The contract for the work was awarded to Per Aarsleff in late 2000, and required the company to restore the toes and sides of two parallel concrete block and Tetrapod covered breakwaters and extend them using rock armoured stone embankments.

As Kallehauge explained, the southern breakwater has been extended by about 330m, and approximately 250m has been added to the northern breakwater. Around 500,000t of rubble stone was required for the project.

This has had the effect of reducing the width of the entrance to the port from around 300m to 150m, which, says Kallehauge, should reduce the swell inside the port and provide more shelter from storms from the southwest.

As Kallehauge explained, Klaipeda port is at the head of a large lagoon which is fed by several rivers, and the combination of river currents meeting Baltic Sea swells up to 2m and onshore winds of 30m/s mean that mooring in the harbour can be dangerous.

Work at the port started in February 2001 with repair and construction work on the breakwaters beginning at the end of March, the site team having built a temporary quay off the northern breakwater and cleared a site to store the different grades of stone required for the project.

Kallehauge says approximately 510,000t of graded granite in six sizes was required for the project, the rock being brought in on a fleet of barges and ships from two quarries in Sweden.

A 900t lifting capacity floating sheerlegs, the Samson, was charted in to work on the project, breaking and removing three shipwrecks at the end of the northern breakwater prior to its extension.

The re-building work on the southern started with Per Aarsleff laying a 75m wide geotextile carpet on the seabed along the line of the new embankment from the transition with the existing breakwater for a distance of 150m.

Once the geotextile was in place, the breakwaters were strengthened by placing a footing of core material on top of it. A new slope of cover stones was constructed using Grade 4 (1.5-4.0t) stones on the inside of the structure and Grade 6 (7-10t) stones on the seaward side.

A line of steel tubular piles was driven through the stone covered geotextile into the seabed at 20m centres and 7m off the centre line on the harbour side of the embankment to provide moorings for the vessels offloading and placing stone onto the embankment.

Kallehauge says most of the stone was placed directly from the barges and ships using Cat 245 and Cat 375 excavators, with the stone being allowed to 'self-profile', prior to final grading on a 1:2 slope.

Kallehauge says the company built about 40m of the initial core before starting to cover the top and slopes with a filter layer of graded granite.

As the core and filter material was put in place, rock armour protection was placed using a 75t Cat 375 fitted with a combination of bucket and rock grapple.

As Kallehauge explained, the rock armouring was placed up to sea level and the entire breakwater was then capped with 10-13t granite blocks, thus leaving a 5.5m wide crest 3.5m above sea level.

The semi-circular pier head core was covered with a layer of 1.5-4t rock, followed by an outer protective ring of 4-7t rock, after which a layer of 25t concrete Tetrapods were lowered into place. Having been built at a facility in Klaipeda, around 40 Tetrapod units per load were transferred onto a barge and then craned into place using a Crawler Crane 7260.

The work on the northern breakwater extension required around 80,000m 3of material to be dredged from the pier head area to a water depth of 14m, after which the northern breakwater was repaired using the same techniques as those used on the southern structure.

Under a separate contract, dredging contractor Rohde Nielsen Dredging has excavated around 1 million m 3of material from the entrance channel to the port, deepening it to 14.5m using the bucket dredger Ajax and the Machiavelli, which was equipped with a Liebherr 994 long reach backhoe.

The hopper dredgers Freja R and Sif R were also seconded to the job to excavate softer material from the seabed, with some of the sand dredged from the channel being used for beach nourishment nearby.

Dredging of the softer material was completed in August last year, with the remainder of the dredging work being completed in April of this year, with final 'cleaning up' work completed in last month.