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The first distinction to make is between the plural of TBM-3 (an upgraded base model which had many variants) and the specific model TBM-3S, which was a post-war ASW variant. The TBM-3S is most recognizable due to the removal of the rear turret and the installation of a rear cockpit in its place for the radar operator.
The type which operated from escort carriers during the war would have been the TBM-3 (in general) and the TBM-3D and TBM-3E which you can remember by thinking (additional) "electronics" - this is the wartime version equipped with the APS-4 radar, hung under the right wing. The TBM-3D was an upgraded ASW variant from the TBM-1D type, fitted with an ASD radar built into the right wing and often a searchlight hung from the left wing.
The British Fleet Air Arm equivalent model TBM-3 / TBM-3 D/E was designated the Avenger III. As you can imagine, the addition of a radar was quite helpful to discover surfaced subs charging their batteries at night or even detecting their periscope / snorkel instrumentation under the right conditions. The base TBM-3 model is where the hardpoints for drop tanks and rockets were introduced. I believe British penetrator rockets were used first for ASW which were then replaced by the HVAR rockets when they became available.
Keep in mind that a set of four 350lb depth charges were much more likely to be used than the Mk 24 torpedo - I just looked and only 340 Mk 24s were launched in the entire war, including both theaters of war and all aircraft which used them (I know PBY Catalinas / Cansos) used them in addition to the Avengers... not sure if any other types did. As you can imagine, that pales in comparison to the number of aerial depth charges dropped....
That said, if equipped with a Mk 24 torpedo, there wouldn't be any issue with equipping rockets and drop tanks assuming a 'late war' TBM-3D or E was used (the tanks were hung inboard of the rockets). The torpedo of course would be held in the bomb bay - the Mk 24 was quite a bit shorter than a standard Mk 13 as well as lighter, so there technically should have been room and weight capacity to perhaps carry a depth charge to two in addition. That said, I haven't heard of mixed armaments being used, as the attachment points in the bay would also need to be modified to do that. These attachment points were already quite complex to handle two very different torpedo types, depth charges, various bomb configurations, and even smoke tanks. Note that on the 3E variant, the APS-4 would have been hung in lieu of the rocket mounts on the right wing. I'm not sure if it was common practice to hang rockets from the other wing, although it technically would be possible.
This cutaway can give you an idea of the general layout of the ordnance. But you can see starting from the outside of the wing, working inward:
(1) attachment point for externally mounted radar (APS-4 as carried on the 3E variant) or four rockets - on the 3D I believe this space was still available for rockets on the right wing as the APS-3 radome was built into the leading edge of the wing at that location.
(2) center pylon which could carry a depth charge, small bombs, or a 58gal or 100gal drop tank
(3) internal bomb bay with either four depth chrages, one Mk 13 or Mk 24 torpedo, or a smoke tank.
View attachment 501011
Source: conceptbunny.com
This will give you an idea of a 3D configuration with the APS-3 and searchlight combo plus rockets. Add the Mk 24 into the bomb bay, and you're good to go.
View attachment 501012
Source: U.S. Navy Aircraft History: Post-War Eastern TBM Variants
Hope that helps!
Thanks for the info.
This picture looks like it has a Yagi antenna on the left wing, and the standard APS-4 radome on the right as well as at least one rocket.
The FIDO was very effective.
Some Statistics on the Mark 24 "mine" a/k/a "Fido homing torpedo [...]
There were a few types of cameras used:
1. A 35mm camera mounted fore of the cockpit windscreen - this would be used as a typical gun camera.
2. A camera mounted in lieu of the ventral machine gun - this would be used primarily for recording rocket attacks. It would be difficult to visually identify an Avenger with this option, so historical notations must be relied upon.
3. The pictures you posted both are good examples of the external cameras used to record rocket attacks. As shown, the camera was typically mounted just outboard of the rocket mounts on the port wing.
4. Various handheld cameras used inside the cockpit by the crew. I doubt these had much use in recording attacks in progress, but they could be used to record target damage after the attack.
5. The 3P variant with camera equipment installed in the bomb bay. This variant's primary mission would be photo recon, so it would be identifying targets for later raids as well as recording results afterwards.
Interestingly, here is the photographic basis for the art you posted:
View attachment 501364
Source: Squadron Signal
If you're asking for a close-up on the camera itself... I'm not sure exactly which cameras were used. As a general representative of what might be used, here is a Fairchild K-20 aerial camera (shown as handheld here):
View attachment 501365
Source: airandspace.si.edu
What's shown above would need to be modified for the external mount. Also, I believe the Royal Navy FAA did not necessarily use the same camera equipment as the USN, so there's that factor too. I wouldn't be surprised if many camera types were used with many of them falling under 'field modifications' to make what was available work for the task at hand.
Some additional info regarding the Mk4 and Mk5 rocket launchers as well as the Mk 54 depth charges:
View attachment 501358
View attachment 501359
View attachment 501360
Source (for all three): Squadron Signal - Aviation in Action #1082
The picture I posted previously of the 3D model with the searchlight is equipped with the Mk 5 / HVARs system.
A couple more notes:
1. A camera was sometimes hung outboard of the rocket rails in order to capture footage of rocket attacks on submarines.
2. The standard USN Atlantic ASW color scheme was Dark Gull Gray and Insignia White.
3. This will give you a general idea of what they would have looked like:
View attachment 501361
Source: Squadron Signal - Aviation in Action #1082
The Mark 24 was designed to have roughly the same dimensions as a 1,000lb bomb and was usually carried in the forward part of the TBF/TBM's bomb bay.
Typical loadout for late 1943 and 1944 was a pair of depth bombs at the rear of the bay, six AN/CRT-1 sonobuoys, three on each side at the front, and a Mark 24 in the centerline position between the sonobuoys. Here' s a picture with the Mark 24 removed (it was top secret and photographing them was absolutely forbidden):
File:TBM bomb bay w sonobuoys.jpg - Wikimedia Commons
A standard attack on a U-boat was supposed to go something like this:Thanks for the info. Were the sonobouys toggled like bombs? How did the pilot choose what to drop at a given time? As I understand it, this type of sonobuoy was a passive sonar - diredtional microphone based, that would broadcast a radio signal of the sounds heard that the operator could receive on his earphones. When you dropped multiple buoys, how did you choose between them for sounds? How did you use them to determine the location of the submarine?
A standard attack on a U-boat was supposed to go something like this:
An Avenger out on patrol would spot a U-boat either visually or on radar. If possible the pilot would work his way round to try and make his initial attack out of the sun, using rockets to try and damage the sub to the point that it couldn't submerge.
If the sub did manage to dive, the Avenger would make a second run and drop both depth charges 'ahead of the swirl', that is at the point where the boat would probably be given its forward motion after diving. The DCs were usually set fairly shallow, say 50ft, the idea being to hit the sub before it managed to get too far away from its initial diving point and before it got too deep.
Then, the Avenger pilot would drop the sonobuoys. Each buoy was identified by a colour, shorthanded as POBRY: purple, orange, blue, red, yellow. The sixth AN/CRT-1 was green, and that was kept as a a backup in case one of the others failed, or if more verification of a contact was needed. Each sonobuoy included a dye marker in the same colour so it was more visible from the air, and transmitted on its own frequency. The Avenger would fly a 'shamrock' pattern like so to drop the buoys in a cruciform shape:
View attachment 534390
In the Avenger the radio operator had a multi-channel radio receiver called an AN/ARR-3, which was pre-tuned for the six buoys. When the pattern was laid, the operator would flip through the channels and try to pick up the sounds of the U-boat. The buoy which picked up the strongest sounds was presumably closest to the U-boat, and the Fido would then be dropped somewhere close to the buoy so it could do its thing. The sonobuoys had a cardboard section which would become waterlogged and disintegrate, causing them to sink after a few hours.