US Navy destroyers can hunt subs. But a dedicated frigate is better

The Type 23 does have the Magazine Torpedo Launch System, which enabled me to lob a torpedo straight into the water next to the ship. That’s a lot, lot better than nothing (as many warships have) and I found it a comfort. But I’m a big fan of ASROC and it is one of the things an Arleigh Burke has that I envied.

Moving on, much of ASW depends on how and where you are operating. A singleton frigate ‘up north’ looking for a Russian nuclear submarine is a different proposition to one operating as part of a carrier strike group in the Indo-Pacific. Task Group operations lessen the need for dedicated frigates to have ASW helicopters because you can operate them from the stability of a large deck, either the carrier itself or a Fleet Auxiliary. From a logistics and support perspective putting all your helos of the same type in one (big) ship makes sense. From an operational, flexibility and redundancy perspective it does not. These are fine margins as ever, but in fighting terms, a frigate without a Merlin onboard is only half a frigate. 

Fourth, and perhaps the most important, is the mindset. A frigate excels at ASW because that is the day job. It’s in the DNA of the team onboard. A destroyer ‘that does a bit of ASW’, or even an aircraft carrier with ASW helicopters embarked will not allocate the same effort or focus to it – they will be busy doing their core tasks – and ASW is not something you can half-do. For the submarines you are up against, it is their life. It needs to be yours as well if you are to stand a chance. 

Thankfully the USN recognised this gap in 2017 when it was announced that the service would build a new frigate. Named the Constellation class it is to be “capable of operating in both blue water (mid-ocean) and littoral (near-shore) areas, and capable of operating either independently (when that is appropriate for their assigned missions) or as part of larger Navy formations.” Numbers are yet to be confirmed, but “at least 20” is the answer for now.

This matters because Russian, Chinese, and North Korean build programmes and the proliferation of underwater drones demand that as many friendly countries as possible be committed to ASW. At the end of the Cold War, the Royal Navy had 32 frigates and the US Navy 52. We Brits were spending 4-5 per cent of GDP on defence. Today those numbers are 11 (on a good day), zero and (a false) 2 per cent.

The Constellation class is having its troubles, but it is good to see the world’s most powerful navy avoiding the beauty-over-numbers trap and recognising the need for smaller, focused capability warships that are still war-resilient (i.e. not Littoral Combat ships) but don’t cost $3 billion a shot. The sooner we see the USS Constellation and the Royal Navy’s Type 26 Frigate on operations, the better.

Tom Sharpe is a former Royal Navy officer. He commanded four different RN warships, including the Type 23 frigate HMS St Albans, in which he operated against Russian submarines in the Greeenland-Iceland-UK Gap