Compact tug handles ships in restrictive areas

The first azimuth stern drive (ASD) tugboat built to a new design to operate in small harbours entered service in Emden, Germany in Q3 2024, assisting ships in tight areas of the port. This low-emissions tugboat is highly manoeuvrable and able to access restrictive areas of harbours.

Käthe Wessels joined the fleet of Emder Schlepp-Betrieb (ESB) on charter from owner Neue Schleppdampfschiffsreederei Louis Meyer and has flourished in its role in the busy German North Sea port.

This 21-m tugboat was built by Damen Shipyards’ Changde facilities in China to Damen’s ASD 2111 design with a beam of 11 m, a hull depth of 4 m and a draught of 5 m, enabling it to manoeuvre large vessels, including vehicle carriers, in shallow-water areas of the harbour. 

Louis Meyer signed the newbuild contract with Damen in September 2023 when the shipbuilder had already started constructing these vessels for its own stock, and it was delivered in June 2024, with additions for operating in northern Europe.

Its propulsion consists of two Caterpillar-manufactured Cat 3512C TA HD/C main engines, with total power of 2,760 kW at 1,600 rpm linked to a Damen selective catalytic reduction exhaust gas aftertreatment system for minimal NOx emissions and compliance with IMO Tier III standards. These drive two Kongsberg Maritime US165S azimuth thrusters with a 2,400-mm diameter propeller.

This Bureau Veritas-class tug has Damen’s patented twin fin on the hull enhancing course keeping and predictable sailing behaviour during both free sailing and bow-to-bow operations. It has a bollard pull ahead of 51 tonnes, and astern of 48 tonnes, a speed ahead of 12 knots and astern of 10 knots.

Käthe Wessels is part of the ESB fleet, which has grown to five vessels supporting ships in the Port of Emden, one of Europe’s largest terminals for handling vehicles and roro cargo. This tug can store 30 m³ of fuel oil and 7 m³ of fresh water, and it has air-conditioned, insulated accommodation for six workers in three cabins.

On the deck is a hydraulically driven, double-drum towing winch able to pull 30 tonnes up to 10 m/min, with a maximum speed of 40 m/min on the second layer and a brake holding force of 150 tonnes. Another electrically driven anchor winch can work up to 10 m/min.

Fendering consists of W-shaped block and cylindrical rubber fenders on the bow and cylindrical fendering on the stern and sides.

Käthe Wessels has keel cooling, two shaft generators of 50 kVA each and a Caterpillar C4.4 harbour generator set of 64.5 kVA, all producing 400 V electricity at 50 Hz.

Other auxiliary equipment includes a DAB Euroinox 40/50T fresh water set, a Distrimex B40 sewage pump working at a maximum rate of almost 7 m³/hr, an Azcue CA-32/05 oily-bilge water stripping pump (10 m³/hr), two Coalester fuel-oil filters, two Azcue CA-50/3 general-service pumps (27 m³/hr), two CJC-supplied PTU3 27/81 MZ-E2PWZ fuel-oil purifiers and an Azcue MR41/10 pump for fuel transfers (12 m³/hr).