Cornwall Wave Hub: equipment issues cause further delay

The cable laying for the Wave Hub has been delayed a number of times over the past week

Plans to lay an underwater cable off Cornwall as part of a £42m wave energy project have been put on hold until the weekend following a series of delays.

The 25km (15.5 miles) of cable for the underwater Wave Hub was to be laid earlier in the week but a winch problem and then weather conditions halted it.

Now issues with a flotation device have led to further delays until Saturday.

The hub will send energy from machines on the sea surface to wave power units ashore which link to the National Grid.

Buoyancy aids

The first part of the operation will see the cable floated to land from a ship 2km (0.75 miles) offshore.

The cable, which is on board the vessel Nordica, is to run from the sea to Hayle Towans Beach in St Ives bay.

It has to be floated to the shore during a high tide and a number of buoyancy aids which are 100m (330ft) long will be needed.

When the cable end is about 200m (660ft) offshore, it will be winched up the beach and joined to a nearby electricity substation.

The Nordica will then sail about 14km (8.7 miles), to what will be the hub's final location about 16km (10 miles) offshore, deploying the rest of the cable on the way.

It is longer than the required 16km because it is to be buried about 2.5m (8ft) under the sea bed by underwater trenching machines.

The Nordica is being used to release the cable into the sea off Hayle

However, after problems with a winch on Monday and sea swells and strong winds in the early hours of Wednesday delayed the cable laying, the team working on that part of the project now have problems with a flotation unit.

The device, called the Sea Serpent, encases the cable with a special cover as it is released from the Nordica.

The complete deployment of the cable was originally expected to be completed next week.

Once it is carried out, the 12-tonne sea-bed hub, which is also on board the Nordica, will then be lowered on to the sea bed.

The hub is due to undergo a series of tests in the autumn.