Van Oord purchases the ‘Pushbuster’ quartet

This quartet of powerful pusher tugs was designed and constructed by Damen Shipyards at Hardinxveld, working in conjunction with DMS and Van Oord, principally in support of major projects being undertaken in Dubai.

Initially six vessels were ordered in a joint venture between DMS and Van Oord, under which DMS purchased and operated the tugs and Van Oord financed the construction of matching dump barges and the Japanese designed ‘Articouple’ coupling mechanism.

Extensive and highly successful trials were carried out with the first vessel, , in November 2008 (MJ Nov 2008) and three more tugs DMS Harrier, DMS Buzzard and DMS Kingfisher were completed by June 2009. In the meantime, financial difficulties in Dubai resulted in the Van Oord projects in the area being curtailed.

The four completed ‘Pushbusters’ were deployed elsewhere and have been working in various parts of the world, as far apart as Finland and Singapore. The fifth vessel was completed by Damen Hardinxveld but without the Articouple mechanism and adapted to become the first Damen Shoalbuster 3511. That vessel was named DMS Osprey and is now operated as part of the DMS fleet. The sixth tug was cancelled.

Damen Shipyards, Hardinxveld and Damen Marine Services broke new ground with the Pushbuster 3511 design. The ‘Pushbuster’ has the proven ability to operate with a matched barge as a true ‘Articulated Tug and Barge’ (ATB) unit, or operate independently to fulfil a range of other functions. With the tug engaged in the notch of the barge, using the ‘Articouple’ system, it is secured by two large horizontal pins protruding from the hull of the tug in the forecastle area and engaged in a series of holes on each side of the barge notch.

This positive connection allows the tug to pitch but not roll, enabling the tug and barge to behave and handle in much the same manner as a ship, with added advantages of increased speed, improved fuel economy and good handling characteristics.

All four tugs measure 35.08m in length overall, with a beam of 11.6m and depth (at the sides) of 5.25m. A double chine hullform incorporates two fixed nozzles set in shallow tunnels. The massive superstructure, over four decks high, gives the tugmaster an excellent view forward over the barge being pushed and a bird’s eye view of the afterdeck, winches, crane and rescue boat.

Each Pushbuster is powered by two Caterpillar 3516 BTA main engines, developing a total of 4,895 bhp (3,650 kW) at their maximum continuous rating (MCR). Power is transmitted via Reintjes reverse reduction gearboxes, to a pair of five blade high performance propellers of 2,700mm diameter, rotating within high performance fixed nozzles. A bollard pull of 62 tons is available at MCR and the vessels have a free running speed of 11.6 knots. Thanks to the four high lift rudders they are also remarkably manoeuvrable.

Late in 2010, all four tugs were purchased by Van Oord Other Equipment BV and are now operated by Van Oord. They have been renamed without the DMS prefix. Blackbird, Harrier, Buzzard and Kingfisher are reported to be working on project in Bahrain.