What if the Blackburn Roc was designed as a single seat fighter?

[Giant Man Eating Rabbits]

There were in OTL 139 Roc's built and they started to enter service in April 1939.
In an ATL that makes it plausible to have the Skua/Roc single seat fighter in service at the same time.
As to the Peledes engine, every engine is new at some time, every indication historically in OTL indicates that Alvis were competent and knew how to build reliable and successful engines.
o in Our ATL having the Alvis engine in service will fly (pun intended). In OTL the Alvis engines did not fly because of political/policy reasons, if adopted by the FAA, say in 1937, by 1939 with a full on two years of flight development, plausible.
The old saying is "where there is a will, there is a way" in OTL there was no will but in a different TL that is another story.

Engine question.

Could the Roc be upgraded to carry the Bristol Centaurus or Hercules engines thus evolving them like the Merlin powered Hurricane & Spitfires as the Perseus seemed a tad limited horsepower wise?

Could that evolution keep the design relevant?, at least until Wildcats and better aircraft come along?

 

[Cryhavoc101]

Engine question.

Could the Roc be upgraded to carry the Bristol Centaurus or Hercules engines thus evolving them like the Merlin powered Hurricane & Spitfires as the Perseus seemed a tad limited horsepower wise?

Could that evolution keep the design relevant?, at least until Wildcats and better aircraft come along?

Centaurus - almost certainly not that's a late war engine

The Hercules I however first flew in 1936 with the Hercules II in 1938 so a 1937 to 1938 development change to the Skua and our Roc fighter is not that far fetched given thats when the first 2 prototypes of the Skua flew

The Herc is longer than the Perseus - 53.15 in (1,350 mm) vs 49 in (1,245 mm) - although not exceptionally so and heavier than a Perseus - 1,929 pounds (875 kg) vs 1,025 lb (465 kg) - but is the same diameter and uses the same Pistons etc (14 in 2 rows of 7 instead of 1 row of 9).

I think in implementation and date the Hercules is a practical choice!

 

[Peg Leg Pom]

But the RAF wouldn't be loosing a single one, because there would be extra aircraft.

Tell that to the RAF squadrons in Britain, France, Norway and the Middle East still flying Gladiators. The Navy will get Hurricanes, or any modern monoplane fighters only when the RAF has all that it thinks it needs, plus a reserve. Realistically the only option the FAA has in 1938/39 is to have more Sea Gladiators built or converted from ex RAF aircraft.

 

[yulzari1]

The assumption seems to be that the engine needed changing and indeed the engine was pushed out further forward after the prototype to balance the CoG so a heavier engine further back can be done.

However, I suggest that the Roc engine was not the problem, albeit somewhat down on wartime peers, but the aeroplane behind it. Keep the Perseus but glue it to a slightly larger Vickers Venom. The short wing will allow a simple straight fold.

A single seat Roc will just go from truly awful to just really bad. Better to have an improved Skua which will at least allow more operational flexibility.

 

[Giant Man Eating Rabbits]

I think in implementation and date the Hercules is a practical choice!

2nded

Here's some figures I've got from Wikiposterous.

Hercules I (1936) – 1,150 hp (860 kW), single-speed supercharger, run on 87 octane fuel.
Hercules II (1938) – 1,375 hp (1,025 kW), single-speed supercharger, run on 87 octane fuel.
Hercules III (1939) – 1,400 hp (1,000 kW), two-speed supercharger, run on either 87 or 100 octane fuel.
Hercules IV (1939) – 1,380 hp (1,030 kW), single-speed supercharger, run on 87 octane fuel.
Hercules V (1939) – 1,380 hp (1,030 kW), civil prototype derived from the Hercules IV but not developed
Hercules VI (1941) – 1,615 hp (1,204 kW), two-speed supercharger, run on either 87 or 100 octane fuel.
Hercules VII production cancelled.
Hercules VIII – 1,650 hp (1,230 kW), very high-altitude version of the Hercules II, single-speed supercharger with an auxiliary high-altitude single-speed 'S' supercharger.
Hercules X (1941) – 1,420 hp (1,060 kW), derived from the Hercules III.
Hercules XI (1941) – 1,590 hp (1,190 kW), derived from the Hercules III, run on 100 octane fuel
Hercules XII – derived from the Hercules IV.
Hercules XIV (1942) – 1,500 hp (1,100 kW), developed for the civil market and used by BOAC, run on 100 octane fuel.
Hercules XVMT – 1,650 hp (1,230 kW), very high-altitude development of the Hercules II, single-speed supercharger with an auxiliary high-altitude turbo-supercharger.
Hercules XVI (1942) – 1,615 hp (1,204 kW), two-speed supercharger, run on either 87 or 100 octane fuel.
Hercules XVII (1943) – 1,615 hp (1,204 kW), two-speed supercharger locked in 'M' gear.
Hercules XVIII – low-level development of the Hercules VI with cropped 12 in (300 mm) supercharger impellers.
Hercules XIX (1943) – 1,725 hp (1,286 kW), a development of the Hercules XVII, the two-speed supercharger had cropped 12 in (300 mm) impellers locked in 'M' gear.

As you can see there's a pretty long development history that covers most of WWII and would allow the Roc to be continually upgraded like Merlin powered aircraft.

Unfortunately it doesn't go into specifics on the diameter, width and weight of these engines in regards to each version.

I do like the look of both the Hercules XVMT & XVIII engines powering an high altitude and low level Blackburn Roc. That might have been something to see as an high altitude interceptor taking on Ju-88's and a low level interceptor taking on doodle bugs or FW-190's.

 

[yulzari1]

Hercules production early on was much delayed and in small numbers. Hence the Beaufighter II with Merlin’s and Wellingtons with Merlin’s. In the necessary production period for a pre Sea Hurricane/ Seafire fighter then you have Perseus (Mercuries being kept for Blenheims), possibly Taurus and Merlins. If you contrast a 930bhp Perseus with a 1,200ish bhp Merlin and Hercules and Taurus then you are not far behind. The A6M, Ki27, MC200, G50 etc. are in that Perseus class so it is a matter of less airframe behind it than the Roc.

 

[Hammerbolt]

2nded

Here's some figures I've got from Wikiposterous.

Hercules I (1936) – 1,150 hp (860 kW), single-speed supercharger, run on 87 octane fuel.
Hercules II (1938) – 1,375 hp (1,025 kW), single-speed supercharger, run on 87 octane fuel.


Unfortunately it doesn't go into specifics on the diameter, width and weight of these engines in regards to each version.

Acording to wikipedia, the Hercules is only 10cm longer than the Perseus, while having virtually the same diameter. The problem seems to be weight: the Hercules II is 400kg heavier than the Perseus! So can't just plop it in, whe're looking at serious shift in the plane's gravity center.

 

[Cryhavoc101]

Acording to wikipedia, the Hercules is only 10cm longer than the Perseus, while having virtually the same diameter. The problem seems to be weight: the Hercules II is 400kg heavier than the Perseus! So can't just plop it in, whe're looking at serious shift in the plane's gravity center.

There is also the CoG shift due to the removal of the 2nd person and weapons etc (Vickers K or entire 4 gun turret) - so its added weight at the front and less weight to the rear - this issue would exist even without a change of engine.

My suggestion was to shift the Pilots seat and mid fuselage fuel tanks (found between Pilot and gunner) rear wards to offset this CoG issue.

This is also an advantage as it allows the windshield to be more aerodynamic than the OTL 'speed brake' design found on the Skua and Roc which was necessary as just forwards of the screen is fuel tanks and filler caps etc which does not allow for any change in that direction.

Note the "Crash Resistant Arches" just behind the Pilot - that is pretty much where I expect the Pilot to sit in our single seat Roc fighter - with the Fuel tanks shirted rearwards to where the gunners position is.

The Pilot sear might need to be slightly raised?

 

[NOMISYRRUC]

Tell that to the RAF squadrons in Britain, France, Norway and the Middle East still flying Gladiators.

"RAF squadrons in Britain, France, Norway and the Middle East still flying Gladiators you're not loosing a single aircraft, because they would be extra aircraft."

Told!

The Navy will get Hurricanes, or any modern monoplane fighters only when the RAF has all that it thinks it needs, plus a reserve. Realistically the only option the FAA has in 1938/39 is to have more Sea Gladiators built or converted from ex RAF aircraft.

No. It didn't work like that.

 

[Giant Man Eating Rabbits]

There is also the CoG shift due to the removal of the 2nd person and weapons etc (Vickers K or entire 4 gun turret) - so its added weight at the front and less weight to the rear - this issue would exist even without a change of engine.

Would extending the fuselage length rectify this? or would it have a detrimental effect on the weight and aerodynamics of the aircraft?

And would it need to have it's wing re-designed also to compensate?

 

[Driftless]

In the end, wouldn't it be more efficient for Blackburn to design a Skua-based fighter, using a "sort of" clean sheet? Blackburn recycles as many components from the bomber Skua as practical (tail, parts of the fuselage, wings?, landing gear, etc), using that as a starting point and designs the rest for its intended purpose, rather than trying to make a silk plain cotton purse from a sows ear? Would it have been possible to convert a Roc into a single seat fighter, enh, maybe. Would it have been plausible, probably not

 

[ennobee]

It would be interesting to see Blackburn use the same basic design it already had for the Roc and Skua and make a third design iteration as a shipborne fighter directly taking on the Fairey Fulmar. L

 

[Cryhavoc101]

Would extending the fuselage length rectify this? or would it have a detrimental effect on the weight and aerodynamics of the aircraft?

And would it need to have it's wing re-designed also to compensate?

If this was a 'instead of turret fighter' fighter then I don't think so - it would be 90 plus odd % Skua

Same wings, same fuselage, same under carriage, same engine* etc etc

*Unless we are replacing the engine? In which case why not replace it in the Skua as well?

In the end, wouldn't it be more efficient for Blackburn to design a Skua-based fighter, using a "sort of" clean sheet? Blackburn recycles as many components from the bomber Skua as practical (tail, parts of the fuselage, wings?, landing gear, etc), using that as a starting point and designs the rest for its intended purpose, rather than trying to make a silk plain cotton purse from a sows ear? Would it have been possible to convert a Roc into a single seat fighter, enh, maybe. Would it have been plausible, probably not

Well they ended up making a fighter out of the Battle sooo.....?

 

[tomo pauk]

If you contrast a 930bhp Perseus with a 1,200ish bhp Merlin and Hercules and Taurus then you are not far behind.

If a better engine is making 30% better power, than you are far behind.
Merlin will also make a lower drag, and better exhaust thrust. It will also make far better power once 100 oct is around (so we have Merlin VIII making 1275 HP at lower altitudes). Merlin III on Sea Hurricanes was pushed to 1440 HP on 100 oct fuel (+16 psi boost), making 315 mph at 7500 ft - eye-watering 90 mph faster than the Skua.

The A6M, Ki27, MC200, G50 etc. are in that Perseus class so it is a matter of less airframe behind it than the Roc.

Having to lug such a draggy aircraft was indeed the big part of the problem. Engine was a draggy item, too, far more than it was the case with Italian, let alone at the Japanese fighters.
FWIW, A6M2 of the Pearl Harbor fame have had 930 HP at 14000 ft, while the Perseus on the Skua or on the Roc was good for ~680 HP - ie. Zero had almost 40% greater power there.

Well they ended up making a fighter out of the Battle sooo.....?

A bit of a stretch, don't ya think?

 

[Reggieperrin]

As to the Peledes engine, every engine is new at some time, every indication historically in OTL indicates that Alvis were competent and knew how to build reliable and successful engines.
o in Our ATL having the Alvis engine in service will fly (pun intended). In OTL the Alvis engines did not fly because of political/policy reasons, if adopted by the FAA, say in 1937, by 1939 with a full on two years of flight development, plausible.
The old saying is "where there is a will, there is a way" in OTL there was no will but in a different TL that is another story.

If I understand things correctly the Pelides was essentially a licensed Gnome-Rhône engine with all the materials, dimensions, tolerances, fasteners, bearings, accessories etc changed from metric/French Air Ministry standards to imperial/British Air Ministry standards. So its a near-certainty that if Alvis made some improvement and got it working as intended, it would end up as somewhere between :

• old G-R 14K - limited development potential, low power - essentially an early-30s modernised 14cyl twin-row Mercury, which is inoffensive but won’t set the world alight.
• newer G-R 14N - absolute dog toffee due to retaining the 2-bearing design while attempting major power increase (to Merlin II levels in 1938), generally disintegrated after single-digit hours of use and did set the world alight, one French aeroplane at a time.

Seems like it would be of little value to the FAA or anyone else, especially when they could instead use the shiny new Alvis factory to build Merlins or Feddens mechanical puzzles.

Bear in mind G-R were one of the world’s largest aero-engine firms and struggled mightily to get their own designs to work as intended. As did their peers R-R, Bristol, P&W, Wright, etc.
For a very small-scale car manufacturer to enter the industry and do better than all the giants using someone else’s old designs - I can see where the Air Ministrys scepticism was coming from. They already had Napier in particular and sleeve valves in general, yet another headache wasn’t needed.

 

[CaptainCalvert]

I just had a disturbing thought.
The single seat fighter retains the turret concept, so the pilot is either placed inside a turret, so he can shoot all round [1], or he has some kind of mirror sighting arrangement to aim the turret guns [2] while flying.

I think I have achieved something difficult here, in that I have made the Roc even less use - and probably much more dangerous - than it was OTL. I await my rightful reward!

[1] so the flight controls are a bit tricky to master...
[2] And you thought a French tank commander had too much to do in a one-man turret?

 

[Driftless]

I just had a disturbing thought.
The single seat fighter retains the turret concept, so the pilot is either placed inside a turret, so he can shoot all round [1], or he has some kind of mirror sighting arrangement to aim the turret guns [2] while flying.

I think I have achieved something difficult here, in that I have made the Roc even less use - and probably much more dangerous - than it was OTL. I await my rightful reward!

[1] so the flight controls are a bit tricky to master...
[2] And you thought a French tank commander had too much to do in a one-man turret?

By comparison, didn't the original incarnation of the MBT-70 tank have the driver in the turret, which by definition could rotate?

 

[sonofpegasus]

I have lost the reference but years ago I found a claim that the Alvis Peledes engine was based on the G&N 14P drawings with the third bearing. If this is the case then the potential development of the Alvis engine could be closer to the 14R than the 14N. I hope that some one on this forum can confirm whether the Pelides did in fact have the third bearing and the longer crank case this entailed.

 

[Hammerbolt]

By comparison, didn't the original incarnation of the MBT-70 tank have the driver in the turret, which by definition could rotate?

Yeah but the driver was inside an independed cupola, that he could rotate. And he also only had to drive. Also, drivers got constantly sick from the weird motion and disorientation, apparently...

 

[The Wooksta!]

Why move the pilot back? He needs the best possible view for landing on a carrier. The windshield isn’t a structural piece, so nicking one from a Fulmar or a Defiant (the latter given B-P built Rocs would be logical) is straightforward.
The Roc wing was that of a Skua, but was given dihedral.
Tbh, it’s probably easier to just re-engine the Skua with a Taurus, give it an extra few guns or replace a pair with 20mm Hispano, delete the second guy, plate over and give it a bubble hood. May need revised fin too.