High-performance escort/multi-purpose tugs for Rimorchiatori Riuniti from Robert Allan Ltd.

February 1, 2008

 

Rimorchiatori Riuniti of Genoa, Italy have taken delivery of the Messico, a new offshore support and escort tug to add to their growing fleet of versatile tugs. This latest vessel, designed by Robert Allan Ltd., Naval Architects of Vancouver, B.C., has been designated as an AVT 36/70 E and is one of a pair of almost identical tugs to be constructed by Astilleros Armon in Navia, Spain.

The new tug, classed by RINA, is suitable for a wide range of duties including harbour towage and ship-handling, coastal towing, salvage and escort operations. It is also equipped for firefighting and oil spill response duties.

 

Particulars of the Voith-propelled Messico, are as follows:

 

Length Overall
Beam, Moulded
Depth, Moulded
Maximum Draft (overall)
Power
– 36.65 metres
– 13.60 metres
– 4.80 metres
– 4.0 metres
– 5,280 kW

 

On trials the vessel out-performed all predictions, achieving a mean Bollard Pull of 82.7 tonnes, a maximum Bollard Pull of 86.33 tonnes, and a free-running speed of 13.96 knots.

 

Tank capacities are as follows:

 

Fuel Oil
Reserve Fuel Oil
Potable Water
Engine Lube Oil
VSP Oil
Fi-Fi Foam
Dispersant
Recovered Oil
– 218 cu. metres
– 130 cu. metres
– 67 cu. metres
– 10 cu. metres
– 10 cu. metres
– 15 cu. metres
– 2 cu. metres
– 130 cu. metres

 

 

Features of the Messico include a large aft deck to facilitate oil recovery operations, a removable escort towbitt to ensure a clear deck during non-towing activities, and oil dispersant spray capabilities. The second tug will have slightly different stern lines to incorporate a 3 metre long stern roller, and a set of shark-jaws. The AVT 36/70 E Class design features a full raised forecastle running nearly half the length of the tug to provide a high standard of accommodation and the best possible sea-keeping capability for operation in exposed conditions. The general layout of the tug is illustrated in the General Arrangement drawing, seen below.

The vessel has been outfitted to the highest standards for a crew of up to fourteen (14) people. Main deck accommodations include three (3) two-person cabins, four (4) one-person cabins, a galley, mess, galley stores, workshop, oil lab, locker room/lobby, and deck store. The deckhouse at forecastle deck level includes four (4) one-person officer cabins. The wheelhouse is designed for maximum visibility with a single control station providing maximum visibility to both fore and aft deck working areas, with the emphasis on the aft deck. The lower deck includes engineer’s stores, and laundry facilities. All cabins are of a generous size, and boast en-suite lavatory facilities. The noise levels throughout the crew accommodation are in the vicinity of 60 dBA, achieved by utilizing advanced methods of isolating main propulsion machinery, as well as high grade insulations and floating floor techniques.

 

 

Main Propulsion for the Messico comprises a pair of MaK 8M25 diesel engines, each rated 2640 kW at 750 rpm, and each driving a Voith model 32R5-265-2 cycloidal propeller in tractor configuration. The indirect escort steering force, yet to be exercised at full-scale, is estimated at 110 tonnes at 10 knots.

The electrical plant comprises three identical diesel gen-sets, each with a 380 volt/50 Hz. power output of 125 kW.

Fire-fighting is to a Fi-Fi 1 Class, using FFS pumps and Monitors.

The main towing winch is a waterfall-style, double drum type, in which the upper drum contains 1,000 metres of 56 mm steel wire rope. The lower drum is a split configuration with a 250 metre synthetic hawser for escorting, and a 150-metre synthetic line for harbour towing. The anchor windlass, in a horizontal axis configuration is fitted with two chain wildcats and two warping heads, which are clutched separately.

Towing flexibility is enhanced by the inclusion of a 70-tonne, radial arm tow hook, while salvage and general stores/deck operations are aided by inclusion of a 25-tonne-metre knuckle boom crane. Ship-handling fenders at the stern (skeg end) comprise a 900 x 450 cylindrical fender above a row of 450 mm “W” block fenders. A 300 x 300 hollow “D” fender provides protection at the main and forecastle deck sheer lines, and “W” block type fendering is used again at the bow.

For more information on the AVT 36/70 E Class tugs, or other high-performance terminal or escort tug designs, please contact us.