Royal Navy warships will be less capable of fighting enemy vessels than they were in the 19th century as Britain’s Harpoon anti-ship missile will be withdrawn in two years – with no replacement in sight.

The news that the elderly Harpoon Block 1C system will be withdrawn by 2018 was broken by military analyst publication IHS Jane’s, and followed up this morning by The Sun and the Telegraph.

Without the Harpoon missile, the Navy’s escort fleet – that is, Type 45 anti-aircraft destroyers and Type 23 anti-submarine frigates – will be left with purely defensive missile weapons, various automatic guns of up to 30mm calibre and a single 4.5” medium gun.

Warships of the late 19th century, such as the RN’s own Edgar-class cruisers – which, at around 7,500 tons' displacement were slightly smaller than today’s 8,500-ton Type 45s – typically mounted secondary batteries of ten or twelve 6” guns, along with primary batteries of two 9.2” heavy guns, meaning after 2018 the RN's frontline warships would be hopelessly outgunned by century-old designs.

The MoD said, in a statement responding to the reports: "All Royal Navy ships carry a range of offensive and defensive weapons systems. Backed by a rising defence budget and a £178 billion equipment plan, upgrade options to all our weapons are kept under constant review."

Douglas Chapman MP of the Scottish National Party, who sits on the Defence Select Committee, told The Register: “This is a truly puzzling decision, and the diversionary response of the MoD, which really fails to deal with the nub of the issue, is becoming something of a regular occurrence."

"Not only does the Royal Navy find itself with a historic low of 17 usable frigates and destroyers," he continued, "we now find that these warships will be left defenceless in a way that surely no other major modern navy would consider acceptable.”

Type 23s carry the Sea Wolf anti-missile missile in addition to Harpoon. The Sea Wolf system is designed to shoot down enemy missiles in flight and is not used as an offensive capability. The frigates also carry helicopters capable of mounting the Sea Venom missile, though this is not a complete replacement and Sea Venom will only reach “initial operating capability” (i.e. not cleared for general deployment unless a war breaks out) by 2020.

We’re not going to be at war with a naval power any time soon. Does this matter?

Yes. Even though Harpoon has never been fired at another surface warship by the RN, the idea is that our ships at sea should be able to deter potential aggressors, be those Iranian naval speedboats in the Persian Gulf ("east of Suez", as the RN quaintly describes the area) or Russian flotillas such as the Admiral Kuznetsov carrier group, which passed through UK waters a few weeks ago on its way to the Syrian coast.

It’s the same argument that applies to the Trident nuclear deterrent. You have a credible capability that could be used at any time which makes potential enemies sit back and think “we could do X, and the RN has never used it before, but what if...”

If the Harpoon is not replaced by 2018 – which seems unlikely, for a number of reasons* as well as the obvious one – the effective offensive range of RN warships will be the 30km of the escorts’ single bow-mounted 4.5” gun.

British naval credibility will vanish down the toilet – and in the modern world where actually firing at another state’s ship could provoke a full-blown war, it is credibility and implied threat that matters most.

Why are we still using this 1980s missile, then?

The Harpoon missile, originally developed by McDonnell Douglas and now supported in UK service by Boeing, dates back to the early 1980s, as this history of it from top British defence blog Think Defence explains.

While Think Defence notes that RN Harpoons “are often considered to be obsolete in a contemporary operating environment” thanks to their lack of modern precision guidance kit, it still makes a bloody big bang when it hits its target thanks to its 220kg warhead.

Given the extent of defence cuts before and as a result of the 2010 Strategic Defence and Security Review, which cost Britain its Type 42 guided missile destroyers and its Type 22 frigates, it is perhaps not surprising that the RN chose to focus on keeping ships at sea rather than buying the latest weapon systems to fit to them.

Currently Harpoon is fitted to the Type 23 fleet. Three of the six Type 45 anti-aircraft destroyers are fitted with Harpoon equipment that was salvaged from the old Type 22 frigates, which were sold off in the late 2000s.

The RN has no other heavyweight anti-ship missile system in service. The Type 23 fleet will continue in service until the late 2030s, with ships being gradually withdrawn as the new Type 26 frigates are commissioned, but naval chiefs, the Treasury and the MoD are still scrapping over what anti-ship missiles to fit the Type 26s with. Ominously, BAE Systems, maker of the Type 26, does not list a primary anti-ship weapon system on its webpage about the future frigate. ®

Bootnote

* Why is it unlikely that the RN won’t have replaced Harpoon by 2018? There’s an option on the table from Boeing to refurbish Harpoon to the newer Block II or Block II+ standards, as it is currently doing on a trial basis for the US Navy. This is the obvious short-term solution until Type 26s start entering service in 2023.

In addition, the key thing with Harpoon is that the contract with Devonport Dockyard to maintain them expires in two years. While the planned out-of-service date for the missile is 2018, in line with the contract ending, these things can be extended if there is a will to do so.

Better to have an obsolete missile than no missile at all.