The £11.5m contract to build the 315m long berth included the installation of six berthing dolphins. Rock sockets ranging from 2.4 to 3.0m diameter and up to 21m deep were drilled from jack-up barges and monopiles 39m long and weighing up to 100 tonnes were then inserted into the sockets utilising semi-buoyant lifts and subsequently grouted into place.

The dolphins were capped with pre-cast concrete tops weighing 140 tonnes, installed with a heavy lift crane barge. Mowlem Marine installed, on average, one pile every eight days.

Two 10m 2, 2m deep portal dolphins were also constructed to carry the linkspan, supported on 23 tubular piles drilled into the hard rock seabed. Overall, the structure contains over 300m 3ofpre-cast and 1,000m 3of in-situ offshore concrete as well as 300 tonnes of structural steel.

Onshore works comprised reclamation and the construction of a 2.8 hectare lorry park.

Last month saw a new ferry berth opened at Scrabster Harbour which will accommodate new and larger ferries sailing to and from the Orkney Islands.

Mowlem Marine's work at Scrabster comprised the construction of a 400m long breakwater quay with associated marine furniture and wave wall to provide a new ferry berth and lay-by berth capable of providing berthing to vessels of at least 9m draft and 150 to 160m length.

The new quay consists of an in-situ suspended reinforced concrete deck slab supported by vertical and raking tubular steel piles. The breakwater element is incorporated below the suspended deck as a twin combi-wall sheet piled gravity structure, while the west face of the structure incorporates a suspended deck structure and supports a ro-ro linkspan bridge to service the ferry berth.

At its peak, the project involved the use of three jack-up barges, one crane barge, three service barges, one tug, one multicat, two workboats and 120 workers.

MJ Information No: 18635