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Correct dimensions and weights

       

 

 

Correct dimensions and weights

Operators are usually unaware of the hovercrafts characteristics advantages and disadvantages. For this reason theirs choice is based on criteria that are outdated or comes from the nautical field experience. These criteria are easily applicable and well-known but misleading in the case of an amphibious vehicle. Instinctively the emergencies operators looks for vehicles that satisfy the traditional requirements (“ ... our team is made of 6 people ... “) without considering the ideal characteristics that the vehicle should have for the mission and the impact of an assessment error.

 

 

The two Rescue operational levels

Emergencies ideally needs two different craft sizes and weights, where the limit of the operational level is represented by the the overcoming of an obstacle of 70/100 cm, lifting by hands (bow first than the stern) by two operators.
This is our SubCompact MACP version, with hull obviously also made with the Softhull technology, therefore unsinkable, shock-resistant, shock-absorber and with excellent displacement.

The second operational level is the limit of portability accessibility and agility with a trailer (250x600)on narrow urban surroundings roads. The vehicle must have sufficient performances, autonomy and power and must can be adaptable to SAR ambulance use. This is our Compact MACP version.

Go beyond these limits, rescue operations are strongly compromised

THIS IMPLIES THAT IN SAR OPERATIONS, THE OPERATOR NEEDS TWO DISTINCT TYPES OF MACP (Compact and SubCompact) IN ORDER TO OBTAIN FULL COVERAGE TO THE OPERATIONAL NEEDS AND RESCUE BECAUSE AT CONTRARY TO WHAT YOU CAN IMAGINE, PASSED THE SECOND OPERATIONAL LEVEL, THE DIMENSIONS OF THE VEHICLES BECOME AN OBSTACLE TO THE OPERABILITY AND NOT AN ADVANTAGE.

 

 

Bumpertree

Bumper Advantages & dimension constraints.

 

MACP compact - 20 ft container

 

Hovercraft technology requires an ideal length/breadth ratio between 2/1 and 2.5/1. In the case of 2.5m maximum breadth it is required a 6.25m long hull. This value gives the possibility of being exactly in the size of 2.50m even while operating, with a hard clearance/skirt heigh of 30 cm max., height/width ratio is optimal when contained between 1/8 and 1/6.
The MACP with single MPS has been designed and built for the project Hoverspill. It is a system of fast intervention in the oil spill emergency.
It takes into account the following constraints:

  • Diesel Engine & Reverse Thrust and fast craft stop (European standards for workboats and geneally for rec-oil boats - intervention in Oil Spills)

  • 2.50 width, for the need to be easily transportable on the road on a trailer

In the world market there is currently no other hovercraft that meet these characteristics.
The width defines the optimal criterion for the length.
Using the reverse formula, a 7 meters, imply an optimum width of 3.20/3.50. In this case it is not possible to keep the vehicle in the constrains given by the road transport that is 2.50m without using an ad-hoc solution for the skirts. A system of movable skirt permits to keep the hull into the 2.50m while not operating and to enlarge the hull up to 3.20m with consequent increase in the footprint (the payload is eventually increased). A larger hull gives the possibility to install higher skirts. Therefore, the environmental conditions determine the constraint limit on which it is possible to determine the optimal size.
From an operational perspective, it must be considered that MACP adopts a propeller with maximum thrust around 320 kg, and the lift can be arranged to adapt to the different widths of the air cushion. The payload is proportional to the footprint, but the inertial forces have to be taken into account. The insulation with the surface "overflown" involves the lack of those organs of directional friction (wheels or rudders) that in the other vehicles are in charge of curvature or braking. In a hovercraft directionality is assigned to the air flows and forcibly confined by the thrust of the propeller. Therefore the recommended payload is limited with the aim maintaining a good maneuverability.
The choice of 7m (i.e for ambulance) has to be seen as limit size for a “compact hovercraft”. With this kind of dimension it is possible to remain within the ideal parameters of engine power, payload, transportability etc.