German shipyard tkMS is going to propose a larger submarine than the current Walrus class in the Netherlands
In an interview with MarineShips.nl, thyssenkrupp Marine Systems (tkMS) provided more information about the plans they have for their proposal for the Netherlands. The German yard will develop over a quote in the coming months, but the contours of their plans are clearly developing.
Screenshot of the Type 212CD E. (Image: tkMS/still YouTube)
tkMS is one of three yards in the race to build new Dutch submarines. We are waiting for the request for quotation from the Defense Materiel Organization (DMO) to send to Naval Group, Saab and tkMS in November.
In the meantime, plans are being made based on the information they have received so far, although not all requirements and assessment criteria are known yet.
After a visit to the shipyard in Kiel in June, more details about tkMS’ plans for the Netherlands appeared on this site. With program manager of the HDW-class 212CD E and former submarine operator Holger Isbrecht, MarineShips spoke again about the design of the 212CD E. This design is derived from the 212CD that is being built for Norway and Germany. The CD E has been adapted to the requirements, insofar as they are known, of the Netherlands.
Basically, however, the boat that tkMS has in mind for the Netherlands is the same as that for Germany and Norway, says Isbrecht. But it is based on the same core components: the same diesels, electric motor, etc. That core has already been developed, other things such as unit and fuel tanks around it have been made bigger.”
The 212CD E with the Walrus. (Image: tkMS)
Longer and bigger
For the first time, tkMS gives some more information about the length of the boat. “The 212CD gets a little bigger than the Walrus class,” Isbrecht says. “The 212CD E gets even bigger.” And that is not without reason. With a larger boat, wanting to add business to the export requirements may be possible further from home.
An illustration of the German yard shows that the design for the Netherlands will be longer than 80 meters. the CD E is significantly longer than the current Dutch Walrus class boats, which are over 67 meters.
The lengthening of a submarine can be viewed if it becomes proportionally too thin. The boat can be more difficult to maneuver and it takes more energy to reach the speeds. The main advantage of the 212CD is that the diameter of 10 meters is already large. Isbrecht: “The length ratio is still good. Our way of adapting the design is to lengthen the hull. The moment we increase the diameter, we have to adjust the interior of the boat, including the cabling. “
Although the diameter of the pressure skin is slightly smaller than that of the Walrus at 7.2 to 7.8, the 212CD E will still have a considerable displacement of more than 3,400 tons, based on the information in the above visual.
New technologies
The Walrus is over 2800 tons, but does not have an outside air independent propulsion (AIP) that takes up quite a bit of space. The 212CD E does have it.
AIP systems are based on fuel cells. tk (or better: HDW) also built these AIP systems in the past, but the fuel cells and systems came from Siemens. This improved version is now all from tkMS. “We’ve improved the system,” Isbrecht says. “And it’s in our hands now. That’s important because it’s a core submarine technology that we want to have under our own control, in view of future plans for submarines to come.”
The 212CD E is also suitable for lithium-ion batteries instead of the old lead-acid batteries. It is not yet certain whether these new batteries will be used in the new submarines. It is often said that lithium-ion batteries have a big impact on design because they are lighter. The lead acid batteries are the boat to provide extra weight and stability.
However, according to tkMS, it is still possible to make a choice between the two versions at a fairly late stage, without having to do a lot of redesigning. “We have chosen to follow two routes,” says Isbrecht. There is a misconception that lithium-ion batteries are much lighter than lead-acid batteries. That is true for the batteries themselves, but if you compare the whole package, you see that it is related. We have added extra heavy-duty materials in the conversion of the lithium-ion batteries.”
“Of course you need different systems if you choose lithium-ion. But that can be done. We have the experience and our goal is to make the safest system for submarines. With lithium-ion you have to look closely at safety, because there is always a chance for a brand. And these are things we focus on in order to achieve the safest possible system.”
Click to enlarge. Accommodation on board the 212CD E. Here you can mainly see the sleeping quarters. (Image: tkMS)
a seating area. (Image: tkMS)
No VLS
With a vertical boat the chances of a launcher seem to increase. But that is not part of the design. However, the 212CD E cruise missiles (maritime strike mentioned in the Defense Memorandum), says Isbrecht. “A vertical launcher has a big impact on design and costs, so it’s not in the design. The maritime strike option has been offering us for some time, but it has now been given more priority because it was mentioned in the Defense Memorandum. technical requirements for the launch of such a weapon are designed with the aircraft of an anti-ship missile.”
The weapons, whether torpedo cruise missiles, could also be American-made, Isbrecht says. The Mk48 torpedo that the Submarine Service is sailing with is an American torpedo and Tomahawk could possibly be added to it. It’s a matter of working with interfaces. We’ve integrated US systems before. It’s not about the design, it’s about how the classified data goes between the torpedo and the other. That’s where the Americans are especially at something.”
tkMS does not say for which countries and which weapons they have done the integration.
According to Isbrecht, the torpedo tubes are no problem for these weapons: “Within tkMS we have our own design and construction tubes that can be used for arbitrary weapons.”
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Building in Germany
At the start of the tender there was no mention of construction in Den Helder, but the navy and DMO did not want their own naval yard -DMI- to become a party in the tender. Are the boats built in Kiel? “In Germany”, replies Isbrecht. Because not only are extra buildings being built in Kiel for the construction of submarines, tkMS has also bought a new yard. “You know that we recently took over a yard in Wismar. That gives us even more flexibility and capacity. We have the freedom to decide whether we can build in Kiel or Wismar. Parts may be built in the Netherlands.”
The maintenance of the boats is done in the Netherlands anyway. That is a requirement and a logical decision for tkMS. “That is very normal. The Portuguese navy, which has two submarines, also does not sail the boats to Kiel, but does the maintenance itself.