New tugs ordered to transport Londons refuse

The existing fleet of tugs and barges currently operated by Cory Environmental will be transferred to the ownership of RRRL and upgraded to meet the precise needs of the new facility. An important feature of the upgrade process will be the provision of four new, purpose built, tugs.

A contract has been signed with Damen Shipyards at Hardinxveld to construct the tugs and work on the design is almost complete. In order to meet the special requirements of RRRL, and to be compatible with the existing fleet of barges used to transport containerised waste, Damen has produced a design based on the well established Shoalbuster 2208.

Among the essential features of the new design is the ability to meet stringent draft and air draft constraints. The Shoalbuster was designed from the outset to operate in very shallow conditions but considerable work was required to reduce the vessel’s air draft sufficiently to enable it to pass beneath the multitude of upriver bridges during the appropriate tidal conditions. The resulting vessel will be 22.65m in length overall, with a beam of 8.00m, a draft of approximately 2.00m and an air draft (full tanks) of 4.28m. The latter will allow the vessel to pass beneath the lowest bridge on the normal routes at high water (spring) tides.

To achieve the required air draft the entire wheelhouse structure has been lowered into the hull considerably. The hull will be strengthened externally with the addition of half-round steel rubbing strakes (produced from thick tubing) to improve impact resistance while working with barges. Likewise, the stern will be rounded and heavily fendered at deck level and bulwarks reduced in height. The usual single push knee has been retained and guard rails provided where necessary. Day accommodation will be provided below decks for the barge crews with shower, mess room and galley. Access will be via a separate entrance and not through the wheelhouse as in a normal Shoalbuster.

Two Caterpillar 3512 TA/B main engines producing a total of 1,440 bhp will drive a pair of Promarin propellers via Reintjes reverse reduction gearboxes. This arrangement will give the tugs a bollard pull of about 16 tons and a top speed of 9.5 knots. A hydraulically powered bow thruster will be installed in the push knee to enhance manoeuvrability, particularly when working with barges on the inside moorings of the new T configuration jetty planned for Belvedere.

Delivery of the first two tugs is scheduled for May 2010, with the second pair in July of the same year. It is envisaged that the final requirement will be for a fleet of five tugs. The new quartet will operate alongside the existing tug Regain, a purpose built twin screw tug put into service in 1997. With the exception of Regain, the remainder of the existing fleet comprising traditional single screw lighterage tugs will eventually be sold.