A work in progress:
For a Hyperscale review and pictures of the sprues: http://www.hyperscale.com/2021/reviews/kits/sw72136reviewjb_1.htm
12 September 2021: For more on the difference in the oil cooler installation between the TBF-1 and TBM-3, see http://tailhooktopics.blogspot.com/2021/09/tbf-1-versus-tbm-3-oil-cooler-location.html
15 August 2021: Added comparison of TBF-1 and TBM-3 power plant installation
Sword Models has continued to build on their 1/72 TBF/TBM kit range by going back to the first Avengers, the TBF-1 (SW72136) and Tarpon Mk 1 (SW72137).
The Tarpon Mk 1 was essentially identical to the earliest TBF-1 with respect to the engine installation, middle crew compartment, and with one exception, the later aft fuselage windows. The significant TBF-1 differences from the TBM-3 were the engine installation and single forward firing machine gun. These are provided for by a new fuselage sprue.
In box and build reviews of the earlier TBF/TBM kits are available on line. Suffice it to say, the accuracy, detail, and quality of parts and decals are commendable, more than adequate to the purpose. Nevertheless, a few notes may be of interest.
Grumman was the winner of a 1939 competition for a new torpedo bomber to replace the relatively new TBD Devastator. Contrary to what appears to be a four-man crew in this photo of the prototype, there were only three although there were originally four crew stations.
The pilot sat up front, the "assistant pilot/bomber" sat immediately behind him with a rudimentary set of flight instruments and controls, and the gunner/radioman sat in the turret. However, the Bureau of Aeronautics suggested that it would be desirable for both the assistant pilot and the gunner to have access to the radio, which clearly could not be accommodated, or his parachute for that matter, in the turret along with a .50 caliber machine gun (his parachute was stored on the side of the fuselage above the cabin door; he did wear the harness). Moreover, the "bomber", more usually referred to as a bombardier, would use a Norden bomb sight located behind a window at the aft end of the bomb bay, for level-flight bomb drops.
In the TBD, the assistant pilot/bomber crawled under the pilot to access the bomb sight, which was located forward of the bombs.
The radios were therefore located back in what was called the tunnel underneath the turret along with a seat that could be folded down from the left side of the fuselage. An opening was provided in the right side of the bulkhead at the aft end of the middle crew compartment for the assistant pilot to move down to the tunnel position. It was certainly easier for him to get back there than for the gunner to get down there:
These were the original windows in the aft fuselage (note in the illustration above of the bombardier kneeling at the Norden sight that the window on the left side of the fuselage does not line up with one in the center of the door; they differ longitudinally by about one half of the frame spacing).
No controls are evident other than foot troughs that would go to the rudder pedals and what appears to be provisions for a control stick. Also noteworthy are the arm rests and the lack of a shoulder harness requirement at that time. To access the passage back to the tunnel, the assistant pilot would climb down to his right.
In any event, the Navy decided to delete the assistant pilot requirement, permanently relocate the bombardier to the tunnel, and assign him the radioman responsibility. This was reportedly effective with the 51st TBF-1 and probably the cause for the redesign of the windows in the aft fuselage to provide more natural light at the tunnel position.
Part of the reason for the move was probably the need to provide a location for more radio equipment, which more or less filled the center compartment although it was still accessible from the tunnel.
The Royal Navy Tarpons were delivered from Grumman with this later window configuration and probably no seat in the middle compartment but the Brits chose to reinstate the center seat (probably without flight controls) and replace the large window in the aft fuselage with a dome for better visibility downward. The gunner was assigned the radio responsibility as the "Telegraphist Air Gunner".
The Royal Navy practice at the time was to require a navigator for carrier-based aircraft, the thinking being that pilot needed all the help he could get to find the carrier on his way back. U.S. Navy pilots, on the other hand, were expected to do so on their own. Chart boards were provided that slid out from the instrument panel so they could plot their position relative to the movement of the carrier in their absence and be able to find it again without benefit of radio direction finding (this is a TBM-3 illustration).
According to Paul Fontenoy, the Royal Navy crewman aft of the pilot was designated as Observer, which covered. his responsibilities that included navigation, gunnery spotting, reconnaissance work, and level-bombing aiming.
The Sword kits provide both the early and later fuselage windows. The instructions aren't explicit about which should be deleted by being painted over but the marking and color scheme illustrations can be used as a guide for that. The access between the middle crew compartment and the tunnel is not represented but could be by simply modifying parts 14 (the forward and middle cockpit floor) and 7 (the aft bulkhead of the middle cockpit).
Two other small details to consider adding by reference to pictures (note that their presence was short-lived) are the light on the backside of the pilot's headrest (it signaled the other bombers in a formation to drop when the lead bombardier did) and an ADF loop under the aft canopy. Note that the fairing between the canopy and the turret (part C10) was retractable (the turret could be swung around to face up and forward) and probably one of the first bits of the actual airframe to be removed and never replaced.
The retracted fairing and the signal light:
The signal light:
And the ADF loop with the turret fairing slid aft: