Is the Royal Navy surface fleet losing the ability to sink other warships?
In the immediate post-Cold War era the focus of naval operations changed from conventional open-ocean warfare towards maritime security, coastal operations and amphibious warfare. The possibility that fleets of warships might again have to slog it out against each other on the high seas seemed increasingly unlikely and even rather old-fashioned. Geopolitical changes manifest in the revival of the Russian Navy and the rapidly growing Chinese military are now driving western navies to seriously re-think their ability to sink warships.
For the Royal Navy this is another unwelcome challenge, faced with limited budgets and few immediately available remedies. Completing the Queen Elizabeth class carriers, the Trident successor submarines and the frigate programme demands the majority of procurement funding. There is little left over for development or purchase of an expensive new generation of anti-surface warfare (ASuW) weapons. The Future Cruise & Anti-Ship Weapon (FCASW) is an Anglo-French project agreed in 2015 that aims to replace several weapons; the Harpoon & Exocet MM40 Anti-Ship Missiles (ASMs) and Storm Shadow/SCALP cruise missiles. A ‘technology demonstrator’ is due in 2019. Whether a potentially complex collaboration with France will deliver an affordable and timely solution for the RN remains to be seen.
The Royal Navy’s anti-ship weapon inventory
The primary weapon of the surface fleet is the ageing US-made Harpoon Block 1C missile carried by the Type 23 frigates and 4 of the 6 Type 45 destroyers. Harpoon has a very modest range of around 60 miles, its original design is more than 30 years old, it is not especially fast or manoeuvrable and is likely to be defeated by countermeasures employed by modern surface combatants. It is supposed to go out of RN service in 2018 but may have to soldier on if there is no replacement to hand.
The Sea Venom missile or Future Anti-Surface Guided Weapon (Heavy) FASGW(H) is being jointly developed with the French navy and is supposed to be in service from 2020. It will be carried by the new Wildcat helicopter (of which the RN will have 24). It is designed for use against fast attack craft or warships up to corvette size and will replace the Sea Skua which proved to be very effective when used in combat during the Falklands and Gulf Wars. The Sea Venom’s range is classified but in theory it should allow the helicopter to stay out of the range of the warship’s air defence systems. However with just a 30lb warhead, against anything bigger than a frigate it has limited use.
By far the most effective way to sink ships is using a torpedo. A hit from just a single torpedo such as the Spearfish will almost certainly be fatal for all but the strongest and largest ships. The first generation of torpedoes just exploded on impact with the ship’s side, punching a hole that would flood the vessel. The warhead of a modern torpedo will produce a rapidly expanding bubble of gas under the ship which will break its back. It is extremely difficult to engineer any ship to be resistant to this.
Without a drastic change in plans, the RN will have just 7 attack submarines available for the next decade or more. If we assume a maximum of 4 maybe able to put to sea at once, it would be difficult to ensure there are enough submarines in the right place at the right time. Although once engaged, the submarine usually has the edge over the surface ship, the torpedoes are much shorter range than most sea skimming missiles. The Spearfish has a maximum range of around 30 nautical miles and can manage only around 3-4 times the speed of a typical warship. To be effective, the submarine must detect and locate the ship, penetrate the anti-submarine screen and get relatively close to its target.
With the return of fixed wing flying at sea, the F35 Lighting will potentially offer another option for ASuW. The simplest solution would be to drop laser-guided bombs such as the 500lb Paveway IV or the Raytheon Small Diameter Bomb II (SDBII). The F35-B could carry these in its internal bomb bays, retaining the aircraft’s stealth characteristics which would be critical as the aircraft would be at great risk by getting close to a warship. Such a mission would require a very well coordinated strike with multiple aircraft to have much hope of success.
Offered by MBDA, the SPEAR 3 (Selective Precision Effects At Range) is a cross between a smart bomb and a mini-cruise missile which has a range of around 60 nautical miles. Although small, 8 could fit internally in the F-35B and launched together would help saturate shipboard defences. The European-made SPEAR 3 would offer much better anti-ship capability and safety for the aircraft than the US-made SDBII but at considerable extra cost. No decision has been made on procurement at the time of writing.
The ideal solution would be for the F-35 to carry a long-range stand-off missile. (This would restore an important capability the RN lost with the demise of the Sea Harrier and the Sea Eagle missile.) There are various candidates but as yet none has been fully integrated or tested with the F-35. There is a air-launched version of the Norwegian Naval Strike Missile which is being designed to fit in the internal bays of an F-35A or F35C but unfortunately it will not fit into the slightly smaller F35-B weapon bay. Larger munitions can be still be carried on external pylons at the expense of aircraft stealth, less critical if launching a long way from the target.
Options for closing the ASuW gap
Unlike the RN, the United States Navy has the funds and several options at hand to quickly address its lack of anti-ship weapons. Working to mitigate its lack of warships in the face of new threats it has developed the concept of ‘distributed lethality’ to make its existing weapons more effective. It has adapted the supersonic Standard SM-6 missile, originally designed to destroy other missiles and aircraft for ASuW use. Although it has a relatively small warhead, the speed and kinetic energy is enough to do serious damage to any ship. The Standard missile family are fired from the Mk41 Vertical Launch System fitted to all US destroyers & cruisers. The RN’s Type 45 destroyers have space for two 8-cell Mk 41 VLS which would vastly expand the range of munitions it could carry, including the SM-6 and the SM-3 Anti-ballistic missile. The 2015 SDSR did not provide funds for this highly desirable upgrade – fixing the Type 45’s propulsion issues must take priority. The Type 26 Frigate will have three 8-cell Mk 41 VLS and could also potentially carry the SM-6, Tomahawk or LRASM for use in the anti-ship role.
The US Navy recently demonstrated that a Tomahawk missile, originally designed to attack land targets (TLAM) could be adapted to hit a moving vessel at sea. The US has large TLAM stocks and the UK has a small stock of submarine-launched TLAMs. Although a relatively slow cruise missile, it is very accurate and has an incredible range of more than 1,000 miles. It is cheap to adapt the existing missiles for ASuW and is something the UK could consider, both to extend the anti-shipping range of its submarines and to carry aboard the Type 45 and Type 26 in future.
Lockheed Martin’s Long Range Anti Ship Missile is the leading contender to replace the Harpoon in US Navy service. Although not especially fast (by Russian standards) the LRASM will be an extremely stealthy and intelligent weapon designed to resist detection and jamming. It is also designed to autonomously seek its own targets without reliance on externally fed data, effectively a very smart weaponised UAV. This will be the ‘gold standard’ for anti-ship missiles and can be air launched or vertically launched from the Mk41 VLS. From an RN perspective, if the US will offer affordable LRASMs for export it would be surely be at the top of its wishlist to equip the both the F-35 and the Type 26.
Naval Strike Missile
Developed by the Norwegian company Kongsberg Defence & Aerospace (KDA), the NSM is a modern medium-range anti-ship missile. It lacks the range, sophistication and larger warhead of the LRASM but would be cheaper and available now. Being relatively lightweight, it could be carried in canisters bolted to existing ships and would offer the RN a straightforward Harpoon replacement. A multi-role version is being developed in partnership with Raytheon who are hoping to sell it to the US which would further reduce costs and make it more attractive to other NATO countries.
If the RN was called to fight a major surface action in the next couple of years it is clear that it would be heavily reliant on the ancient Harpoon and the hope that one or more of its tiny SSN fleet could come into action. While there are exciting ASuW options becoming available in the future, all come with considerable costs and as ever it will be a matter of trying to decide on priorities for naval capability.
Building on their extensive ASuW missile development experience, many analysts consider the Russians and Chinese to be about 10 years ahead of the US and Europe. It is sobering to consider that both China and Russia have hypersonic anti-ship missiles (Mach 5+), ballistic anti-ship missiles and cavitating torpedoes either close to maturity or already operational. In a future post we will examine the vulnerability of the RN’s surface fleet to the new generation of weapons being fielded by potential adversaries.
- How vulnerable is the Royal Navy’s surface fleet to a new generation of weapons? (Save the Royal Navy)
- US Navy ships and submarines to carry new anti-ship Tomahawk missile (Washington Post)
- US Navy Reveals Anti-Ship SM-6 Missile (National Interest)
- No UK Spear Cap 3 Decision on F-35 until 2018 (Defence News)