B-24 Vs U-Boat

Discussion in 'The War at Sea' started by chipm, Jul 19, 2020.

  1. chipm

    chipm Well-Known Member

    With a surfaced U-Boat and an attacking B-24, did one have an advantage.?
    You guys know a lot more about how much AA Fire a U-Boat had.
    I imagine it varied from None in to beginning to maybe one or two dual or quad 20mm later in the war.?
    If a U-Boat had a couple of dual 20mm and you were "diving" a B-24 to strafe and/or drop bombs.....who was at a bigger disadvantage.?
    Thank You
  2. TTH

    TTH Senior Member

    Some quick online research suggests a few tentative conclusions.

    Firstly, thanks to its speed, range, payload, and toughness, the Liberator was one of the best anti-submarine aircraft available to the Allies. Various figures are given, but Liberators sank or participated in the sinking of approximately one hundred U-boats. By contrast, an Osprey Publishing thread I found says that 24 Liberators were shot down by U-boats; that's a 4:1 ratio in favor of the Liberator. The key period came during the so-called "Battle of the Bay," the bay being Biscay. This was the main in-out route for U-boats from the ports of western France, and in 1943 the Allies launched a major air offensive there. It was at this time that Doenitz put more AA guns on his boats and ordered them to fight it out with aircraft. Doenitz' new policy was a mistake. The bay fighting was intense and Allied aircraft suffered significant losses, but German U-boat losses were a good deal worse, on the order of two boats lost for every Allied aircraft shot down. That was a very bad rate of exchange, especially since the Allies could build more aircraft faster than the Germans could build U-boats. Of course an individual duel between a Liberator and a U-boat might go either way depending on tactical circumstances and the skill and experience of the crews involved, but just as U-boats might team up so aircraft could do the same and win a tactical advantage that way. As time passed, better anti-sub munitions became available to Allied airmen and this increased both the likelihood of a hit and the damage inflicted by hits. Some things I've read suggest that the greatest danger to Liberators and other Allied planes in the bay was not U-boat AA but the long-range JU 88 fighters which patrolled the area. However many AA guns it carried, I have to think that a U-boat was safest submerging and not exchanging gunfire.
    Last edited: Jul 19, 2020
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  3. chipm

    chipm Well-Known Member

    OK... Great..... Thank You.:)
    I suppose i knew that Biscay was a battle ground, it makes sense, i just never realized the large scope of it.
    If i were a B-24 crew, i would rather get hit with 20mm and make for England from Biscay and not from out in the middle of The Atlantic somewhere.:omg:
    Thanks Again
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  4. TTH

    TTH Senior Member

    The Liberator is often dismissed as not being as tough as the B17, but all American combat aircraft were very ruggedly built. A single hit from a 20mm would not knock a Liberator down unless it killed the pilot or flamed a fuel tank. Liberators could take some damage and still stay in the fight.
  5. ltdan

    ltdan Nietenzähler

    Correct - In an attempt to counter the air threat German subs were literally stuffed with AA guns.
    U-441 was even rebuilt into a "Flakkreuzer" with two quad 20mm and a single 3,7cm gun.
    The outcome was a fiasco:
    Their second patrol as U-boat Flak began on July 8, 1943. 12th the boat was fired upon by three Beaufighter aircraft from No. 248 Squadron RAF. Ten men were killed and thirteen others injured, including all officers. Naval surgeon Dr. Paul Pfaffinger, an experienced submarine doctor, took command and brought the boat back safely to Brest, after which the German Cross in Gold was awarded. At this time the submarines were flaked a fault and as U-Flak 1 was converted back to its original configuration and returned to U-441 .
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  6. Peter Clare

    Peter Clare Very Senior Member


    The early B-24 Liberator I carried four 20mm cannon in a pod that utilised the forward bomb bay as can be seen in this photo. No.120 Squadron RAF Coastal Command were the first to operate with this type and had great success against the U boat.
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  7. Another major advantage the Liberator had over the U Boot was their on board radar, especially at night or when the sky was cast. It enabled the aircraft to remain undetected while accurately locating the boat from within the cover of clouds or obscurity, and then suddenly attack from the best position.

    A good summary of Allied anti submarine warfare from the air can be found here:
    Sub Hunters Over the Bay of Biscay - Warfare History Network

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  8. chipm

    chipm Well-Known Member

    I am no aviation expert, but i guess i see a "blister" at the bomb-bay forward.?
    What are those 4 things sticking up near the tail..... some type o RADAR or RADAR Jamming equipment.?
    Thank You
  9. chipm

    chipm Well-Known Member

    Impressive information..... Thank You
  10. Peter Clare

    Peter Clare Very Senior Member

    The “4 things sticking up near the tail” were early ASV ( Air to Surface Vessel radar)
  11. chipm

    chipm Well-Known Member

    10-4..... Thanks :salut:
  12. Trackfrower

    Trackfrower Member

    Some Liberators also had Rocket Projectiles.
    Terry Bulloch had some success.
  13. ltdan

    ltdan Nietenzähler

    The losses due to radar-guided air strikes in 1943 were in fact a tale of errors and confusion:

    When in June 1941 a Hudson of the Coastal Command made an emergency landing in Brest the new ASV Mk. II fell into the hands of the Germans. Subsequently, the submarines received the passive Metox radio measurement observation device (FUnkMeß-Beobachtungsgerät/FUMB) with a practical range of about 10km
    Until March 1943, the device was used with good success, but then again losses raised as British aircraft received the ASV Mk III with shorter wavelengths who could no longer be detected by the FUMB
    This fact, however, was not known to the Kriegsmarine and led to the false conclusion that the aircraft were guided by detecting the impulses (self-radiation) emitted by the FUMB itself. An experiment apparently confirmed this assumption and therefore the use of the devices were prohibited on 31 July 1943
    As a desperate consequence the now blinded submarines received more and more flak, which however was of little to no use
  14. Ewen Scott

    Ewen Scott Well-Known Member

    Details of the 72 U-Boat kills that Liberators were involved in are here
    Boeing B-24 Liberator - Aircraft - Fighting the U-boats - uboat.net

    Success against the U-boats should not just be looked at in terms of U-boat sinkings. That ignores the contribution of the many aircrew who flew thousands of hours over the bleak Atlantic and never even saw a U-boat, let alone attacked one. Success can be measured in terms of U-boats that spotted an aircraft and dived without ever being seen. Once dived they were effectively neutered due to their slow underwater speed. Success is convoys arriving safely at their destination with only minimal losses, unlike during the various "Happy Times" when both escorts and aircraft were lacking.

    What is sometimes forgotten is that although the B-24 was the most produced 4 engined heavy bomber (19,257 of all versions built to Oct 1945) less than 200 had been built by the time of Pearl Harbor.

    Coastal Command only received 11 Liberator I (as in Peter Clare's post above) and 9 Liberator II in 1941 and for the first year of operations there was only 120 squadron was equipped with them. It was only with the receipt of the Liberator GR.Mk.III (based on the B-24D which entered production in Jan 1942) from mid-1942 that numbers of aircraft and squadrons began to increase. And lets not forget the 2 B-17 Coastal Command squadrons that came into service from mid-1942.

    As for Liberator's toughness, that depends. If the wing was hit by flak and the spar damaged then it had an alarming tendency to fold due to the undercarraige retracting into it. It was also difficult to ditch. In that event the roller bomb bay doors collapsed, and the fuselage broke around the rear of the wing, potentially trapping any crew in the aft fuselage. The USAAF 8th AF preferred the B-17, going so far as to convert 5 groups in the mixed B-17/B-24 3rd Air Division from Liberators to B-17s in the July / Aug 1944.
  15. Ewen Scott

    Ewen Scott Well-Known Member

    Weapon fits varied over time and aircraft were shuffled around to ensure that squadrons had the most appropriate fit for the time in the areas that they were working in. So for squadrons operating in daylight over the Bay of Biscay in 1943/44 rocket fits were popular. While the most published photos of Liberators with rockets show them on the nose, the most common fit had them on retractable and reloadable rails in the bomb bay. Once U-boats began using snorkels from mid-1944 rockets were no longer effective and were withdrawn.

    One of the most effective weapons against a submerged sub was the Mark 24 Mine (Fido) a homing torpedo. Crews were under strict orders that it was not to be used if there was any chance of a U-boat crew seeing it launched.

    Aircraft operating at night also received a Leigh Light in a pod carried under the starboard wing.
  16. Ewen Scott

    Ewen Scott Well-Known Member

    There was a constant electronic battle throughout WW2. The metric ASVII radar was countered by the Metox detector. 10cm ASVIII was introduced in Feb/Mar 1943, and the Germans captured and H2S set from a Stirling bomber, which was basically the same device in Feb and began to work on a new detector, Naxos, which was deployed in U-boats from Sept. Then the allies moved to the 3cm wavelength from late 1943 with the H2X blind bombing set. That began to be deployed in an anti submarine role from mid-1944 on the Swordfish III with the first Liberator GR.VIII reaching squadrons in Nov 1944.
    Technical pages - German U-boats of WWII - Kriegsmarine - uboat.net

    Sonobuoys were also introduced from about mid-1944
  17. Robert-w

    Robert-w Banned

    Not the real issue - which was how fast they could train aircrew - which took much longer than building replacement aircraft.
  18. ltdan

    ltdan Nietenzähler

    What made the B-24 so attractive as armed long-range patrol aircraft was the comparatively high lift-drag ratio and great range due to it´s design for economic travel speed.
    However, these design advantages also made them more vulnerable to battle damage
    Their closest German counterpart, the Junkers 290, shared almost comparable strengths and weaknesses
  19. Dave55

    Dave55 Atlanta, USA

    The surgeons were another addition Doenitz made when he added all the AA guns and told them to fight it out on the surface.
    Last edited: Jul 19, 2020
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  20. TTH

    TTH Senior Member

    Quite true.

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