Two IMT 958 multi-role emergency response and rescue vessels (ERRVs), Grampian Fortress and Grampian Freedom, entered service this year in the North Sea. At 58m long, Grampian Fortress and its sister vessel are fitted with daughter craft and fast rescue craft as one would expect but are also able to transfer and store limited deck cargo and provide offshore locations with fresh water and fuel if required.
The contract for the vessels dates back to September 2013, when North Star Shipping, which is part of Craig Group, awarded a contract to the Spanish yard for six ERRVs of two different types – four IMT 950 designs, known as the D-class, of which four units had already been delivered to the same owner in 2012, and two IMT 958s, denoted the F-class.
Grampian Fortress and Grampian Freedom are 58.2m overall with a beam of 13.2m and are a further evolution on the earlier IMT 950 design, with a diesel-electric propulsion system and the additional functions of cargo-carrying capacity and backloading operations. In line with most of North Star’s fleet, the vessels will be engaged in standby and emergency response and rescue duties, primarily supporting oil rigs in the North Sea, where they will spend 28 days of every month, only returning to port for crew changes, loading fuel, stores and spares. The F-class are Group B standby rescue vessels, designed and outfitted to rescue up to 300 people in the UK sector. To withstand the demanding operating conditions of the North Sea, the ships were designed for the often harsh weather conditions, hence the high and covered bow area and wheelhouse shifted as far aft as practical to reduce greenwater wash. The hull lines are fine forward with a semi-bulbous bow lengthening the waterline length to improve the hull performance.
The diesel-electric propulsion arrangement was selected because it offers several advantages, including greater propulsion redundancy, flexibility, reduced fuel consumption and hence reduced emissions. The vessel has four main generators sets of 599kW each, driven by high speed engines to generate the vessel’s electrical power for propulsion and all consumers on the ship. Each generating set comprises a Caterpillar C18 engine with two gensets connected to it. The main propulsion system of the vessel comprises two azimuth thrusters aft and two tunnel thrusters forward. Initially, the project had a single tunnel thruster forward, but the owner decided on a second thruster being fitted as it allows for retrofitting of a DP2 system should potential future charters for the vessel so require it.
The dedicated survivor spaces and treatment area have been incorporated at main deck level, for easy access of survivors into the accommodation. All the UKOOA regulatory accommodation outfit and equipment, as required for this kind of vessel, have been carefully studied and laid out to enhance a speedy access and flow of survivors to the different treatment, resting or sitting areas. On the outside deck, the hot water rinsing showers are next to the entrance, after which able survivors access the reception area for registration. From here, they would be directed to the treatment room, waiting area (for treatment), recovery area outfitted with beds or sitting area below deck, depending on their physical state. This deck also houses all washroom facilities for survivors. For rescue operations, the vessel is provided with a Delta Phantom daughter craft and one Solas approved Avon Searider 6.5m fast rescue craft. Other appliances for rescuing survivors from the water are the Dacon scoop and a rescue basket, both of which are operated from onboard the vessel and do not require any of the ship’s crew to leave the safety of the vessel in adverse weather conditions.