Black Adder is Another First for Robert Allan

Bearing the unlikely name Blackadder, the high performance azimuthing stern drive (ASD) tug was the first major new vessel in steel to be constructed by Titan Marine Engineering of Auckland, New Zealand. The new Ramparts 2400 design developed by Robert Allan Ltd.

of Vancouver, British Columbia, was chosen after an extensive investigation by a project team from the Port Company. The shipyard was supported during the construction by Robert Allan Ltd who prepared complete steel part drawings for NC cutting using ShipConstructor software developed by Albacore Research Ltd. of Victoria, BC, and also complete piping arrangements and spool parts.

Blackadder is being used in the Port of Lyttelton to provide an upgraded capability to handle the larger generation of ships calling there. The tug is built to Lloyd’s Special Service Craft Notation 100 A1, SSC, Workboat, G3, for New Zealand Coastal Service, as well as to the requirements of the New Zealand Maritime Safety Authority (NZMSA). A vessel of 23.85m in length overall, the tug has a beam of 11.00m and maximum draft of 4.60m.

The propulsion system comprises a pair of Caterpillar 3516B diesels each rated 2,500 bhp (1,771kW) at 1,600rev/min, coupled to Rolls-Royce Model US 205 fully azimuthing propulsion units through a system of Cardan and line shafting. This combination delivers a bollard pull of 60 tonnes, and a free running speed of 12.5 knots.

Blackadder is designed as a dayboat for normal operations with a crew of two persons, but is also fitted with overnight accommodation. The wheelhouse accommodates all the control functions, as well as a small pantry and crew seating area.

Below decks there are two staterooms, a crew lounge and an office area.

The entire wheelhouse unit was fabricated from aluminium as a totally self-contained module, mounted on four pairs of rubber isolation mounts.

This approach ensures that the noise levels in the wheelhouse, which is located directly over the engine casing, are less than 70dBA.

Due to the requirements of the NZMSA regulations, and the impact of these on manning requirements and qualifications, the vessel has a unique auxiliary power system. Many major services such as pumps and vent fans are hydraulically-driven, and electrical services are supplied by either 24 volt DC or through DC/AC inverters.

There are no diesel generator sets onboard.

Deck machinery includes a combined hydraulic towing winch and windlass forward designed by Marine Industrial Design and built by the shipyard.

During normal ship-handling operations the towline is led forward through a primary towing fairlead, but for occasional tows over the stern the hawser is led aft, under the isolated wheelhouse, and through a second fairlead aft.

Fendering comprises a pair of cylindrical fenders forward, the upper tier of 500mm diameter, and the lower 800mm diameter.

The transom is protected by corner segments of the 500mm diameter cylindrical fender, and the balance of the main sheer is fitted with ring-mounted aircraft tires.

The Ramparts 2400 Class tugs reflect nearly thirty years of professional experience on the part of Robert Allan Ltd. in the design of high performance compact tugs. This new class of tug has already attracted considerable attention from other tug owners, and further orders for similar vessels are expected to follow shortly.