When grounding is part of the job

A grounded vessel is generally the last thing a seafarer wants to be involved with. For the crew on Maersk Connector, however, it is part of the job. They go on ground with the low tide, lay cables from offshore wind turbines to shore and pull back to sea with the high tide. 

The grounding and cable laying abilities of Maersk Connector are especially valuable in areas where there is a big difference between the high tide and the succeeding low tide, as is the case at Morecombe Bay in Northwest England. Photo: Maersk Supply Service

Facts on Maersk Connector:

  • 138 m long and 27 m wide
  • A 7,000 tonne capacity cable carousel is located in the middle of the ship
  • It has a 100 tonne subsea crane
  • It can accommodate 90 people

Never once having grounded a vessel, Captain Peter Grøn was going against his nature and 20 years of experience when he steered Maersk Connector closer to shore, deliberately getting stuck with the low tide.

“We had planned it for a long time and gotten used to the idea, but actually doing it was very unusual,” Peter Grøn explains after having successfully completed the first so-called ‘engineered grounding’ in Maersk Supply Service’s history in late May.

In and out

The unusual situation called for an unusual vessel. Maersk Connector is the first large power cable layer that can sail right up to the shore and go aground fully loaded with cable, allowing the crew to lay cable from offshore wind turbines to shore in single length, before easing safely back to sea with the high tide. This process is cost-efficient and a single length cable creates a better flow of power than does a cable with a larger number of connecting joints.

Maersk Connector’s first expedition went to Morecombe Bay in the Northwest of England and everything went according to the meticulously prepared minute-by-minute plan. The vessel and its 75 man strong crew completed the job, connecting the extension of the Walney offshore wind farm to shore, and grounding no less than five times over the course of three days in the process.

“If we didn’t get it right, we would have had to wait a full month for the next high tide,” says Peter Grøn.

No trial run

“This operation raised the industry standard for cable laying,” says Jacob Westh Olsen, Operations Supervisor at Maersk Supply Service.

Olsen was the focal point of the month-long planning, which lead to the grounding and involved the client, third party surveyors along with technical and fleet teams at Maersk Supply Service.

Poster image
The grounding and cable laying abilities of Maersk Connector are especially valuable in areas where there is a big difference between the high tide and the succeeding low tide, as is the case at Morecombe Bay in Northwest England.

Grounding a vessel

Grounding a ship is a technically complex operation, requiring precise positioning, detailed planning and very detailed survey of the seabed

The advantage of going close to shore and ground is that the cable can be pulled ashore in one piece which mean more cost effective cable laying and better utilization of cable capacity

The success of Maersk Connector indicates the practice could become more widespread in the industry

The grounding was planned around the cycle of the tide, which peaks twice a month. Thus, the tide would behave differently just a day or two before or after, making it a different operation altogether. 

“We did some practicing and simulations, as much as we could, but a real trial run, dealing with the whole package in the environment and also taking in the weather was not possible,” says Jacob Westh Olsen.

Maersk Supply Service
Captain Peter Grøn and Jacob Westh Olsen debrief at Maersk Supply Service headquarters in Lyngby after the successful pulling off the first ‘engineered grounding” in Maersk Supply Service’s history. Photo: Peter Elmholt

As a part of the preparations, a corridor on the seabed was surveyed and checked for obstructions and suitability to ensure the vessel would be safely grounded. A smaller anchor-handling vessel was needed to place four anchors around the vessel and then the tide took over, placing the vessel on the seabed, giving the crew its window to lay down the cable.

Teamwork is key

The planning process intensified in the final two months before the grounding and the pressure was also heating up – not only for the crew on Maersk Connector, but also for the offshore team, including Jacob Westh Olsen.

“The vessel is built for it and we were prepared, but we still had to pull it off. I stayed close to the phone, and when they called, it was with good news,” he recalls, pointing to teamwork as the key to the success.

“It was a great success and a first step to building a solid track-record for Maersk Connector.”

Maersk Connector is on a 7-year contract with a client, which will see the vessel making more groundings and other complex operations across Europe while working on new renewable and interconnected power cable projects. Hopefully also allowing Captain Peter Grøn to get used to the situation.

“But I’ll probably still have butterflies in my stomach the next couple of times,” he says.