Designed by Robert Allan Ltd. the RiverWijs Emma and RiverWijs Rowan were constructed for operation at the LNG terminal in the Port of Dampier, Australia. According to Robert Allan, they are the latest edition of a "venerable design," meeting a shallow draft requirement of 5 m, that allows them to be moored in a tug pen during cyclone season.
The vessels are built in accordance with the Lloyd's Register of Shipping requirements for the notation: LR +100 A1, TUG, +LMC, UMS, IWS, Fi-Fi 1 with waterspray, Unrestricted Voyages
Particulars
Length overall (excluding fendering) 32.55 m
Breadth, molded 12.40 m
Depth, molded 5.40 m
Draft, navigation 5.00 m
GRT / NRT 494 / 148
Tank capacities
Fuel oil 202,000 liters
Potable water 32,000 liters
Main engine lube oil 3,100 liters
Z-drive lube oil 1,200 liters
Hydraulic oil 500 liters
Z-drive hydraulic oil (resupply) 1,200 liters
Sludge tank 4,300 liters
Oily water 4,300 liters
Grey water 3,300 liters
Sewage holding tank 4,700 liters
Foam - 10,000 liters
Propulsion is by a pair of resiliently mounted Niigata 8L28HX main engines, delivering 220 6kW at 750 RPM. Drives are Niigata ZP-41, turning fixed pitch props with a diameter of 2.7 m. Electrical power is provided by two CAT C6.6 diesel generators, each rated 100kW.
On trials, RiverWijs Emma and RiverWijs Rowan met or exceeded expectations with the following results:
Maximum bollard pull, ahead 83.8 tonnes
Maximum bollard pull, astern 78.9 tonnes
Maximum free running speed 13.5 knots
The main forward towing / hawser winch is a Kraaijeveld KASW-20-H-TR-22D/22D, in the SAFE- WINCH configuration. It is supplied with 200 m of 72 mm diameter line and line pull varies from 25 t at 20 m/min to 7.5 t at 60 m/min, with a brake holding capacity of 200 t. Aft deck equipment consists of a 5 t Kraaijeveld vertical capstan, towing bit and Mampaey tow hook with 100 t SWL.
Bow fendering consists of a 900 mm diameter hollow cylindrical fender forward, with a lower run of 480mm x 300mm "W" block fenders. A second strake of cylindrical fender runs below the larger upper course. The stern and transom corners are also fitted with 480 mm x 300 mm "W" block fender and the shear strake is fitted with 350mm hollow "D" fendering.
The vessel is outfitted to the latest Australian standards, with three one-man cabins and one four-man cabin. There is a fully outfitted galley and an expansive crew lounge/mess room and ship's office. The wheelhouse is equipped with a large split style console forward for control of the majority of vessel operations. Below decks is a large Machinery Control Room overlooking the machinery space and a fully equipped workshop. All accommodations and control spaces are fully air-conditioned.