Tri-motors - any thoughts?

[Shortround6]

Some airframes just don't take to upgrading very well. I kind of like the Armstrong Whitworth Whitley but even a pair of Sabres isn't going to turn it into a fast bomber

Near as I can figure stuffing 3000hp into a Wellington with NO CHANGE in drag will give you 265mph. Since the Wellington can't fly at that speed for more than a couple of minutes it's chances of limiting Bf 109s and 110s to stern chases are pretty limited even in 1939/40. Going to the real world and the extra drag of the 3rd Pegasus and the attraction is really fading. Use the extra power to lift bombs and fuel and you pretty much have the same performance as a MK III at best. Not a game changer and with fewer planes available do you have any net gain at all? I don't know how the Early Wellingtons did but the later ones did pretty good getting back on one engine. it is related to the power to weight ratio. Increase the empty weight too much and some of your extra power goes into moving the extra weight.
Some twins had a negative climb rate with one engine out and others did fairly well. It also depends on at point in the mission the plane is hit and what provisions are made for lightening the plane. Some planes had fuel dump valves and nozzles to rapidly dump fuel to lighten the plane. You still haven't said where the bombardier goes in the Wellington.

You are right, you didn't say to take the rear turret out of the Wellington, but I am pointing out that speed only works if the speed you wind up with is very close to the speed of the fighters, even 80% won't do. I have also pointed out that just pulling guns and gunners won't get you the speed needed from an existing airframe.
It sounds like you are planning to stick another R-2600 into the nose of a B-25
The result Might go 370mph if you use a real early B-25 with no turrets at all but you are going to increase the empty weight by 3000-3500lbs, pretty much the entire bomb load, all forward of the nose wheel. And at full speed you are going to sucking fuel at close 600 gallons an hour or 10 gallons a minute. Obviously you can use the extra power to lift mo weight but you are running out of room for bombs and fuel without a total redesign of the wing structure.

Those are might tough changes to work into an existing design.

 

[tomo pauk]

I admit that making a plane as a tri-motor from ground up is far better than to try a redesign that involves addition of the 3rd engine.
A 3 x R-2600 bomber would be sized between Z.1007 and B-24, the bombardier can go where it went for the Z.1007.

 

[model299]

The DC-10 comes to mind, too.

let's not forget the 727.....

 

[rank amateur]

In 1942 Blohm Voss came up with a rather nice idea for a 3 engined fighter bomber the Blohm Voss BV P 170
check Blohm Voss BV P.170 Luft '46 entry

Rather unorthodox, but that was their thing at the time. Seems almost a shame that they didn't proceed. On the other hand the Iatlian SIAI Marchetti SM79, arguably the most famous of all Italian trimotors had versions with only 2 engines amongst others with 2 1220hp Jumo 211. I would certainly like to know what a sm79 with 3 Jumo would have been capable of.

 

[davebender]

B&Vs timing couldn't have been worse. Milch has just wrecked the excellent Bomber B and Me-210C light bomber programs. He isn't going to fund a new light bomber proposal during 1942.

 

[rank amateur]

The Bomber B might look excellent on paper but it would take years to provide the necessairy engines. So I have to cut Milch some slack. Well, I think the P170 with twice the load of the Me210 might classify as medium bomber but I guess with its projected speed it would have made an excellent backup for the do335 project whilst using the proved BMW801 engines. Even Milch could have seen this.

 

[davebender]

Bomber B might look excellent on paper but it would take years to provide the necessairy engines.

The 2,000 hp Jumo 222A engine passed its 100 hour endurance test during April 1941. The Do-217 bomber entered mass production during 1941.

Looks pretty straight forward to me. Power the Do-217 airframe with 2,000 hp Jumo 222A engines rather then 1,539 hp BMW801a engines. You will turn the underpowered Do-217 into an outstanding medium/heavy bomber with a payload similiar to 1942 versions of the American B-17.

 

[rank amateur]

The 2,000 hp Jumo 222A engine passed its 100 hour endurance test during April 1941. The Do-217 bomber entered mass production during 1941.

Looks pretty straight forward to me. Power the Do-217 airframe with 2,000 hp Jumo 222A engines rather then 1,539 hp BMW801a engines. You will turn the underpowered Do-217 into an outstanding medium/heavy bomber with a payload similiar to 1942 versions of the American B-17.

So why didn't they? How come the jumo 2222 never got of the ground?

 

[davebender]

For the same reason the Me-210C never got off the ground (Hungary excepted). Milch killed these programs for no apparent reason except internal German politics.

 

[Shortround6]

So why didn't they? How come the jumo 2222 never got of the ground?

Because it didn't work.

Passing a type test may mean an engine is ready for production or it may not. I don't know about German engines but the Allison passed a type test in 1937, in 1940 the engines had to be de-rated to a lower power than the type test engine and reworked to bring them up to par, The Sabre passed a type test well before 1940 as did the Vulture and even the Centaurus passed a type test in 1940 or before.

They built around 270-280 JU 222s and yet fewer than a dozen airframes ever flew with them, and those had constant trouble. Using those engines in combat planes without additional work may have been a bigger fiasco than the initial DB 606 deployment.

 

[Siegfried]

Because it didn't work.

Passing a type test may mean an engine is ready for production or it may not. I don't know about German engines but the Allison passed a type test in 1937, in 1940 the engines had to be de-rated to a lower power than the type test engine and reworked to bring them up to par, The Sabre passed a type test well before 1940 as did the Vulture and even the Centaurus passed a type test in 1940 or before.

They built around 270-280 JU 222s and yet fewer than a dozen airframes ever flew with them, and those had constant trouble. Using those engines in combat planes without additional work may have been a bigger fiasco than the initial DB 606 deployment.

A type test is only a milestone, however it indicates considerable promise and that the fundementals are OK. A 100 hour type test suggests about a 25 hour MTBO if experience of the BMW 801, Sabre and PW 2800 are considered. If the Jumo 222 passed a 2000hp/100 hour type test in April 1941 it would reaonably capable of producing that level of power in field conditions about 1 year later perhaps 1.5 years latter to give time to freeze the design for production. The problem form the Jumo was the demand for 2500hp takeoff, which just to hard, and the huge amount of time wasted in converting it from aq 45 Litre engine to a 55 Litere engine in order to make the power in a crude simple way.

The othe problem is that it only had one airframe as customer: the Ju 288. When the airframe was decoupled from the engine (it was to utilise the DB610) the engine had no customer anymore.

Look at napier's faulty Sabre; the company wasn't making a competitive engine so it production potential was being underutilised The Typhoon, a simple fighter rathyer than a complicated bomber needed a powerfull engine to be a viable and to compete with the potent FW 190 which created a crisis in the RAF. Hawkers was making Hurricane's, a seriously outmoded product that needed to be replaced by something better like the Typhoon.

The Jum0 222 doesn't seem to have been particularly troublesome: the DB610 howerver was in comparison to the test program.

Hence it just make sense to utilise the Napier product in a new Hawker airframe. Napier's production potential was being underutlised whereas Hawker Hurrican desperately neede replacement.

The Luftwaffe had by then the BMW 801 working quite well, they were usable in the Ju 88 and FW 190. No airframe had been prepared for the Jumo 222.

If fitted to upgraded versions of the Ju 88 family it would have made a very potent fast bomber. It was in fact scheduled for the Ju 388, with speeds of 440mph expected for the two stage supercharger versions.

 

[Shortround6]

I remain unconvinced, given the Germans inclination to cobble together bits and pieces to produce short runs of various types of equipment the idea that they would leave several hundred "good" engines sitting in a warehouse while they cobbled together practically anything else that would fly seems strange.

 

[davebender]

Why not the Do-217, which becomes a Do-317 when Jumo 222 engines are installed?