Bristol's twin-engined planes?

[fastmongrel]

Would it have been possible to use the H P Hampden instead of the Beaufort. It seems to have been liked as a torpedo bomber with Pegasus engines when used off Norway, maybe modify the H P Herefords to take the Hercules instead of the original Dagger to Pegasus conversion.

 

[davebender]

Handley Page H.P. 52 Hampden medium bomber [UK] - Steve Jackson Games Forums

785-gallon standard fuel tanks

The Hampden might work as it carries plenty of internal fuel. An essential item for a maritime attack aircraft.

- Delete bomb bay unless it can carry an aerial torpedo or aerial mine.
- Delete defensive weapons except rear facing turret behind the cockpit.
- A couple forword firing machineguns are ok for flak suppression. These would be fired by the pilot.
- Crew size would drop to 3.
- High speed @ 100 meters = survivability for a torpedo bomber. Choose engines accordingly.
- Standard maritime survival equipment such as life rafts which can be dropped.
- Ditching is more likely then bailing out for a damaged aircraft. That must be considered as some aircaft were inheritly bad at ditching.

 

[tomo pauk]

To do what? In the 1930s nobody believed that France would be defeated, so there was no (visualised) chance of the Germans using the Channel, meaning that they had to go round the top of Scotland, and risk the attentions of the Navy, and all destroyers carried torpedoes.

Think you should ask someone else the question - it was RAF that ordered not one, but two dedicated torpedo bombers in the late 30's.

The Beaufighter was rushed into service as a nightfighter, to replace the Blenheim fighter, and was only considered for other roles when the Mosquito proved that it could take over the nightfighting role, especially with the two-man crew together, rather than several feet apart.

It would've been interesting to have Bristol's plane with thinner wings bomb bay - something that would be faster than Beau some 20 mph, on same HP, but with same terrific firepower.

Would it have been possible to use the H P Hampden instead of the Beaufort. It seems to have been liked as a torpedo bomber with Pegasus engines when used off Norway, maybe modify the H P Herefords to take the Hercules instead of the original Dagger to Pegasus conversion.

Hampden in torp bomber role seems like a natural choice, even more appealing with Hercules; too bad it was not to be.

 

[fastmongrel]

- Delete bomb bay unless it can carry an aerial torpedo or aerial mine.

Most British mediums and heavies seem to have been specified to have a torpedo capable bomb bay. I would imagine the Hampden was the same. I would also think about getting rid of the glazed nose and use the space for guns. 2 x Vickers S guns plus 4 x mgs with lots of tracer would tick my box thats going to put a flak gunner off his breakfast. Though if the plane is going to be used for long range patrols I cant see the RAF wanting to lose the navigator, did the Hampdens navigator sit in the front.

 

[tomo pauk]

Navigator was seated behind the pilot, so your version looks very plausible.

http://media.photobucket.com/image/recent/Iainart/sc1f311.jpg

Item No.12 is the navigator's seat on the pic.

 

[fastmongrel]

Navigator was seated behind the pilot, so your version looks very plausible.

Recent image by Iainart on Photobucket

Item No.12 is the navigator's seat on the pic.

Had a look and it looks like the navigators position is No 33 with his map table No34. No12 is the navigators position for using the sextant but there might be room to fit the navigating station behind the pilot if he is not needed for bomb aiming.

 

[davebender]

It would also add a lot of weight to the aircraft. That means less payload for fuel, protective armor and perhaps a second torpedo.

I'm not saying your nose mounted weapons are bad per se but there's no such thing as a free lunch. 1930s aircraft engines are likely to produce no more then 1,000 hp so we need to keep weight as low as practical.

 

[tomo pauk]

Hercules being mandatory to lift such a weaponry on Hampden?

 

[fastmongrel]

I was thinking of a Hercules version when I got a bit excited about a heavy forward firing armament

 

[Juha]

Would it have been possible to use the H P Hampden instead of the Beaufort. It seems to have been liked as a torpedo bomber with Pegasus engines when used off Norway, maybe modify the H P Herefords to take the Hercules instead of the original Dagger to Pegasus conversion.

IIRC Hampden was used out of necessarity because it was available, BC was retiring them and had range. It could carry a torpedo almost internally, with modified bomb bay doors. IIRC the modified doors were partially open at rear part of them when torpedo was carried. But IIRC the crews thought that Hampden was a bit too large for torpedo work, ie unnecessry large target to Flak gunners.

Juha

 

[Shortround6]

While the Hampden was the smallest of the 3 Pre war medium bombers it was still a large airplane. Cutting 2 feet of the bottom of the fuselage is not going to turn it into a speed demon. That is also where the bomb bay is so now you have some real redesign to do.
Mr. Benders idea of deleting all armament except the upper rear station and some forward firing guns for flack suppression isn't worth much because the initial Hampden gun fit was exactly 3 guns, one out the top rear, one under the fuselage and one fixed in the nose ahead of the pilot. Dropping one Vickers K gun buys next to nothing. later versions doubled the armament to paired Vickers K guns top and bottom and one or two(?) fixed Brownings. The flexible mounts had no power assist so their weight was minimal. The fuselage was a skinny as an A-20, crew could not change positions in flight without extreme difficulty if at all.

The British 40mm (2pdr) aircraft cannon is a lousy flak suppression weapon. It's low velocity means that it has less practical range than a 20mm Hispano and it's rate of fire (100rpm?) means 4-6 shots per barrel per attack compared to a 20mm Hispano's 24-36 shots per barrel. Given the weight of the Vickers S gun it really comes up short as a suppression weapon.

here is were the lack of development of the poppet valve engines hurt the British. The Pegasus was the British equivelent of the Wright Cyclone. With more development it might have been good for 1100hp in 1940 and heading for 1200hp. Cuts the need for the early 1300-1400hp hercules considerably, especially considering the Pegasus is hundreds of pounds lighter.

 

[davebender]

Unlike the A-20 the Hampden had a large internal fuel capacity. A crucial difference for maritime attack.

In a perfect world I'd prefer an A-20 with larger internal fuel tanks for maritime attack. Perhaps stretch the fuselage a bit like Junkers did with the Ju-88H or put large, well protected fuel tanks in the wings like Messerschmitt did with the Me-210. But that's a different discussion. Australia has no influence over the A-20 so such a design change must be initiated by the U.S. Army Air Corps.

 

[merlin]

Sorry, but Hampden A-20 are surely irrelevant as far as the thread is concerned - they are not Bristol aircraft!
Intriguing thought about the Albemarle - if it wasn't for the need for it to be made out of non-strategic material - and of course made by Bristol - how much better would it have been??

 

[tomo pauk]

My take on the last verison of the Bristol twin engined plane, built from 1942, would be a 1600-1700 HP Hercules, 4-5 Hispano (two in wing roots, other added in the lower nose), 4 gun BP turret (neatly faired, not just a slapped one like at Beau V); night fighter with as good Merlin as possible, maybe with lighter turret armament (or none). Both inner- and outer-wing racks.

Any takers for the Bristol's twin engined (multi role) plane, in service, say, from Spring of 1943 until VJ day? Multitude of engines are available, from different Merlins, Hercules makes 1670-1770 HP, Griffon, LL R-2800, Centaurus for 1945... Then, the Molins cannon, S class, down to Hispano, maybe it's time to go for a tricycle, a Cookie-capable bomb bay (no bulges), laminar-flow wing, full span flaps...

 

[Shortround6]

My take on the last verison of the Bristol twin engined plane, built from 1942, would be a 1600-1700 HP Hercules, 4-5 Hispano (two in wing roots, other added in the lower nose), 4 gun BP turret (neatly faired, not just a slapped one like at Beau V); night fighter with as good Merlin as possible, maybe with lighter turret armament (or none). Both inner- and outer-wing racks.

Why the wing root cannon? In existing Bristol aircraft the wing roots were full of fuel tanks. Putting guns in the wing roots means fuel displaced by guns has to be carried some were else. In 1942 leave Beaufighter pretty much alone. If you want a night fighter with upward firing armament just do what the Germans did. Stick a pair of Hispano guns firing upward between the pilot and the rear seater. A lot less weight and drag than any turret no matter how well faired. If you are trying to defend from the rear give the observer of pair of .303 Brownings and get on with it. Even this will slow the plane but a 600lb turret with four .303s slows the plane more and really doesn't offer that many advantages for a twin engine fighter.
You can't really use the same plane for too may jobs. A Beaufighter cannot substitute for a twin Hercules powered bomber. A twin Hercules powered bomber should be carriying 2000-5000lbs of bombs and that is too much to carry outside the plane without incurring too much drag. Unless you are trying for a Hercules powered Mosquito, in which case the 20mm guns and the turret start becoming redundant. Please remember that Mosquitos AS USED in WW II were pretty much limited to four 500lb bombs or one 4000lb cookie. No eight 500lb or four 1000lb or even two 1000lb missions.
Bringing the Hamden back for a moment, at a certain point in WW II it was the ONLY British bomber that could carry a 2000lb armor piercing bomb inside the bomb bay. The Whitley even with it's 7000lb total bomb load didn't have the size bomb bay needed to house the bomb and neither did the Wellington.

Any takers for the Bristol's twin engined (multi role) plane, in service, say, from Spring of 1943 until VJ day? Multitude of engines are available, from different Merlins, Hercules makes 1670-1770 HP, Griffon, LL R-2800, Centaurus for 1945... Then, the Molins cannon, S class, down to Hispano, maybe it's time to go for a tricycle, a Cookie-capable bomb bay (no bulges), laminar-flow wing, full span flaps...

Sort of the same problem, what do you really want it to do?

"a Cookie-capable bomb bay (no bulges)" bomb bay means a big fuselage for a fighter/night fighter aircraft.

See the Bristol Type 163 Buckingham and Brigand. They didn't to try to use the same fuselage for the different roles.

Maybe they didn't make the best use of the space but here is a cut away of Brigand.

http://img.photobucket.com/albums/v11/leecoll/BrigandCutaway001.jpg

 

[tomo pauk]

Why the wing root cannon? In existing Bristol aircraft the wing roots were full of fuel tanks. Putting guns in the wing roots means fuel displaced by guns has to be carried some were else.

Since 'my' 1940 Bristol is going to have a bomb bay, the cannons their ammo need to somewhere else (compared with Beaufighter). Two of them are going into wing roots, a pair can be located outboard of the engines, another pair (or 3 pcs) can use the bomb bay, installation akin to the Ju-88's one. On the variants where the bomb bay is used for the original purpose, 4-6 LMGs can be located in the nose.
The fuselage was fuel-free (in Beau), so in this instance some fuel can go at the upper part of the hull (from lower wing line towards the top).*

In 1942 leave Beaufighter pretty much alone. If you want a night fighter with upward firing armament just do what the Germans did. Stick a pair of Hispano guns firing upward between the pilot and the rear seater. A lot less weight and drag than any turret no matter how well faired. If you are trying to defend from the rear give the observer of pair of .303 Brownings and get on with it. Even this will slow the plane but a 600lb turret with four .303s slows the plane more and really doesn't offer that many advantages for a twin engine fighter.

Yep, British 'Schraege Musik' does sound great; I did post my reservations about the rear armament of the Bristol. As for leaving the Beau alone, my proposal is looking for something of better performance

You can't really use the same plane for too may jobs. A Beaufighter cannot substitute for a twin Hercules powered bomber. A twin Hercules powered bomber should be carriying 2000-5000lbs of bombs and that is too much to carry outside the plane without incurring too much drag. Unless you are trying for a Hercules powered Mosquito, in which case the 20mm guns and the turret start becoming redundant. Please remember that Mosquitos AS USED in WW II were pretty much limited to four 500lb bombs or one 4000lb cookie. No eight 500lb or four 1000lb or even two 1000lb missions.

Bringing the Hamden back for a moment, at a certain point in WW II it was the ONLY British bomber that could carry a 2000lb armor piercing bomb inside the bomb bay. The Whitley even with it's 7000lb total bomb load didn't have the size bomb bay needed to house the bomb and neither did the Wellington.

If you were following my proposal for the 1940 Bristol, you will note that it would be of mid- or high-wing variety (=allowing for a decent bomb bay), with only 2 'permanent' cannons - rather a different animal than the Beau.

Sort of the same problem, what do you really want it to do?

"a Cookie-capable bomb bay (no bulges)" bomb bay means a big fuselage for a fighter/night fighter aircraft.

See the Bristol Type 163 Buckingham and Brigand. They didn't to try to use the same fuselage for the different roles.

Maybe they didn't make the best use of the space but here is a cut away of Brigand.

http://img.photobucket.com/albums/v11/leecoll/BrigandCutaway001.jpg

Again, a low-wing airplane has problem to make for a good/great bomber.
As 'what it (a 1943 Bristol) will do', it will bomb, make torp, rocket cannon attacks - everyday stuff.

*edit: the cannon ammo can go within the 'hull part' of the wing, so the fuel carried is not that affected. The 2 of the 4 wing racks can do wonders for the combat range, though.

 

[wuzak]

Please remember that Mosquitos AS USED in WW II were pretty much limited to four 500lb bombs or one 4000lb cookie. No eight 500lb or four 1000lb or even two 1000lb missions.
Bringing the Hamden back for a moment, at a certain point in WW II it was the ONLY British bomber that could carry a 2000lb armor piercing bomb inside the bomb bay. The Whitley even with it's 7000lb total bomb load didn't have the size bomb bay needed to house the bomb and neither did the Wellington.

Someone mentioned in here a while ago that Mosquitos used, on occasion, 2 x 1000lb target indicators. Which are the same size as the 1000lb MC bomb.

Also note that the Mosquito IX and XVI with the bulged bomb bay could do a 8 x 500lb mission if required - using the 6 x 500lb Avro carrier internally, and 1 500lb bomb under each wing. But BC preferred to use the 4000lb HC Cookie or the 4000lb MC bomb.

You sure the Wellington couldn't carry the 2000lb AP bomb? IIRC the 2000lb AP bomb was a small diameter, longish bomb. And two could fit in the Mosquito's bomb bay (not sure about the rack).

 

[Shortround6]

Getting back to the original premise.

Beaufort was designed produced in order to equip the RAF with a torpedo-bomber.
My take on that would be a plane with a bomb bay, mid- or high-wing, featuring maybe both slats fowler flaps, so the wings can be of somewhat thinner profile. Low-risk part of the engines would be covered by usage of the Pegasus engines (for prototypes 1st series), wing being stressed for Merlin and Hercules (such planes built from, say, Spring of 1940). The MGs would be 4 in the wing roots (replaced with belt-fed Hispano when available), space for 4-6 in outer wings, 2 in the back. An adaptation for the NF job would include 4-6 belly mounted MGs, ammo feed from bomb bay (all akin to the NF Blenheim); we should have the Merlin, or even Hercules versions by then. Radar as available. All in all, a British Ju-88?

The Beaufort was designed as an easy development from the Blenheim. While the British had a lot of aircraft companies, none of them were very big with large design staffs. This is one reason some contracts got shifted around and why some company's proposals were turned down. Supermarine may have had some good ideas (sketches) for twin engine fighters or bombers but they were way behind schedule on the Spitfire so the likelihood they could turn those sketches into working hardware in the time needed was pretty slim. Same with Bristol, first attempt (type 150) at the Beaufort was a slightly stretched Blenheim, Pilot moved forward 4 feet and turret moved aft a bit. Navigators position was eliminated and Bristol Perseus VI engines specified. RAF turned down the idea of a long range torpedo bomber without a navigator and the plane started to grow. Here is were the time line gets interesting.

Blenheim first flight 12 April 1935 but this was not the full military version.
First full military version is first flown 25 June 1936. Hundreds of Blenheim's are already on order.
1936 the RAF orders the first 78 Beauforts off the drawing board.
March of 1937, Blenheim I goes into service with first squadron.
24 Sept 1937 Prototype Blenheim IV first flies.
15 Oct 1938 First production (and 1st prototype) Beaufort flies. Production moves slowly as first aircraft is tested.
Fall of 1938, proposal for fighter version of Beaufort made (Beaufighter) and accepted.
19 July 1939, First Beaufighter flies about 8 months after work begins. 300 Beaufighters ordered two weeks earlier.
Nov 1939, First Beaufort issued to service squadron (literally, first Beaufort to fly) First real production machines show up in Jan 1940.
July 27 1940, first 5 Beaufighters handed over followed by 5 more on 3 Aug.

Taking time to design new wings with high lift devices and test them would have delayed things even more.
The Taurus engines in the Beaufort were giving trouble in ground running even before the first flight and many of the losses suffered by Beauforts in the spring/summer of 1940 were not due to enemy action but the Taurus engines.

Sometimes it takes time for things to develop. Fowler flap was "invented" in 1924 but not test until 1932 by the NACA, it was first used on the martin 146 prototype in 1935 and then the production Lockheed 14 Airliner in 1937. Any practical experience on how it works is not available until about the middle of the Bristol development history.

 

[tomo pauk]

Would it be easier for Bristol RAF to introduce the all-new combat aircraft within 4 years, or to introduce two major redesigns of an existing plane in the same time frame? While both Beaufort and Beaufighter surely show lineage with Blenheim, I strongly doubt that anything from Blenheim was usable on those two planes (cockpit instruments and LMGs only?).
Anyway, I wouldn't bet my house on anything proposed in an what-if form. But saying that Bristol was incapable to introduce a completely new aircraft within 4+ years is a tad too much.

Taking time to design new wings with high lift devices and test them would have delayed things even more.

I'm fine with that - instead in Autumn of 1938, the new Bristol flies 1st time in Autumn of 1939, in service for BoB?

 

[Shortround6]

I am not so sure about the "major" redesigns. Beaufort may have used pretty much a Blenheim wing with a bit under 2 feet added at the center. A "new" fuselage or an added to fuselage? Blenheim I went 12,500lbs loaded but a Blenheim V went 17,000lbs. Beauforts went to 22-23,000lbs, Beaufighters went to 25-26,000lbs. A selling point of the Beaufighter was that it used the Beaufort wings, tail and landing gear with a new fuselage. The selling point is born out by the 8 months from start of work to first flight. While not a record it is one of the faster developments of the WW II era. Putting the Hispano guns were the old bomb bay was solved the room problem, solved the center of gravity problem and solved the reload problem. First 400 Beaufighters used drum feed cannon with 3 spare drums per cannon. reloading done by rear seat man. Far from an ideal solution but better than one drum per gun until landing.
Bristol may have been able to come up with a new design in 1936-37 and gotten into service by the BoB. But it means realizing that one of the most advanced aircraft in the RAF in 1936-37 ( the Blenheim was the fastest bomber in the world at that time) will be obsolete in just 1-2 years, stopping all development of the basic design and starting all over again with a new airframe using an engine that won't be in production until 1940. Many other aircraft evolved during those years rather than have all the old work thrown in the dust bin and new starts made.

There were several screw ups that lead to the Blenheim staying in combat service as long as it did. There were several screw ups in the government specifications that also lead to a less capable aircraft.
The Specification that lead to both the Beaufort and Botha was both not far reaching enough and yet too ambitious. If you have a twin 840hp bomber in hand asking for a twin 900hp machine to succeed it is not very far reaching. Asking for twice the bomb load at the same or greater range and as much or more speed while carrying a heavier defensive armament one only slightly larger engines (specified by the government, not the airframe makers)pretty much doomed the successors (it doomed the Botha anyway) and the failure of Bristols own Taurus engine meant the Beaufort was both late and made in small numbers. WIth no other small twin bomber in hand the British were forces to continue with the Blenheim.
Specifing basicly the same defensive armament as a WW I DH-4 for a 1936-40 bomber when the RAF was ordering 8 gun fighters shows a real disconnect in thinking. And the idea that ANY bomber, no matter how well it might roll or turn or loop for a bomber, had the ability to bring a single fixed .303 gun to bear on an enemy fighter simply boggles the mind.
The British could have done a lot to improve things without going to a whole new design but it requires the development of a lot of auxiliary equipment. Getting a small turret with twin belt fed Brownings in service sooner. Getting into the constant speed propeller business sooner ( adjustable/controllable 2 pitch props doesn't really cut it). Spending a bit more time improving the Mercury and Pegasus engines, if you are going to build a few thousand more Mercurys' after 1938-39 for combat planes spending a little time/money might not be a bad thing. SOmebody come up with a wind tunnel so some form of scientific drag reduction could be done on a number of airframes.