Introductory presentation on the Hover Craft.

2. HOVERCRAFT
As modes of transportation have evolved over the years,
finding more efficient and economic ways of movement
have been the chief goals of developers. It is from this
evolution that the hovercraft arose.

3. OUTLINE OF PRESENTATION
Introduction
History
Models
Elements of a Typical hovercraft
Design Configurations
Operation of the Hovercraft
Design Considerations
Use of the Hovercraft
Environmental Impact
Hovercraft in Guyana
Conclusion

4. INTRODUCTION
What is a Hovercraft?
A hovercraft is an amphibious vehicle that can move
with equal ease on both land and water or any other
terrain. It is also known as an air cushion vehicle.

5. INTRODUCTION
Hovercraft on land Hovercraft on water

6. HISTORY
 1716 Emmanuel Swedenborg (Swedish Designer & Philosopher)
He first conceptualized the idea of supporting a vehicle on a cushion of
air but his project was short lived and his craft never built.
 Mid 1870s Sir John Thornycroft (British Engineer)
He developed the air cushion effect idea further by building and testing
a number of models but no applications were found since the
technology to implement the concept did not exist at the time.
 1952 Sir Christopher Cockerell (British Engineering)
He invented the hovercraft. He found the missing link that everyone
else missed. Developed the hovercraft principle further and got his idea
patented in 1955. With diligent work he was able to bring his idea to
reality with the first commercial hovercraft in 1959. From there on the
idea took with numerous developments with the vehicle.

7. Models
British Aircraft manufacturer Saunders Roe
SRN1
The first practical model to be made. It was powered by one (piston)
engine, driven by expelled air and could carry little more than its own
weight and two men.
The SRN1 During Trials in 1959

8. Models
SRN1

9. Models
Other developments led to larger and more efficient hovercrafts which
can carry passengers such as the SRN2 to SRN6.
SRN4

10. Models
Other developments led to larger and more efficient hovercrafts which
can carry passengers such as the SRN2 to SRN6.
SRN6

11. Models
Vickers VA-3
This was the first true passenger carrying hovercraft.

12. Models
Many companies continued the development
of the hovercraft.
British Hovercraft Corporation (Saunders
Roe & Vickers)
UK Cushion Craft
Hovermarine

13. ELEMENTS OF A TYPICAL HOVERCRAFT
Hull
This is where the driver operates the hovercraft and passengers or cargo
are located. It is the main body of the hovercraft which acts as the base
for attaching of the other parts.

14. ELEMENTS OF A TYPICAL HOVERCRAFT
Lifting System
This consist of a centrifugal fan attached to a
motor or an engine, which provides air for the
cavity underneath the craft (called the plenum
chamber) and also for filling the skirts.

15. ELEMENTS OF A TYPICAL HOVERCRAFT
Thrust System
This consists of propeller or ducted fan that moves air from
in front of the craft and accelerates it out the back. This
accelerated mass of air then generates thrust which pushes
the craft forwards.

16. ELEMENTS OF A TYPICAL HOVERCRAFT
Skirt
This is the flexible wall that is attached all around the
bottom of the craft. The skirts prevents the pressurized air
from escaping from the plenum chamber.

17. ELEMENTS OF A TYPICAL HOVERCRAFT
Engine
A typical hovercraft typically uses one engine but larger
sizes can use more sometimes up to six engines. They
usually utilized the typical marine engines since they are
quieter and fuel efficient.

18. ELEMENTS OF A TYPICAL HOVERCRAFT
Control System
This consists of a set of rudders that steer the craft by
directing the air from the thrust system toward either left
or right which consequently steers the craft.

19. ELEMENTS OF A TYPICAL HOVERCRAFT
Control System

20. ELEMENTS OF A TYPICAL HOVERCRAFT
Air Box
This is a box like structure at the rear of the hovercraft
located behind the propeller. It diverts some of the thrust
air underneath the hovercraft.

21. DESIGN CONFIGURATIONS
They can be designed with one or more engines. One is
used for driving the lift fan and the other used for driving
the thrust fans.
Some Hovercraft use the principle of ducting to allow one
engine to perform both lift and propulsion by directing
some of the air to the skirt and the rest of the air is passed
out of the back for thrust.

22. OPERATION OF THE HOVERCRAFT
Principle of Operation

23. OPERATION OF THE HOVERCRAFT
Principle of Operation

24. OPERATION OF THE HOVERCRAFT
The lift fan pushes a large volume of air under the hovercraft which is
prevented from escaping by the skirt.
As the fan continues to force air into this cushion, the pressure under the
hovercraft increases.
When the pressure under the hovercraft exceeds the weight of the hovercraft,
the hovercraft begins to rise off the ground this can be around 6’’ to 105’’
depending on the size of the craft.
Eventually the hovercraft raises high enough to lift the skirt off the ground.
Air begins to escape through the gap between the ground and the skirt
(called the hovergap).
At some point the hovercraft reaches equilibrium point at which the amount
of air being forced into the cushion can not exceed the amount of air escaping
through the hovergap.
At this point the hovercraft is hovering at its maximum hover height.
The hover height and hovergap which result at this stage can, with certain
limits, be adjusted through the design process.
Fans mounted on top creates thrust air which is used to propel the hovercraft
forward and moving the thrust air with rudders controls hovercraft direction.

25. OPERATION OF THE HOVERCRAFT
Brakes & Steering
Steering
Steering is accomplished by use of the rudders. The rudders are
placed at the back of the craft in the direction of the thrust air
flow. As the direction of the rudders are changed so is the
direction of the craft.
Brakes
Hovercraft have no braking system. Simply reduce power until
the craft no longer hovers. Thrust reversers can be used.

26. OPERATION OF THE HOVERCRAFT
Fuel Consumption
This will depend on the speed and other conditions which
the craft is driven under. But it uses less gas as compared to
cars and boats under the same condition. Hovercraft speed
range is about 30-75 miles per hour.
A typical gasoline car averages 3.2 gallons per hour whereas an average
hovercraft gets about 2.8 gallons per hour.

27. OPERATION OF THE HOVERCRAFT
Safety
They have not been any major accident
involving hovercrafts. Only the occasional
break down due to lack of maintenance.
Based upon information the hovercraft
seems to be one of the safest means of
transportation.

28. DESIGN CONSIDERATIONS
Carrying Capacity
Pressure = Force/Area
A bigger hovercraft, one with a bigger overall area can
carry more weight than a smaller hovercraft with a fan
the same size. Therefore, the surface area should be
kept as large as possible reducing the pressure needed.
Aerodynamic Drag
This is the force that the thrust must overcome. The
drag can be reduced by reducing the frontal area of the
craft.

29. DESIGN CONSIDERATIONS
Thrust
The propellers used must be able to overcome the
aerodynamic drag.
Skirts
Depends on the usage of the hovercraft.
Stability
The location of the various components and loadings so as
not to overload any particular area which may make the
craft unstable.

30. USE OF THE HOVERCRAFT
Personal Use

31. USE OF THE HOVERCRAFT
Search & Rescue
The hovercraft can travel on virtually all terrain
Hovercraft life boat

32. USE OF THE HOVERCRAFT
Search & Rescue
The hovercraft can travel on virtually all terrain
Hovercraft being used for a rescue
operation

33. USE OF THE HOVERCRAFT
Mass Transportation
Passenger ferries (goods, vehicles)
Passenger-carrying hovercraft, off shore from Ōita Airport

34. USE OF THE HOVERCRAFT
Mass Transportation
The Hovertravel service between the Isle of Wight and mainland England is currently
the only public hovercraft service in the United Kingdom

35. USE OF THE HOVERCRAFT
Recreational Purposes
Sporting activities
A Formula 1 racing hovercraft

36. USE OF THE HOVERCRAFT
Research & Military uses
A U.S. Navy Landing Craft Air Cushion, an example
of a military hovercraft

37. ENVIRONMENTAL IMPACT
 The air cushion enables a hovercraft to operate over environmentally
sensitive areas such as muskeg or mudflats without disturbing the
surface.
 The ground pressure exerted even by a fully loaded hovercraft is so low
that the craft can pass over bird eggs without breaking them.
 The lack of disturbance on water minimizes the potential for bank
erosion and does not disturb swimmers or canoeists.
 Unlike many boats, engine exhaust fumes are not directed into the
water and poisonous anti-fouling compounds are not required on
hovercraft.
 They require no docking mechanisms and can land safely on virtually
any kind of shore.

38. HOVERCRAFT IN GUYANA
Can Hovercrafts replace speed boats?
Given that:
1. Can travel over the surface of the water without
concern for the depth or hidden obstacles
2. Can travel against the current of a river with no
reduction in speed
3. They are unaffected by small waves and offer a
comfortable smooth ride
4. Have sufficient cushion height to pass right over a
person in water
5. Can come right up to the shore even if there is no water

39. HOVERCRAFT IN GUYANA

40. CONCLUSION
The hovercraft is in operation today throughout
the world for a variety of purposes and its use is
growing giving raise to new and improved designs
resulting in greater applications.
With its safety and adaptability it can become one
of the most important and economical means of
transport in the future.

41. THANK U!