New RAstar Tug for Svitzer Marie of Denmark

Svitzer Marine Ltd., a division of Svitzer AS of Copenhagen, Denmark, has taken delivery of their latest high-performance tug from Astilleros Zamakona SA.  The Svitzer Pembroke is the latest of the RAstar Class true escort tug designs from Robert Allan Ltd., Naval Architects of Vancouver, BC.

The RAstar 3600 class Svitzer Pembroke falls in size between its five 111.5-ft (RAstar 3400) and one 128-ft (RAstar 3900) cousins all working at the Milford Haven terminals, and all built to Robert Allan Ltd. designs.  This latest vessel was designed to perform a wide range of tasks, including ship-handling, LNG carrier escort, ocean towing, salvage and anchor handling duties.  The RAstar class hull form ensures the highest standards of both escort towing capability and superior sea-keeping in the heavy sea conditions encountered in these operations.

The Svitzer Pembroke is classed for unrestricted duty and accordingly was built to Lloyd’s Register of Shipping Class: X100A1 Escort Tug, Fire Fighting Ship I with water spray, X LMC, UMS, IWS, and in full compliance with SOLAS and International Loadline regulations.

The particulars of the new tug are as follows:
Length, o.a.    117.5 ft
Beam, moulded    47.5 ft
Depth, moulded    20 ft
Operating draft, max    21.8 ft
GRT    734

Tank Capacities are:
Fuel oil    320 m3
Potable water    31 m3
Fi-Fi foam capacity    16 m3

Propulsion comprises a pair of General Electric 16V228 diesel engines, each rated 3052 kW at 1050 rpm, and each driving a Schottel model SRP 3030 controllable pitch Z-drive unit. With this propulsion system, the vessel performance satisfied all expectations, with a recorded Bollard Pull of 105 tonnes, a Bollard Pull astern of 97.5 tonnes and a free-running speed of 13.5 knots.  The indirect steering and braking forces are estimated at 115 tonnes steering and 150 tonnes braking at 10 knots.

The Svitzer Pembroke is well-equipped for its various towing and escort duties: the fore deck is fitted for typical ship-handling and escort work, with a Rolls-Royce model TW 2250/850/AW 26U2 H combination hawser winch and anchor windlass. The winch features a towline render / recover system for escort operations and has capacity for 250 metres of 76 mm diameter high strength towline.

The aft working deck is dominated by a double drum, hydraulic-driven Rolls-Royce towing/anchor-handling winch which has a 200m wire capacity of 64 mm (dia.) synthetic rope on seven layers, a stalling load of 100 tonnes. 1st speed step 86 tonnes at 0 – 7 m/min, 2nd speed step 32 tonne at 0 – 18 m/min, 3rd speed step 9 tonnes at 0 – 45 m/min and brake holding load 250 tonnes. Also fitted are tow pins and shark jaws, a 1500mm diameter x 3 metre long stern roller, a 10 tonne tugger winch at 0 - 10 m/min with a brake holding load of 12 tonnes, and a hydraulic knuckle-boom type deck crane of 17 tonne-metre capacity.

Electrical power is derived from a pair of Cummins model K19-CP380DM/5 diesel gen-sets, each rated 390 kW at 1500 rpm.  Also installed is a Cummins model 6B-CS74DM/5 harbour gen-set rated 74 kW @ 1500 RPM.  The fire pumps are rated 1430 m3/hour each, both driven from main engine front PTO's.

Like its counterparts in the Milford Haven fleet, Svitzer Pembroke is outfitted to the highest standards for an operating crew of up to eight (8) persons.  Facilities on board include spacious crew rooms for the full complement in four (4) single, each with individual en-suite toilet and shower facilities and two spacious double cabins.  Public spaces include a generous combined lounge/mess area and a fully equipped and modern galley.

In common with the majority of Robert Allan Ltd. designed tugs, a great deal of attention was paid throughout the design process to mitigate the propagation of noise and vibration.  This includes the essential resilient mounting of the main engines, isolation of all exhaust system components, and the extensive use of visco-elastic floating floor systems throughout.  The shipyard executed all these requirements exceptionally well, and the reward was an extremely quiet ship throughout, as attested to by the following noise level results at free running:

Main Deck:
Galley    66.9 dBA
Mess/Lounge    59.0 dBA
Master's Cabin    58.6 dBA
Chief Engineer Cabin    59.5 dBA

Lower Deck:
Crew Cabins    58.6 dBA