VESSEL REVIEW | Kratt – Estonia's new biomethane-powered workboat for maintenance, research and emergency response

The Estonian State Fleet (ESF), the agency directly overseeing and managing Estonia's public watercraft, has taken delivery of a new multi-purpose workboat.

Designed and built locally by Baltic Workboats (BWB), the 38- by 10-metre (120- by 30-foot) Kratt will carry out a wide range of maritime tasks from buoy handling and fairway maintenance to marine research, pollution response, and rescue operations.

A reinforced hull capable of sailing through 40 cm (15 inches) of level ice at two knots and a maximum draught of only three metres (10 feet) mean that the vessel can be used across a broader range of marine environments.

BWB said Kratt is Estonia’s first large workboat to use biomethane as her primary fuel.

Hybrid electric propulsion for greater operational flexibility

In addition to having four 350kW biomethane generators, the vessel is also equipped with a 400kWh battery bank for electric propulsion, allowing her to perform various maritime tasks while limiting her environmental impact.

On biomethane, the vessel can travel up to 1,000 nautical miles at a speed of seven knots though a top speed of 11 knots can be achieved.

On battery power, she can operate for up to two hours at five knots.

The battery bank will also allow the vessel to use electrical power for up to ten hours while at anchor, reducing the need to run auxiliary engines as well as lowering fuel consumption, emissions and noise levels.

Designed from the outset to replace single-use platforms

Andres Laasma, Director General of the ESF, said the acquisition of Kratt is in line with the agency's transition from single-use vessels – that are also likely to spend most of each year tied up pierside – to more economical multi-purpose platforms.

The new vessel will also replace some of the ESF’s earlier vessels, which are now between 30 and 40 years old on average.

Kratt’s primary task is seasonal buoy and fairway maintenance, but she will also serve as a platform for modern marine research. The vessel is suitable for environmental, oceanographic, hydrographic and geological surveys throughout the Baltic Sea.

The vessel provides accommodation for six crewmembers and up to ten scientists. Other facilities include a mess, a recreation and fitness room, a galley, utility and office spaces, and wet and dry laboratories with a total area of approximately 50 square metres (540 square feet).

Full deck and research equipment suite

The laboratories have permanently installed research systems and equipment including a seawater flow-through system, sampling equipment, workstations, and connection options for additional equipment.

The deck is meanwhile equipped with systems and fittings needed to launch and recover research equipment, containers, buoys and seabed stations. The deck features a stern A-frame, an Iron Fist crane, and space for a tender and its dedicated davit.

The vessel can support activities including water and sediment sampling, seabed sonar surveys, towing research equipment, the use of remotely operated and autonomous equipment, and meteorological and biological observations.

Even without resupply, the vessel can still operate at sea for up to seven days.