Salvage grab
Smit Salvage needed an oversized grab to deal with a wreck. Idea came up with a concept, completed the design and built and delivered the machine, all in the space of six months.
The brief
In 2004 an oil tanker passing through the Malacca Strait collided with a vehicle transporter carrying four thousand cars, making a hole in the hull. The ship and its load of Hyundai, Kia and Japanese cars sank to the sea bed, where it remained standing on end off the Singapore coast. Smit Salvage landed the contract to recover the vessel, measuring nearly two hundred metres.
Smit asked Idea to come up with a design for a new grab, based on an existing 11 metre wide model. The redesign would need to deliver increased gripping capacity and allow work to be carried out at a greater depth.
Concept
With this challenge in mind, Boezeman, Rezette and a group of Idea engineers settled down in a conference room with a flipchart. In the same room, engineer Hans Rinner recalled how the giant grab was created. Photos of the machine, suspended from a giant floating crane during initial testing, are pinned up around the room. Four fitters are at work on the grab as it hangs above the water.
In the brainstorm sessions nobody is allowed to shoot down ideas. "You can't have people writing off an idea as impossible," says Rinner, "otherwise you lose that crucial 'out of the box' thinking."
This is how the initial concepts come into being: someone offers a possible solution and the rest think the idea through. "Sometimes there would be three of us drawing at the same time."
Idea went to the client with three possible solutions, and asked the client to think about how they would work with these in practice. The suggestion involving a rack and pinion mechanism was rejected as being too vulnerable to damage. The option selected involved three hydraulic cylinders at the centre of the grab.
Engineering
Idea then set about turning this idea into a working machine. You wouldn't think it possible when looking at them, but FEM calculations showed that the machine's massive plates would distort under the immense forces involved. The plates were therefore reinforced. During the engineering process, Rinner realised that the hydraulic power pack powering the cylinders would be better located on the grab rather than the floating frame. The large and vulnerable hydraulic line leading from the ship to the sea bed could then be replaced with an electrical cable. "Who do you think you are, Jules Verne?" asked the power pack supplier, "We've never done it this way before." The photos on the wall show that the power pack was eventually mounted on the grab. A large blue cylinder can be seen below the fitters working on the machine.
Fabrication
"I can be stubborn at times," says Rinner. "I have my responsibilities as Project Leader, so if I think something is essential, I stick to my guns." For example, Rinner wanted to have the grab fabricated by a machine manufacturer in Genemuiden, while the client's preference was for a location in Rotterdam. "With hindsight they accepted I was right. The factory in Genemuiden was one of very few with the capacity to fabricate this grab. I thought putting it together outdoors in the depth of winter was too risky. The works at Genemuiden also had a milling machine standing eleven metres high, and a crane in the peak of the roof with a capacity of 250 tonnes"
Innovation
The underwater grab is a good example of the way Idea work, taking innovative solutions from the initial concept right through to delivery and commissioning. "We have the confidence to take full responsibility for the calculation work," says Rinner. "We also know that what we design can be made. We know where to find the people to do that for us."
"We enjoy the challenge of doing something new, we like to see things through to a successful outcome, within the deadline. We can generally overcome any set-backs along the way." Six months after the order was placed, the grab was on a barge on its way from Genemuiden to Rotterdam.