Best medium bomber of WWII?

With the GT-1, Wiki says they hit a carrier and two other ships

I did a little thought experiment, and it ends up coming out with Mosquito 1st place, Ju 88 2nd, Wellington 3rd.

This is just a bit of guesswork, but I was a bit surprised myself how it came out, and it kind of rings true.

Mosquito is still clearly the standout. Wellington, in spite of the fact that's not the fastest or most accurate bomber, gains benefit for versatility, range, cost effectiveness and years in action. Ju 88 somewhat similar. The American bombers were good but limited by their range and somewhat small bomb load. Same for the Russian bombers, though they look pretty good too, especially the Pe 2 which had a significant impact for a long time.

A lot of this is a bit arbitrary so it could nudge this way or that of course. It's just a bit of structured guesswork. But I thought it was interesting.

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EDIT: Slightly modified it to reflect time in front line service as well as time overall, with a second total reflecting merits without consideration of time in service (so more about the design) Top 3 still remain the same. Interesting that the top 3 are still the top 3 without considering time in service.

I really like that chart. I'm sure someone will argue this point or that but it's a good attempt to quantify the unquantifiable.

Still thought the G4M would have done better.
Does that mean I'm a fanboy?

SaparotRob said:

Still thought the G4M would have done better.
Does that mean I'm a fanboy?

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I think the G4M was good - better than a lot of others I didn't include on the list. But it certainly had it's flaws and it peaked pretty early. By 1943 it wasn't much of a factor any more.

I did pick the B-25.

Reluctant Poster said:

With glide torpedoes or standard? I haven't found any records of B25s mounting successful torpedo attacks.

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Were there any successful torpedo attacks by USAAF aircraft? I believe they were tried with B-26s, but I believe that was it.

Apparently the glider bomb ones with B-25s. Several with PBYs but those were Navy or Marines I think.

Title of the thread is best medium bomber, not most versatile airframe.

How good or bad an airframe was as a night fighter should not make much difference to what kind of bomber it was.

There was a difference between European combat and pacific theater combat. Range was much more important in the Pacific. Planes that had good or very good records in Europe might have been near useless in the Pacific (or judged much more harshly) while some Pacific bombers (Japanese ones?) get judged harshly because of the compromises made to give them the long range needed.

The JU-88 is often overrated because it was so versatile. It was a very valuable resource for the Germans but as a bomber it often left something to be desired.
Most of the bomber versions weren't really all that fast, Most of them didn't have much range when carrying bombs inside, Most of them had pretty poor defensive armament.
Fortunately for the Germans most of the time their targets weren't very far away so the short range wasn't quite the handicap it might have been in other circumstances.
Over short distances (or medium) it could carry a pretty fair bomb load but had to do so with the bombs outside the plane so listed speeds are an illusion (at least for entering contested airspace).
How valuable it was as a long range day fighter or night fighter changes nothing about it's problems as a bomber.

B-25 sucked as a night fighter (if it was even ever tried?) but it was a pretty fair medium bomber.
It couldn't attack without escort (unless at night) but them most if not all medium bombers except the Mosquito (if that is a medium bomber) had the same problem.
A modified B-25C or D (belly turret taken out, one .50 cal out each side and one in the tail with a seated gunner) as done both in the Med and South East Pacific has a much better defensive set up than most non american bombers on the list. It still has the twin .50s in the power top turret.
A B-25C or D has just about 50% more fuel in the internal tanks than the JU-88. A JU-88A-4 might be just a touch faster at around 20,000ft but the B-25 might be faster at 15,000ft?
A lot depends on the load or gross weight of each and the JU-88 has to be running clean (no under fuselage or under wing bombs).

Yes the JU-88 can dive bomb but if it can't reach the target then what??

I don't disagree with most of that - in fact my main criticism of the Ju 88 is that it's most important service as a bomber was in the first couple of years of the war, by the late war they were mostly effective as a night fighter, long range fighter or maritime patrol aircraft.

However a couple of things. First, the bombing accuracy was high, and that really did matter. It turns out hitting the target is really important. It's also harder to do and rarer to find a machine which could be made to do it than I think many leaders even fully realized during the war. This is why the Germans were still using the obsolete, fixed undercarriage 200 mph Stuka so late in the war. We know from Allied records that Ju 88s often did hit their targets and caused a lot of harm. So that makes them a good bomber in my book.

You make a plane that can carry 10,000 lbs of bombs 10,000 miles, but if you can't hit anything it really doesn't help much as a bomber. Maybe UPS will buy it.

Versatility also does matter, even if it begins to define the aircraft out of the parameters of being a bomber at all. It's part of what really mattered to people fighting the war. A design that runs it's course in it's first intended role but then has a second or third or fourth life as a military aircraft is better overall.

I don't, by the way, remember ever claiming that a B-25 was used as a night fighter. They (mainly the British) did use the DB-7 / A-20 at that role, and I never said it was particularly good at it. I think it was active for most of 1941

By mid 1942, many existing bomber types couldn't survive a front line raid even with escorts.

Also, the thing about having to carry bombs outside of the bomb bay and this affecting range and speed en-route to the target, this is hardly unique to the Ju 88. Many bombers had this problem, and even the ones with very large bomb bays which fit their whole load inside of it often actually flew at very slow cruising speeds en route to their targets anyway for various other reasons.

What was relatively rare about the Ju 88 is that after dropping it's bombs it had quite good performance, certainly compared to a Wellington or a Blenheim, or a He 111 say. And that is often when bombers were shot down. Ju 88 performance was good enough to evade fighters both before and after a strike, such as a Malta on a few occasions.

When they were using it as a dive-bomber that also seemed to help with survival a bit. Somewhat more dynamic form of attack and I think it was a little harder for AA to hit them.

pbehn said:

And a reversed coolant flow to supply the leading edge radiators. which were on opposite sides of the engine. Not a huge difference but the exact opposite of the "power egg" philosophy.

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How many Merlin aircraft had the "power egg"?

The Beaufighter II, certainly - because the power egg was designed for it.

The Lancaster I/III - converted Manchester to Lancaster quickly using the power egg.

The Miles M20. Designed around the power egg as an emergency fighter.

Did the Handley Page Halifax have them? Not in the early versions, at least.

Merlin Wellingtons didn't use them, nor did the Whitley.

Spitfire and Hurricane did not use them.

The Mosquito was trialled with them, but they were not adopted for production.

Didn't say you said the B-25 was used as a night fighter. Just pointing out that versitily, while often useful to war planners or air forces has little or no bearing on how well a bomber did it's original job. The B-25 was used mostly as a bomber or strafer, It did medium level attacks, low level attacks, most could carry a torpedo but the high quality US torpedo (sarcasm) prevented any success in that role, or even more than a handful of missions in that role. Russians used them as long range night bombers.

We get into a lot of arguments about accuracy. If you can make a surprise attack (or be well escorted) then dive bombing can work very well against high value targets with not so good AA defense. BUT, you can't dive bomb at night or in bad weather (cloud cover) . If you don't have surprise the defence can create bad weather (poor visibility) with smoke generators.
JU-88s did sink a lot ships, but it was at short ranges from their bases for the most part wasn't it?

The Ju-88 seems to offer a lot flexibility but how much is an illusion? It can carry four 1100lb bombs outside but at max gross weight fuel capacity might be down to about 500 imp gallons? Cruising speeds with such a load was????
I know the JU-88-1 used rockets to get of the ground at high gross weights and some sources claim the A-4s did also, not sure about that though.
Two 1100lbs might be just as effective and allow more fuel but you could put 2000-3000lb inside a B-25 and go 1200-1500 miles.

The JU-88 had crap for defensive armament.

Schweik said:

What was relatively rare about the Ju 88 is that after dropping it's bombs it had quite good performance, certainly compared to a Wellington or a Blenheim, or a He 111 say. And that is often when bombers were shot down. Ju 88 performance was good enough to evade fighters both before and after a strike, such as a Malta on a few occasions.

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Something seems a bit off, Ju-88 was good for 292mph at 17,390ft at 27,557lbs. Granted with bombs and 1/2 the fuel gone it would be a bit faster. But that is max speed and not max cruise or any speed that could be maintained for more the 5 minutes or so. Granted in combat you do what you have to do. But the Blenheim IV was good for 265mph or bit better. Is an extra 20 to 30mph the difference in survivability? (Yes the Wellington was bog slow) The He 111H-16 was supposed to do 270mph 19,685ft with bombs gone and 1/2 fuel. However this was down to 248mph at 6560 feet, I doubt the JU-88 was much more than 20-30mph faster at the same altitude. Maybe speeds in the high 200s are all that is needed?

ThomasP said:

As has been brought up already, the problem is what criteria are we to use?

If we are including potential effect/effectiveness of a design then there are many contenders. If we use actual effect/effectiveness then I would have to say it is a toss up between the Ju 88 and Wellington.

Both designs entered service pre-war.
Both designs were produced until the end of the war.
Both designs were produced in larger numbers than any other bomber by their respective users - with ~15,000x Ju 88 and ~11,000x Wellington.
Both designs remained largely unchanged other than detail mods and engines.
Both designs were used for multiple purposes:

Ju 88
light-medium bomber
dive bomber
torpedo bomber
reconnaissance (tactical and strategic)
heavy fighter
night fighter

)

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The Weakness of the Ju 88 (and Ju 188) was the bomb bay. Internally it could only carry 50kg/110lb bombs (quite a few though) and perhaps a little known 65kg or 70kg bomb. Had it been a mid wing layout it might have carried say 2 x 500kg, 4 x 250kg or even 4 x 500kg internally. Even with only 1000kg/2200lbs internal it would have a great annoyance to the RAF as the bombs and their racks cost about 14% in speed.

The Ju 88S1 with a speed of 380mph would have been very hard to intercept but with external bombs it slowed down.

Of course the external bombs facilitated dive bombing and the amazing precision the Ju 88 often demonstrated but from 1942 that was completely superfluous and that slide bombing with the StuVi 5B bomb sight worked from a shallow dive.

Koopernic said:

The Ju 88S1 with a speed of 380mph would have been very hard to intercept but with external bombs it slowed down.

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That was with the NO2 running and at higher altitudes than B-17s bombed at. Accuracy was going to be dismal.

Similar idea to the B-28, the planned successor to the B-25. Looked cool on paper, but only really at 25,000 ft

North American XB-28 Dragon - Wikipedia

Shortround6 said:

That was with the NO2 running and at higher altitudes than B-17s bombed at. Accuracy was going to be dismal.

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The Maximum speed of the Ju 88 S-1 was 610kmh/378mph at 8000m/26246ft when using GM-. That's only 1246ft higher than B17 altitude. (25,000ft). The bombing accuracy would be OK if they used the EGON-II blind bombing system or Zyklops and the Lotfe 7 was about as accurate as the Norden, certainly no worse than a Mosquito or B-17 at similar altitude. Note "GM-1" Nitrous Oxide was used above the full pressure altitude of the engine so it didn't 'hot rod' the engine mechanically and place undue stress on it, it only maintained power at full pressure altitude.

A hypothetical 378mph Ju 88S1 capable of carrying 1 ton of internal bombs penetrating at about 350mph was going to be a hard target especially if it used a speed dash or small dive. Many Ju 88S-1 were used as pathfinders and I presume the target markers fitted internally. Carrying full sized bombs had to be done extermally.

From Wikipedia.de
Schnellbomber mit strömungsgünstiger Glasnase und ohne Bodenwanne, nur ein 13-mm-MG 131 als Abwehrbewaffnung. Die Maschine war zum Einsatz über England und der Westfront vorgesehen; allerdings reichte die 1943 vielversprechende Geschwindigkeit 1944 nicht mehr aus, um feindlichen Jägern zu entgehen. Gleichzeitig wurde die Strahltriebwerkstechnologie serienreif, daher wurden nur eine kleine Serie Ju 88 S produziert, bevor die deutlich schnellere Arado Ar 234 mit Luftstrahltriebwerken vom Typ Jumo 004 als Schnellbomber zum Einsatz gelangte.

• Ju 88 S-1: BMW 801 G-2 mit GM-1-Anlage, Höchstgeschwindigkeit ohne Bombenlast ca. 600 km/h in 6000 m, mit GM-1 ca. 610 km/h in 8000 m, verfügbar ab Herbst 1943
• Ju 88 S-2: statt GM-1 mit Triebwerksanlage BMW 801 TJ mit Turbolader, ohne GM-1-Anlage, verfügbar ab Frühjahr 1944
• Ju 88 S-3: Jumo 213 A mit GM-1-Anlage, Höchstgeschwindigkeit ohne Bombenlast ca. 600 km/h in 6000 m, mit GM-1 ca. 615 km/h in 9000 m, wenige Maschinen verfügbar ab Spätsommer 1944

Translated version:
Fast bomber with low-flow glass nose and without bottom tub, only a 13 mm MG 131 as defensive armament. The aircraft was intended for use over England and the Western Front; however, the promising speed of 1943 in 1944 was no longer sufficient to escape enemy hunters. At the same time, the jet engine technology was ready for series production, so only a small series Ju 88 S was produced before the significantly faster Arado Ar 234 with Jumo 004 air jet engines was used as a fast bomber.

Ju 88 S-1: BMW 801 G-2 with GM-1 system, top speed without bomb load approx. 600 km/h in 6000 m, with GM-1 approx. 610 km/h in 8000 m, available from autumn 1943.
Ju 88 S-2: instead of GM-1 with engine system BMW 801 TJ with turbocharger, without GM-1 system, available from spring 1944.
Ju 88 S-3: Jumo 213 A with GM-1 system, top speed without bomb load approx. 600 km/h in 6000 m, with GM-1 approx. 615 km/h in 9000 m, few machines available from late summer 1944.

Bombing from high altitude just didn't (and doesn't) work that well regardless of the bombsights, because of clouds, fog, wind, smoke generated on the ground, etc.

Laser guided or GPS guided helps but I don't think even those are dropped from 25,000 feet.

Schweik said:

Bombing from high altitude just didn't (and doesn't) work that well regardless of the bombsights, because of clouds, fog, wind, smoke generated on the ground, etc.

Laser guided or GPS guided helps but I don't think even those are dropped from 25,000 feet.

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From what I've heard they drop from high altitude. Remember a lot of the ground level over there is in the 4k+ range, so subtract that from drop altitude. Also being high conserves gas, which in turn allows longer station times, which means fewer airframes need to be used, and fewer tankers.

Cheers,
Biff

I would like to know more about the tu-2, since I heard it was similar to the pe 2 but had a better performance and payload