Torpedo Armament
This remained the same as the earlier Colossus class with three submerged 21 in torpedo tubes, one firing on each beam and one astern. The torpedoes used by the Orion class battleships were the Whitehead 21 in Mk2 these had a range of 4,000 yards at 35 knots or 5,500 yards at 30 knots and had a TNT warhead of about 400 lbs.
Read more about this topic: HMS Thunderer (1911)