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Given that the Bristol Type 153 was never built either as a finished aircraft or mockup or even AFAIK a reduced scale wind tunnel model, I don't think we may much to go on. How fanciful are these drawings - is there anything official from Bristol's design table?Pretty conventional Type 153 was to be powered by a Bristol Hercules, armed with 4 cannons (per spec), and was among the 1st designes supposed to have the bubble canopy.
I refuse to believe in pixie dust or anti-gravity paint or perpetuation motion power plants.resident contrarians here who default to telling us why something can't or won't be done.
Bristol was not promissing the moon with the Type 153 - under 360 mph. Perhaps they should've promised 400 mph?Bristol aircraft designs and speed don't seem to go together. Bristol could talk a good top speed but never got any where near the paper speed.
they had to knock off 40mph because they specified a cockpit heaterBristol was not promissing the moon with the Type 153 - under 360 mph. Perhaps they should've promised 400 mph?
Now throw in the Hercules HE.IS engine which is rated at 1295hp at unknown altitude.
Please note that Lumsden does not list a Hercules HE.IS version, not to say he was infallible but it makes looking up the specifications hard.
He does list a dry weight of 1845lbs for the Hercules I.
The Hercules I & II were rated at 1375hp at 4,000ft.
Perhaps the HE.IS was planned for a higher FTH?
But it would have been a single speed supercharger.
Perhaps you are right, but it doesn't seem to have been made?My take is the same wrt. the HE.IS - a hi-alt version of the early Hercules engines. Or, sometingg like the FS-only version of the Hercules III?
What I am somewhat interested in was the 1800lbs of engine in 6,000lb gross weight fighter.
again compare to the A6M2 or compare to a P-36/Hawk 75 with an R-1830 and compare the 4-6 rcmgs to the 4 Hispano guns.
Or compare the Bloch 152 with it's under 1400lb engine.
The claimed speed would have put a Fw 190 to shame while carrying a heavier load of guns.
Well, for an under 1300hp engine at around 12,000-12,500ft compare to the Fw 190 with it's engine only making a similar amount of power (like cruising).Yes, the expected weight is suspiciously low. Would've went to 7000 lbs easily IMO, plus the weight of protection for pilot and fuel tanks.
Claimed (expected) speed was nothing special vs. Fw 190?
Well, for an under 1300hp engine at around 12,000-12,500ft compare to the Fw 190 with it's engine only making a similar amount of power (like cruising).
The 'advantage" of the FW 190 somehow disappears and the whole FW 190 showed the British how to install radial engines story goes away
The Taurus was a bad choice on my part, but my thinking is Bristol knows its got the Hercules coming, so build your fighter to accept whatever engine is available now with provision to accept the Hercules when its ready. The first Bf 109 prototypes flew with 434 kg Rolls-Royce Kestrel engines and first operational aircraft were powered by the 442 kg Jumo 210 - they knew this was smaller and less powerful, but it got the program moving along until the much heavier 756 kg DB 605 was ready. Gloster did this with their F5/34 prototype, flying with a Bristol Mercury as the intended (and designed for) Perseus was not yet ready - though Gloster had the advantage that both engines were of similar size and weight.Designing a 4600lb fighter with a Mercury (under 1100lb) engine so you can upgrade to the 1900lb engine when it becomes available requires quite a bit of foresight.
You skipped a couple of steps.The first Bf 109 prototypes flew with 434 kg Rolls-Royce Kestrel engines and first operational aircraft were powered by the 442 kg Jumo 210 - they knew this was smaller and less powerful, but it got the program moving along until the much heavier 756 kg DB 605 was ready.
Part of the similar size and weight were because the Mercury and the Perseus used same number of cylinders of exactly the same size (146mm bore and 165 mm stroke). They also ran at the max RPM.Gloster did this with their F5/34 prototype, flying with a Bristol Mercury as the intended (and designed for) Perseus was not yet ready - though Gloster had the advantage that both engines were of similar size and weight.
because Messerschmitt never intended to use an engine the size/weight/power of the DB605 in 1934-36If Messerschmitt can sort out how to utilize a lightweight engine whilst the intended larger engine is being prepared I don't see why Bristol couldn't.
All good points. The difference for Bristol is that I'm suggesting they are intending to use the Hercules in their new fighter, but since Roy Fedden's dept needs more time, a less powerful, yet available Bristol radial will go in place of the Hercules. So a swap out rather than indepth Bf 109 D to E redesign in the plan. It's the only way I can see the Type 153 entering service in place of the Whirlwind.You skipped a couple of steps.
because Messerschmitt never intended to use an engine the size/weight/power of the DB605 in 1934-36
Beyond finding another platform for sleeve valves I've never understood the point of the Perseus. Just make an incrementally better Mercury.Part of the similar size and weight were because the Mercury and the Perseus used same number of cylinders of exactly the same size (146mm bore and 165 mm stroke). They also ran at the max RPM.
Why people expected the planes powered by the Perseus to have significantly better performance requires the special paint or strong drink before signing the contract/s.
The Hercules used the same cylinders as the Perseus so at any given point in time (stage of development/type of fuel available, etc) the Hercules was going to give you 14/9s of the power of a Perseus ( divide Perseus by 9 and multiply by 14). A few percent off for different friction losses and or plumbing losses.Or just forget all this, and we delay this fighter until the Hercules is good and ready. The challenge there is by then the Spitfire, Hurricane, Typhoon, Fulmar and Martlet have all the resources and glory, with the Tempest, Firefly and other lend lease fighters soon to enter the picture, so there's no need for the Type 153.
Best plan is the expedite the Hercules program and get the Type 153 prototype flying with its intended engine in 1938.
Bristol was doing 357mph at 12,500ft (3660 meters?)BMW 801C was making, for the 30 min limit, 1310 PS at 14400 ft (2400 rpm). Fw 190A-1 seems to be good for 390 mph on that setting, at least going by the two charts posted here.
More than 30 mph advantage over the Type 153 figures.
You have a few problems,
1, Bristol for the most part, didn't build good superchargers. They weren't bad but they were not in the same class as RR.
2, Bristol until the middle of war, didn't build very good engine nacelles for radial engines (or give the airframe makers any good ideas) which meant high drag for installed power. Very few other people were building good radial installations either.
3, The Hercules was a little on the small side, It was world class when it started out in 1936-37 but it fell behind a little bit by 1940-42.
Hercules was 2,360 in³ (38.7 L) as were the French Gnome-Rhone engines. The US had the R-2600 and in 1940 the R-2800, Germans were working on the 2550 cu in (41.8 L) and the Russian ASh-82 was 2514 cu in ( 41.2 L)
Bristol was doing 357mph at 12,500ft (3660 meters?)
You may be right.
But the Bristol is claiming a high speed for that amount of power.
Since this is a what-if, you have a better aircraft, airframe/engine choice-wise of getting Petter to design the Whirlwind from the outset with Merlins and dispensing the complicated flap/cowl arrangement. Make the thing simpler and it'll be better than it traditionally was.