Fast bombers alternatives for 1939-40

Ad: This forum contains affiliate links to products on Amazon and eBay. More information in Terms and rules

That is, in essence, to design an entirely new airplane.
 
Hence Gloster Gladiators being sent to France initially which, with the Westland Lysanders, could cope with the worst of the airfields (almost lliterally fields). As time went on the improvements made to the fields plus the availability of more Hurricanes allowed the RAF to replace all the Gladiators with Hurricanes by May 1940.
 
To Grey Geist: The issue was BFW did not have the engineering capability to bring the Bf 162 design to a mass production status. It is really difficult to produce aircraft when the design is not complete! Also you may not be aware, Ju 88s were produced by no less than 8 manufacturers, beginning in 1940. I will also address the performance issue: In my opinion, if the Bf 162 had been redesigned to carry the same bomb load that the Ju 88 did, the speed probably would not have been significantly better and the range probably less.
ArtieBob
 
Going in a different direction, could the early B-17s have been evolved to be a high speed bomber instead of the flying fortress it became?

I imagine something like the B-17E, without the ball turret and waist gunners. Still have the upper and tail turrets.

5 man crew? Pilot, navigator, bombardier, upper turret and tail turret gunners.
 
The 1935 RLM request was for a tactical "schnellbomber", not a bomb truck.

The the decision for the Ju88 over the Hs127 and Bf162 was made not for it's speed, but capacity.

As it stands, with the RLM constantly moving the goal posts, the Do17 ended up being their "schnellbomber", which is a bit ironic, since the Ju88 was an answer to the 1935 request, but entered service after the Do17, which was not part of that competition at all.
 
GrauGeist
"The 1935 RLM request was for a tactical "schnellbomber", not a bomb truck."
When is ever a bomber, even a light bomber, not a "bomb truck"? That appellation is imprecise and is
imho, a "non sequitur".

"The decision for the Ju88 over the Hs127 and Bf162 was made not for it's speed, but capacity."
As I presented in my first post in this thread, translated quotes of primary document from
the RLM on evaluation of the Ju 88 versus Bf 162 do not agree. I gave the title and date, look it
up and it is clear the issue was BFW's inability to complete the design engineering to meet requirements.
Performance did not appear the decisive factor. If there is any primary documentation you have seen that
would indicate otherwise, please identify it.

"As it stands, with the RLM constantly moving the goal posts, the Do17 ended up being their "schnellbomber",
which is a bit ironic, since the Ju88 was an answer to the 1935 request, but entered service after the Do 17,
which was not part of that competition at all."
I would dispute the idea that the Do 17 was ever considered as the "ersatz Schnellbomber". The data I have
indicates the fastest production versions of that type were about 25 mph slower than the Ju 88 A-1 at altitude
and even slower by comparison at sea level. If one considers that the Do 215 is a Do-17 variant, it is a little
faster than the Ju 88 A-1, but about the same speed as the A-5 (still 1940) with no bomb load, as according to
the C-Amt Monatsmeldung, all production Do 215s were "B" model recce versions. Concerning the date of service
entry, the first prototypes of the Do 17 flew in 1934 as a commercial aircraft design, but were not considered
viable for that purpose, so the aircraft was modified to military use and probably reached units in early 1937
as a stopgap. By comparison, even with all the RLM changes, the Ju 88 first flew in 1937 and was in production
at several locations in 1939. By mid 1940, the total of Ju 88s was far ahead of total of Do 17s (with production ending).
Based on the data, it seems logical that if the Do 17 had been considered superior in any way, it would
have been kept in production, like the He 111.

ArtieBob
 

That LeO 451 had 1,000 hp Gnome Rhone 14N (which I know you love as a powerplant, right?) and yet it made 308 mph. And at fairly low altitude in the fairly thick air, no less.

How about instead just put some 1,600 hp R-2600s in it? Would that make it go faster?

The DB-7 / A-20A made 350 mph with those, and probably was not quite as well streamlined.
 
I'm intrigued by the idea of having two engines in the fuselage as a way around the drag from the engine nacelles in a traditional twin engine design.

The XB-42 was mentioned earlier in the thread, with contra rotating props in the rear. Then there's the Do 335 with props both in front and rear (yes, this was a fighter, but just as an example of the concept. And then we have contra rotating props in the front, as in the Bolkhovitinov S-2M-103

 
Last edited:
Then there's the Do 335 with props both in front and rear (yes, this was a fighter, but just as an example of the concept.
Seems like the Do 335 started out as a fast bomber, with switch to the fighter job being necessitated by the dire German situation in 1944? There was still the bomb bay present in 1945, with extra fuel tank as alternative payload there.
If Germans (or other people, the push-pull concept of installing the engines was public knowledge in the 1930s) made a real bomber is such a layout, it would've been capable for very high speeds with then-current engines, preferably the V12s.
 

I'm not a big believer in that approach in general, but the French had a couple of experiments along those lines too

like this weird thing






They also had this weird bomber which had three engines, the third being just to power the supercharger!




 
Bolkhovitinov "S" is the correct name. "2M-103" means "with two M-103 engines" - you can find this in the text available at your link..
 

Just removing the guns will not give you enough of a speed boost to make difference. The only engine that gives enough power that probably will fit is the R-2600. There will be a 3,000lb to 4,000lb weight penalty, but a R-2600 powered B-17 will be able to climb to, and cruise at high altitudes more economically offsetting the weight somewhat.

I think a single pilot on a four engine aircraft is a mistake.
 
This may be a mistake. Without turbos (and Wright never got the R-2600 to play with the Turbo nicely) the power levels crossover at the higher altitudes.
The Turbo R-1820 was good for about 1000hp at 25,000 or higher at max continuous (1 hour rating or truly max continuous, run it at that level until the fuel runs out).
A 1700hp R-2600 was lucky it could make 1000hp at 25,000 without a turbo even at Military power (5 minute rating)
The Turbo powerplants in the B-17 and B-24 are often under rated. Granted they were not as good as larger engines for take-off and low altitudes but up at around 25,000ft they were giving very little to The Merlins, Hercules, BMW 801s.
 
Would swapping the R-1820s for V-1710s (appropriately updated nacelles) allow your B-38E to operate on speed alone?
Can you add a 5th engine on nose - like the test turboprops, for an additional 1,400hp?​
 
Just removing the guns will not give you enough of a speed boost to make difference.

The weight helps. Save at least 1,000lb from halving the crew.
Another 1,200 - 1,300lb from removing the ball turret
180hp to get rid of 3 M2 brownings and ~500lb for ammunition.
Also improvments in drag without as many bits hanging out.

The B-17E with belly turret, tail turret and upper turret managed 317mph on 1,200hp.



I think if speed is desired, a change to the V-1710 would be in order.

At first there would only be a small power improvement, but mid war there will be a few hunder hp advantage per engine.


I think a single pilot on a four engine aircraft is a mistake.

It worked OK for the British.

The bombadier doesn't do a lot if he isn't bombing and his gun is taken away. He can work as a second pilot, or flight engineer, when he isn't aiming.
 
Bodie is the only author that I can recall that makes the claim that the R-2600 was unsuitable for turbos. The only two turbo R-2600 installations that I know of are the A-20 and the F6F-2. The Turbo A-20 was just a really dumb idea for a tactical bomber that primary mission is dropping 20lb frag bombs. The AAC realized this and dropped the turbo. The A-20 did have a lot of problems with its installation... But so did everything else at the time, so..? The F6F-2 was pretty much the same. The TEC turbo needed a good deal of development work and it didn't offer any advantage over the R-2800-10 until ~21,000ft. This was above the majority naval aerial combat.

From a technical perspective I can't see anything about the R-2600 that would make it any less suitable for turbo-supercharging than the R-1820 or R-3350. In fact the R-3350's troubles largely stem from its deviation from 1820/2600 practices.
 
I think if speed is desired, a change to the V-1710 would be in order.

At first there would only be a small power improvement, but mid war there will be a few hunder hp advantage per engine.
V-1710-91/R-1820/R-2600B
TO/ mil power
1425, 1200, 1700
Normal rated
1100, 1000, 1500
Max lean cruise
795, 750, 1125

Above 23'000ft or so the B-17 had to cruise in auto-rich in order to produce enough power to maintain a suboptimal cruise profile. The V-1710 doesn't offer enough improvement to change this fact.
The negative effects of climb on range is another consideration. Like all the other ETO heavies, the B-17 doesn't have enough power to climb straight to altitude at the higher take-off weights efficiently. Proper step-climb and/or cruise-climb procedures can alleviate this to some extent but it's obviously not that viable when most of your flying is over enemy territory.

A 10% increase in rated power is definitely helpful. But once again the R-2600 offers a 50% boost.

For a long range bomber cruising speed is very important. Not only does it reduce total exposure time, it increases the the area in which the bomber can be at any given moment. The V-1710 doesn't give any meaningful advantage over the R-1820. The R-2600 does.
 

Users who are viewing this thread