DISCOVER Magazine #7

Rapid development of tugs for use at ports and terminals

Published in category: Harbour & Terminal

Towage history

The towage industry has a history dating back over 180 years to when the first tugs were being used, mainly to assist sailing ships in and out of harbour. Development in propulsion and hull design was slow for well over a century but in recent years tug design and its associated technologies have continued to change at spectacular rate.

Specialist naval architects and shipbuilders work hard to meet the exacting demands of tugowners and their clients. Damen has contributed enormously in the development of vessels tailored to meet the demands of their clients with well researched hull and propulsion designs. The company’s policy of developing high quality vessels to standard designs has proved highly successful.

Increasingly higher bollard pull figures are still in demand, as ships grow larger, but modern tugs also need the ability to apply that bollard pull in exactly the right place at the right time. Safe operation, economy, in terms of manpower and fuel, along with reliability and maintainability are high on the tugowners list of priorities.

Damen has produced a range of efficient single and twin-screw vessels in their Stan Tug and Workboat ranges since the 1970s and continue to do so. In keeping with Damen practice the vessels are designed for series production and regularly updated.

Among the hull and propulsion designs that have evolved, the most popular choice for shiphandling today is the azimuthing stern drive (ASD) propulsion system, followed by Tractor tugs using propulsion units located beneath the forward portion of the hull.

In 1993 Damen reacted to demands from the towage industry by introducing the first ASD Tug 3110. Named the Citta Della Spezia, the 30.82m tug had 3300 bKw main engines and a bollard pull ahead of 57 tonnes and 46 tonnes towing astern. That vessel was an immediate success, remaining in production for many years with over 100 built.

A close relationship with clients, including after sales service, enables each design to be continuously reviewed and refined in the light of operational experience. As part of that process new vessels are introduced, and others discontinued.

By 2000, a direct successor to the ASD Tug 3110, the ASD Tug 3111 was introduced, with many refinements and a bollard pull of 65 tonnes. It was the handling characteristics of this tug that made true ‘bow to bow’ operation a reality. The first ASD Tug 2810, a smaller 60 tonnes bollard pull version was also introduced at this time. That design has grown enormously and remains the vessel of choice in many ports around the world. SMIT Harbour Towage alone has 20+ and a total of 150 + have been built. The ASD Tug 2810 design was chosen to be Damen’s first ‘true hybrid’ tugboat .

Demand for a, powerful, agile, ‘compact’ ASD tug capable for assisting large ships in confined waters led to the development of the ASD Tug 2411. The 24.47m tug, of 4180 bKw and 70 tonnes bollard pull is capable of operating with a crew of two. Many have been sold worldwide in competition with designs from elsewhere.

In recent years a massive demand for shiphandling tugs to operate in difficult tidal and weather conditions at exposed wharves, offshore oil and gas terminals, causing intense competition among shipyards, designers and propulsion manufacturers.

Research and development into new concepts never stops

Damen introduced the high performance ASD Tug 3213 to meet those demands in 2009. Built specifically to carry out shiphandling, towing, fire-fighting, and escort duties in exposed locations the first four tugs went into service with SMIT. The 32.14m vessels are powered by Caterpillar engines developing a total of 5420 bKw. The result is a bollard pull of 95 tonnes and a top speed of over 14 knots ahead and astern.

Three years later the 80 tonnes bollard pull ASD Tug 3212 was introduced and immediately attracted great interest in the towage industry. This powerful ASD design has all the attributes required for use in ports, at exposed terminals and offshore.

The first ASD Tug 2913, a new compact tug with a bollard pull of 80 tonnes will be delivered to a German client early 2015. This new variant will fit neatly in Damen range, between the Damen ASD Tug 2810 and the very powerful offshore terminal ASD Tug 3212.

Two_ASD_Tugs_2411_provide_ fire_fighting_cover
Two ASD Tugs 2411 provide fire-fighting cover at the Medway Port LNG terminal.

The SD Bountiful an ATD tug operating on charter to the British Royal Navy.

Smit Barbados acting as stern tug on a container ship in the confines of Liverpool Docks.

Svitzer Portgarth one of the first ASD Tugs 3110 working in the Port of Bristol.

ASD Tug 2411 Svitzer Warden on duty at the Medway Port of Sheerness.

ASD Tug 2810 assisting a ship in the locks at the Port of Liverpool.

Research and development into new concepts never stops and several exciting new designs are coming to fruition. Damen will be strongly represented at the ITS 2014 in Hamburg, with the introduction of the ASD Tug 2810 Hybrid and Rotor®tug ART 80-32 Hybrid and other new projects.

The first ASD Tug 2810 Hybrid ordered by Iskes Towage & Salvage has been completed and four others are under construction, three for the Royal Dutch Navy and one for ‘stock’. Also completed will be the first Rotor®tug ART 80-32 Hybrid, the result of unique co-operative arrangement between Rotortug B.V., Robert Allan Ltd. and Damen. Damen has carried out the detailed engineering and construction of two vessels.

Text & Photo’s By Jack Gaston

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