Designing an amphibious flood response vehicle?

[cardboard]

I am an undergraduate studing for my masters in automotive engineering at loughborough university. a team of us have been asked to design an amphibious flood response vehicle. a basic desgin spec has been put together

weight - 3 tonne, 2 tonne payload
length - 5m
width - 2m
height -2m
minimum ground clearence - 300mm
engine needs to produce 150+kw
2 x UJ440 electric marine jets will produce enough power to move at 20knotts

i dont know if any of you have heard or seen of the gibbs humdinga http://www.gibbstech.co.uk/humdinga.php

but effectively it should be something similar to this

i would really appreciate any ideas or information any of you may have with most of the team not really being that clued up on marine engineering with only me and one other team memeber ever really been out on the water sailing.

our biggest problems our waterborn stability, the weight distribution, hull design and fueling but i think 1 tank with bafflers would be sufficeint here but maybe not?



anyway we would really appreciate any input

many thanks

tom

[kach22i]

Will the craft be expected to enter urban (city) areas? Lots of floating debris, water may so full of nasties, low spray a must, maybe a low wake hull design will help too (look up "M-Hull").

Will it be rescuing people off of roof tops?

What will the mother ship look like, or will it be air dropped?

Do you favor a monohull over a catamaran, if so why?

Catamaran would be more stable, right?

This crazy thing gave me a wild idea, I'm just silly I guess.

http://blog.modernmechanix.com/2006/...et-fuel-tanks/

[cardboard]

yes but it will be primarily a vehicle. we have looked at a flat hull but this poses turning issues and maybe a partial multihull

it does not need ladders as such and only needs to pick up 4 passengers per journey.

no mother ship it will be able to drive at 100mph on road and drive straight into the water and out again

[RatliffFranklin]

Originally Posted by cardboard

yes but it will be primarily a vehicle. we have looked at a flat hull but this poses turning issues and maybe a partial multihull

it does not need ladders as such and only needs to pick up 4 passengers per journey.

no mother ship it will be able to drive at 100mph on road and drive straight into the water and out again

Such vehicles are already available. They're called airboats.

http://americanairboats.com/ar-502bobl.htm

[kach22i]

Originally Posted by RatliffFranklin

Such vehicles are already available. They're called airboats.

http://americanairboats.com/ar-502bobl.htm

The problem with "AirBoats" is that they must be trailered to the launch site. Small hovercraft have the same problem, plus in urban conditions operate in "under the hump" speed conditions and spay nasty water everywhere.

If you were to air drop a AirBoat or Hovercraft that would be different, which is why I asked the question.

Delivery is everything.
Delivery is everything.
Delivery is everything.


To assume that both lanes of traffic would not be "outgoing" is a huge mistake in my opinion, but it's an establish criteria now for the design problem.

One must study what went wrong at Hurricane Katrina to appreachiate this. Hovercraft and other volunteer rescuers were turned back...........don't ask me why. They came by road, that's all I'm going to say.

[RatliffFranklin]

Originally Posted by kach22i

The problem with "AirBoats" is that they must be trailered to the launch site. Small hovercraft have the same problem, plus in urban conditions operate in "under the hump" speed conditions and spay nasty water everywhere.

If you were to air drop a AirBoat or Hovercraft that would be different, which is why I asked the question.

Delivery is everything.
Delivery is everything.
Delivery is everything.


To assume that both lanes of traffic would not be "outgoing" is a huge mistake in my opinion, but it's an establish criteria now for the design problem.

One must study what went wrong at Hurricane Katrina to appreachiate this. Hovercraft and other volunteer rescuers were turned back...........don't ask me why. They came by road, that's all I'm going to say.

Airboats are all terrain vehicles. They can get themselves to a launch site.

Airboats were not turned back in Katrina. Operating in flooded New Orleans was not much different from operating in a Louisiana swamp.

[kach22i]

Originally Posted by RatliffFranklin

Airboats were not turned back in Katrina. Operating in flooded New Orleans was not much different from operating in a Louisiana swamp.

Not ALL hovercraft were turned back either, but under such conditions when communications are in disarray things can get all messed up.

If one guy (with little training) is told "no one in" he follows orders, not knowing who is there to help and who is there to loot. Also rescuing a "volunteer rescuer" is not very well thought of by the authorities when chaos is everywhere.

Several airboats and hovercraft ran out of gas because their supplies got stolen, and more people seemed to remember to bring water not spare gas.

I'm on a mission from God, stealing gas will be forgiven...........not my gas buddy!

BIG IDEA

The craft, what ever it ends up being tows it's own fuel supply..................and that supply is either guarded 24/7 or is somehow configured so no one will be able to steal it, siphon it or other such stuff.

[Earl Boebert]

Well, I think that whatever you did would have to stand comparison to the good old DUKW (for light work) and the Weasel (for crunching through serious wreckage.). An ex-Marine friend of my parents (WWII vet) swore by both those things. The DUKW was designed by Olin Stephens' brother, BTW.

Cheers,

Earl

[rwatson]

Already in production - try
www.sealegs.com
but fit it with jets if you want to (perhaps a Yamaha water jet outboard leg)

[kach22i]

I don't think the "sealegs" are meant to substitute trailer wheels let alone make it a self-propelled or self-delivering emergency vehicle by land.

The question of useful size as found in the DUKW & Weasel is a fair one. Perhaps your craft is a little small to be up to the task of anything but small scale.

[RatliffFranklin]

Self-delivering emergency vehicle by land?

Airboats can cross frozen lakes, muddy fields, and dirt or paved roads.

[kach22i]

Originally Posted by RatliffFranklin

Self-delivering emergency vehicle by land?

Airboats can cross frozen lakes, muddy fields, and dirt or paved roads.

So can hovercraft, but I would not go on a cross country trip in either one to get to the site of a disaster unless the darn thing was on a trailer.

I have an ORV (off road vehicle) sticker on my hovercraft but I can't go driving it down my street, can I?

[RatliffFranklin]

Originally Posted by kach22i

So can hovercraft, but I would not go on a cross country trip in either one to get to the site of a disaster unless the darn thing was on a trailer.

I have an ORV (off road vehicle) sticker on my hovercraft but I can't go driving it down my street, can I?

The point you're missing is neither one needs to come off the trailer until the roads become impassable. And airboats don't have skirts that can be ripped or snagged by debris.

[kach22i]

Originally Posted by cardboard

yes but it will be primarily a vehicle. ............
no mother ship it will be able to drive at 100mph on road and drive straight into the water and out again

May I suggest a flat deck somewhere for stretchers?

[monckywrench]

"Amphibious" implies being able to negotitate areas that are not open water or open land.

An APC-styled unarmored tracked hull with external pontoons for better floatation/higher freeboard would be able to surmount obstacles, self-recover with winches, protect the passengers and crew, and provide power and light once in place by tapping the supply for the electric water jets.

Water propulsion could be handled by waterjets, but wheels aren't much good in muddy wreckage.

A "shrunken" version of the Aris Gator modified M113 would be a good place to start,, as would the Weasel.

"The craft, what ever it ends up being tows it's own fuel supply..................and that supply is either guarded 24/7 or is somehow configured so no one will be able to steal it, siphon it or other such stuff."

A wheeled pontoon trailer with a transfer tank and pump would be one solution.

"it will be able to drive at 100mph on road "

Useless "rich mans toy" feature whose inclusion will compromise disaster response performance off-road.
Use synthetic rubber band tracks for superior mobility over the mixed terrain found in disaster areas. They can do about 70mph which is plenty.

The Humdinga is very nice but would high-center driving over wreckage, disabled cars, etc. Good luck driving up a sloping, muddy river bank.