10 metres a minute – Stemat and N1 head for Jersey

air 3

The 4,000-tonne power cable laying vessel the Stemat Spirit is now fast approaching Jersey waters and all mariners are advised to keep clear. A mobile exclusion zone around the Stemat and its support vessels is force. No vessels are to pass within 1,000 metres of either side or ahead of her, or within 500 metres of her stern without prior clearance from Ports of Jersey.

The operation to install a third 100MW cable between France and Jersey, Normandie 1 (N1) began in earnest on Wednesday. After a complex but text book beach landing of the French end of the cable by Jersey Electricity specialist Dutch contractors VBMS on the beach at Surville, the Stemat and her 50-strong eased away from the Normandy coast.

Main route map

By late Friday afternoon they were able to deploy the vessel’s full power and dynamic positioning system which carefully manages the thrusters to ensure the precise 27km route for the cable is adhered to. Since then the Stemat has been laying the cable at a rate of 10 metres a minute. This is much faster than the Normandie 3 cable that Jersey Electricity installed in 2014 because N1 is being laid on the seabed rather than buried beneath it.

Once the Stemat is approximately 1.5km off the east coast of Jersey, likely late Sunday evening or early Monday morning, the crew will wait for a suitable tide from which to offload the cable here ready for connection to the primary substation at Archirondel. All being well, this is currently expected to be on the rising tide of Tuesday afternoon and will likely take around two hours.

Jersey Electricity Senior Projects Engineer and N1 Project manager Jeremy Willis is aboard the Stemat and last night said: ‘The operation is so far going to plan. The VBMS team both on board and on the beach in France have performed exceptionally so it’s fingers crossed for a continued safe crossing and successful landing at Archironel.’

the crew will wait for a suitable tide from which to offload the cable here ready for connection to the primary substation at Archirondel. All being well, this is currently expected to be on the rising tide of Tuesday afternoon and will likely take around two hours.

Bay map

Jersey Electricity Senior Projects Engineer and N1 Project Manager Jeremy Willis is aboard the Stemat and last night said: ‘ The operation is so far going to plan. The VBMS team both on board and on the beach in France have performed exceptionally so it’s fingers crossed for a continued safe crossing and successful landing at Archironel.’