: 1,700miles



Hi PMN1,

Many thanks, what were the engine types, Taurus? Kestrel? Exe?

[PMN1]

Speculating on why the Monarch wasn't proceeded with.

It would have been ideal for naval aircraft but until the angled deck it wasn't possible to use contraprops on carriers. The problem was that if an aircraft missed the wire and ran into a crash barrier the blades of the props would strike each other, shatter, and spread fragments like shrapnel. There were tests with contra prop spitfires in 1942. This is the same reason why there was no quick fix for the Seafire XVIIs problems.

Interestingly , in his 'World Encylopedia of Aero Engines' Bill Gunston states

'Instead, Forsyth went ahead in October 1935 with the totally new P.24, aimed at carrier-based aircraft'.


In his write up on the Sabre he says

'In 1935 the Air Ministry fell for a proposal that Napier should build a 'hyper' engine running at high rpm with many small but highly rated cylinders, the output being 2,000hp'


Now, the Ministry favoured RR and Bristol but what if they had been forced (suggestions as to how please??) to give Fairey's engine a chance rather than Napier's?

What does this do for WW2 designs, for example with the Manchester potentially having less engine problems, does it still turn into the Lancaster as per OTL, does it get Merlins or Hercules sooner?

[PMN1]

Hi PMN1,

Many thanks, what were the engine types, Taurus? Kestrel? Exe?

Taurus for the home market, with the cyclone a possibility for foreign sales.

[merlin]

I think for Fairey, the 'establishment' never forgave them - for importing the American Curtis D-12 engine!
In part it gave a bias to liquid cooled engines afterward - low frontal area.
The Hawker Hart/Hind/Fury all owe their looks to the Fairey Fox.

[PMN1]

If the P.24 was chosen over the Sabre, this doesn't leave Napier much of use, any suggestions as to how its resources are used?

[Wuzak]

If the P.24 was chosen over the Sabre, this doesn't leave Napier much of use, any suggestions as to how its resources are used?

Building P.24s?

[PMN1]

Building P.24s?

I doubt if Fairey would like that, but the Air Ministry would find it amusing after being forced to give Fairey a chnace.....revenge for the red hot pokers that would have been needed for them to 'agree'.

[ChrisMcD]

If the P.24 was chosen over the Sabre, this doesn't leave Napier much of use, any suggestions as to how its resources are used?

That was the point. Napier's factory was Victorian. Apparently some of the lathes were incredibly ancient - as supplied by Maudsley!

http://www.design-technology.info/engineers/page10.htm

Napier's development team and technology were compared favourably by Setright against Rolls themselves.

But their production was rubbish, remember all those comments about Sabres being delivered full of machining swarf etc.

This, in turn, was due to their poor management - which was why the UK Government forced a takeover in 1942 by English Electric (apparently Napier refused to be taken over by Rolls)

[PMN1]

Would the flight test records for the 1939 Battle flight still exist somewhere?

[Nick Sumner]

But their production was rubbish, remember all those comments about Sabres being delivered full of machining swarf etc.




I think this was because of their inability to manage expansion through the shadow scheme effectively. I strongly doubt that any swarf was found in Napier built engines from the old factory at Acton - they were hand fitted by craftsmen. Perhaps someone could confirm or correct this but I've a feeling that the swarf problems were from the new factory at Liverpool.

[ChrisMcD]

I strongly doubt that any swarf was found in Napier built engines from the old factory at Acton - they were hand fitted by craftsmen. Perhaps someone could confirm or correct this but I've a feeling that the swarf problems were from the new factory at Liverpool.

Hi Nick,

You are probably right - but my point was that Napier's management was very poor and that this showed up in all sorts of areas. They were described as 'tinkering' with the Sabre rather than developing it and using hand built examples to scrape though tests - which rather agrees with your feelings about Acton.

[Groggy]

Hi Nick,

You are probably right - but my point was that Napier's management was very poor and that this showed up in all sorts of areas. They were described as 'tinkering' with the Sabre rather than developing it and using hand built examples to scrape though tests - which rather agrees with your feelings about Acton.

HIfolks Merry Xmas
To return to the P24, Correction on details for Fairey P24 Monarch

The type actually flown only weighed just over 1,800lbs that makes it lighter than most marks of RR Griffon. And with its prop at least 300lbs lighter than the Griffon with Contra-rotating prop
And almost 500lbs lighter than the Napier Sabre. This makes it the best engine for the Big Mosquito the Martin Baker Fighters, the Typhoon and the Tempest.
The later mark for American production the two stage four speed P24 ( 2,182lbs) would have given the Tempest a 500mph plus top speed at 35000ft altitude and if Ford had put that engine into production all this by probably early 1943,

Any thoughts??

[ChrisMcD]

HIfolks Merry Xmas
To return to the P24, Correction on details for Fairey P24 Monarch. If Ford had put that engine into production.
Any thoughts??

Hi Groggy,

That reminds me. Wasn't one of Fairey's problems the fact that they were not set up to manufacture engines? As I remember all the Fairey Fox's actually had Curtis D12 engines.

[Wuzak]

Hi Groggy,

That reminds me. Wasn't one of Fairey's problems the fact that they were not set up to manufacture engines? As I remember all the Fairey Fox's actually had Curtis D12 engines.


Fairey planned to build D12s under licence but they never did. They never built any production engine of any kind, as far as I can tell.

[PMN1]

With the P.24 being tested throughout 1939 and flying in Battle K9370 from June 1940, when could you expect full-scale production had it been given the go-ahead?

[Red Admiral]

With the P.24 being tested throughout 1939 and flying in Battle K9370 from June 1940, when could you expect full-scale production had it been given the go-ahead?

I'd imagine two years or more myself given Fairey's pretty much non-existant engine production facilities. There'd probably be widespread opposition from the other engine companies if other production lines had to be set up.

[PMN1]

I'd imagine two years or more myself given Fairey's pretty much non-existant engine production facilities. There'd probably be widespread opposition from the other engine companies if other production lines had to be set up.

Definately widespread opposition but could they do anything about it - the later nationalisation of Shorts because of lousy management suggests the government would not take too kindly to opposition their stated aims.

[PMN1]

Interesting reports posted by joncarrfarrelly here


http://www.secretprojects.co.uk/forum/index.php?topic=3462.new;topicseen#new

[PMN1]

Page 6 of the second report in the link mentions a F-32.....

Captain Forsyth states the following developments should be undertaken in this country (the US)

Undertake F-32, a 5.25 x 6 engine with 4 blocks of 8 cylinders

Undertake 5.5 x 6 engine for 3,000hp

Undertake 6 x 6 engine for 3,400hp

[Wuzak]

Looking at these documents over the last couple of days has shed some light on the P-24 Engine. So, what can we deduce from them?

This first thing is that the USAAC didn't seem overly impressed with the design.

As an engine, aside from the fact that two independent power units are mounted in a single crankcase, the performance is not outstanding nor are there any features that appear unusually advantageous.

It would appear that the often quoted 4 speed 2 stage supercharger for the P-24 never existed, and that the real situation was that each engine had its own 2 speed single stage supercharger.

The P-24 seems to have only been tested on 87 octane fuel. Whether this is a case that only operational units and officially sanctioned programs had access to the 100 octane fuel.

Forsythe predicted that the P-24 would have a take off power of 2600hp on 100 octane. Based on single stage two speed supercharged Merlins with 100 octane the target power should have been somewhat higher – 2900-3000hp. The USAAC believed a more realistic number was 2460hp.

The critical altitude of the P-24 was deemed to be too low.

The ratings given are with an engine of such a relatively low critical altitude that the Rolls Royce Merlin engine, Series 60, weighing 560 pounds less, delivers 160 more horsepower at 30,000 ft.

Considering that the P-24 was basically twice the capcity of the Merlin.

The engine is mainly compared to the Sabre, by Fairey and, consequently, the USAAC. One advantage the reports see in the P-24 is that it has more space in the crankcase than the Sabre. Forsythe was of the opinion that the P-24 was a better production proposition than the Sabre. At the time I guess he was right, in that the P-24 was quite conventional, and Napier was having difficulty with production of the sleeves. That doesn’t account for the fact that the Sabre was, at that time (August 1941) in production.

Some of the features that the USAAC were not impressed with:

The camshafts were carried in four bearings, but they were arranged such that an excessive length of the camshaft was unsupported.

Four adjacent intake ports were fed by a single intake passage, causing flow restrictions, and thus requiring higher boost for a given BMEP.

As the intake manifolds were a part of the crankcase section, the USAAC felt that the intake air would be heated by its proximity to the head and cooling passages that performance would be lost. Also:

This type of manifolding does not lend itself readily to modification in the event that air or fuel distribution were not entirely satisfactory. In addition, and backfires or damage to the intake manifolding from any other cause would necessitate replacement of the complete case or head assembly.

Because the loads imposed by each of the crankshafts could be anywhere between in phase and completely out of phase, as the cranks were not synchronised, the USAAC did not see the crankcase design as being sufficiently strong (one clue as to why the P-24 was remarkably light at 2150lbs).

The crankshafts had no counterweights, which would mean that there were increased stresses in the crank and the crankcase. (another clue as to the lightweight nature of the P-24, and by inference the P-16 and P-12).

There was no consideration in dealing with torsional vibrations. (The Merlin, etc, had spring drives, vibration dampers and the like to cope with the TVs.)

The supercharger drives were by bevel gears. It was thought that the existing design would not be strong enough for future developments with higher critical altitudes and boost. They reference tests they were doing on a Daimler-Benz DB-601:

The German DB-601 incorporates this same feature and an actual failure of the bevel gear drive was experienced during the dynamometer calibration on this engine.

The report also mentions that the method of head attachment may cause problems (studs screwed directly into the cylinder block rather than by through bolts with nuts), as well as using a separate head (the Allison V-1710 had separate heads, and the Merlin was changing to separate heads for the 60 series, which was to cure sealing problems).

Fuel consumption was considered to be normal – ie not great or poor, just average.

Finally, it would seem that production for the P-24 was going to be someway off, with at least 2-3 years of development left. From an attached page of an excerpt from a report by Ron Hazen (of Allison):

Mr. Devereux [of Fairey] expressed himself as believing the design was considerably cleaner than the Sabre and a much better production job although he thought that two or three years development still remained before it would be ready for production. I gather that it was in its present stage a fairly good engine at 1500 horsepower and 2250 pounds.

The final conclusion being that the USAAC didn't see any benefit of moving forward with the P-24, either by financing the development or recommending a US engine manufacturing alliance.

Some of the features of the engine were not satisfactory, most of these would have meant an increase in the engine's weight in order to allow for increased longevity and power. It would seem that the construction of this engine at that stage would not have allowed for Merlin levels of boost. Also, mention of the P.12 is made, with it being described as a 750hp engine with maximum rating of 900hp. It would also be reasonable to conclude that the light weight of that engine compared with similarly sized contemporaries would make it less amenable to development of higher powers.

Some interest was shown in the dual rotation propellor system, but it was thought to be not applicable to engines with dual rotation capability then under development in the US.

At the end of the day Fairey had no production facilities (part of the reason for the overtures to the US), no experience of protracted engine development, and no production experience. The P24 was 2 to 3 years away from production, at best. No wonder the MAP refused to divert resources to it, and that the USAAC was not receptive.

[tartle]

Have been following the 'Alternative to the Westland whirlwind' thread ... stumbled to here when Googling p24:
I have a copy of the P24 spec for the moderately supercharged engine:
Summarising it specifies
rated power: 1,500 bhp @ 2,600 rpm
max Take off power: 1,540 bhp @ 2,300 rpm
rated altitude: 9,500 feet
normal rpm: 2,600 rpm not normally exceeded for continuous cruising at any altitude.
max permissible rpm: 3,000 not to be used for more 5 minutes consecutive running.
diving rpm: 3,150 rpm at not more than 1/3rd throttle opening.
max permissible boost: +3 lbs/sq in.(for not more than 5 mins)
rated boost: +2lbs/sq in.
fuel: DTD 230 [ I think is 87 octane]
bore: 5.25"
stroke: 6.0"
capacity: 3118 cu. in (51 litre)

The flight engine rating data is:
rated altitude: 10,000ft
rated boost: +1/2 lb/sq in
max permissible boost: +3 lb/sq in
normal rpm: 2,400
take off rpm: 2,
bhp @ 2,400 rpm @ 10,000 ft - 1,275
bhp @ 2,750 rpm @ 10,000 ft - 1,425
bhp @ 2,130 rpm @ +3 lb/sq in boost - 1,300

-------------------
In the documents referred to by Wuzak and others above we see that A G Forsythe is referring to 5 hours running at 2,000 to 2,300 bhp and 20 hours at 2,000 to 2,100 bhp.; I guess these must be the results from test bed running at high boost and/or 100 octane fuel.

In 'Rod' Banks book ' I kept no Diary' he refers to " Fairey's [D12] initiative stirred things up and one result was the Rolls-Royce Kestrel..... Later put in hand the design of a vertical H type, liquid-cooled, poppet valve, double crankshaft (unconnected) engine, each shaft driving one half of a contra-rotating propeller - rather on the lines of the Zerbi Fiat racing engine. Graham Forsythe had the design responsibility and engineering development of this 1,800 bhp engine, the Prince, and I helped him with advice on valve and piston design. But the engine received no support from the Air Ministry, perhaps rightly so in view of the number of engine manufacturers already existing, though in my opinion, it had the makings of a reliable high-power unit."

[Groggy]

Hi PMN1,

The proposed Fairey/Ford P24 (about 1940) would have given about 2,000hp at circa 36,000ft. So we have a potential 400mph bomber by the middle of the war?


Fairey P13/36 - to be powered by 2 P24's though Vulture and Sabre engine options were avaialble.

Based on the P4/34 light bomber, with 2 P24 engines it would have a top speed of 327mph at 17,000ft though Tony Butler's book only says 4,000lb bombload rather than the 8,000lb that the spec called for.

Span 85ft, length 55ft, WA ?, Max TO 38,678lb, twin 0.303" MG in nose and quad 0.303" MG in tail.

This to me looks the most 'right' of the P13/36 submissions, to me the rest look like dogs or look out of proportion (Manchester).

http://img.photobucket.com/albums/v136/paul1/FaireyP1336.jpg

[Wuzak]

Hi PMN1,

The proposed Fairey/Ford P24 (about 1940) would have given about 2,000hp at circa 36,000ft. So we have a potential 400mph bomber by the middle of the war?

Really? The USAAC report from 1941 says that the Merlin 60-series was 160hp more powerful than the Fairey P.24 at 30,000ft.

Having looked through this thread and re-reading the reports I think that the P.24 design had many hurdles to overcome before it became a reliable engine.

The intake design being particularly atrocious.

http://forum.keypublishing.co.uk/attachment.php?attachmentid=50448&d=1098014523

[Groggy]

Hi Nick,

I agree that it could make an interesting landing I remember some one talking about a Wyvern accident. But the establishiment did not seem to consider saftey as a priority. in my opinion half WW2 Bomber Command casualties could have been avoided by sensible procurement: remember it was the Queen that was being proposed for Naval aircraft but it would still have had the same problems.
There was a range of specialist engines proposed by Fairey from 1933 onwards and the Prince was better than any RR engine at the time Faireys were still not considered.




Speculating on why the Monarch wasn't proceeded with.

It would have been ideal for naval aircraft but until the angled deck it wasn't possible to use contraprops on carriers. The problem was that if an aircraft missed the wire and ran into a crash barrier the blades of the props would strike each other, shatter, and spread fragments like shrapnel. There were tests with contra prop spitfires in 1942. This is the same reason why there was no quick fix for the Seafire XVIIs problems.

[Wuzak]

There was a range of specialist engines proposed by Fairey from 1933 onwards and the Prince was better than any RR engine at the time Faireys were still not considered.

Really?

The Kestrel was in production and in service in 1933. It was in the same power class as the Prince. And it was lighter.

Since the P.24 was based on the Prince I would assume that some of the concerns with the P.24 could be applied to the Prince - like not having any crankshaft counterweights.

[Groggy]

Hi Wuzak,
For the most part I would have agreed with you, but Lumsden’s figures for the Fairey engines would have been revised if a new edition had been possible. The arguments need revising based on original Fairey documents.
The American criticisms, observations were made before the P24 Battle was shipped across. All American pilots were impressed by the take-off and smooth running.
Forsyth apparently took some of criticisms on board, for example he quickly redesigned the crankshaft in a balanced form and revised, added American turbochargers. The engine dry weight, mass with these modifications was only about some 2,210lbs yet giving about the same output at 20,000ft as the Griffon on the MB5 and retaining that sort off output up too 35,000ft which the Griffon could not.
The P24 (2,210lb) as an engine plus Fairey contra-rotating airscrew (560lb) was significantly lighter than the equivalent much later Griffon package. I am sure that I read that the Griffon’s CR airscrew needed Martin Baker input to solve lubrication problems, certainly on those used on the Shackelton post-war. At the time the equivalent American liquid cooled experimental engines with CR airscrews by Wright’s, General Motors, and Lycoming would have weighed an extra 1,000lbs or more. None of which had flown or done anything like the running time off the P24. The point is that the P24 was flying with few if any problems and it was reliable, I agree that it could be improved but as it stood it was better than anything else when it was first flown.
Interesting comparison of the P12 with the Kestrel which it’s self was a response to a previous Fairey Curtiss D12 adventure. The P12.S was marginally lighter than the Kestrel.
At the time in question given similar octane rating, altitudes and rpm settings the P12.S gave an extra two-hundred hp. It was reliable compared to the RR PV12 and the later early Merlin that had real shortcomings at the start of its service career.
The P12.S could have mounted two machine guns and a 20mm cannon, arguably more use than eight Brownings and a flexible wing.
The proposed the P16.S (1,130lbs) variant derived from the refined P12.S with a Fairey airscrew was lighter than the updated Kestrel known as the “Peregrine” with airscrew of the same time period.
The P16.S had similar advantages, more power than a Merlin significantly greater than the Kestrel of the same period.
The tragedy was that RR with a superbly talented work force and finite resources did not pursue the Griffon, Exe and Pennine with vigour. Merlin was rather like a midget on steroids put up against heavyweights that choice cost lives.



Really?

The Kestrel was in production and in service in 1933. It was in the same power class as the Prince. And it was lighter.

Since the P.24 was based on the Prince I would assume that some of the concerns with the P.24 could be applied to the Prince - like not having any crankshaft counterweights.

[Wuzak]

Hi Groggy,

Firstly, I agree the Kestrel was designed by Rolls-Royce in response to the Curtiss D-12s imported by Fairey for the Fox. Rolls-Royce actually built two engines - the Kestrel and the Eagle XVI. The X-16 Eagle XVI was Rolls-Royce's preferred engine, but the V12 Kestrel (F) was preferred by the RAF because of better visibility over the nose.

The Kestrel was a later generation design than the Curtiss engine, and thus had more development potential.

The Prince P12 was a 700hp class engine. Later development units (used for the P24 program) using 100 octane fuel may have cracked 900hp, but this was in the late 1930s. The Peregrine, an updated Kestrel, was rated at 885hp using, IIRC, 87 octane fuel.

The Prince P12 was also rated at a lower altitude than the Kestrel.

The Griffon 65, with 2 seed 2 stage supercharger weighed under 2000lbs - some 200lbs lighter than the P24. The contra prop consisited of an extra set of gears with an idler. It surely would not weigh 200lbs more? The props were out of Rolls-Royce hands, being built by Rotol or de Havilland.

From my limited knowledge of the contra-props system on the Griffon I understand that the development difficulties lay in pitch control, not in lubrication.

The USAAC report indicates some concerns with the lubrication system of the P24.

I have a book on the Tornado, which should shed some light on the weight of the contra-prop system. The only contra-prop version of the V-3420 flown, as far as I can tell, was the remote gearbox unit used in the P-75. The Lycoming was similar in weight to the Tornado, and matched/bettered the P24 power at 80% of the capacity.

When was the P24 fitted with turbochargers? Being basically a double engine, that would require two turbos, two intercoolers, and piping. Looks like a lot of extra weight.

For my part I seriously doubt that claim. I'm sure the USAAC would not supply turbos to be used in such a project on an engine that they had determined was unsuitable for production or development before they'd even received the demonstration unit.

The P16S was the 16 cylinder version of the P24. It was about as powerful as Merlins were 1941/1942 - earlier than a production P16 could possibly have been available. Basically Merlin power in a Griffon sized engine. Wiki lists the weight of the P16 as 2180lb, but that is what the Wright Field report states for the P24. But no way was it 1130lbs. Probably similar to a two stage Merlin (1650lbs).

The P16, like the P24, was first run in 1939. The USAAC report was authored in late August 1941. By the time the Fairey engines would become available in numbers would be too late for the war.

Rolls-Royce dumped a number of projects to concentrate on the Merlin and Griffon. The Griffon was developed very rapidly, and was available by 1942. But most of the aircraft using V12s in the RAF inventory were already fitted with the Merlin, and the Merlin production was in full swing. Stopping the Merlin to concentrate on the Griffon would have been more costly.

The Exe was an effective engine, but its size went against it. Had it been the size of the Pennine (ie 2800ci) it would have been more useful. The Pennine was a late war (1944) project that had little chance of being in the war. In fact its intended market was in post war transports.

[Wuzak]

If you look at this picture of the P24 you can see that the intake setup is kinda horrific.

http://upload.wikimedia.org/wikipedia/commons/9/91/Fairey_p24.jpg

[Wuzak]

Kimble McCutcheon, Tornado, Wright Aero's Last Liquid Cooled Piston Engine, gives a weight increase of 150lbs for the contrarotating reducion gear over the standard reduction gear. So that would be 2550lb (2400lb standard).

[Groggy]

Hi Wuzak,
Fair comments,agree with most, but just a small point, There were two types of P16 designed. The first was the V type P16 a elongated P12.Designed circa1934 put to the Ministry January/February 1935. There was a H version a P16 called the "Queen"
. I have a copy of the letter to the Minister of Supply written by Forsyth and giving the proposed P24 american adapted engine as 2,210lbs
will post again when I have more time.


Kimble McCutcheon, Tornado, Wright Aero's Last Liquid Cooled Piston Engine, gives a weight increase of 150lbs for the contrarotating reducion gear over the standard reduction gear. So that would be 2550lb (2400lb standard).

[Wuzak]

Hi Wuzak,
Fair comments,agree with most, but just a small point, There were two types of P16 designed. The first was the V type P16 a elongated P12.Designed circa1934 put to the Ministry January/February 1935. There was a H version a P16 called the "Queen"
. I have a copy of the letter to the Minister of Supply written by Forsyth and giving the proposed P24 american adapted engine as 2,210lbs
will post again when I have more time.

Not sure how successful a V16 would have been. As far as I know no V16s were remotely successful.

Still think it would have weighed somewhat more than what you quoted.