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Collimatrix

Design Contest Supplement: Typical Weights in a Modern Tank

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Since we've got the new AFV design competition going and not everyone has solidworks, I thought I would share this information from Technology of Tanks so those who do not have CAD/CAM programs could come up with a reasonable accounting of what a tank ought to weigh:

-Armor usually contribute between 35% and 51% of the total mass of the vehicle. The lower figure is typical for light tanks, the higher for MBTs. If the armor were reduced to the minimum necessary for structural purposes it would still be about 20% of the total mass. The highest figure on record is 57% for the armor of the IS-3.

-The tracks contribute about 8% to 10% of the mass of the vehicle in the case of steel link tracks. On a fast track-laying combat vehicle the tracks are getting slung around over all sorts of rocks and whatnot, so they need to be tough, which means that they're heavy. Band tracks weigh 25%-50% less than steel link tracks, but band tracks can only be used on lighter vehicles. The heaviest vehicle I know of that uses band tracks is the Turkish Tulpar IFV at 32 tonnes.

-Suspensions contribute about 8% to 10% of the total mass of the vehicle. Hydropneumatic suspensions are the lightest, but not by an enormous margin. Higher performance suspensions weigh more.

-The power pack, that is the engine and the transmission together, account for about 12% of the vehicle's mass.

-Guns typically contribute 3% to 7% of the total mass of the vehicle, although cramming the very largest gun possible into the very smallest tank possible can bring this up to about 10%.

-Ammo generally weighs less than the gun. Fuel weighs about the same as ammo.

On any fictional or notional tank design, I'll be looking to see if the weight of the components are within these bounds. If they're not there had better be a damned good explanation.

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Do we need to give you an itemized list of everything? Because while for the folks with SolidWorks that may be OK, for the folks who don't have it that will be very difficult.

I have that tank weight estimator program lying around somewhere, though, maybe I can post that.

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Do we need to give you an itemized list of everything? Because while for the folks with SolidWorks that may be OK, for the folks who don't have it that will be very difficult.

I have that tank weight estimator program lying around somewhere, though, maybe I can post that.

It'll be kinda difficult for me as well, because I did everything in the same freaking part, instead of making an assembly.

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It'll be kinda difficult for me as well, because I did everything in the same freaking part, instead of making an assembly.

 

I also sort of think the incentive is backwards here. I admit to speaking from selfishness in saying this, but I am going to basically complete what would be the preliminary design phase in a development program. Like, my work would be enough to make part of a proposal. It won't be perfect, and it likely won't conform to colli's specs because of that.

Hell, it's barely going to meet my requirements, if it does, but that doesn't mean a second development spiral couldn't shake it out.

It sounds like I'm overthinking it - guilty - but I would ask colli not to over think it either, because none of the designs he'll be judging will be actual, real tanks. They're just proposals, which are always optimistic.

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I've given it some thought and there are three ways to give a decent accounting:

 

 

1)  Draw it up in Solidworks and give a brief breakdown of the parts weights.  Since they should be as subassemblies, this ought not be too difficult.

 

2)  Estimate the size, then calculate armor thicknesses for the roof, sides, front and rear, then add other components vendor specs or the guide above or the spreadsheet or similar.

 

3)  Have the design be based on an existing one with modifications accounted for.

 

 

Obviously, some mix of the three is fine too.

 

I'm not going to be a huge ass about it, but the mass of armor, drivetrain, running gear, guns ammo and fuel should be accounted for and in the same ballpark as real vehicles.  As long as it's close it's convincing enough for our purposes.

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