VESSEL REVIEW | Vasily Ilyin – All-weather-capable passenger hovercraft to operate on Russia's Yenisei River

Russian builder Paryashchiye Mashiny (PARMA) has completed construction on a new hovercraft designed to carry passengers and cargo.

Vasily Ilyin (Василий Ильин) belongs to the Project PM44 series of hovercraft designed by PARMA in compliance with both Russian Maritime Register of Shipping and Russian Classification Society rules. It will be operated on the Yenisei River year-round, having been designed for both summer and winter sailings.

Versatile craft for year-round operation

The vessel has an LOA of 17 metres (56 feet), a beam of six metres (20 feet), a ground clearance of 0.9 metre (three feet), and space for 40 passengers, two crewmembers and up to four tonnes of assorted cargo. It is designed for operating in outdoor temperatures of between -40 degrees Celsius and 35 degrees Celsius and a maximum wind speed of up to 12 metres per second at any time of the year.

The hull is built from sheet and profile rolled waterproof aluminium. The hull is riveted (with the exception of small parts made on welding). Corrosion protection for the hull is provided by an aluminium-magnesium composite.

The air-cushion system will meanwhile enable manoeuvring over ice, snow, shallow water, and swamps. The vessel is capable of overcoming smoothed ledges up to 90 cm high and unsmoothed surfaces up to 65 cm high.

The hovercraft boasts amphibious capability courtesy of the structure being detached from the screen by holding the air cushion under the body with a flexible fence. The lifting height depends on the speed of the engines and the trim angle.

A two-tiered, flexible fencing arrangement is adopted with removable elements around the perimeter of the lower tier and with a flexible receiver in the upper tier. This allows the removable elements to remain elastic so that when passing over an obstacle, the flexible elements are deflected and easily pass over the obstacle without resisting its impact.

Only the lower segmented layer, which consists of many independent elements, comes in contact with the surface. Each element is attached to the receiver with four latches. Replacement is simple and does not require special tools and skills.

Durable, efficient propulsion guaranteeing enhanced manoeuvrability

The propulsion arrangement consists of two Kama-Dizel 223kW (300hp) six-cylinder diesel engines driving four-bladed, controllable-pitch propellers housed in fixed nozzles. The angle of pitch of the propeller blades is controlled via the turn indicators installed in the control panel.

Two centrifugal blowers are provided as air cushion blowers. These are mounted on shafts supported on both sides by self-aligning bearings.

Separate control of the supercharger revolutions and sectioning of the air cushion zones allows the crew to create different pressures in the left and right halves. This makes it possible to create an artificial roll, which is useful during manoeuvres and helps to neutralise the effect of lateral gusts of wind.

In the event of a failure of the engine or the supercharger of one of the sides, the jumper between the zones is removed and the flexible enclosure is filled with air from the working supercharger. The hovercraft can continue to move forward even on one supercharger.

The helm operator can switch the pitch of the propellers between forward and reverse positions with the aid of foot pedals. The propellers also have speed control to provide differential thrust if needed, as the nozzles cannot be rotated.

The total fuel capacity is 800 litres (180 gallons), which will permit a maximum endurance of 12 days.

Recent sea trials proved that the vessel can attain maximum speeds of 54 knots on frozen surfaces and 37 knots on open water. Operation is possible even in wave heights of up to 1.25 metres (4.1 feet) and no more than four hours from the nearest shelter at cruising speed.

Significant passenger transport capacity

The main passenger cabin also boasts a toilet, luggage racks, USB charging ports, and a fixed fire suppression system. For emergency evacuation, two 25-person liferafts are also available.

The wheelhouse electronics include displays from Raymarine, angle of attack indicators, and onboard diagnostic computers. LED and xenon lighting are used throughout the interior spaces while the wheelhouse itself boasts a three-layer structure that includes an FRP and laminate inner layer, an insulated honeycomb middle layer, and a reinforced FRP outer layer.

The hovercraft itself can be transported by road, rail, or heavy lift vessel.