Twin/three engined bomber for 2nd half of 1941: how would you do it?

[tomo pauk]

By choosing existing airframe, engines and guns, what kind of a twin/three-engined bomber would you like to see in service, in 300 copies at least for 2nd half of 1941? As German, you need to defeat Communists quickly, as a Soviet you need to beat back Nazis beyond Berlin, as an Japanese you are fighting in vast Asian territory...
The god blend of firepower (bombs, guns...), range vs. payload, cruising max speed, survivability when contested by fighters AAA, reasonable performance from deck to 20K is what is required.
You may choose to design two types if you like, one lighter, another heavier type. Eg. if you feel like having German engine mounted on Italian airframe, featuring British guns, go ahead and post something about it

 

[davebender]

A no-brainer.
- The largest German aircraft program from 1939 onward. No need to retool.
- Production cost per aircraft is falling rapidly due to economy of scale.
- Powered by Jumo211 engines which were in plentiful supply by 1941.
- Accuracy. 50% of bombs within a 50 meter circle. Roughly 10 times as accurate as level bombers such as the Do-217 and He-111.
- Speed, maneuverability and crew armor provide decent survivability.
- The Ju-88 was also an excellent torpedo bomber for maritime attack.
- The Ju-88 was also an excellent long range recon aircraft.
- Combat proven by 1941. The Ju-88 gets the job done in a variety of missions. Crews like it. So do maintenance personnel.
- With larger DB603, Jumo213 or BMW801 engines the Ju-88 has the ability to become an outstanding night fighter. An important consideration as the Me-110 was supposed to be superceded by the Me-210 during 1942.

 

[tomo pauk]

No doubt Ju-88 was a superb plane.
Yet, this is not poll about what was the best twin/three engined bomber for 2nd half of 1941. As stated in 1st post here, you can mix existing airframe, engine, guns etc, in order to 'have' best piece of hardware.

Eg. Ju-88 airframe, Hercules engines, Russian HMGs is one attempt. Pe-2 airframe, Merlin 40 series engine, US HMGs is another one.

 

[rank amateur]

How about a SM79 with 3 DB601N or merlins xx? Would be a fast ship. Makes you wonder about a Mosquito with 3 engines. Now that would would be even more than a handful for every fw190 trying to intercept.

 

[tomo pauk]

...not for 1941 (we don't have Mossie produced in numbers yet - one of reasons we talk about 2nd half of 1941), but that SM.79 would've been a speedy plane indeed. Will try to sqetch it

 

[Shortround6]

One problem with borrowing one countries engines to use in another country is that the fuel doesn't transfer over does it

If the Italians had 100 octane just stuff the Bristol Pegasus XVIII into the SM.79. Should bolt right in as the Alfa engine was a license built Pegasus. The British engine offers 1050hp for take-off, 1065hp at 400meters and in high gear of it's two speed supercharger 965hp at 4000 meters.

There were SM 79s made with two engines, both Fiat R 80s and the Romanians used two Jumo 211s of 1220hp.

A few SM 79s were reputed to have been built with 3 1350hp Alfa 135 RC32 engines but performance may not have been recorded?

 

[davebender]

Not likely. However the SM.79JR could have been built in quantity.
Savoia-Marchetti SM.79 - Wikipedia, the free encyclopedia

SM.79JR
Twin-engine version for Romania, powered by 895 kW (1,200 hp) Junkers Jumo 211Da engines. Eight Italian built aircraft (designated JIS.79B by Romania), followed by 36 license built JRS.79B powered by the Jumo 211Da and 36 JRS.79B1s with 1,029 kW (1,380 hp) Jumo 211F engines. Production continued until 1946.

IMO the SM.79 had acceptable performance but it's not worth extensive development. If Italy is short of Alfa Romeo radial engines they should purchase BMW132s from Germany.

 

[tomo pauk]

Indeed, fuel situation makes a lot of difference
For the sake of discussion, the choice of Pegasus with more power would've increased speed to be on par with Ju-88 perhaps.

Re. German radials: perhaps BMW/Bramo 323 would've been also cool, giving 1000 HP @ 3000m.

Re. unlikely engines: both inlines are within rules from 1st post

 

[davebender]

Savoia-Marchetti SM.79 - Wikipedia, the free encyclopedia
Produced 1936–1945
Number built 1,350

That's not many aircraft for such a long production period. What was the production bottleneck? Importing German made engines makes little difference if airframe production capacity is too low.

 

[Dannybb55]

How about a Vickers Wellington with R 2600s like a B 25 or R 2800s from a B 26 and give her Martin turrets with 50 cals and good sights. Then she would have an extra 1000 hp and real defensive firepower. Go ahead and fill her wings with extra gas tanks to give her more range or more bomb load.

 

[tomo pauk]

Perhaps using 1350 planes with better power-to-weight ration would've been better than using 1350 planes with lower such ratio? To reduce window of opportunity for Gladiators, Hurricanes, P-40s, Fulmars?

 

[Dannybb55]

One problem with borrowing one countries engines to use in another country is that the fuel doesn't transfer over does it

If the Italians had 100 octane just stuff the Bristol Pegasus XVIII into the SM.79. Should bolt right in as the Alfa engine was a license built Pegasus. The British engine offers 1050hp for take-off, 1065hp at 400meters and in high gear of it's two speed supercharger 965hp at 4000 meters.

There were SM 79s made with two engines, both Fiat R 80s and the Romanians used two Jumo 211s of 1220hp.

A few SM 79s were reputed to have been built with 3 1350hp Alfa 135 RC32 engines but performance may not have been recorded?

The RA had 100 octane fuel, that is why they built the DB 601 which required C 3.

 

[rank amateur]

Hello gentlemen, I known the sm79 was built with 2 Jumo's. I had only wished they would have used 3. And ofcourse it wasn't the most suitable plane for further developement, but it was a usefull, much liked plane. Unlike the sm84 which preceeded it. Better engines could have extended its usefullness a lil further

 

[Shortround6]

Just what year are you planning this conversion for?
Wellington MK IIIs had Hercules engines of around 1500hp in 1942. later ones had Hercules engines of over 1600hp. That extra 1000hp just went to under 800 and if you mean the 1850hp ones used by the B-26A and early "B"s then you are down to 200hp-500hp depending on altitude. The R-2800s only weigh another 450lbs each and are going to need bigger propellers.

 

[davebender]

There's no such thing as a free aircraft engine either. The USA can afford to build any aircraft engine they want. Italy cannot.

1941 Engine Prices in German Marks.
30,875 Jumo211
27,970 DB601
12,400 BMW132

IMO the reliable, fuel efficient, readily available and dirt cheap BMW132 radial is the engine Italy should purchase if they intend to increase SM.79 bomber production.

 

[Glider]

Wellington gets my vote. Take out the front turret to save some weight and use the saving for a hand held .50 HMG in the Dorsal and Ventral position with a 303 hand held in the nose.
Good range, good payload decent defence and a very flexible aircraft. Only one I know that carried 2 x torpedo's internally.

2nd Choice Do 217 with HMG instead of LMG.

 

[Milosh]

There's no such thing as a free aircraft engine either. The USA can afford to build any aircraft engine they want. Italy cannot.

1941 Engine Prices in German Marks.
30,875 Jumo211
27,970 DB601
12,400 BMW132

IMO the reliable, fuel efficient, readily available and dirt cheap BMW132 radial is the engine Italy should purchase if they intend to increase SM.79 bomber production.

Was the BMW 132 really that available? The Arado Ar 196, Arado Ar 197, Blohm Voss Ha 140, Blohm Voss BV 141, Heinkel He 114, Heinkel He 115, Henschel Hs 123, Junkers Ju 160, Junkers Ju 52, Junkers Ju 86, Junkers W34 all used this engine.

It was not a powerful engine with a power output of ~800hp.

 

[davebender]

These aircraft which used BMW132 engines were out of production by 1941:
He114
Hs123
Ju160
Ju86. BMW132 version. Later versions were powered by turbocharged diesel engines.
Junkers W34. A very durable aircraft. Over 1,000 still in service during 1944!

These aircraft which used BMW132 engines did not enter mass production.
Ar197.
Ha140.
Bv141.

These aircraft which used BMW132 engines were produced in only small numbers:
Arado Ar 196. 1938 to 1944. 541 total.
He115. 138 total.

It appears to me the Ju-52 was the only mass production aircraft powered by BMW132 engines during 1941.

I think the 960 hp BMW132K was the main production version by 1941.

 

[parsifal]

I wonder how a beaufighter configured to carry rockets, bombs, or torpedoes or alternatively with twin 40mm ATGs fitted would have faired. Primarily a fighter with a more extensive than usual fighter bomber conversion carried out

 

[tomo pauk]

The Beaufighter was tried with 40mm in lieu of one pair of 20mm. So the version with 2 x 40mm, 6 LMG, AND the substantial heavy load was very feasible.
Why it was not produced? Perhaps it was regarded that Hurricane IID was sufficient cheaper (as a tank buster)?