VIDEO: Bollard installation at Antwerp-Bruges

One of Europe’s busiest ports has maximised its quay space with seven new 250t bollards at its Noordzee Terminal, a big jump from the four 150t bollard formerly in place.

This minimises the space required between two vessels and addresses the problem of increasingly larger ships overloading the bollards.

When the terminal was commissioned a quarter of a century ago, the average container ship carried around 5,000 TEU. As the size increased, the quay wall was deepened by three metres and to make best use of the length of the quay, ’all kinds of technical interventions’ were carried out over the years.

Antwerp-Bruges is calling the bollards ’the final finishing touches’ to allow today’s 24,000 TEU mammoths to dock with as little lost space as possible.

Engineering

Sailing speed of passing vessels and their water displacement, types of mooring ropes, tide, wind and othr factors had to be taken into account.

Cut-outs had to be made in the quay wall head, which topped the existing anchored diaphragm wall. Steel frames were then placed in the four cut-outs by chemically anchoring and recessing them.

To ensure the quay remains stable, the frames were also anchored into the subsoil by 50 metre-long tensioned anchors.

“Extensive study work by engineering, architecture and consultancy firm Sweco and review of study and execution by independent technical expert SECO Belgium preceded this doubling of the bollards campaign, testing the limits of what was feasible,” said the port authority.

“Together with PSA Antwerp, we determined the locations and preconditions. Hye NV from Burcht carried out the works. An excellent collaboration between the various partners.”

“Bollards are anticipated to have a long life, with many being in quayside use for 40, 50, or even 60 years plus,” said Jeff Main, managing director of the UK firm Bollard Load Testing, writing in the journal Port Technology International. “However, bollards with such a long life-span were not always designed to moor the new generation of mega-ships.

“The forces experienced by bollards are considerable, magnitude may be up to 2000kn (200 tonnes plus) with even larger bollards used as supplementary mooring in storm conditions.”