LNG integration into existing system exactly on schedule thanks to good planning
The devil is in the details. For example in the fact that conventional shipbuilding steel becomes brittle at extremely low temperatures. Of course you learn that in your studies. But when installing a tank for liquefied natural gas (LNG) on a ship, “one must also remember that detail,” says Thorsten Pohle. At the moment the 52-year-old ship engineer has plenty of opportunity to put his extensive expertise to the test: As Project Manager at German Dry Docks (GDD), Pohle is responsible for the world’s first conversion of a container carrier to the environmentally friendly LNG operation. “The appeal of the WES AMELIE project lies in the various technical challenges,” says Pohle. This also means that no detail is overlooked..
Shipping company promotes environmental protection at sea
As one of the larger German managers of ships, the Wessels shipping company from Haren / Ems has taken up the cause of environmental protection at sea. As a pilot project, the 151-meter container vessel WES AMELIE aims to demonstrate that low-emission dual-fuel operation with LNG is technically and economically feasible. The use of gas engines is not really new in the shipping industry. LNG tankers, for example, use the boil-off gas from the cargo as fuel. However, such ships have been designed and built around the gas drive system: “In the case of conversions, the challenge is to integrate the new complex LNG system into the existing and also complex structure of the ship,” explains Pohle: “You have to deal with what is available and there is only little scope for new installations.”
For around two and a half years, Wessels has planned the conversion of the WES AMELIE together with the project partners MAN Diesel & Turbo, the engineering firm SMB Naval Architects & Co, the LNG specialist TGE Marine Gas Engineering, the classification society Bureau Veritas and the conversion shipyard German Dry Docks. Now the implementation of this project is being realized at GDD. Bremerhaven’s conversion specialists received the order, among other reasons, because GDD has a correspondingly good infrastructure and had convinced with a view to planning and implementation in the discussions which had taken place beforehand. For the realization phase, the project partners moved into two open-plan offices next to the dockyard – “this simplifies communication,” says Pohle, “In such a complex project you must be able to exchange ideas quickly.”
In principle, the project is divided into four major areas: the construction and installation of the pressure tank, holding 500,000 litres of gas, the gas control and piping system between the tank and the engine, the engine conversion from heavy oil to dual fuel operation, and finally the entire sensor system, electronics and electrical engineering that control the machine. “A lot of the tasks are carried out in parallel or in a tightly timed schedule,” explains Pohle, “as we want to keep the shipyard period as short as possible.” After all, the WES AMELIE, commissioned in 2012, is intended to return to the feeder service on the Baltic Sea as soon as possible.
As early as last November, the GDD team had started the first preparatory work. The required docking time for the five-year class of the ship was used for the necessary exchange of the coupling and flywheel of the main engine as well as preparatory reconstruction work in the planned tank installation area. In the second project phase certain elements such as the tank foundations and the tank compartment hood were prefabricated. Thus, in the third phase of the project, which began with the arrival of the WES AMELIE in Bremerhaven, the actual conversion could be started immediately. „We started the steelwork on the very first day,” Pohle reports. Among other things, e.g. the installation of the foundations, the placement of the control system is important “For this, we used empty spaces in the immediate vicinity of the tank,” explains Pohle.
Accurate overview at an early stage
While placing the tank and subsequently the hood is a widely visible sign of the conversion, most of the work is hidden below deck. This includes, in particular, the installation of the entire pipeline system between the tank and the engine, as well as the installation of the control electronics together with all the necessary cables. However, for the preparation of this work it wasn’t sufficient to look at the old construction plans: “You have to get an accurate overview of the actual situation on site. Some things may have been done differently during the construction than originally intended in the construction plans,” Pohle says.
On several previous visits to the WES AMELIE, the project manager and his team had therefore obtained an accurate picture of the actual conditions on board and marked the areas to be worked on. This saves time now: “We were able to start the work immediately after the arrival of the ship, as everyone already knew what to do,” Pohle says.
Among the participants were the deputy project manager Carl Jascha Ewert and the engineer Lasse Tebelmann, who, together with Pohle, are supervising the conversion. “In such a large-scale project, good cooperation is essential,” emphasizes Pohle. If, at a point in the complex project, there were delays, this would have an immediate effect on a lot of work in other places. “You can work with any number of people on this project, but you have to plan very precisely who does what and when,” Pohle stresses the importance of good logistics and planning for such a project. Apparently the preparation was good: “So far, everything has gone smoothly – we are exactly on schedule,” says Pohle.
“We are very pleased with the good cooperation with Mr. Pohle and his team as well as the progress of the conversion work at GDD so far,” says Christian Hoepfner from the Wessels shipping company.