Facts and Figures

Client
PetroPort AB

Period
2012-2013

Contractor
Boskalis Sweden AB and Terramare Oy

New jetty project, Stenugnsund, Sweden | Client: PetroPort AB

The jetty contract at the Stenungsund chemicals port consisted of an extensive complex that included, in addition to a chemicals quay implemented as a projecting jetty, the construction of pipe bridge support structures, a harbour field, a control room building and roads. As a separate contract, dredging of the harbour area, which preceded the construction of the jetty, was also carried out at the site.

Extensive complex built in two-year project

A new jetty was constructed for the increased capacity needs of Stenungsund chemicals port, located in western Sweden. The client was PetroPort Ab, which also manages the completed jetty. Construction was preceded by dredging of the harbour area, which was completed as a separate contract. The contract, which consisted of the dredging of soft clay, was implemented efficiently and on schedule by the bucket dredger Grävlingen.

Diverse work stages of the Stenungsund jetty project

The early stage of the Stenungsund jetty project involved the clearing of the shore area, the preparation of conduits for the road leading to the jetty, for the fire and rescue access road, and for water pipes and electricity cables as well as foundation work in the jetty area’s harbour field (18 x 90 m/1,600 m2). On the shore area, some underwater drilling and blasting was also performed, during which the presence of the chemical industry required special care and attention. Piling work for the jetty was launched in March 2011, as was the establishment of a control room building immediately adjacent to the site. The jetty piling work was completed by the end of May. For the efficient progress of the work, it was significant that in the neighbouring area there was a harbour field available in which a tubular steel pile plant could be established. Steel, ice-protection and concrete element work was also carried in the same area. Completed elements could be conveniently transported to the work site on a work pontoon.

Strongly anchored piling

Installation of ice protectors

The 245 metre-long chemicals quay, implemented as a projecting jetty, is in terms of deck structure mostly steel and relatively light, but the lateral stress of the mass of cargo ships required strong piling. A total of 98 tubular steel piles, most of which are anchored into the bedrock, were driven under the jetty. The 75 mm-thick steel anchor bars were injected into the bedrock to a depth of six metres. The shore at the site deepens relatively sharply, so the piles at the outer end of the jetty are up to 64 metres long. Piling was performed using the grab bucket dredger Meri-Pekka, equipped with a piling unit.


Approximately 3,500 metres of tubular steel piles were driven at the site. Ice protectors were installed in the piles, and finally they were reinforced and concreted. Concreting was carried out using concrete trucks, which were transported to the site on the work barge Lossi and along a temporary pontoon jetty.

As the area has busy traffic consisting of chemical-containing cargo vessels, possible risk situations were prepared for by formulating a rescue programme. This programme included, for example, a compartment intended for rescue by ship as well as respirators. In addition, the port communicated the arrival of cargo ships carrying ammonia.

The Stenungsund jetty project employed a total of 15 Terramare personnel as well as staff of Hansson & Söner Ab, an onshore subcontractor. Subcontractor Berg & Grundsäkring AB was responsible for the anchor drilling of the tubular steel piles.

STRUCTURAL ENGINEERING KEY FIGURES: JETTY

Concrete structures:

Concrete

3,000 m3

Reinforcement

210 tonnes

Steel structures

90 tonnes

Tubular steel piling works:

Tubular steel piles

3,500 m (98 units, 6-64m)

Reinforcement

160 tonnes

Concrete

1,060 m3

Ice protectors

98 units