Hello from amphibious car builder

[windowman]

Hi i was just looking around for info and noticed "Axelbrit" is building the same car as me ,I would be interested to know how it is going and what stage you are at and hopefully we could swap info and tales of woe.
Regards Brian

[dccd]

Hello I am also building a amphib car, I call it the Hum-Duck, we had a storm through here known as "Katrina" and it made me realise the world needs a amphib rescue tug with barges. I am at the stage of bringing together the sub-systems for cooling, brakes ect. the hull mold is done, body shell about 75%. Tell me about your Car.

[Frosty]

Ive had it in my mind to build an anphicar for years but never got round to it. here in Thailand steel and machining is dirt cheap ,the problem is I would not be able to register it and use it so whats the point?

Have you got some pics? there are so many problems to get around --its not an easy job .

I for one am extremely interested in how you have solved engineering problems

[westlawn5554X]

I am really interested to turn my neighbour cars into amphi... I am serious. This may bear to be fruitful long discussion.

[Frosty]

Originally Posted by westlawn5554X

I am really interested to turn my neighbour cars into amphi... I am serious. T

Just let the handbrake off.

[westlawn5554X]

Mmmm... not a bad idea... Gracias.

[dccd]

Originally Posted by jack frost

Ive had it in my mind to build an anphicar for years but never got round to it. here in Thailand steel and machining is dirt cheap ,the problem is I would not be able to register it and use it so whats the point?

Have you got some pics? there are so many problems to get around --its not an easy job .

I for one am extremely interested in how you have solved engineering problems

I would also like to know more details about Windowman's project. My own amphibian is specific to flooded urban rescue and patrol. Many of the problems vanish when you start with a clean slate, many problems seem to be from the desire to keep too much of the donor car and its mis-matched weight distribution.

You can see the general brochure of my design at: www.industrialobject.com go to the amphibian page.

[windowman]

Hi sorry for the delay ihave been busy with work.
I am building a Searoader using guidelines purchased from Mike Ryan at Searoader.com .There are some pics of my car on the plans page of the site but they are not very current as I now have all the lower bodywork forward of the rear axle complete. The exhaust is fitted ,all the new brake lines are fitted and bled and I am just about to start wiring.
The power in the water is by a twin cyl kubota diesel (sourced from Axiam microcar) which will be coupled to 2 outboard legs which will be mounted in tubes within the rear hull and the whole vehicle is to be run on carbon neutral veg oil.
I am building it for mainly river use as launching or mooring costs around here are unrealistic and it should also prove to be a usefull vehicle for work.
I will send Mike a message and get him to update the pics.
Regards Brian

[dccd]

That is a clever vehicle and I am a big proponent of propeller propulsion when it come to best low speed capability. How do they assure the watertight integrity of the drive axel tubes?

[windowman]

As I mentioned before I am using outboard legs ,these will be bolted through the side of the 8" tubes using the cavitation plate as a flange,this will use the seal behind the prop to prevent the ingress of any water and will leave the driveshafts within the hull to easily connect up to the engine .
The main drive axels for road use are land rover items and therefore already watertight.

[RatliffFranklin]

Originally Posted by dccd

That is a clever vehicle and I am a big proponent of propeller propulsion when it come to best low speed capability. How do they assure the watertight integrity of the drive axel tubes?

Due to debris in flooded urban areas, the best propulsion options would be water jets or tires that double as paddlewheels. The vehicle could be driven to the scene on normal road tires then outfitted with paddle tires.

[Frosty]

Originally Posted by windowman;

The main drive axels for road use are land rover items and therefore already watertight.

The LandRover front swivels were hardly water proof for normal road use and were a constant course of oil leakage by pitted swivels.

The swivel face was only sealed by a large ring,--it used to be felt under a steel ring.

If it is the same today!!

A large belows type rubber cover would be better like the type used on CV joints.

This will be serious maintenace, grease liberally, daily.

Are the brakes then inboard or outboard.

[dccd]

Originally Posted by RatliffFranklin

Due to debris in flooded urban areas, the best propulsion options would be water jets or tires that double as paddlewheels. The vehicle could be driven to the scene on normal road tires then outfitted with paddle tires.

There is one water jet that would be adequate for my application of low speed, high bollard pull. That is the Traktor jet, it was developed for long line? purse net boats which needed to pull about a mile of net and be able to run over its lines etc. These were small boats with a big diameter jet, the Traktor we looked at has a 18" dia impellor for 140 hp, it could be fit but the jet would wash anyone or anything clear off the towed barges behind it. The Merq outdrive we are using has been modified with metal prop duct and some debris skeg ahead of it. All the jet powered amphibs under 10 knots would do better speed with deployable props IMHO, its just not as sexy.

A compact paddle wheel was considered and may still see the light of day. If you look at efficiencies and bollard pull of the old steam river paddle wheelers it was very impressive, shallow and hard to foul.

Axel integrity is the real crux of the problem, double lip seals on the outboard axels, as on any out drive are our solution. I was hoping to hear some other ideas. The axel tube/gear also has to be well ventilated to avoid the temp related suck that happens when a hot differential hits cold water, perhaps into the engine PVC?

[Frosty]

A hot diff hits cold water?Perhaps into the enginePVC???????

Why will the diff be hot?

Why will it vent to the engine?

Whats a PVC?--do you mean a TCV

All axles are vented, it only needs a nipple fitting and a pipe to take it up above the water line.

[dccd]

Jack, a differential gets hot under normal use, more so if towing/turning, simple mechanical friction, think of the diff clutches when manuvering!

In most flood cases the water is cold which increases the temp differential, this is a common amphib issue. Most axels do have a vent as you have mentioned. PVC is a "positive crankcase ventilation" valve, it keeps pressure from building up in the engine crankcase. It was a thought to do the opposite at the differential vent, keep it pressured a little above atmosphere, this will assist the seals from pushing in under water. With only a static vent, the air pressure in the axel becomes less than the water pressure as soon as it submerges, yes?