Trans RINA, Vol 154, Part C1, Intl J Marine Design, Jan - Jun 2012
the load. Stern tank is intended to counter balance weight of cabin and superstructure over bow and also serve as an auxiliary or for transporting fuel.
The construction makes extensive use of composite materials to reduce mass. GRP most widely used with CFRP employed for
components where increased Figure.5 Deck storage area
When “On Cushion” the hovercraft is 3.4m above the ground. When “Off Cushion”, the craft sits upon skids running along the hull and the height of the deck decreases to 1.4m. Lift fans are controlled by computer in order to set craft down evenly. The hovercraft is designed so it can be loaded/unloaded using the existing infrastructure along the Ice Road route as shown in Figure.6
durability is needed. Aerospace-grade aluminium used for hull and structural elements. The skirt made from neoprene-coated nylon with disposable fingers made from natural rubber.
being
Figure.6: Loading TEU while off cushion
4.3 ENGINEERING SPECIFICATION Through
dialogue with hovercraft
design
engineers
parametric calculations were carried out using and Excel spreadsheet to determine the engine power and fuel load requirements for the hovercraft under various payload conditions and inclines relating to the research in to the portages delineated in the introduction. Resulting in the following technical considerations:
4 x marine gas turbines driving 4 x directional ducted 1.8 m variable pitch propellers to provide propulsion
Lift is provided by 8 x 1 m centrifugal lift fans driven off same gas turbine engine via gearbox Normal
optimum operation would involve
running each engine at 25% power to provide total lift power of 3755 kW.
In the event of engine failure, each engine is capable of providing total lift power if required (In effect, three fail-safes)
The hovercraft has a total of 7 fuel tanks 6 x 1500 litre along the mid port/starboard sides and 1 x 4000 litre tank at the stern. Maintaining an even distribution of mass across the cushion area is crucial therefore like an aircraft, the fuel is “trimmed” between tanks to even out
Figure. 7: Technical configuration of propulsion system
4.4 ACCOMMODATION AND COCKPIT DESIGN
The cockpit workload is divided between a pilot and a navigator as the vessel will have more in common with a HSC (High Speed Craft) than a truck, operating over all terrain rather than following a
fixed road. Design
dialogue with operators informed the design process of the crew needs. Resulting in accommodation design for two crew members to live in for up to a week, with provision for:
sleeping; cooking; washing and toilet
facilities, along with personal and mission equipment storage. The GA of the cockpit and accommodation is shown in Figure.8.
As an integral part of the interior design process DHM (Digital Human Modelling) manikins were used
to
ergonomically resolve the interior space. They are shown in Figure. 9. The blue manikin represents 2.5th percentile US female, with the green manikin representing a 97.5th percentile US male (both 18-64), with dimensions from from Peoplesize.
C-6 ©2012: The Royal Institution of Naval Architects
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