Every space is interconnected
“A handle on a hatch,” says Marijn Hage, Senior Naval Architect at Nevesbu, considering the design for a submarine, “it has to be in exactly the right place. As a submarine designer, you have to put yourself in the shoes of the users. Suppose a crew member with a fire extinguisher needs to pass through this hatch very quickly. He has his hands full, but thanks to the well-placed handle, he can pass through efficiently and timely extinguish the fire. I really enjoy having to consider these scenarios when designing. The crew must be able to act quickly and correctly. There’s not always room for a second chance on board.”
Albert Jurgens, Commercial Director at Nevesbu, also takes great pleasure in logistically correct submarine design. “Every space is interconnected in a submarine. It must be made up of logical lines. To get to the engine room, you shouldn’t first have to pass through the command centre. There shouldn’t be lines passing through a workspace. Submarine design is about designing cohesion.”
Marijn Hage and Albert Jurgens are the tutors of the Masterclass Submarine Design and have given this course four times at Nevesbu. Last summer, for the first time, the masterclass was available for open registration. Twenty-three colleagues came along. Engineers attended from member companies of the Dutch Underwater Knowledge Centre (DUKC). Such a course is quite extraordinary. Submarines are no longer made in our country. Nevertheless, the Netherlands has put itself on the international submarine map with the Walrus class – for which Nevesbu supplied the design, and later that for the life-extension programme. Albert: “In order to keep those submarines relevant and perhaps build innovative new ones in the future, it’s important as a country to retain and further develop our knowledge, otherwise we will soon be 100% dependent on foreign countries. And sometimes you want to be able to change something about a submarine without anyone knowing.” A Masterclass Submarine Design is not likely to feature on the list of courses in every other country. There are hardly any companies that provide open training. “You often come across them as part of a sales process for new submarines”, says Albert.
‘Dive-boat’ or ‘under-sea-boat’?
For the readers, Albert and Marijn would first like to clear up a misunderstanding about the distinction between a ‘duikboot’ (dive-boat) and ‘onderzeeboot’ (under-sea-boat). In English, the word submarine is a collective word for both. A ’duikboot’ is capable of submerging. It sails above the water and only heads down when danger is imminent or when in attack mode. An ‘onderzeeboot’ has been built to permanently sail underwater and carry out enemy attacks underwater. “Since the Second World War, we only see the latter,” says Albert, “because the arrival of modern electronics has led to easy detection of a ‘duikboot’. A submarine (onderzeeboot) can be invisible for a long time. You could compare a submarine to a space station, but then underwater. It’s completely independent and seeks as little contact with the outside world as possible. This allows missions to be carried out in secret.”
Albert describes a submarine as a high-tech machine. “You will find more technology within every cubic metre in a submarine than in any other vehicle.” A submarine is like a miniature village squeezed into a steel tube. From the design phase to the christening, the construction of a submarine takes just ten years. “We’re talking about hundreds of thousands of components that have to be connected in exactly the right place and with each other in order to flow together into one system.” And all this in a cylinder that can reach depths of hundreds of metres. “The design work is therefore extremely complex”, Marijn says with a smile. “There’s a reason why we need four days to give the students of the masterclass an idea of what this involves.”
A submarine’s purpose is to perform its mission without being seen or noticed. For instance, this may include activities such as keeping an eye on coastal and sailing routes, eavesdropping on connections and positioning special forces on land. The design must be adjusted to satisfy these requirements. Length and noise are very important factors. The larger a submarine, the better the living comfort inside, but the easier it is to detect. Living comfort is, therefore, at odds with safety. Furthermore, a large submarine can suffer deformation at depth or even implode. Albert: “A submarine will ‘shrink’ as it descends to greater depths. This is due to the increasing water pressure. I think you can comprehend how important it is that all the piping is capable of bending.”
Noise increases the risk of detection. A submarine is certainly not silent. When the batteries are charging, the pumps and diesel engines produce a gentle hum. The propeller and the water that flows along the hull also produce noise. Likewise, opening the lids of the torpedo tubes. And yes, when a submarine has been submerged for quite some time, it must occasionally catch a breath of air with what is literally a kind of snorkel. Oxygen is needed to again run the diesel engines and, of course, the crew also appreciates a breath of fresh air. Marijn: “To avoid the situation that a submarine has to suddenly resurface making a lot of noise during a secret mission, it’s preferable that it can stay underwater for as long as possible. This is the reason why the batteries are becoming bigger, in combination with large diesel engines for charging.” And yes, the longer it’s underwater, the worse the air quality becomes. There are so-called ‘scrubbers’ on board that remove carbon dioxide from the air to keep it as pure as possible. In an emergency, so-called oxygen candles could also be utilised. These are canisters that produce oxygen based on a chemical reaction.
Fifty sweaty youngsters
Living aboard is not exactly romantic. Albert: “Imagine the smell of fifty sweaty youngsters in a high school changing room.” And having to put up with that for several months. You sleep with five other people in a bunk, a kind of cupboard built into the wall. The bed planks are stacked so closely together that you can hardly raise your knees. There is no such thing as privacy and annoyances can quickly escalate. For this reason, team building is extremely important because, during a mission, everybody must work together like a well-oiled machine. Every single person forms a part of the whole. Albert: “Every crew member must be extremely stable and social as well as able to live in a small cramped environment and cope with stressful situations.” The chef plays an essential role in this. “Good food is one of the most important things when it comes to keeping the crew happy.”
Modular construction set
The four-day masterclass consists of elements such as energy, auxiliary & combat systems and hydrostatics & hydrodynamics. Of course, the masterclass students also get the chance to design a submarine of their own with the help of the ‘Volume Estimation Tool’ (VET), with which Marijn graduated from Nevesbu a few years ago as a naval architect. “When designing a submarine, it all revolves around achieving neutral buoyancy. An accurate estimation of the weight and volume of your design is also essential”, says Marijn. The VET method is structured like a kind of construction set. Each module represents an element of a submarine: sleeping, living, fuel, working, energy generation, etcetera. “A more mixed crew, means that extra consideration must be given to privacy. The destination also determines the design, as different waters have different densities. For instance, the seawater around the equator has a different density to that in a Norwegian fjord. We are, therefore, increasingly adding to the set of requirements in order to gain insight into every piece of the puzzle. Either way, the submarine’s centre of gravity must always be secured to prevent the submarine from pitching vertically. It needs to hover in the water.”
Marijn points towards the top of a submarine, to an opening of 60 centimetres wide. “Everything has to go through that”, he says. “This means that it must be possible to disassemble every component. A new diesel engine enters the submarine in hundreds of pieces. This is what makes designing a submarine so fascinating. Everything you think of on the drawing board must be able to fit through that 60-centimetre opening.”