Response Boat-Medium (RB-M)

The Response Boat - Medium (RB-M) is in service with the US Coast Guard (USCG).

The Response Boat - Medium (RB-M) can be armed with general-purpose machine guns. Image courtesy of Michelle Hill, US Army Corps of Engineers.

The Response Boat - Medium (RB-M) replaces 41ft utility boats (UTBs) of the USCG.

A 45ft Response Boat - Medium (RB-M) demonstrates its capabilities along with a 24ft special purpose craft - shallow water.

The Response Boat - Medium (RB-M) can cruise at a maximum speed of 45kt.

The Response Boat-Medium (RB-M) is manufactured by Kvichak Marine Industries, and Marinette Marine Corporation of Fincantieri Marine Group (FMG), for the US Coast Guard (USCG). The RB-Ms are designed to perform multiple missions of the USCG.

The Response Boat-Medium (RB-M) can conduct a range of missions including search-and-rescue (SAR), ports/waterways/coastal security, marine environmental protection, recreational boat safety, enforcement of laws and treaties (ELT) drug and illegal migrant interdiction.

Response Boat Medium-C (RBM-C), a sister-ship of the RB-M, is in service with the Los Angeles County Sheriff’s Department (LASD), the New York Police Department Harbour Unit and Seattle Police Department Harbour Unit.

Response Boat-Medium (RB-M) project history

The USCG initiated the RB-M project to standardise and revitalise its fleet of shore-based boats. The project is implemented to replace the ageing fleet of 41ft utility boats and various non-standard utility boats (UTB).

The USCG placed a production contract with Marinette Marine Corporation (MMC) for the design, construction and delivery of the RB-M in 2006. MMC teamed up with Kvichak Marine Industries to build and deliver up to 250 RB-Ms at a rate of 30 boats a year under a $600m multi-year contract.

Marinette Marine builds 50% of the boats, while its teaming partner Kvichak Marine constructs the remaining 50%. The first RB-M was delivered to the USCG in March 2008.

In September 2011, MMC was awarded a $23.9m contract for an additional 11 RB-Ms. MMC received an $89.6m contract from the USCG in February 2012 for an additional 40 RB-Ms.

The USCG received the 100th RB-M in August 2012 and 125 boats have been delivered to USCG boat stations across the US as of August 2013.

Design features of RB-M

RB-M is of all-aluminium construction and features double-chine Deep V hull design delivering high speed and constancy in different conditions. The pilothouse is fitted with shock-resistant seats for greater crew comfort. The survivor’s compartment accommodates five personnel. The pilot house and cabin are equipped with climate control system.

The boats are provided with large fendering to avoid damage during berthing. The boat features recovery platforms on port, starboard and stern-side.

The boat has a length of 44.5ft, maximum beam of 14.7ft and draught of 3ft. The displacement of the RB-M is 36,500lb. Each boat can complement a crew of four.

Mission systems aboard RB-M

The RB-Ms are equipped with Furuno NavNet navigation system, navigator forward looking infrared (FLIR) camera system, Motorola XTL 5000 VHF Radio, LVIS crew communications system, automatic direction finder (ADF), magnetic compass, differential global positioning system (DGPS), two weapon mounts and towing reel. The weapon mounts can be armed with M240B general-purpose machine guns.

The boats in service with the LASD are fitted with KLEIN 5000V2 multi-beam high-resolution sidescan sonar, and RS-700 Gamma/Neutron radiation detection system capable of detecting chemical, biological, radiological, nuclear and explosives (CBRNE) agents.

Propulsion details of the Response Boat-Medium

The Response Boat-Mediums are powered by two MTU DDEC Series 60 diesel engines driving two Rolls Royce Kamewa FF3753 waterjets through twin disc MG-51 14-SC transmissions. Each engine develops a power output of 825hp (615.2kW). The vessels also integrate two AuraGen Viper G8500X AC/DC gensets and Vector-Stick integrated control system.

The waterjet propulsion with no propellers under the boat allows the safe retrieval of personnel from the water and protects the engines from debris. The propulsion system provides high manoeuvrability and a maximum speed of 45kt. The 495gal fuel storage capacity of the boat provides a range of 250nmi at 30kt. The RB-M has an endurance of 24 hours.

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