Armon deliver two high performance escort tugs

The tugs were constructed by Astilleros Armon in Navia, Spain to a design from the drawing board of Robert Allan Ltd (RAL) designated AVT 36/70 Escort class.

The 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.

Izbaizabal Diez and Izbaizabal Once measure 36.65m in length overall, with a beam (moulded) of 13.60m, a depth (moulded) of 4.80m and a maximum draft of 4.00m. Internal tanks spaces can accommodate 218m3 of fuel oil, 130m3 of reserve fuel and 67m3 of drinking water. Provision is also made for 130m3 of recovered oil, 10m3 of engine lubricating oil, 10m3 of VSP oil, 15m3 of fire fighting foam and 2m3 of chemical dispersant.

A pair of MaK 8M25 diesel main engines, each rated at 2,640 kW (3,540 bhp) at 750 rpm, provide power for the propulsion system. Each engine drives a Voith 32R5-265-2 cycloidal propeller with a blade orbit of 3.2m and located forward of amidships in ‘tractor configuration’.

This combination is designed to deliver a bollard pull of 70 tonnes and provide a free running speed of not less than 13.5 knots. The indirect escort steering force in escort mode is estimated at 110 tonnes at 10 knots. An operating range at economical cruising speed is estimated at 3,500 nautical miles.

Three identical 125kW auxiliary generators supply electrical power at 380 volt, 50 Hz for the vessels’ systems.

Shiphandling fenders at the stern (skeg end) are arranged in a ‘two-stage’ configuration. During push-pull operations a 450mm diameter cylindrical rubber moulding takes the initial impact and below that is mounted a row of 450mm ‘W’ section block fendering. A 300 x 300 hollow ‘D’ section fender protects the main and forecastle deck sheer lines, and ‘W’ block fendering is used again at the bow.

The main towing winch is of the double drum waterfall type, with an upper drum carrying 1,000m of 56mm steel wire rope for towing operations at sea and a lower split-drum with 250m of synthetic towline for escorting, and a150m synthetic towline for harbour towing.

Also included in the outfit of towing gear is a single set of remotely operated tow pins and line handling equipment, a tugger winch and a 70 tonne radial arm towhook. The work deck aft has a protective hardwood surface and salvage, general stores and deck operations are aided by fitting a 25 tonne/m knuckle boom crane.

Both tugs are equipped for fire-fighting to Fi-Fi 1 standard, with two remotely operated water/foam monitors installed at the aft end of the bridge deck and a self-protection spray system.

Izbaizabal Diez and Izbaizabal Once are fitted out to the highest standards for a crew of up to 14 people. Main deck accommodation includes three two berth cabins, four single berth cabins, a galley, mess room and galley stores. Also located on the same deck is a workshop, a recovered oil laboratory, locker room/lobby, and deck store. The lower deck includes engineer’s stores and laundry facilities. Four single berth cabins at forecastle deck level are fitted out for the officers. All cabins are of a generous size, and include en-suite lavatory facilities. The noise level throughout the crew accommodation is in the order of 60 dBA, achieved by utilising advanced methods of isolating the main propulsion machinery and high grade insulation and floating floor techniques.

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 afterdeck.

Technical specification

Length overall: 36.65m

Beam (moulded): 13.60m

Draft: 4.00m

Bollard pull: 70 tonnes

Speed: 13.5 knots