BattleTech - The Board Game of Armored Combat
BattleTech Game Systems => Ground Combat => Topic started by: marauder648 on 05 May 2019, 03:29:36
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And I got thinking that to get the tank to go faster would require more than just an XL engine delivering more power. The Mars is a big 'ol tank and the closest thing we've ever really had to its quad track layout is the experimental T-95 tank destroyer which had two tracks on either side to support its not inconsiderable 95 tons.
(http://cdn-live.warthunder.com/uploads/25/5419f2371e6a62ce89dfa9b17ed842403c5ab9/T-28_Super_Heavy_009.jpg)
The Mars has its tracks far more widely spread though and this would be a problem.
(http://cfw.sarna.net/wiki/images/0/03/Mars.gif?timestamp=20101224145231)
Those inner tracks would be a maintenance nightmare, if you throw one of the tracks or suffer damage to them, you can't have the crew work on them because the rest of the tank's in the way, everything track/roadwheel related would be a full on workshop job. And then there's the amount of space they take up internally, one of the inner tracks goes beneath the fighting compartment for the turret and although it seems to be an unmanned turret you've still probably got a turret basket and all the loading/power systems that would have to be placed around the area where the track bulges up into the hull. Unless the inner tracks are kind of like those on the TOG
(https://encrypted-tbn0.gstatic.com/images?q=tbn:ANd9GcR11Zk-kNZ5IT_4ATvP49ytVaAgE03yiUY6mnPxjsLiwuqecI6AFQ)
Where they go up at the front and back for the drive wheels and then dip down to try and eliminate any major extension up into the hull.
But anyhow, the Mars XL. When making a vehicle, you have things like the clutch, the power system, breaks etc, all built to go to certain tolerances and speeds. If you then start doing things like adding weight etc you strain them and overwork them, leading to failures. We've had RL experience with this in WW2 where tanks like the Panther, Ferdinand/Elephant and Tiger II were too big and heavy for their transmissions or clutches and went through them at an alarming rate.
And slapping a more powerful engine into a Mars and expecting it to go faster would have the same problems. Its tracks, its suspension, clutch, transmission etc would all be built around a max speed of 32kph. Putting a more powerful engine in there and trying to force a system that is designed and built to do one thing by going well above what its meant to makes me think that the Mars XL would be an absolute nightmare for techs.
Even if you re-worked the Clutch, added a new gearbox and transmission as well as worked on the suspension and tracks, you'd probably have a vehicle that would have a voracious appetite for components. Something tells me that the Mars XL would be still rated to go at 32kph, and its driver and crew would be told that they could only 'give it the beans' to quote Clarkson for short periods of time and only basically in emergencies. Because if you don't you will break the power train or snap a track and you will be stuck until techs or a dropship can get out to you (seeing as the Clans have nothing that i'm aware of that can recover and carry a Mars outside of a Dropship).
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Concerning maintenance, maybe it raise and lower specific tracks?
This would require the suspension system to be build for this, but it is plausible.
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Concerning maintenance, maybe it raise and lower specific tracks?
This would require the suspension system to be build for this, but it is plausible.
Some kind of pnumatic system that when its getting repaired the track that needs to be worked on is pushed down? Yeah that makes sense, otherwise you'd have to take off one track and all its road wheels and then what ever divider there is between them and then get at the other one which would be a nightmare.
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What about the tracks as a magnetically-driven belt of plates that slides over the surface on rails and re-enters the hull through a slit? In theory you could design that so that even if a portion of the track were blown off it wouldn't prevent the remaining segments from functioning. The entire track mechanism could then be articulated separately from the hull in several places to smooth out the ride.
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Mars tech crews are washed elementals that can carry the massive jack needed to tilt the tank on its side to reach the treads
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Nitpick, but despite lacking a turret the T28/T95 was actually designated as a tank rather than a tank destroyer due to its intended role.
And while the Mars might be comparable in size to that impractical monstrosity, the modern M1A2C Abrams is compatible in size to the Tiger II yet has far greater mechanical reliability due to much more advanced components and construction techniques being available. I think it's likely that the Mars is similarly much easier to build and maintain than a T28 (it also has substantially better speed and maneuverability- by Battletech standards the T28 had a movement rate of 0/1).
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Well - think it got more in common with the Object 279
(http://i59.fastpic.ru/big/2013/1029/39/8d74537527e0fe3666c677514995d839.jpg)
track maintenance is an issue - but they could use continuous rubber bands (there exists repair sets or segmented rubber band (4 segments)) - would help a lot in maintenance.
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I find that thinking about the motive systems of the TRO3060 Clan Vehicles is a quick route to a headache.
Sure as hell drawing them was
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I find that thinking about the motive systems of the TRO3060 Clan Vehicles is a quick route to a headache.
Sure as hell drawing them was
Well, clans consider vehicles as third rate.
They simple used utility vehicles like a road roller (Ishtar) or tractor (Mitras, Hachiman, Ares) or land train (Ku) or paver (Zorya)
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Yeah, putting guns on construction vehicles does explain some looks... ::)
A super suspension system could explain the Mars, thought. If the tracks can be extended by 2-3 feet it would make mobility AND maintainability much better!
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Those inner tracks would be a maintenance nightmare, if you throw one of the tracks or suffer damage to them, you can't have the crew work on them because the rest of the tank's in the way, everything track/roadwheel related would be a full on workshop job. And then there's the amount of space they take up internally, one of the inner tracks goes beneath the fighting compartment for the turret and although it seems to be an unmanned turret you've still probably got a turret basket and all the loading/power systems that would have to be placed around the area where the track bulges up into the hull. Unless the inner tracks are kind of like those on the TOG
Do you know how they fix it if a tank breaks track?
(https://i.pinimg.com/originals/9e/8c/58/9e8c58ae913aa522f54d22a954e51a91.jpg)
You drive off one track after using a sledgehammer to knock the pin out (or it breaks in the field). Work is done on the 'broke' track and then the vehicle goes in reverse until its lapped right back to the same place and new pin gets put in. SOOOOO grateful I never broke track in the field- or had to deal with it in the motorpool even. My TC & I were cursing up a storm and praying devoutly at the same time when I put our M1068 up on a rock that was covered by snow during the night before.
(http://www.livesteammodels.co.uk/dhmg/images6/11810.jpg)
(http://thepatriotperspective.files.wordpress.com/2012/06/breaking_track-mlrs.jpg)
wow . . . MLRS . . . that really looks like my old unit area
Btw- Moltke or Carnivore suspension?
(https://www.thanksbuyer.com/image/ebayimages/data/201704/53733/1493110460-2.jpg)
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Colt, what's that last chassis?
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Dunno exactly, it came up when I did a couple of searches. I think its a remote robotics set up, but each side's tracks being split in two reminded me of a couple of designs with regards to the 'how' like the Carnivore.
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Never try to rationalise batteltech designs. Its a game. If any of the mech designers had half a brain all mechs would have reverse knee joints (i.e. mad cat/marauder) instead of the dumb human skeletal type joints.
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Never try to rationalise batteltech designs. Its a game. If any of the mech designers had half a brain all mechs would have reverse knee joints (i.e. mad cat/marauder) instead of the dumb human skeletal type joints.
Whoa, that's a little harsh.
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Nah, chicken walkers are only better over open ground. They're not so good with stairs... *ED_209_falling.gif*
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OT note: Birds actually have knees in the same orientation humans have. They're just extreme toe-walkers, the "knee" is the ankle...
Anyway, I've never heard that reversed knee joints would be significantly different that forward kness in function.
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All I can think of is that Chaos Irregular description of a Raijin in combat where it was hull down behind the crest of a hill by squatting down (like a chicken sits on eggs) to cover most its frame though the weapons still poked above the crest to fire. Its going to be faster to do that b/c its already part of the way along in the process unlike say a Centurion's humanoid legs.
Going back to it though, wider treads offer a larger ground cushion that helps to prevent a tank from getting mired. If you cannot expand the width of a single track, then using a second set might make sense. Look at a lot of the post WWII designs, they were built for operations in Europe with a set expectation of ground saturation. I want to say some of the tanks used in N Africa were fine there but bogged down when put in use in Europe. I wonder if the Merkava has the same tread-width as the Leopard, Centurion or old Soviet tanks.
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According to this site : http://mathscinotes.com/2016/06/tank-track-ground-pressure-examples/
Nato tanks run 25 to 26.5 inch track widths. Modern soviet/russian tanks run 22 inch widths.
I haven't found a source for the merkava, but i have found a number of unsourced claims of 25 inches.
Generally the issue is less track width so much as track area relative to tonnage.
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Yeah, I was wondering about the Israeli design being less b/c it was not needed in their theater BUT . . . since they built off of some shared concepts/work with the Brits it would not be a surprise not to change it.
Track width is just a easy way to increase the area. I will say afaik they never tried to shorten the length of the M270, since it does offer increased stability as a firing platform. It certainly does not have the firing problems HIMARS has when it goes to shoot.
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BT tanks (let's assume there are no wheeled tanks) will have a very low groundpreassure.
First because those things are large. Really large.
The classic Po for example will be much larger compared to a M1. (The main reason is ammunition, 2 tons of AC ammo can not be stowed easily. At least not when you don't want to ignore lessons of tank warfare.
(Mentioned Po will have 48-60, 140mm rounds (56 saboted 90mm APX)
The second reason, afaik the speed tanks can do is offroad speed - so they have wide tracks, powerful engines and superb transmission.
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The classic Po for example will be much larger compared to a M1. (The main reason is ammunition, 2 tons of AC ammo can not be stowed easily. At least not when you don't want to ignore lessons of tank warfare.
(Mentioned Po will have 48-60, 140mm rounds (56 saboted 90mm APX)
A ton of ammo takes up a bit over a cubic meter. It's really not all that bad.
The reason for BT vehicles being huge is their crew compartments are much, much larger than IRL vehicles. They have bigger crews (sometimes much bigger, a Behemoth has more crewmen than a Maus despite not needing manual loaders or a radio operator) and there is more space per crewmember. Some vehicles give the crew space to walk around inside IIRC. And things are even worse for Clan vehicles because with the crews often being washed Elementals they need bigger seats and more headroom.
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Yeah, the Po weights less than a loaded Abrams IIRC . . . though on a flat plain I think the Abrams can go faster?
BT tanks are more crewed like WWI tanks to be honest . . . or perhaps taking off the Bolo types though since the setting does not have AI, all the auxiliary guns have to be manned by individuals.
THOUGH . . . some recent fiction matches up with what someone talked about for TO&E planning purposes. First Price Caleb Hasek-Sandoval-Davion was the track commander of a M1 Marksmen that he rode into combat. The vehicle was crewed more like modern tanks- driver, TC, gunner and IIRC someone else was sitting in the turret, alternate gunner maybe in place of the loader? And the internal spaces were pretty tight when he was needing to bail out. Isle of the Blessed has a pillbox'd Manteuffel save Davion in his Marauder, and the TC checks to find the 2 or 3 other crew are dead in the vehicle. Sniper's Shrek has a crew of 3 . . . so the rules about crew are ignored- BUT if you consider those missing folks as support for each vehicle then it makes sense. Dedicated techs and ammo loaders- who in current doctrine are second/back up crew.
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You do realize that as this tank is fusion powered it doesn't have a gearbox, and might not even have a clutch, right?
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we had diesel driving electric motors during ww2
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You do realize that as this tank is fusion powered it doesn't have a gearbox, and might not even have a clutch, right?
Is that to me or the OP?
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You do realize that as this tank is fusion powered it doesn't have a gearbox, and might not even have a clutch, right?
Then how does it move?
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Engines directly on the wheels. Electric motors can have the torque needed. With the right power supply system it won't need a clutch either.
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Electric motors don't stall. They can direct-drive the wheels.
Or, as I suggested upthread, they could use linear motors to drive the tread plates directly and not have any wheels at all.
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Hang on - tracked vehicles roll on wheels which sit on tracks. I can't see how this could be done without wheels?
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Hang on - tracked vehicles roll on wheels which sit on tracks. I can't see how this could be done without wheels?
You have the tread plates moved directly by linear induction motors mounted in the hull. Like a maglev train, except the vehicle is the "track" and the "train" is a loop of treads. Change your inertial frame of reference and you see that the tread plates which are in contact with the ground are stationary and the vehicle is what's moving, just like with a normal tank. The plates at the rear of the vehicle are lifted up and plates are laid down in front of the vehicle as it advances forward.
To reduce the sliding friction between the hull and plates you would need bearings, either roller/ball bearings or magnetic bearings.
Because the plates are not a belt held in tension by rolling wheels, they don't have to perfectly interlock, either. You can have each plate be individually articulated to the hull on its own bearings, so that if one is blown off the rest of the loop continues moving around the raceway.
Suspension would be accomplished by articulating the raceway itself on shock absorbers that sit between the raceway and the rest of the hull.
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Electric motors don't stall. They can direct-drive the wheels.
Or, as I suggested upthread, they could use linear motors to drive the tread plates directly and not have any wheels at all.
Not going to happen b/c how do you propose to fix that broken track in the middle of a muddy field?
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Not going to happen b/c how do you propose to fix that broken track in the middle of a muddy field?
Because every plate is individually driven with its own linkage, a break in the track shouldn't stop the vehicle from moving unless the damage is so severe that the raceway itself is ruined--which would be analogous to a damaged axle in a wheel-driven vehicle. You could blast half the plates off and still generate useful traction. Unlike a conventional track it doesn't depend on being held in tension for the vehicle to make progress.
Also, if the raceways are articulated separately from the hull, then the same mechanism should be able to be used to lift a seized track section off the ground so that the seized plates/raceway segment could be replaced. If the damage is too severe to do that, you probably have bigger problems anyway.