Double double-enders for Calmac

The

Scottish west coast is about to see the introduction of two new double-ended ropax ferries being built in the UK for ferry operator Caledonian MacBrayne (Calmac).

The

first of these newbuildings,

Coruisk

, will run on the 30-minute Mallaig to Armadale route on the Isle of Skye while the other ferry,

Loch Portain

, will service the 70-minute service from Leverburgh, at the south end of Harris, to Berneray, which is joined by a causeway to North Uist.

Coruisk

The

Coruisk

, a sheltered waters double-ended ferry, is currently under construction at the UK yard of Appledore Shipbuilders (Hull No.190) in north Devon. When delivered in early June, this newbuilding will replace Calmac?s existing 1989 built Lord of the Isles on the short Mallaig-Armadale service, for the summer months. During the winter period the new vessel will operate on CalMac?s upper River Clyde routes, standing in for vessels undergoing dry-docking and repair.

Powered by two Schottel type STP 1010 twin propeller azimuthing units arranged forward and aft on the centreline, each STP features two three-bladed twin FP propellers with an output of 1,140kW at 300 rev/min.

The

se are protected by a longitudinal skeg structure to maximise stability and course keeping.

The

design and supply of roro cargo access equipment for the

Coruisk

was done by TTS Ships Equipment AS in Bergen, Norway, and included bow visor, bow and stern ramps, side ramp and hydraulic/electrical systems.

The

width of the forward ramp is 3.5m and the aft one is 4m while the side ramp on the forward port quarter is 6.1m wide and 5m long with 1.5m long finger flaps.

A bow visor is fitted at the forward end of the vessel and is hydraulically operated from the bridge.

The

visor takes one minute to open and provides a clearance of 5.2m.

The

main deck is strengthened to take vehicles with a maximum axle load of 14t on four wheels (8t axle load) and meets the regulatory requirements for the carriage of hazardous cargoes at any position on the car deck.

Gangway access provisions are made on the mezzanine and passenger decks in the bridging structure where there are passenger rooms, a lounge/cafeteria, snack bar, emergency generator, control console space and a switchboard room.

The

wheelhouse is located on the fifth tier level amidships above the passenger accommodation and provides crew members with an all-round vision.

Lifesaving equipment comprises a 4.5m RIB with an outboard motor and located at mezzanine deck level port side forward. Life rafts for passengers consists of four 65 person and one 30 person inflatable units.

The

power plant consists of two medium speed MAK 6M20 diesels each with a 1,140kW output at 1,000 rev/min, driving a transmission shaft to the STP propulsors to give a service speed of 14 knots. Two Cummins 6CT8.3D(M) diesel gensets with a total output of 328kW provide electricity power while a Cummins 6BT5.9D(M) with a 62kW output serves as an emergency generator.

The

vessel has two separate engine rooms each housing one of the main engines together with one genset.

Central controls are mounted in the wheelhouse for speed setting of each engine and suitable for one-man operation. Control stands for the Schottel propulsors are mounted forward and aft in the wheelhouse to ensure ease of use and maximum all-round visibility from the control position. In addition, there are control stands in the bridge wings.

The

Schottel equipment has a way-dependent electro-hydraulic proportional steering system. This works in such a way that with a small angle of steering the corresponding steering speed is low and with bigger angle of steering the speed is higher.

The

control system also has a propeller interface for autopilot and voyage data recorder.

A pair of stabiliser fins was supplied by Brown Brothers, a subsidiary of Rolls Royce, in the shape of the Aquarius 50 folding-fin stabilisers.

The

first set of this type was fitted to Calmac?s Lochnevis in September 1999 and took six months to execute.

The

delivery time for the

Coruisk

installation was reduced to four months.

Loch Portain

Loch Portain

, due to be delivered sometime this month (May) from the UK shipbuilder McTay Marine in Bromborough, Wirral, is a smaller version of the

Coruisk

but with a different propulsion system in the shape of Schottel pump jet propulsors. Designed as a roro passenger/vehicle ferry, it has an open vehicle deck and hinged ramps at each end and can carry 196 passengers and 32 cars or a mix of cars and commercial vehicles with a maximum axle load of 8t.

The

power plant for the 50m long vessel consists of four high-speed Cummins KTA 38 M06 diesels each with an output of 559kW at 1,600 rev/min. Each unit is connected by a shaft coupling to a steerable Schottel pump-jet propulsors type SPJ 132 T with a rating of 422kW at 1,000 rev/min.

The

SPJs are arranged fore and aft, port and starboard and, at the time of writing, a trial speed of 10.5 knots is envisaged with the engines operating at 85 per cent mcr, i.e. about 470kW.

The

propulsors are also fitted with ?finger type? inlet grids to prevent seaweed and other objects from damaging the units.

Built to comply with the MCA intact and damage stability criteria requirements, the newbuilding has deadweight of 160t on a summer load draught of 1.5m. Operating as a cargo-carrying vessel only, i.e. no passengers, the deadweight will increase to 230t causing a corresponding increase in draught, to 1.65m.

The

four tier bridging structure incorporates the main passenger seating area, a vending machine area and the purser?s office while extra seating areas are available on the open decks forward and aft for 76 passengers. Life-saving systems include one 4.5m RIB to act as a M.O.B. boat and five 50 person canopied

liferafts.

Calmac operates a fleet of 29 passenger car ferries serving 22 islands and four peninsulars in the Clyde and the Western Isles, together with some inter-island and two mainland services.

The

Company was formed in 1973 from the amalgamation of the Caledonian Steam Packet (founded in 1889, and one of several Clyde steamer companies) and David MacBrayne (founded in 1851, and the main provider of cargo and passenger services in the Western Isles).