This article is a translation of the original Dutch article 'Nieuw, anders en beter', published by the Belgian newspaper 'De Tijd' in 'De Wereldspelers', an initiative of Tijd Connect, supported by Jan De Nul Group. Click to read the Dutch article online.
Employees of dredging and construction company Jan De Nul Group are encouraged to share their wildest ideas. Often, they get the chance to realise these ideas themselves. There is no strict company hierarchy that smothers creativity. On the contrary, with its flat organisation the company aims to encourage innovation and critical thinking. It’s precisely this environment that allowed young engineer Dries Lammens to work out a solution to save the vegetation of a beautiful nature reserve, while still allowing critical machinery, weighing several tonnes, access so that Jan De Nul could succeed in winning an offshore wind cable laying contract on the east coast of England. In another example, it is thanks to the critical eye of transport supervisor Maarten Tronckoe, that the transport and lifting of very heavy steel pipes are now executed in a much more safe and efficient way. Praise was their reward, not only from their employer, but the wider industry also recognises their drive and creativity.
“Everything at Jan De Nul Group is big, including the equipment with which we work.”
Maarten Tronckoe has seen the weirdest things when it comes to transporting steel dredging pipes. ‘This can and must be done better and – above all – safer,’ concluded the transport expert of Jan De Nul Group.
With its internal ‘Imagine Think Act’ (ITA) programme, Jan De Nul Group is continuously searching for better and safer working methods. A fine example of this philosophy was recently rewarded with the IADC Safety Award. With this award, the international association of dredging companies honoured the work of Maarten Tronckoe’s team. The transport supervisor of this global company combined existing techniques to lift, load and transport dredging pipes of different sizes and diameters in a much more safe way, that is now recognised as industry best practice.
Maarten explains that these pipes are essential for dredging works: “A dredging vessel fills itself with dredge spoil. This spoil must then be transported and re-used for reclaiming plots of land. For this process, we need a great variety of pipes, which are fixed onto the vessel. Just to highlight their importance: in a recent land reclamation project in Nigeria, we installed about 30 kilometres of pipes to move dredging sediments, which is about the distance between Antwerp and Brussels. That is truly impressive. For such projects, we have to mobilize pipes from different storage sites and dredging projects worldwide to the site.”
It goes without saying that the transport of heavy pipes that are 12 metre long and have a diameter of 1 m must be done safely. “Everything at Jan De Nul Group is big. Not only the projects but also the equipment with which we work. A truck transporting a couple of pipes, for instance, already has a 20-tonnes load. Of course, you want these pipes to be properly secured.” Obvious but not simple. Maarten explains: “A steel pipe is round and thus tends to roll. It is difficult to secure it. Traditionally, a couple of beams or wedges were nailed against it, a bit like carpenters do. But this is not only labour-intensive, it is also dangerous.” Transport expert Maarten believed that this could and had to be done better. He started looking for a fixing system and, after an intensive search, opted for a kind of rubber frames of manufacturer DHATEC to secure pipes on a loading platform to prevent them from rolling. The frames are only intended for preventing sideward movements. That is why Maarten and his team created a programme that automatically calculates how many lashing straps the truck driver or warehouse worker should use to prevent forward movements.
During the loading and unloading process, the pipes are hooked on using hooks at both ends, after which they can be lifted with straps. Here as well, Maarten increased safety: “We developed a new hook that fits on all our pipes. There was one disadvantage though: the hook was heavier than the previous types. That is why we came up with an additional solution to improve the ergonomics for our loading and unloading staff. To begin with, we no longer use heavy steel ropes for lifting the pipes but flexible carrying straps. We then insert a length-adjustable crossbar in between the carrying straps so that the hooks automatically end up closer to the outer end of the dredging pipe with the hook safely and securly in place. In this way, our loaders no longer need to pull the heavy hooks over a long distance to be able to hook the pipe.
Click here to watch the video showing this improved working method.
“We first conceived and built these machines in under nine months."
Cable laying machines that weigh tonnes but don’t disturb the ground onto which they drive any more than the impact of a walking human being. Such capability was needed for a job in an environmentally sensitive area. And thus the team of Dries Lammens, engineer with Jan De Nul Group, began at the drawing table.
In October 2017, Dries Lammens received the Young Engineer Award from marine and offshore media group Navingo. This award recognises the work that the marine design engineer of Jan De Nul did in designing and building an environmentally sensitive solution for the Race Bank export cable, an offshore wind farm owned by Danish energy giant Ørsted ( formerly DONG Energy) off the east coast of England. During the Race Bank project, Jan De Nul buried two export power cables, from the offshore wind farm to the onshore substation located on the mainland, while crossing an 8 kilometres environmentally sensitive nature reserve.
A technical masterpiece. No one was allowed to walk over the salt marshes and low-growing grasses, let alone drive over it with conventional machinery. Therefore, Dries helped to conceive two new machines that could solve this challenge. The engineer explains: “The Sunfish and the Moonfish have been specifically designed to cause as little disturbance as possible to the ground, even though both machines are very heavy. Thanks to the wide caterpillar tracks of, each, 15 metres long and 2.4 metres wide, the ground pressure amounts to only 15 Kilopascal. By way of comparison: the impact of a human footprint on the soil is almost double. Result of this “lightweight solution”? The machines leave shallower marks in the subsoil than traditional caterpillar vehicles such as draglines.”
Meanwhile, the cables have been properly buried at a depth between 1.5 and 5 metre, depending on the location. The first 2 kilometres of the tidal area, covered with vegetation, was a job for the Sunfish. “This machine, which can go partly below water, operates according to the principles of a V-shaped plough. It cuts through the vegetation layer and lifts the soil to install the cable beneath it, after which everything is neatly covered again.”
This solution could not have been delivered by current equipment available on the open market. Again Lammens: “Existing machines usually work with a mechanical chain cutter, which would cause too much damage to the subsoil.” He admits that the innovation for the Sunfish is not completely new though: “Farmers are already using such ploughs to put drainage pipes below the ground. However, the combination of the low ground pressure and the fact that the machine can go partly below water, does make it unique.”
The remaining 6 kilometres across the tidal area were a job for the Moonfish, which does operate fully under water. “The Moonfish is equipped with a kind of mechanical chainsaw, which makes a trench in the soil in which the cables are installed. We couldn’t use this technique in the salt marsh area because it would disturb the soil too much. The unique selling point of the Moonfish is its cutting depth combined with the low ground pressure. This cutting depth reaches 6 metre, which is a lot more than is currently available on the market. The Moonfish is also a ‘tidal machine’, as it can operate both on land and in water. That’s something most trenchers are not capable of.”
Dries also visited the site to follow up the works. How was it for him to watch these machines live at work? Wasn’t he scared that something might go wrong? Dries smiles and says: “I do admit, it came with a healthy dose of stress. In the end, we conceived and built these machines in under nine months. We even had to take both machines to the field of a farmer nearby our offices in Belgium, where the machines were also built, to test them.”
Read more about these machines on annualreport.jandenul.com.