21-in T.R. Torpedo Tube (UK)
The 21-in T.R. Torpedo Mountings were the Royal Navy's first triple torpedo mountings, and were employed in [["W" Class Destroyer (1917)|"W" Class destroyers and light cruisers designed shortly before and during the Great War.
T.R. Mark I
The T.R. Mark I mounting was first employed in the "W" class destroyers of the 1917 Programme, and it inaugurated the triple tube format for the Royal Navy, offering destroyers three times the ready torpedo numbers of destroyers designed just six years previously.
The design featured slack fit construction to simplify repair and adjustment while reducing weight, special access doors to expose all principal adjustment controls for parameters such as gyro angle, running speed, etc and holes for air service and other supplies, single ball firing gear with local hand-releasing gear, and more powerful impulse charge of 17 ounces (rather than 10 ounces as in previous tubes), providing a pressure of 65 psi and torpedo speed of 32 feet per second on firing.
The torpedo layer sat on the right-hand tube, with a director stand and instrument panel in front of him and handles for local firing below. The tubes could be locked to either 90° Green or Red, as well as (presumably) right ahead or aft. The torpedo within the tube was supported on two side-bearing bars, and entered the water at an angle of about two degrees. The outer diameter of the tube was 23 inches. Hinged access doors were sealed by india rubber pads on the inside and were secured by four locking levers.
|Length of cut-away part of lip||7' 9""|
|Length of circular part of lip||3' 9""|
|Lip length overall||11' 6"|
|Length of rear portion||11' 6"|
|Radius, lip to pivot||12' 11.5"|
|Radius, rear end to pivot||11'|
|Diameter of tube||23"|
|Distance, face of door to pivot||10' 3"|
|Weight, complete with racer and pivot||14,746 pounds|
The tubes were satisfactory in testing, though the torpedoes left at lower velocity than anticipated (varying between 31.2 and 34.5 fps with two models of torpedo under different conditions) due to friction which was attended to by alterations. The new access doors proved sufficiently tight to not compromise operation in firing.
- Annual Report of the Torpedo School, 1917. Plate23.
- Annual Report of the Torpedo School, 1917. Plate24.
- Annual Report of the Torpedo School, 1917. p. 76, 77.
- Annual Report of the Torpedo School, 1917. pp. 76, 77.
- Annual Report of the Torpedo School, 1917. p. 78.