Guns, missiles and drones – naval actions in the Red Sea

HMS Diamond has now been formally allocated to US-led operation Prosperity Guardian which will protect merchant ships transiting the Red Sea and Gulf of Aden. Here we look at the recent naval operations and consider the current situation in the region.

Warships assemble

Combined Maritime Forces (CMF) are based in Bahrain under the command of a US Navy Vice Admiral with an RN Commodore (Currently Cdre Phil Dennis) acting as his deputy. One of the 5 task forces operated by CMF is Combined Task Force 153 (CTF 153) which is responsible for the Red Sea area and will run Operation Prosperity Guardian. It is not yet clear precisely how this will function, the protection of commercial vessels is not a simple task but can be achieved in two main ways. This can either be by grouping vessels into a convoy surrounded by warships or by creating a safe Maritime Security Transit Corridor (MSTC) with warships on independent patrols responsible for sanitising the corridor. The latter is more likely as convoys are cumbersome to assemble and cause delays while modern sensors and weapons can cover a much wider area than their historical counterparts.

Warships from around the globe are being allocated to this mission, given that the free movement of shipping so critical to the world’s economy. This is a lesson that is repeatedly learned and then quickly forgotten by politicians and media when shipping returns to normal. HMS Diamond is in the Red Sea and HMS Lancaster has been in the Gulf of Aden for some time. US destroyers USS Carney, Mason and Thomas Hudner are likely to be joined by reinforcements with USS Laboon, Delbert D. Black and The Sullivans now on their way through the Mediterranean. Also in the region are FS Langaudoc (France), ESPS, Victoria (Spain), JDS Akebono (Japan) and ROKS Yang Man-Chun (South Korea). Italy, Norway, the Netherlands, Canada and Germany are also preparing to send warships. As a nation that has benefited enormously from the free flow of seaborne trade, in large part enabled by Western navies and UNCLOS rules, China also has a stake in keeping the Red Sea traffic flowing. There is a Chinese destroyer and 2 frigates based in Djibouti but they are unlikely to join a US-led coalition.

HMS Duncan is believed to be heading home on completion of her extended Mediterranean mission. Presumably, she was not needed to escort the LRG(S), RFA Argus and RFA Lyme Bay on the proposed humanitarian aid mission to Gaza. This was likely scrubbed as being too risky and impractical and it will be interesting to see if LRG proceeds through the Suez Canal as originally planned. HMS Dauntless has returned from her Caribbean deployment and the Power Improvement Project (engine upgrade) was proven a success but she will have to be dry docked for a Fleet Time Support Period as other work has to be done. HMS Somerset has become the first RN surface ship to carry land-attack missiles. Although primarily an anti-ship system, Initial Operating Capability with the Naval Strike Missile (NSM) has been declared after she was finally fitted with the missile canisters at Haakonsvern naval base in Norway. She will conduct live firing and Fleet Weapons Acceptance trials in the new year.

The right tools for the job

There is a complex discussion around the HMS Diamond’s use of £1-2M Sea Viper to take out a cheap drone. The only official description of the target as a ‘drone’ is ambiguous as it could mean anything from a small consumer UAS used for reconnaissance up to a much more complex attack drone capable of delivering a large warhead over several hundred miles. Given the type of UAS that has been used against merchant ships recently, it was likely an Iranian-made Shahed series delta wing loitering munition/UAS that are rocket-launched but have a small piston engine and a payload of around 50kg of explosive. These are being mass-produced and also employed by Russia against Ukraine and probably cost as little as $20k.

CO Cdr Pete Evans and the crew of HMS Diamond should be congratulated, having just arrived in theatre and immediately being called into action. Obviously employing the weapons system to hand is the right thing to do and the cost of the Sea Viper is not a consideration compared to the value of the merchant ships being protected, or more widely reassuring the mariners and ship owners responsible for carrying $billions of world trade passing through the Bab el Mandeb Strait. The incident instead highlights more existential issues about how surface warships met the threat of massed drone attacks and the Royal Navy’s inability to bring better Counter-UAS weaponry into service more quickly.

Around the same time as Dimond was in action the Pentagon has said USS Carney shot down 14 armed drones and at the time of writing, international navies claimed to have downed something like 34 missiles or drones in the Red sea in the past 2 weeks. The USN is understandably unwilling to discuss what weapons were used but it it likely her 5 inch Mk 45 Mod 4 gun was employed, if not alone, in combination with missiles. Having good accuracy and advanced ammunition types the Mk 45 has a maximum range of up to 27km but is probably effective against aerial targets at substantially less distance and depending on the rounds used. Until the Type 26 and Type 31 frigates are in service the RN has only the 4.5-inch Mk 8 gun which is really only useful in the Naval Gunfire Support role, with software support for its original limited anti-air capability withdrawn some time ago.

The 30mm cannons carried by HMS Diamond and Lancaster have limited accuracy against small aerial targets and is effective out to about 2-3km. Although the Phalanx CIWS carried by the Type 45 can be effective at defending the ship it is mounted on, it is not much use in an area defence role. In this case, the warship’s job is to protect other ships and it must be able to engage threats over a wide area and destroy them as far away as possible.

It has been obvious to navies for some time that mass drone attacks could overwhelm even the best missile defences, officially Sea Viper can launch a salvo of 16 missiles simultaneously but if these attacks were sustained at this kind of intensity for even a short period, the ship would have to withdraw with empty silos and a complex logistical operation would be needed to reload her in an overseas port.

HMS Lancaster is equipped with Sea Ceptor. The Type 23 frigates have been upgraded with 32 of these modern point defence and local area defence weapons that have a has a range of around 25 km and can create a defensive umbrella over a small convoy of merchant ships or a naval task group. Sea Ceptor is probably marginally inferior to Aster 15 against hard manoeuvring targets but is cheaper and also offers a limited anti-surface capability. The Type 45s will eventually receive an additional 24 Sea Ceptors of their own but this upgrade is several years away, something that HMS Diamond could very much do with right now.

The RN has not been blind to the threat posed by drones and it should be noted how well suited the Type 31 frigate will be for escorting merchant vessels in this scenario. Armed with a 57mm and and two 40mm guns which have high rates of fire and advanced ammunition they are ideal answer to attack by cheap aerial drones. Without recourse to expensive missiles, the 40mm Mk 4 is effective out to about 10km. Together with a good radar and Sea Ceptor for dealing with more challenging threats at longer-range, the ‘Inspiration class’ may prove to be a great design as gunnery makes a comeback as the answer to massed attacks by uncrewed systems.

Hitting back

There has been considerable speculation about why the US has not attacked the Houthis directly to deal with the source of the problem rather than just attempting to play goalkeeper, intercepting their indiscriminate attacks on merchant vessels and warships. Even without the growing support from international partners, the military capability is already in place with the arrival of the USS Dwight D Eisenhower CSG in the Gulf of Aden during the last few days on top of TLAM-equipped destroyers, cruisers and submarines while the amphibious ships of the 26th Marine Expeditionary Unit (MEU) have been poised in the Red Sea for a while.

The political situation is complicated, firstly the US and virtually every country on earth except Iran and perhaps Russia, do not want the conflict in Israel to become the spark for a wider Middle East war. In particular, US ally Saudi Arabia is keen for the conflict not to escalate as it has tried to withdraw from its proxy war with Iran in Yemen and there has been an uneasy and welcome peace between the two sides recently. This might explain why the Eisenhower strike group left the Persian Gulf where any strikes against Yemen would require the use of Saudi airspace.

The Houthis are not just a rag-tag bunch of terrorist but are now and substantial Iranian proxy force armed with ballistic and cruise missiles that could strike targets well beyond their coastline. The US base at Camp Lemonnier in Djibouti is within range and lacks adequate air defence, at least for now. Houthi radar targets were stuck by US Tomahawk missiles in 2016 but subsequently, they have improved the mobility and camouflage of their bases and weapon systems making it much harder to locate and knock out them out with a few air strikes.

Even if Houthi capabilities are temporarily degraded, over time they can be resupplied and continue to present a threat that would require a long-term commitment to contain. The US Navy is already over-stretched and there is not the capacity or the political desire to become engaged in another sustained conflict. It is extremely unlikely any troops will be deployed into Yemen which might be the only way to permanently nullify the threat.

The Houthis and Iranians believe that causing chaos in the Red Sea can really hurt Israel but the effects are limited. The Port of Eilat has seen an 80% drop in revenue but Israel has Mediterranean ports and overall this will have little impact on the war in Gaza. Instead, Houthi actions are having wider consequences and will likely alienate even countries that Iran might consider partial allies, including the Chinese. While a major US strike on Yemen remains a possibility, perhaps instead back-channel diplomacy will persuade the Houthis and their Iranian masters that their campaign in the Red Sea will ultimately achieve nothing.