No time off for crane

At 35m long the vessel is one of the largest Damen Shoalbusters so far; this gives a spacious working area but Wijngaarden needed a capable crane to move cargo and equipment around the deck. What the operator decided on was an HS Marine long reach knuckleboom with three telescopic extensions; this means it could lift 12 tons at 15m in order to reach the full width of the vessel while still keeping a tight, neat footprint.

However, Wijngaarden had a few specific challenges to overcome explains Giovanni Patini of HS Marine. “This vessel’s contracts aren’t just for a couple of weeks, they can last three years so they expect to have a crane working perfectly with no problem for the whole contract – they don’t want to have to stop operations because of some crane issue.”

Therefore it’s been designed to be straightforward, robust and very easy to maintain, even down to the small things like marked tags showing parts numbers on each of the lines and cables: “We keep everything as clear and simple as possible,” he said and pointed out that all the looser items, like the hoses, are sheathed against abrasion and tucked neatly out of the way.

However, HS Marine also understand the pressures on the crew: Mr Patini explained: “We understand very well that even if you write in the manual that certain points need to be greased once a month, if it’s not easy to do people simply won’t do it. So we have a manual, centralised grease system with all the lubrication entry points at the same place. It does mean that it’s got a better chance of getting done.”

Further, crane is fully tested before delivery, and not just within the stated parameters. “The crane is tested at 100% of its stated capacity, but we also know that when you’re on the sea there’s always the potential for some dynamic factor from the waves pushing the load over this maximum,” he said. “So we step up and test both crane and winch at 125%.”

There’s also a ‘traffic light’ warning system for the operators: “The lights on the remote control and the screen will remain green until you reach 90% of the crane’s maximum load, but over this the light becomes yellow to tell you it’s close to the limit – although at that point the system still lets you carry on. But go over the 100% and the light becomes red - and at that point you can only perform a move which reduces the lifting moment of the crane. So, you can’t hoist or swivel – but you can telescope in or lower the load.”

He added: “The system will also record how long the overload was, and it will also tell you how far you were over capacity.”

Protection against corrosion is one of the most important elements of a long maintenance schedule said Mr Patini. “If you check more standard technical specifications from the yard, it will say something like ‘300 micron thickness, three layers’.”

“However, on our cranes we carry out the painting in house just because we want to have control over it. We provide the same 300 micron thickness but made up of seven layers which results in much, much better adhesion - it’s the only way you can be sure of gaining the maximum effect from the coating.”

By Stevie Knight