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monkey13 - n/a
29-Nov-07, 12:03 PM
Hi I'm a design student at Coventry University designing a concept hovercraft. However I have no experience of controlling a hovercraft and what are the best ways of controlling larger hovercraft between 8m 26ft in length. What are the major problems or difficulties in controlling Hovercraft?



Thanks Nathan

tonybroad - n/a
30-Nov-07, 05:56 PM
what's the concept ?



the biggest problem is having no brakes ! but seriously hovercraft are not as difficult to control as people think it just takes some time to get the feel of them



will your craft have a seperate lift fan or a single fan feeding skirt and for thrust, large single fan craft appear more difficult to manage than ones with seperate lift



there's plenty of pics on www.hovercraftvideo.co.uk look under the cruising pics to see larger craft



good luck - keep us posted



Tony

GavinParson - n/a
1-Dec-07, 07:04 AM
what's the concept ?





there's plenty of pics on www.hovercraftvideo.co.uk look under the cruising pics to see larger craft







Tony




What 26ft craft? I don't think so! For craft that big control is a completely different matter to leaning on bends.

Best you contact a commercial manufacturer such as Griffon or Slingsby.

You enter the realm of ballast shifting, skirt shifting and propeller pitch changing.

Or look at the River Rover which has elevons to roll the craft thus increasing the turning effect.



Most amateur cruising craft employ none of these systems and rely on driver weight shifting and use of rudders alone.

tonybroad - n/a
1-Dec-07, 03:10 PM
I had in mind the James Bond Osprey 5 which i've seen fly - how long is one of those



Tony

jar2 - n/a
1-Dec-07, 04:27 PM
The Osprey5 is 16' long.



The largest craft I have is 18ft - control isn't too bad most of the time. The Sevtec front partition "braking" system works pretty well at most speeds. The technique involves partially deflating the front partition which causes the nose skirt to drag a ittle, then using the rudders to pivot the craft around the nose - it basically amplifies the effect of the rudders. It only works well when you have some forward motion - at zero speed I sometimes have to get out and shove the nose around in tight corners http://hovercraft.org.uk/images/icons/smiley_icons/icon_cry.gif .



Most of the big craft seem to use directional thrusters to control direction at slow speed.

Bill Baker - n/a
4-Dec-07, 09:17 AM
1 Skirt shift

2 adjustable ballast

3 bow thrusters

4 reverse thrust



1

Is a method of pulling the skirt inwards on one side and letting it out on the other thereby moving the centre of gravity causing the craft to roll equivalent to body leaning on a smaller craft.

Or shortening the hover length to induce a delicate plough-in as described by John

2

The cross channel craft pumped fuel / water to ballast tanks at each corner for trim adjustment.

3

Vents on the front corners to push the nose across normally using bursts of lift air.

4

Reverse thrust ether by prop pitch adjustment or by re directing the thrust air forwards or more accurately obliquely sideways to give both braking and some rear thrust.

Bill.

Ps Nathan I went up to Lanchester Uni at Coventry (same as Coventry? ) ten or more years ago to comment on projects on what sounds like a similar course