From the 1970’s onwards I will make the assertion that we have made the best Hunter-Killer SSN’s for a number of reasons. Prior to the 1970’s the US holds that distinction, firstly because their reactor was a generation ahead of ours or equal and secondly because our torpedo’s were god awful, to the point where the US practically begged us to adopt either the Mark 45 or Mark 48 torpedo’s because they were genuinely concerned that we had turned NATO’s best submarines into NATO’s worst purely because the options were a modernised torpedo from 1926 with no homing system or a torpedo so slow that anything that wasn’t a submarine could outrun it and a nuclear submarine could also outrun it whilst submerged.
From Churchill and then Swiftsure onwards (Trafalgar is a heavily upgraded repeat Swiftsure) it is undisputed we have the best Hunter-Killers.
Just on Churchill, you have a better generation reactor, a superior hull form, pumpjet propulsion (on Churchill, before that a better propeller), you’re quieter, you have more ready torpedo tubes, better sonar integration and a digital combat management system.
Swiftsure and Trafalgar only improve this disparity by adding pumpjets particularly and acoustic tiling.
For reference in the 1980s HMS Sceptre collided with a Soviet submarine she had been stalking that changed course rapidly after being given a new tasking. She sculked off at high speed. The Soviet submarine was a Delta-III class SSBN and reported to have collided with an American Sturgeon class submarine (the quietest US submarine at the time), but also noted that they believed their passive sonar had broken in the collision, because they didn’t detect the submarine move off at speed post-collision, but by the time they had switched to active sonar, the submarine was out of range. Turns out the sonar was fine, they just hadn’t heard the Sceptre.
The pumpjet on the Swiftsure class was that quiet that they could move off at top speed and remain undetected at ranges the Soviets had expected and tested that they should have heard a Sturgeon class submarine.
Spearfish itself is a revolutionary torpedo, longer range, heavier warhead, twice as fast better homing than the equivalent Mk.48 torpedo. I’m actually very surprised Australia is sticking with them for SSN-AUKUS, i’d honestly expected a switch however I suspect that’s because the Collins class uses them but the swap would not be that costly when compared to the price of the programme. But the RN will not switch to Mk.48 because Spearfish is that much better.
Astute is still the best Hunter-Killer out there, it just needs to leave port. Its a similar situation to how the Chieftain is regarded as the best tank of its era as long as it breaks down in the right spot.
The Astute’s are:
The quietest submarines out there, they have more ready torpedos, they have better torpedo’s, they have the best sonar system in service anywhere, they have the quietest propulsion system fitted to a submarine, they have large weapons stocks, they exceed 30 knots (35 is reported) submerged making them the fastest Hunter-Killer in service, they have a superior hull-form.
Their only issue is the maintenance, which isn’t inherent to the submarine, they’re the least maintenance intensive nuclear submarine the UK has ever constructed. However the last government let the company that manufactures the steel wires to hoist them out of the water for maintenance go bankrupt. A suitable alternative is yet to be contracted as a result, the 6 of them in service can’t go to sea as they can’t operate without maintenance, and the one that just rolled into sea trials will only be sea-worthy for maximum 18 months post-commission without maintenance.
The sub is great. The people managing them are the issue.
