PART 1: TUGS
When a new ship is unveiled, it is only logical that a lot of attention is directed at its more technical aspects. These are different for every type of vessel that Damen builds. To put it simply, patrol vessels need to be fast, Shoalbusters need to combine shallow draught with bollard pull, and dredgers need to have reliable power. The subject of ship design goes so much deeper, however. In fact, the human element – namely the safety and well-being of a vessel’s crew – is a subject that Damen never underestimates. André de Bie, design & proposal engineer Tugs, uses Damen’s range of New Generation Tugs to illustrate this point.
“Of course we have targets for bollard pull and performance, but the safety and welfare of the crew really is the basis of a good design,” begins André. “From the shape of the hull and the layout of the deck, to the wheelhouse design and the functionality and organisation of the engine room. Even the colour of the interior. All these aspects are integrated into the total design.”
Taking the hull as the starting point, the first thing you notice is its round-bilged form. “This is the most efficient shape; an optimised hull can deliver the same amount of performance with less power. This leads to a reduction in vibrations, noise, fuel consumption and emissions and gives the captain a very predictable vessel.” For a tug captain, concentrating hard on the task of assisting an incoming container ship, for example, this predictability means one thing: safer operations.
Moving up to the superstructure, the wheelhouse can be best described as the nerve centre of the tug. Therefore, it is paramount to ensure that it is kept out of harm’s way. This is achieved by having a high degree of tumblehome. This is the narrowing of the vessel as it rises above the waterline. For a tug, the larger the tumblehome, the closer it can get to the vessel that it is assisting without the risk of damage. The lines of sight from the wheelhouse are also very important; the captain should have excellent visibility of the deck and also the surroundings.
"We have called this the Full Vision Bridge, as a captain must be able to see all the key points during manoeuvres."
Reducing noise and vibration
Damen has also paid special attention to the glass used in the wheelhouse. “One of the biggest dangers a tug faces is the towline snapping – this could easily break a window. We have developed the Damen Safety Glass to prevent this.” The glass to which André is referring is a shatterproof glass that can withstand multiple impact blows before actually penetrating. “This makes the wheelhouse a much safer working environment,” he adds.
Because the Damen Safety Glass has a twin-layered composition, it means that it is not only safe, but also quiet. “Noise levels are extremely important for both safety and welfare. When sound levels are low, then communication between the crew and over the radio is a lot easier and there is less risk of misunderstandings. This is one of the basics of safety. And in terms of crew welfare, noise levels are also closely related to fatigue.” Other design elements that tackle the double challenges of noise and vibration include flexibly-mounted main engines, large exhaust silencers, insulated floors and cabin-to-cabin insulation. The RSD 2513 even takes this a step further by having a flexibly-mounted superstructure to create a low-vibration working and resting environment.
Safety in control
Looking closer at the layout, and remembering a tug’s raison d’etre, the effective positioning of deck equipment is definitely a priority. Again, the RSD 2513 serves as a prime example, André notes. “This is a safe working environment that is free of obstacles and with a smooth layout. It has a closed bulwark and rounded corners. There are no tripping hazards and it is easy to clean and easy to maintain.” On the subject of layout of controls and systems, optimizing safety and ease-of-use has been at the forefront the design process. For example, there are four computers on board; one in the engine room, one on the deck level and two in the wheelhouse. “This redundancy means that there is no need for the crew to go below deck during an operation – they can read all the data and operate all the required equipment from the deck level. This is a very important safety issue that the crew do not have to go below deck.”
On the bridge, the results of this close attention to layout design are also evident. Allowing the captain to focus on the task at hand – controlling the propulsion – radio communication is operated by a switch on the thruster controls and winches can be controlled by foot pedals. The most frequently used and essential actions have designated buttons, and secondary functions are found in automation screens. Once again, this is a decision that has significant ramifications regarding safety – making controls more straightforward leads to less mistakes.
“The key point is that all these aspects have been integrated into one vessel in one integrated design process. This is, of course, linked to the strong point that we are the designer, the engineer and the ship builder in one company,” André concludes.
PART 2: FAST CREW SUPPLIER 7011
While the first part of this article has highlighted the importance of ensuring high standards of safety and wellbeing of a ship’s crew, it must also be stated that there is another category of people that come into contact with a vessel. These are passengers, and Damen has numerous vessels in its portfolio that take on the job of transporting passengers from A to B.
These includes ferries and water buses for the public transport sector, as well as Fast Crew Suppliers from twelve to 50 metres that transport technical crews to their offshore workplace. Here, director business development & market intelligence David Stibbe discusses how the welfare of these technical crews has impacted the design and layout of the Fast Crew Supplier (FCS) 7011.
Damen’s range of Fast Crew Suppliers has recently been expanded to include the FCS 7011, a vessel designed carry up to 150 offshore personnel at speeds of up to 40 knots. “In making the basic design requirements for the FCS 7011, safety and speed were number one, but comfort was closely associated,” says David. “This was because of motion sickness. We have to make sure that technical crews feel physically well when they are on board.”
The FCS 7011 has been developed in response to a requirement from offshore oil & gas companies. They need a vessel to transport technical crews to offshore installations such as FPSOs and semi-submersible production platforms. These platforms are generally beyond the boundaries of the continental shelves, and therefore journeys of up to 150 nautical miles, taking five hours are not unheard of.
“Comfort is a key topic for the offshore majors because they have to compete with each other to attract skilled personnel. As such, we have invested in a huge amount of research into this vessel in order to meet their needs. This has also included cooperation with TNO [the Netherlands Organisation for applied scientific research].”
A bullet point list of the results of this research would contain several items relating to the physical characteristics of the vessel. “Comfortable, fully-reclining seats and mid-ships accommodation, combined with an optimised hull form to eliminate slamming and minimise vertical accelerations,” David explains. “This is in addition to good air circulation and large windows with plenty of natural light.”
On arrival at an offshore platform, the passenger disembarkation process also exhibits methods to maximise safety and well-being. First of all, he says, the FCS 7011 is equipped with a gyroscope to stop vessel roll when positioned adjacent to the platform. “And then there is the motion compensated personnel gangway, an Ampelmann S-type, specifically designed for this vessel to create a seamless flow of passenger movement.”
David’s conclusion is tellingly similar to André’s, and is clearly a major reason for Damen’s success over the decades. “All the key components of this vessel have been aligned early in the design process,” he says.
"The end result is a fully integrated solution."
RSD Tug 2513
Fast Crew Supplier 7011
Fast Crew Suppliers
TNO [the Netherlands Organisation for applied scientific research]