Editing Oberon-class submarine (section)

===Armament===
{{More citations needed section|date=June 2015}}
[[File:Attack Periscope Type CH74 - RAN Oberon Class Submarine 1957-99.jpg|left|thumb|upright|[[Barr and Stroud]] Attack Periscope Type CH74 – RAN ''Oberon''-class submarine]]

[[File:Fire Control Consoles - HMCS Onondaga.jpg|left|thumb|Torpedo fire control consoles aboard HMCS ''Onondaga'']]

The ''Oberon''s were originally armed with eight {{convert|21|in|mm|1|adj=on}} torpedo tubes: six tubes in the bow, and two short tubes for antisubmarine defence in the stern.<ref name=compedium/> The submarine normally carried a payload of 20 torpedoes for the forward tubes; a mix of [[Mark 24 Tigerfish]] and [[List of torpedoes#21" Mark VIII|Mark 8]] torpedoes, while only the two preloaded [[British 21 inch torpedo#21 inch Mark 20 Bidder|Mark 20S]] torpedoes were carried for the stern tubes.<ref name=compedium/> [[Naval mine]]s could be carried instead of torpedoes: the torpedo payload would be replaced with up to 50 [[Stonefish (mine)|Mark 5 Stonefish]] or Mark 6 Sea Urchin mines.<ref name=compedium/>

The forward torpedo tubes are constructed in two sections bolted together across the bulkhead at the fore end of the torpedo compartment. The {{convert|116|in|cm|adj=on}} long inner section is constructed of {{convert|0.5|in|cm|adj=on}} rolled steel fitted with welded flanges and support brackets.  The outer section is constructed of a similar tube {{convert|175|in|cm}} long but with a reinforced {{convert|1.125|in|cm|adj=on}} thick section behind the main bulkhead. The internal door hinges at one side with two locking mechanisms, a swing bolt opposite the hinge and a rotating locking ring attached to the tube which presses down on the ten projecting lugs around the door. The outer end of the tube is sealed with a domed bow cap. Bow shutters close across the bow caps so as to preserve the streamlined shape of the bow when the cap is closed.

[[File:Ocelot-TorpedoTubes.JPG|right|thumb|Forward torpedo tubes on {{HMS|Ocelot|S17|6}}]]
The bow caps and shutters are mechanically linked to a hydraulically operated drive rod from within the torpedo compartment. The bow cap opens first behind the shutter, which then folds back against it forming a smooth exit tube. Interlocks prevent the doors at both ends being opened at the same time but the inner door is also provided with a test cock to check whether the tube is full of water before opening and remains held nearly closed by the swing bolt after the locking ring is released. The tube internal diameter is 22.5 in, wider than the torpedo, which is designed as a loose fit inside the tube. Torpedoes could be fired either electrically or with compressed air.{{Citation needed|date=February 2024}}

The aft torpedo tubes passed through the ballast tank at the rear of the submarine. A {{convert|31|in|cm|adj=on}} section projected into the boat through the bulkhead, forming overall a relatively short tube of {{convert|12|ft|m}}, but of {{convert|25|in|adj=on}} diameter.

With the retirement of the Mark 20S torpedo in the 1980s, the stern torpedo tubes were decommissioned and the torpedo ballast tanks were thereafter used for storing beer.<ref>{{cite book|title=The Encyclopedia of World Sea Power|page=[https://archive.org/details/encyclopediaofwo0000unse_v9e5/page/42 42]|author=Chris Bishop and Tony Cullen|publisher=Crescent Books|year=1988|isbn=0517653427|url=https://archive.org/details/encyclopediaofwo0000unse_v9e5/page/42}}</ref>