50 ton Explorer vehicle (wip)

[wbnc]

When you get into the neighborhood of 50 dtons, I start to think about the Modular Cutter. A very ground useful vehicle in that size range would be a vehicle to carry Modular Cutter modules while planetside.

So how about something like this: a giant truck with docking clamps on both ends. To load a cutter module:

1. The truck folds its docking clamps down flat, folds support cradles vertical, and folds outriggers out the side for extra stability and weight support.
2. The cutter lands in the support cradles.
3. The truck activates powered rollers to slide the cutter forward or backward until the module is aligned with its docking clamps.
4. The cutter unclamps the module, releasing it into the truck's cradles.
5. The cutter flies upward and away.
6. The truck folds its docking clamps up to mate with the ends of the module.
7. The truck retracts the outriggers, and is ready to drive.

I can imagine at least three types of undercarriage. The most obvious type is ordinary wheels, which would only be practical on a paved surface (or heavy duty gravel track like the NASA rocket crawler roads). Another obvious type is a tread structure, which would probably be several sets of tracks for redundancy. A third possibility would be rocker carriage wheels, which would spread the load onto a larger surface area and operate on somewhat rugged terrain while retaining a lot of the speed and maintenance advantages of wheels.

I had the same idea. But tryng to work out how to pull it off. cutter modules are designed to fit into a starship so they are not an ideal shape for a ground vehicle..although that can be worked around.

wheels are a good all around system. The biggest dump trucks used can handle 350 short tons of ore on four wheels...big wheels but wheels none the less. Russian mobile launchers are wheeled and carry around a fully loaded ICBM...with decent cross country capability.

There are some unknown unknowns.

How much does a docking clamp weigh once it's on a planet with standard gravity?

Wouldnt need a docking clamp for just trundling around the surface. that doesn't require a lot of hardware just a few clamps and supports. An overhead load bearing rail system would work to allow modules to be loaded and unloaded. I'd say about 5 tons (weight wise) can handle 20 to thirty tons of gear. once on the truck, the bed of the truck can handle the load.

 

[steve98052]

wheels are a good all around system. The biggest dump trucks used can handle 350 short tons of ore on four wheels...big wheels but wheels none the less. Russian mobile launchers are wheeled and carry around a fully loaded ICBM...with decent cross country capability.

Good point; tracks are a waste of hassle except in specialized settings, like a snow-cat.

I looked up the mass of a cutter module in GURPS Modular Cutter, and a basic cargo module has a loaded weight of 144 tons. An armored cargo module is 287 tons. A giant ore dump truck is going to drive only on purpose built roads, so wheel loading is an issue. On standard roads, it would take up two lanes and be an over-height load, because the module is 21 feet (6.4 m) in diameter and 42 feet (12.8 m) long. (Standard shipping containers are about 8 feet wide, 9 feet tall, and 40 feet long.) That much mass would probably best be carried on a lot of wheels to avoid cracking the paving. For road use, I'd build it like two low-riding trailers side by side, with eight axles and 32 wheels, arranged like this (not to scale):

00----00 00----00
00----00 00----00




00----00 00----00
00----00 00----00

For off-road, height isn't a concern, so instead of fixed axles each pair of axles (or even each cluster of four wheels) could be rocker mounted.

Wouldnt need a docking clamp for just trundling around the surface. that doesn't require a lot of hardware just a few clamps and supports. An overhead load bearing rail system would work to allow modules to be loaded and unloaded. I'd say about 5 tons (weight wise) can handle 20 to thirty tons of gear. once on the truck, the bed of the truck can handle the load.

That's something I overlooked. Right, no need to include docking clamps -- but it does need a way to lift the module off the flatbed. A crane that can lift a load that heavy and wide off the side or the end would be huge. One possible solution would be for the module to be a gantry crane that retracts to get it out of the way of the cutter (and to reduce the height of the road version), but swings up above the module to lower it to the ground or lift one from the ground, as well as connecting the front and rear of the carriage.

A simpler design might be to have the cutter unload modules directly onto the ground (presumably with roll blocks), and for the truck to move sideways over the module, and lower the lengthwise beam into the module's mounting groove. To move sideways, the truck could either rotate its regular wheels 90 degrees or have a extensible set of sideways wheels. The latter seems simpler; I often see retractable wheels on trucks for extra load capacity, and it would make sense if similar wheels were mounted sideways. They'd only move the unloaded truck at low speed, so they could be smaller than the main wheels.

Finally, since such a truck is purpose built to complement the Modular Cutter, it would be cool if it could be collapsed into a module itself.

 

[AnotherDilbert]

I looked up the mass of a cutter module in GURPS Modular Cutter, and a basic cargo module has a loaded weight of 144 tons. An armored cargo module is 287 tons.

Seems a bit light.

A cutter module is 30 dT or 420 m³. Fill it with gravel, ore, or something similar and it will mass around 600 tonnes. Fill is with solid steel and it will mass around 3000 tonnes.

Good point; tracks are a waste of hassle except in specialized settings, like a snow-cat.

You need firm ground for wheels, the ground pressure can become very high. Any soft ground such as sand, mud or even damp ground would restrict your mobility?

 

[wbnc]

wheels are a good all around system. The biggest dump trucks used can handle 350 short tons of ore on four wheels...big wheels but wheels none the less. Russian mobile launchers are wheeled and carry around a fully loaded ICBM...with decent cross country capability.

Good point; tracks are a waste of hassle except in specialized settings, like a snow-cat.

I looked up the mass of a cutter module in GURPS Modular Cutter, and a basic cargo module has a loaded weight of 144 tons. An armored cargo module is 287 tons. A giant ore dump truck is going to drive only on purpose built roads, so wheel loading is an issue. On standard roads, it would take up two lanes and be an over-height load, because the module is 21 feet (6.4 m) in diameter and 42 feet (12.8 m) long. (Standard shipping containers are about 8 feet wide, 9 feet tall, and 40 feet long.) That much mass would probably best be carried on a lot of wheels to avoid cracking the paving. For road use, I'd build it like two low-riding trailers side by side, with eight axles and 32 wheels, arranged like this (not to scale):

00----00 00----00
00----00 00----00




00----00 00----00
00----00 00----00

For off-road, height isn't a concern, so instead of fixed axles each pair of axles (or even each cluster of four wheels) could be rocker mounted.

Wouldnt need a docking clamp for just trundling around the surface. that doesn't require a lot of hardware just a few clamps and supports. An overhead load bearing rail system would work to allow modules to be loaded and unloaded. I'd say about 5 tons (weight wise) can handle 20 to thirty tons of gear. once on the truck, the bed of the truck can handle the load.

That's something I overlooked. Right, no need to include docking clamps -- but it does need a way to lift the module off the flatbed. A crane that can lift a load that heavy and wide off the side or the end would be huge. One possible solution would be for the module to be a gantry crane that retracts to get it out of the way of the cutter (and to reduce the height of the road version), but swings up above the module to lower it to the ground or lift one from the ground, as well as connecting the front and rear of the carriage.

A simpler design might be to have the cutter unload modules directly onto the ground (presumably with roll blocks), and for the truck to move sideways over the module, and lower the lengthwise beam into the module's mounting groove. To move sideways, the truck could either rotate its regular wheels 90 degrees or have a extensible set of sideways wheels. The latter seems simpler; I often see retractable wheels on trucks for extra load capacity, and it would make sense if similar wheels were mounted sideways. They'd only move the unloaded truck at low speed, so they could be smaller than the main wheels.

Finally, since such a truck is purpose built to complement the Modular Cutter, it would be cool if it could be collapsed into a module itself.

Te good thing aboutthe vehicle is that it Wouldnt be using roads very often, andif it did they would probably have escort cars to clear the way and check for low bridges....cause, ya don't want to see a 50dt vehicle encounter and commuter car, or bridge in an unplanned fashion.

the wheel layout seems like a good one. I have seen trucks designed to carry slate way up in Canada... lots of wheels..a LOT of wheels. The articulation would come in handy in areas where you have tight curves...so Yep, probably at least one or two would be articulated...ya know the vehicle you are describing sounds a lot like a bigger version of the Landmaster from the movie Damnation Alley. If ya haven't seen it go watch it its good old fashioned cheesy goodness.

I may work up a version of your suggestions for giggles I'll see how it works out. And yes a modular landmaster would be a nifty idea for certain scenarios

I looked up the mass of a cutter module in GURPS Modular Cutter, and a basic cargo module has a loaded weight of 144 tons. An armored cargo module is 287 tons.

Seems a bit light.

A cutter module is 30 dT or 420 m³. Fill it with gravel, ore, or something similar and it will mass around 600 tonnes. Fill is with solid steel and it will mass around 3000 tonnes.

Good point; tracks are a waste of hassle except in specialized settings, like a snow-cat.

You need firm ground for wheels, the ground pressure can become very high. Any soft ground such as sand, mud or even damp ground would restrict your mobility?

most of a typical module would be empty space unless ou were using it for a bulk cargo hauler..which is sort of doable but a lot of overkill. I figure if I went with 150-200 tons as a max load for a full set of modules I'd be pretty well covered. After all an M-1 Abrms main battle tank is only 70-80 tons..and it is one of the densest vehicles I can think of off the top of my head.

Ground pressure and terrain woud be an issue anytime your dealing with a massive vehicle. I think the drive system would be highly situation dependent. If you're operating in an area that is boggy or has lots of streams you'd end up with track or Grav units. while a wheeled vehicle would do for open plans low hills and places like death valley. Any vehicle this large would probably need a couple of outriders to move ahead and scout a trail, to avoid it getting trapped in bad terrain or suddenly rolling into soft ground.

 

[AnotherDilbert]

most of a typical module would be empty space unless ou were using it for a bulk cargo hauler..which is sort of doable but a lot of overkill. I figure if I went with 150-200 tons as a max load for a full set of modules I'd be pretty well covered. After all an M-1 Abrms main battle tank is only 70-80 tons..and it is one of the densest vehicles I can think of off the top of my head.

An M-1 put into a packing crate is about 89 m³ or 6 dT. You could have 5 tanks (and a lot of empty space) in a 30 dT module. A module full of water, MREs, or ammo would be much heavier than 200 tonnes.

Ground pressure and terrain woud be an issue anytime your dealing with a massive vehicle. I think the drive system would be highly situation dependent. If you're operating in an area that is boggy or has lots of streams you'd end up with track or Grav units. while a wheeled vehicle would do for open plans low hills and places like death valley. Any vehicle this large would probably need a couple of outriders to move ahead and scout a trail, to avoid it getting trapped in bad terrain or suddenly rolling into soft ground.

Where I come from, where is it is generally damp or snowy, such a wheeled vehicle would be considered capable of negotiating bad roads (at least most of the time), but not very off-road capable.

 

[steve98052]

I looked up the mass of a cutter module in GURPS Modular Cutter, and a basic cargo module has a loaded weight of 144 tons. An armored cargo module is 287 tons.

Seems a bit light.

A cutter module is 30 dT or 420 m³. Fill it with gravel, ore, or something similar and it will mass around 600 tonnes. Fill is with solid steel and it will mass around 3000 tonnes.

I double checked on that, and I discovered that the "Lwt." abbreviation in the book meant "light weight" -- empty of crew, fuel, cargo, ammunition, etc. -- not "loaded weight". So you're correct. Even an empty module is heavy.

You need firm ground for wheels, the ground pressure can become very high. Any soft ground such as sand, mud or even damp ground would restrict your mobility?

Putting lots of wheels on the ground, with rocker carriages to keep the wheel loading on each wheel fairly similar, and powering all of the wheels, makes a vehicle that's almost as tolerant of bad terrain as a tracked vehicle. Mars rovers used that sort of wheels, and they've managed to avoid being mired in spite of adverse terrain and partial mechanical failure.

Ground pressure and terrain woud be an issue anytime your dealing with a massive vehicle. I think the drive system would be highly situation dependent. If you're operating in an area that is boggy or has lots of streams you'd end up with track or Grav units. while a wheeled vehicle would do for open plans low hills and places like death valley. Any vehicle this large would probably need a couple of outriders to move ahead and scout a trail, to avoid it getting trapped in bad terrain or suddenly rolling into soft ground.

Indeed. It might even make sense for such a vehicle to run on wheels, but mount a pair of front and rear tracks, more like those of a snow-cat than a bulldozer, that can be lowered to give a shove in cases where even 32-wheel drive isn't enough traction. And of course tracks or grav would be necessary on some kinds of terrain, though I'm not sure it would make sense to land a cutter on the wrong side of a swamp if it's possible to land the module where you want it to end up.

I mentioned the idea of designing the truck to fit itself into a cutter module, or even collapse itself into a cutter module ready to lift. I wonder whether I have enough Legos to try to visualize that idea with tangible pieces.

 

[Condottiere]

In regards to the Mars landers, two things come to mind:

1. They're light.

2. Mars has one third standard gravity.