Meticulously planned masterpiece
Reconstruction of the “Peter Pan” is one of the most complicated shipbuilding projects
With the reconstruction of the Baltic Sea ferry “Peter Pan”, the team of German Dry Docks (GDD) is currently working on a complicated shipbuilding project. “It’s a good thing that we can rely on our team,” says David Porath, who heads the project together with Jascha Ewert and Conrad Schmidt.
Ship extensions are not uncommon. But what is currently happening in Dock V of German Dry Docks is in a class of its own. There, the originally 190-meter-long “Peter Pan” of the Lübeck TT-Line is currently being “stretched” to almost 220 meters using a 30-meter-long centrepiece. In contrast to other projects of this type, however, the hull of the Baltic ferry is not only cut vertically in order to then insert the new section: “As we wanted to leave the previous passenger area untouched, we had to cut the trunk vertically in a Z-shape,” explains Project Manager David Porath. In addition, also the horizontal cutting line follows a complicated pattern.
A year-long preparation of every detail
To get straight to the point: The complex project has worked out. The German Dry Docks crew is now working hard to link the new middle section with the fore and aft ship: “When we’re done, no one will be able to tell that we’ve rebuilt the ‘Peter Pan’,” Porath is convinced. Such a perfect piece of work requires appropriate preparation. For about a year, the German Dry Docks project engineers meticulously pre-planned every technical detail and process of the project. “It was not only about simply ‘extending’ the ship,” explains the project manager: “Among other things, we will install an additional vehicle deck and a new access ramp and disconnect and move another ramp.”
One of the major challenges in cutting apart the two hull parts was to keep the passenger area in the front half of the ship unchanged. The 35-meter-long, 29.5-meter-wide and four-deck-high area weighs 850 tons and protruded like a balcony far beyond the end of the front hull half. “We secured the overhang with a total of six supports,” explains Porath. This auxiliary construction was quite an engineering performance in itself: a system of hydraulic rams and shift tracks had to be specially installed in order to gradually install the supports and later be able to remove them step by step when the centre section is being inserted. It took five days to carry out the cut. Seven days were required for the construction of the auxiliary construction.
Show of strength with five millimetres tolerance
The show of strength which the German Dry Docks team performs is reflected in a few figures: The foredeck, which remained standing in the dock after the cut, weighs 8500 tons. The new middle section, which was built at Pella Sietas in Hamburg, has a mass of 1500 tons. The stern, which was pulled out of the dock and moved back into it, weighs 6500 tons. In order to keep this section stable for the floating in and out of the dock as well as for for the time spent at the quay, a pontoon as well as a special buoyancy construction had to be mounted at the stern. In a kind of steel cage eight 32-meter-long and 7 four-meter-long airbags were installed under the hull part. Despite the weights and sizes of the components, the extension of the “Peter Pan” is precision work: “For the assembly, we have to put the two old sections and the new middle piece together to an accuracy of five millimeters,” emphasizes the project manager.
Logistically challenging project
The rebuilding of the “Peter Pan” is considered a complicated shipbuilding project, not only because of the challenges for engineers and shipyard workers. “Logistically, the whole thing is extremely demanding as well,” says David Porath. Each component is needed at a precise time. There are only short time windows to bring large objects, such as the new access ramp, on board. At the construction site, space is naturally limited anyway. Storage areas are necessary but, at the same time, must not obstruct the work. “We have a tightly timed schedule as the ship is supposed to be back in operation in due time,” Porath explains the time pressure. Numerous trades and companies are also involved in the project – up to 600 workers and engineers have to be managed so that the work can be carried out quickly and efficiently.
“Peter Pan” will be even more environmentally friendly
But the effort is worth it. With the extension, the TT-Line not only takes into account the steadily growing traffic on the Travemünde-Trelleborg route, but the conversion also benefits the environment. “Through the extension, the company, which attaches great importance to an environmentally friendly ship operation, will further improve the emissions balance of its already environmentally friendly fleet “, explains the managing director of the shipping company, Hanns Heinrich Conzen. Even before the conversion, the “Peter Pan” was considered an environmentally friendly ship – she is equipped with a particularly efficient diesel-electric drive. During conversion, she will now also get a new bulbous bow, which further reduces the flow resistance and thus the fuel consumption: “Overall, the emissions per freight unit transported will be reduced by 25 percent,” stresses Conzen.
In Bremerhaven, the whole project is being followed closely by the public. This is also due to the history: Both the “Peter Pan” and her sister ship “Nils Holgersson” were built in the city and are considered an example of the great skills of the city’s shipbuilders. “With this project, we can now seamlessly continue that,” says David Porath.