It is a system that allows the largest sea-going vessels to moor safely at the quay even in extreme weather and high swells: ShoreTension.

This year, the Dutch Royal Boatmen’s Association Eendracht (KRVE), which conceived and developed the system, is celebrating its fifteenth anniversary. It is therefore time to reflect with three men who were at the cradle of ShoreTension: Gerrit van der Burg (director of ShoreTension and member of the KRVE for 43 years), Ton Leenderts (ECT operations manager) and Ben van Scherpenzeel (director of Nautical Developments, Policy & Plans at the Port of Rotterdam Authority).

It is immediately clear that these three gentlemen have known each other for years. Anecdotes fly back and forth, followed by the harmonious, booming laughter of three experienced port men. In the middle of the table in this meeting room of the KRVE on Heijplaat sits a bowl of almond-filled pastries, still warm from the oven.

First, back to the beginning. The fact is that ShoreTension came into being as the result of an incident in which things went badly wrong. On a stormy January day in 2007, a container ship broke loose from the quay at the former ECT Delta Terminal on the Maasvlakte. The vessel went adrift and rammed into a jetty at the Maasvlakte Oil Terminal, causing a massive oil spill and more than a hundred million euros’ worth of damage.

Additional lines not the right solution
That incident paved the way for change, says Ben van Scherpenzeel. ‘We knew that sea-going vessels would only get bigger. And we knew that the forces acting on vessels would increase with the arrival of Maasvlakte II. The further you go towards the North Sea, the more free rein the elements have,’ he says, with a warm pastry in hand.

‘It also showed that you can’t compensate for these enormous forces by simply adding more lines. Not only does that become a tangle of ropes, but there is often insufficient space to tension them properly, meaning they hang there largely for show. That’s when the idea emerged to use additional lines from the shore and tension them from there. That was the seed for ShoreTension.’

To measure is to know
The KRVE recognised this problem as well. Gerrit van der Burg decided to examine closely just how great the forces on the mooring lines actually were. ‘To measure is to know,’ says Van der Burg. ‘It turned out that the real forces on the lines were far greater than those predicted by theoretical models. We had to find a solution for that.’

This was eventually found in a hydraulic system that operates entirely without electricity. How it works? It’s actually quite simple. ShoreTension is a mobile, fully hydraulic system that issues the ropes, or mooring lines, to a vessel from the shore, rather than the other way around. A cylinder in the recognisable bright orange unit on the quay keeps the lines continuously under controlled tension, moving dynamically with forces such as wind, current and wave action.

Instead of the lines having to absorb peak loads, or the vessel jolting or even breaking free from the quay, ShoreTension ensures that the tension on the lines remains constant and the vessel is safely on the ‘handbrake’.

Ton Leenderts: ‘For ECT, this was extremely interesting. In the first place, it was obviously a safety issue for us as a terminal, but it was also about efficiency. If a vessel breaks loose, an entire terminal shuts down. With ShoreTension, we were able to drastically reduce those risks.’

From left to right: Ton Leenderts (ECT), Gerrit van der Burg (ShoreTension) and Ben van Scherpenzeel (Port of Rotterdam Authority).

Revolutionary
The road from idea to fully functioning system was a tough one, Van der Burg acknowledges. It took extensive testing before the system became operational and fully reliable. With a wink, he says: ‘In 2007 I was still blonde, by 2010 I was grey.’ Issuing a line to a vessel was revolutionary. It was completely the opposite of what had long been standard practice in the maritime world. ‘And you should know,’ says Van Scherpenzeel, ‘seafarers are conservative people, and people in ports are conservative seafarers. Change in the maritime world always takes time. You really have to earn trust.’

Leenderts made sure that tests could be carried out with the unit at the ECT site. ‘You have to create space for innovation,’ says Leenderts. ‘That, too, is a matter of trust. We dared to take a leap forward, purely on the basis of mutual trust.’

Van der Burg got the opportunity to demonstrate that ShoreTension worked in 2009. ‘We had a first fully tested unit that was just ready for commercial use when the MSC Nikita was involved in a collision in the North Sea,’ he says. ‘The stern was tilted at 43 degrees and was largely submerged. How do you safely re-dock such a vessel? That was achieved with ShoreTension.’

Commonplace
Today, ShoreTension can rightly be described as commonplace in the maritime world. Approximately 350 ShoreTension units are now in operation worldwide, across 27 countries and 64 ports, from Rotterdam to Australia and South America. ShoreTension continues to develop. A vertical ShoreTension unit is also available, operating on the same principle but taking up less space on the quay.
The next step for ShoreTension is to apply the system to vessels coming alongside at sea. Van der Burg: ‘That means working with two moving parts, which presents a significant technical challenge.’
Source: Port of Rotterdam