These activities include extensive testing carried out on inland waterways with a full size bunkering tanker by the research institute MARIN.

Mariette is 4.11m in length with a 1.53m beam and a draft of 0.60m. It was transported to Southampton by truck. The vessel is powered by two 5 horsepower outboard motors and the hull form incorporates large bilge keels to improve directional stability and aid storage ashore.

At Seawork the little tug gave a convincing demonstration of the DOT system by handling the ‘Pushycat’ workboat ‘Wiljay’ of Williams Shipping, a vessel three times her size and weighing 12 gross tons. Using indirect towing methods and the advantages of the DOT’s oval track and tow hook system, Mariette was able to tow and steer the bigger vessel without difficulty.

The attendance of Mariette and representatives from Mampaey at Seawork was opportune. MacDuff shipyard is constructing a new tug to a design by associates Macduff Ship Design that will be the first commercial vessel in the world to be fitted with the novel DOT system. Peterhead Port Authority ordered the 13m vessel, which is similar to the Fair Maid, produced previously for Perth Harbour and fitted with a conventional Mampaey tow hook. After witnessing demonstrations with the Mariette in the Netherlands, both Macduff and Peterhead Port Authority were convinced that the new tug would benefit greatly from fitting the DOT system. A model of the new tug was on display at Seawork and MacDuff Ship Design has received an Innovation Award for their work on the project.

The DOT system makes towing at low and higher speeds safe and controlled, and when towing sideways the tug cannot capsize. Optimal balance is achieved by the oval shape and minimises the need of propulsion power to control the tug. Significant improvement is offered in ship assistance and improvements in crew and vessel safety. The system consists of an oval shaped rail built into the tug’s structure with a free moving carriage on the rail to support the towing hook.