The Royal Marines, the CB90 and the Future Patrol Boat

Two Swedish fast attack craft have been loaned to the Royal Marines as the Navy looks at patrol boats of the future. Navy News reported yesterday that the first two of four Combat Boat 90s have been handed over to 1 Assault Group Royal Marines for several months of intensive trials.

The Royal Navy is looking at acquiring a new class of ‘force protection craft’ capable of fending off enemy fast boats and dealing with threats on land. As a secondary requirement, the future boats will be expected to carry up to eight Royal Marines ashore during amphibious operations.

The CB90’s been in service with Swedish and half a dozen other navies since the early 90s (hence the craft’s name) and can carry up to 21 troops at speeds of around 40kts (46mph) – as well as mount machine-guns and grenade launchers. There’s nothing similar in the current RN or RM inventory, so the Royals are borrowing the Swedish craft to see what they can do and to incorporate what they learn into the design of the future fast boats.

A CB90 fitted with a PROTECTOR RWS turret armed with an M2HB .50 machine gun on the mast ring.

Experts from RM Instow will test fast navigation, force protection, working with assault ships and carrying commandos with the Swedish boats; in return the Royals are lending the Swedes some of their 43 Offshore Raiding Craft – hence Col Ola Truedsson, head of Swedish 1st Marine Regiment proclaiming the loan “a win-win situation for both countries”.

The CB90s, which have been readily adapted so they can be operated from the davits of assault ships, will undergo around 12 months of trials with the green berets.

The Combat Boat 90

The CB90 is an exceptionally fast and agile boat. Its light weight, shallow draught, and twin water jets allow it to operate at speeds of up to 40 knots (74 km/h) in shallow coastal waters. The water jets are partially ducted, which, along with underwater control surfaces similar to a submarine's diving planes, allows the CB90 to execute extremely sharp turns at high speed, decelerate from top speed to a full stop in 2.5 boat lengths, and adjust its pitch and roll angle while under way. Developed for Sweden, it has drawn US interest, is used by the german navy from their Berlin class support ship’s davits and had been adopted by Norway, Greece, Mexico and Malaysia.   

The official Swedish Navy designation is Strb 90 H (Stridsbåt 1990 Halv pluton, literally: Combat Boat 1990 Half platoon); the H refers to the fact that it can carry and deploy a half platoon of amphibious infantry (21 men) fully equipped.

In 2002, the Swedish Navy ordered an additional 27 boats of a slightly different type, designated Strb 90 HS, and intended for deployment in overseas peace-keeping operations. It is unclear what the S refers to; it may be short for Skyddad (protected), as the Strb 90 HS is armored. Apart from the addition of armor, the HS model features NBC warfare protection (the whole boat can be over-pressurized), air-condition for deployment in tropical conditions, fuel cooling system, 220V generator and more powerful engines. The factory sometimes refers to it as the CB 90 HI, where the I probably stands for International. The protection level is STANAG4 NATO, against armor piercing 7.62 x 51. The weight increase is 3.8 tons, and the more powerful engines make up for the difference.

This is probably the variant the Royal Marines are testing. 

The weapon fit comprises a 12.7 mm machine gun (or a 40 mm grenade launcher, or a Remote Weapon Station, or other weapons included an Hellfire launcher) carried on a ring mount aft of the wheelhouse and a double 12.7 mm mounted in front of the helmsman’s position. The twin mount is fixed in traverse and aimed by pointing the craft - hence the elevation and fire controls are incorporated in the maneuvering levers at the helmsman’s position. Additionally, the CB 90 H can also carry 2.8 ton of mines or the modified Hellfire-type RBS 17 SSM system.

The Twin .50 mount fixed in front of the Helmsman's position.

Several Strb 90 H have been converted by the Swedish Navy to fill various roles:

• The Strb 90 L is outfitted for battalion-level command and control, with computer and communications equipment and an auxiliary generator to provide electrical power when the engines are not running. The L stands for ledning (command or leadership). The Royal Marines don’t need this, as their command and control facilities would be provided, when needed, by the LPDs.
• The Strb 90 KompL is a plain Strb 90 H in which portable computer and communications equipment has been installed, allowing it to temporarily provide company-level command and control. Electrical power is provided by a rather loud portable generator installed on deck.
• The Strb 90 HS is designed for overseas peace-keeping and rescue operations. It is modified to keep its crew comfortable in Mediterranean conditions, with air conditioning, an auxiliary generator, a head, and more comfortable crew stations. More importantly, it is armored, and its engines have been upgraded to compensate for the added weight. This is the variant that has the Royal Marines eye, almost certainly.
• At least one Strb 90 H, pennant number 802, is equipped with a decompression chamber.
• The Swedish Police operate one unarmed Strb 90 H equipped with bunks, a pantry and a crew lounge.
• The Swedish Sea Rescue Society operates two unarmed Strb 90 Hs converted for search and rescue.
• Hellenic Coast Guard operate also since 1998 three CB90 under the CB90HCG which is a slightly different version of the Norwegian Navy Version

The Royal Norwegian Navy operates 20 CB90s under the designation SB90N; the N simply stands for Norsk utgave (Norwegian version). The S90N differs from the Strb 90 H in a few areas:

• It is armed with only one 12.7 mm machine gun, instead of three.
• The anchor winch is motorized, and the anchor is mounted at the stern, allowing a grounded S90N to tow itself afloat rather than risk damage to its impellers.
• It carries an auxiliary generator which provides electrical power to navigation and communications systems even when the engines are not running.
• The "Troops transportation room" has a higher deck height, making it possible for most people to stand without crouching.
• It has two water tight compartments in the bow, having an extra room for toilet and stores.
• It has a much more sophisticated navigation equipment based on GPS-technology delivered by Kongsberg Seatex AS.

At least one S90N has been reconfigured into a floating ambulance.

In 2004, the Royal Norwegian Navy conducted tests (including a live fire exercise) to evaluate the effectiveness of the SB90N as an aiming and launching platform for the Hellfire missile. One SB90N was equipped with stabilized Hellfire launcher based on the PROTECTOR M151, and its machine gun was replaced with a gimbal-mounted sensor package containing visible-light and infrared cameras and a laser designator. Although the tests were successful, there is currently no indication that the Royal Norwegian Navy will actually deploy SB90Ns armed with Hellfire missiles in regular service. The Hellfire can still be carried on the boats without launching platforms and be fired from shore with the Portable Ground Launch System. The Royal Navy boats could be fitted with the Brimstone, which has also been validated for surface-surface launches, even from boats. This is unlikely, anyway, due to cost. It would remain a possibility. 

The CB90 has been selected by the US Navy as its "Riverine Patrol Boat", with 18 planned. 

The US Navy has bought two CB90 HS for use by the newest incarnation of the brown-water navy, the Navy Expeditionary Combat Command’s riverine group. These boats are fitted with 2 .50 machine guns front and one PROTECTOR RWS on the mast behind the cockpit, and there are four more mounts for crew-served weapons along the hull, all of them with electric connections so that M134D miniguns can be mounted, offering a fearsome firepower. The Americans want to operate 18“Riverine Patrol Boats”.

The space also allows rigging as a dive boat with portable hyperbaric chamber, or strictly as a gunboat with options to mount machine guns, grenade launchers, a mortar tube and Hellfire missiles.

It has been used in other navies as an ambulance. It can also be rigged for extended voyages with racks and a galley. The Swedish navy loads its boats in the well deck of amphibious warfare ships, although the RCB is not meant for long sea transits.

The Fire Support CB90

In July 2006 the Swedish Defence Materiel Administration (FMV) has awarded a contract for the development and production of two prototype armored advanced mortar systems (AMOS) to BAE Systems Hagglunds AB. The two prototypes, based on CV90 tracked platforms, was delivered to the customer in early 2011.

One of the two CB90 boats fitted with the AMOS breech-loading mortar system turret. This little boat can now deliver a quite fearsome volume of fire.

The AMOS, developed as a joint venture between Patria Vammas (Finland) and Hagglunds (Sweden), is a twin barrel 120mm, breech loaded mortar turret mounted on wheeled or tracked chassis (tracked CV-90 and wheeled Patria/AMV/Piranha carriers). The two mortars are mounted on a common cradle with equilibrator and an automated loading device. The system is designed for ultra-rapid fire rate, reaching a claimed 26 rpm burst, with multiple rounds simultaneous impact (MRSI) at 14 to 13,000m range. One added advantage of the Amos is that the barrels can be lowered to deliver direct fire during urban warfare or other scenarios, making it an extremely powerful weapon.  

In Service in the Royal Navy

This programme should not be undervalued. The Royal Marines do not move often in terms of procurement, but when they do, they do it silently, away from the spotlight, and tend to get what they want. And that often ends up being a luck for the whole of the British Armed Forces: the case of the Viking, procured for the Marines’s amphibious operation and grown to fame in Afghanistan, so much that the Army asked the Royal Marines training and support to use the vehicle as well, until they ultimately procured the bigger but very similar Warthog.

At the moment, the Royal Marines’ main targets are the PACSCAT fast landing craft to complement/replace the LCU MK10, and the Future Patrol Boat, which will be a more ambitious and powerful patrol asset than the Offshore Raiding Craft.

Such future patrol boat could have a role in support of special forces raids on enemy coastline, they could supply fire support to the Marines landing ashore while also bringing in almost as many men as a LCVP MK5 landing craft, but it could also be carried on davits of vessels such as the Bay class LSD(A) to redeploy abroad in roles such as Counter Piracy. It would be a less ambitious but still very effective “Mothership” vessel: deploy one ship, and you have two or more small patrol boats expanding the area covered and secured by several hundreds miles of radius.  

The Offshore Raiding Craft was inspired and shaped by operational experience gained in riverine patrol ops of the Royal Marines in Iraq. Even LCVP MK5 were used for the patrols.

A CB90 patrol boats squadron would also deliver improved coastal security at home and abroad. For example I can think of Gibraltar: following continuous (and worsening) incursions of the Spanish coastguard vessels interfering with the sovereignty and even the security of military operations in the port, like when they had to be pushed away from the maneuvering submarine USS Providence they were harassing, before something bad could happen.

 

The Government of Gibraltar is very concerned about the situation, and HMS Sabre and HMS Scimitar, two armed P2000 boats, are massively outmatched by the big vessels of the Guardia Civil, so that numerous calls have been made to the MOD to commit a stronger Royal Navy presence in the waters of the Rock.

A couple of heavily armed CB90s forward deployed would be the correct answer even to this requirement. Sad that this needs to be done because of the behavior of an allied nation, but then again this is what we get, and the situation in Gibraltar must be fixed.

The Navy News article suggests that the Royal Navy is keeping its options open, and might develop a whole new patrol boat. Personally, I think this is unlikely. And I also feel it is unnecessary. The CB90 is proven, effective, and does the job. With minimum modifications, it will make for a formidable asset which will have the advantage of being cheap to procure and run. I’m a big supporter of the CB90. A Royal Marines Fleet Protection Boat Squadron with them would expand massively the capabilities of the corp in a whole range of roles and geographic conditions, from very swallow waters near the coastline to deep along rivers into the mainlad, as during operations in Iraq, which were the main source of inspiration for the development of the heavily-armed Offshore Raiding Craft.

General characteristics CB90 HS

Displacement: 13,000 kg (28,660 lbs) Empty, 15,300 kg (33,730 lbs) Standard, 20,500 kg (45,190 lbs) Full

Load Length: 15.9 m (52') Overall 14.9 (48') waterline

Beam: 3.8 m (12'6")

Draught: 0.8 m (2'8")

Propulsion: 2 x 625 bhp Scania DSI14 V8 Diesel; 2 x Kamewa FF water jets

Speed: 40 knots (74 km/h) Range: 240 nmi (440 km) at 20 knots (37 km/h)

Complement: 3 (two officers and one engineer)
  Up to 21 troops with full equipment

Armament:  2 × Browning M2HB machine guns in the front
  1 × Mk 19 grenade launcher/ .50 M2HB / M134D minigun or RWS turret on the mast
  4 naval mines or 6 depth charges