New Carrousel Tug Design is Offered by Novatug

The Carrousel towing system allows the towing point to rotate through 360º around the tug, enabling the vessel to make full use of indirect towing methods in complete safety. The prototype Carrousel tug, Multratug 12, has proven the system under trials conditions and while carrying out numerous harbour towage operations. The results show that the braking and steering forces generated by the tug can be multiplied by a factor of five, whilst safety remains guaranteed.

At the same time operating costs (fuel, maintenance, surveys and damages) are substantially decreased.

The newly developed winch system introduces further flexibility, allowing towlines up to 60m in length to be handled with the prototype and greater lengths with a larger winch in production models. Developed exclusively for the Carrousel system, the hydraulically powered winch is a highly innovative piece of equipment mounted directly on the travelling carriage of the Carrousel. A single, split, winch drum rotates about a vertical axis. The upper portion carries up to 75m of 36mm steel wire towline and a smaller eccentric lower drum is used to provide braking on a single layer.

A hydraulically operated fairlead is used to guide the towline between each part of the drum. Hydraulic power is provided by a small diesel driven power-pack mounted on the Carrousel. The winch has a maximum holding load of 140 tonnes and a line pull of 5 tonnes and is controlled by a radio link from the wheelhouse.

Following the success of the Multratug 12 prototype and extensive tank testing of purpose built Carrousel tug models Novatug is now offering the towage industry a Compact Carrousel harbour tug design.

The hull will have a length overall of 26.85m, a beam of 11.40m, design draft of 4.50m and incorporate a long box keel.

Two main engines of up to 2,650kW will power twin controllable pitch propellers rotating within fixed nozzles. Twin rudders, with trailing edge flaps, will be capable of operating in unison or independently. A bollard pull of up to 100 tons is predicted and a speed of at 100 percent MCR of 12 knots.

Novatug’s commercial manager Walter Jacquet says, “The new tug design and the ability to use the Carrousel system with a towing winch now opens up the possibility of substantially reducing the operating costs of harbour tugs while enhancing safety and efficiency.

”We have had fantastic results using the winch version of the Carrousel on our test tug, Multratug 12, which has completed over 30 live operations with the winch, and over 300 with the hook version. We are already getting commitments to build the new tug.”

According to Jacquet, conversion of existing tugs to take the Carrousel system is straight forward, and Novatug is offering a larger 35m 120 tonne bollard pull escort tug design in addition to its new compact design. “We have already had a commitment from two major North European tug operators to build one of the escort tugs, and one of the compact vessels, ” he says.