engineering plausibility question thread

The idea behind landing craft is to deliver as much men and material onto a beach in the shortest possible time. If the landing is opposed this hopefully allows you to overwhelm the defences before additional enemy forces can reach the area. If the landing is initially unopposed it gives you enough force to advance inland, deal with smaller enemy units and form a strong defensive line before you can be counter attacked.

In this light landing craft have to be;

Cheap enough to produce in large numbers.

Deliver troops in the shortest possible amount of time.

Not cause damage to the landing site that could hamper additional landings.

Be capable of operating on as many different types of landing sites as is possible.

Be reliable, and adaptable; Meaning that they are capable of bringing in supplies and equipment to support troops days or even weeks after the initial landings. Basically act as general cargo ships when not involved in combat operations.


Now the types of design you are thinking of;

Are needlessly complex, adding to costs and reducing the number that could be produced.

Would take longer to deliver troops and clear the way for additional landing craft, since driving onto a beach and getting back off would take a lot longer than just running up to the shore dropping the ramp and reversing.

Tracks and wheels will churn up beaches, damaging them and making them impassable to following craft.

Seriously limit potential landing sites, since wheels and even tracks will simply get stuck on certain types of beach. Other locations would shred tires as they try to land.

Complexity means more things to go wrong, or at best more things you have to maintain. This reduces reliability and the length of time the craft could conduct operations of any kind. A low bow also limits the conditions the craft can operate in, reducing adaptability.


Now an amphibious combat vehicle has the same cost and landing issues here. But at the end of the day they can still act as a standard combat vehicle of that type and be deployed the same way. Which is to say that being amphibious is an additional ability to the vehicles basic function, not a vital part of it.

One thing to keep in mind is that your weight in the boat will change with the deployment. When it comes in, it is loaded with men/equipment/whatever. Once it deploys, the weight is gone. That alone will let the nose ride higher in the water for the retreat and return to base. No need for pumps or changing ballast, just a successful deployment.

Taken and noted, in reply?..

Get an argo-cat.



What I am suggesting is no more than a robust version of this... one that isnt all plastic and carbon fibre, more metal and bullet resistant at that.
This craft has been used in the past extensively by the Peak Park Ranger service to help rebuild paths across Bog and Peat moorlands.
Its a low impact vehicle, it does not damage plant-life on precious moss and other rare plant surfaces, its light, agile, and only causes damage if you tool about with it.

So make it heavier, maybe more wheels, up to a total of say 10, for real heavy loads, and make them retractable upwards into the hull design for a more water dynamic profile.

The tyres are low pressure, they do not get stuck. Even in the stickiest parts of a swamp.

I have suggested a landing craft of similar type, just "Armoured" at the font end to prevent harm.
I am suggesting a craft that can roll over boulders underwater at the entrance to any beach, can be used to deliver in reverse with a ramp back door where a landing is detrimental, but can also roll up onto a beach where there is a firefight and provide a safe cover for exiting troops, and then either swing round or wide turn or even reverse back to the water, where water jet propulsion may take over from a unguarded prop that may clang on close to the surface obstacles.

I am trying to provide a one-size-fits-all solution.

Cost?.. what price "Bullet resistant"?..
Robust MUST be the order of the day.
Complicated?.. yes may be it is to imagine such.
But if you go with the idea of a generator providing electric thrust to all wheels and jets, then the parts are almost "Plug and play" if they get damaged.

What is needed here is an amphibious APC, I am just trying to work this through in my mind.

The British started with Landrovers in the Afghan conflicts, what they came away with was Ocelot.
Mine resistant APC.
Is that "Over" complicated, or just "safe" when compared to a landrover?..





Consider this idea, take away the turret and cannon, make it float.

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what you end up with is this...



All I am suggesting is putting pontoons around the wheels to make it float higher in the water to allow shallow water transition and putting water jets in them to provide thrust, also reducing the size of the wheels and making them low pressure wide profile  to fit snugly into the pontoon when retracted to aid in flotation and make the base of the craft more water-dynamic and less liable to damage surfaces.

If they can build them [above] then they can work on my idea?.. an idea that may be more robust and easier than a hovercraft to aim at the beach, and can be a sort of amphibious transit van in its ability to deliver loads, of either equipment or troops.

And as I say, make each wheel a separate entity in its self, make it capable of raising one leg at a time, then if you get a puncture, you dont even need a jack.
Or if you need to replace just one leg, all you need is a socket set, remove one, place in another, "Plug and play".

I have a sliding mount external hard drive enclosure, that is also plug and play.
All I need is a sata drive, an internal sata drive, I just slot it into the front of my tower, I dont even need to turn off the pc, it senses there has been a change in the drive dynamics, and the pc does all the work loading drivers for the "new" drive.

If all that can be done with the motor running on a PC, why cant we get you some of that on an APC and make it amphibious at the same time?...

Complicated part, make it an all wheel steer.
That way if it can crab sideways, its easier to park....
You can play around with the wheels as well, on good hard surfaces retract all but four, that makes driving easier.
When wheels extended, have a sliding cover that goes over the intake and exhaust of the water jets to reduce FOD.
Also have the ability to change the tyre pressure from inside the cab.
It also can "kneel" when you got to get a load on board, or get under a lower bridge, it can also put all wheels on the ground on unstable road surfaces at the twitch of a switch to manage weight distribution on a weak bridge or the like.
It can be semi-retracted on the un-used wheels, to make certain of not getting beached, when on land.
Or it can have four wheels under the cargo and two to steer, making it six in all, to manage heavier loads on hard tarmac.
All 10 wheels to be only used when needs must, on sand or loose surfaces, even snow.
Its up to whoever to decide how many of those wheels are driven, but of you make the motors light enough to be part of all of the wheels, make them all driven when extended, it will have more grip than a F1 car when needs must?.


And on that score, may I be the first to volunteer to test it on s snowy slope with all wheels retracted using extension of one of the two rear wheels to steer it down the possible most tense bob-sleigh ride I may ever take?..

now as to your other ideas; consider. would you want to drive an HGV truck with individual lift on all wheels, selectable drive to all wheels, selectable steering to all wheels; and then take it into the most hostile environment known to man, while potentially under fire?

As protected as that truck,was, it would not stop a 120mm cannon shell or a TOW missile, or similar that an invasion force against a defended beach would face.

Agreed, but, first, I aint going on my own am I?.. and second, compared to a rubber dingy with half a dozen squdadies in it, its going to stop a lot of small arms fire?..
You either get a small tank that can swim, or you get something between the two, what we are trying to find is a reasonable mid-form armoured amphibious APC that can ferry troops to the beach?.. will it protect against everything?.. maybe not, but it will stop the small arms lead flying about?..
We are also trying to KISS, trying to find something reliably small simple and cheep which is why I am suggesting plug-and-play parts and all electric motors with one single diseasal engine turning a generator, maybe a "single wire" one, simple to run service and legendary reliability, and the motors in the wheels.
Get a few dozen of them swarming the beach, you have a sizeable squad as a beach head, that can use the vehicles as a primary shelter.
I would hope that the spotters in spy planes and intelligence guys have found a spot that isnt too heavily armoured to land, from there, once the beach head is secured, they can land more heavily armoured tanks?..

1; The design you are listing is anything but simple.

2; It has long been known that the key to amphibious attacks is getting off the beach as quickly as possible. Troops that waste time or are unable to get off a landing site take horrendous casualties.

3; Using vehicles as shelter is not a good idea. They make for great fixed reference points for artillery attacks.

4; Military planners do their best to find unprotected landing locations, but this is often impossible because the enemy is quite capable of doing the same thing. The number of such locations is limited, especially when you have to consider sites that also are suitable for bringing in large amounts of supplies.

you have never seen a jet ski up close and personal, have you?

and yea al-yew-min-look-at-me-i'm-british-ee-umm. 100% guaranteed never rusts.



and yes, a lot of jag-yew-ars are still running, too. there's a company here that strips out the british engine and wiring and replaces them with Chevy components, so people can own a jaguar and drive it, too.

you may have missed that after hurricane katrina, when the flooding began to subside, they found that some of the original pumps were still running, so badly flooded that the discharge was still under water.

of course, I live in the northern part of the country, where we've learned not to build below sea level.

and the reversing baffle on them is made of aluminum. which is why the mechanism jams after a year. the impeller and nozzle are made of sterner stuff, but the whole thing gets flushed after every use, and the skis are rotated out on a two or three year cycle.