The new facility takes the form of a 'dogleg' pier with four berthing faces. It is being constructed using a concrete deck on tubular piles which have been driven into the bedrock and encased with reinforced concrete.

The project is being carried out by R J McLeod (Contractors) Ltd and the company's subcontractors Harbour and General Works who are primarily responsible for the civils work on the project. Consultants Arch Henderson & Partners are acting as project engineers on behalf of the Department of Engineering and Technical Services in the Orkney Islands Council.

Prior to construction work starting, HR Wallingford was commissioned to carry out a wave study for the new facility to determine whether there were any conditions which might adversely affect berthing operations, and Fugro was contracted to carry out the necessary site investigation.

As Stewart Craigie in the Orkney Islands Council's Engineering & Technical Services Department explained, the design produced by R J McLeod uses a series of horizontally braced frames at deck level, which are bolted to the tubular piles. The frames support pre-cast concrete units, with a 750mm thick concrete deck.

Craigie said a total of 466 tubular steel piles range from 610mm diameter sections to 1,067mm diameter were required, the longest being 24m in length. To protect them from corrosion, the piles have an Impressed Current Cathodic Protection (ICCP) system.

As Craigie explained, the entire project is a huge undertaking, requiring approximately 15,000m 3of concrete and 1,300t of reinforcement, so R J McLeod had to set up a 'batching plant' to prepare and supply the concrete required.

The quartet of berthing faces will be 153m, 116m, 161m and 225m long respectively, and are dimensioned to accommodate, respectively, cargo ships, the Northlink ferries and cruise ships.

The ro-ro berth should be complete in July 2003, said Craigie.