Damen have constructed over 100 tugs of the ASD 3110 type to clients around the world but the Algerian order illustrates the flexibility this design offers.

Unlike many of the tugs of this type, produced for other clients, the vessels are less powerful but intended to carry out a wide range of towing, mooring, water transfer, fire fighting and pollution control duties.

The Sidi Abderrahmane delivered in May is typical. Built on a standard 30.82m hull the vessel has a beam of 10.2m and draft (aft) of 4.70m. The hull incorporates a long, shallow, box keel and the normal highly developed underwater shape common to all ASD 3110s. Bureau Veritas classification 1+ HULL + MACH Tug, AUT-UMS applies for Unrestricted Navigation.

All seven vessels, are powered by two Mak 6M20 main engines generating a total of 3068bhp (2280 bkW) at 1000 rev/minute.

Power is transmitted to a pair of Rolls Royce US 155 fully steerable propulsion units incorporating propellers of 2000mm diameter. While undergoing trials Sidi Abderrahmane achieved a bollard pull ahead of 37.2 tonnes, a bollard pull astern of 34.2 tonnes and a free running speed of 12.6 knots.

Hydraulic power is provided by two pumps driven by the main engines. An electrically driven stand-by pump also powers the deck crane when the main engines are shut down. Electrical power is supplied by two MAN D2866E generators, each rated at 113 kVA, and a MAN D0824 LE 201 harbour set.

Unlike most modern ASD tugs the new Algerian vessels will tow over the stern in the conventional manner and have no winch on the foredeck. A Kraaijeveld single drum towing winch fitted aft has a line pull of 10 tonnes at 10 m/minute and a maximum brake holding load of 80 tonnes.

The tugs are heavily fendered in the bow with three sections of tubular rubber, attached with heavy duty webbing fasteners.

A pair of high holding power (350kg) Pool anchors are handled by a conventional Kraaijeveld anchor windlass, incorporating two warping heads. An Effer 10.000 2S deck crane is fitted on the after deck of each vessel.

Sidi Abderrahmane and her sisters are also equipped with three fire fighting monitors, two at wheelhouse roof level and one fitted on a telescopic masthead.

The fire fighting pumps are also driven by the main engines and capable of supplying 800 cu/m/hour at a pressure of 11bar.