SUBMARINES:  CHATHAM BUILT

A Class: Large Patrol Submarine
When the war started in the Pacific, there was a clear need for a long range patrol submarine designed specifically for the Far East. This design would become known as the A Class.
These boats would be of all welded hulls, carry a large armament of torpedoes and to cover the long distance from base to patrol areas, they would be fast on the surface.
Unfortunately, it was decided that these submarines would not be built until yards had completed existing orders and had room on slipways. The result of this command decision was that the A Class would not be completed in time to see any action. In fact, when Japan surrendered, only two boats had been commissioned and these were still on their work-up in Scotland.
Accommodation in the A class was superior to the previous boats. Each crew member had his own bunk. Air in the boat was circulated through a compartment which contained 2 55,000 BTU/hr Freon Air Conditioning Units. Fresh water capacity was increased and distillers and refrigeration were installed.
The original order was for 46 A Class but in October 1945 with the war at an end, 30 were cancelled. Vickers were the lead yard building 10 boats, Cammell Lairds and Scotts built 3 and 2 respectively and of the Royal Dockyards, only Chatham from an original order for two, built one A Class.
One of the major modifications to British submarines after the war, was the fitting of Snort Masts. Six of the A Class were completed with a snort mast.
This allowed for a number of endurance tests on both boats and crew. In 1947, Alliance (now on display at Gosport) remained dived for thirty days covering over 3,000 miles.
Between 1955 and the early 1960's 14 of the boats were modernised. Affray which had been lost with all hands in 1951 and Aurochs considered not worthy of modernising were the two exceptions. The modifications gave the boats a streamline casing and a high fin which surrounded the masts. Although the deck guns were removed, their mounting were left to allow refitting of the guns if required. This proved to be good planning as the guns were indeed required. As late as 1974, Andrew still had her gun fitted.



a class.pic
a class.pic

A Class:  Information
 
Original Build
After Conversion
Commissioned
1945 to 1948
1955 to 1964
Length (feet):
279ft 3"
279ft 9"
Beam (feet):
22ft 3"
22ft 3"
Surface Displacement (tons):
1375
1375
Submerged Displacement (tons):
1620
1620
Speed (knots):
Surface: 18.5 Dived: 8
Surface: 19 Dived: 10
Armament:
6 x 21" Bow Tubes
4 x 21" Stern Tube
1 x 4" Gun
1 x 20mm Oerlikon 3 x .303 Lewis Guns
4 x 21" Bow Tubes
2 x 21" Stern Tubes
Propulsion:
2 x 4300 bhp Supercharged Diesel Engines
2 x 1250 bhp Electric Motors
2 Shafts
2 x 4300 bhp Supercharged Diesel Engines
2 x 1250 bhp Electric Motors
2 Shafts
Range
15,200 nm
11,000 nm
Complement
61
64



A CLASS
BUILT AT CHATHAM




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