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Bit of an odd question, but it's been bugging me for ages. On armoured military vehicles (both irl and miniatures), sometimes older ones, you often see square armour panels with a grooved X cut into them. What are these for? What purpose do they serve?

Here's an example of what I mean, the two rear panels on this vehicle:

Indentations are often used to strengthen large panels - a flat panel of a certain size when (say) a weight is placed upon it will tend to bend equite easily. A panel of the same size which has been produced with an indentation is a lot stronger, and will take a greater amount of weight before deforming.

This is why you see a lot of fuel canisters with these kinds of markings (see the excellent German "jerry" cans vs the crappy British versions during WWII), as they contain large weights of fuel and use comparatively very thin metal sheeting in their construction.

Also, as a practical reason, sci-fi vehicle designers, prop makers for movies, etc. probably prefer having details over flat plates as the 'detailed' pieces are more interesting.

For Heavy Gear a lot of designs use that motif. In the case of many Gears, the butt plate has a X on it, which unfortunately also indicates the vehicle's gas tank! Many designs have them on the hip guards as well, but I think historically in-canon 'older' designs are more likely to use them than newer designs.

What Silver said and most toys and minis that you see that have them are simply copying a design element from the German Panther, which is arguably one of the most astheticly pleasing classic tanks:

Great OP. I always wondered that myself.

Yep, I've learnt something today

Maelstrom808 wrote:What Silver said and most toys and minis that you see that have them are simply copying a design element from the German Panther, which is arguably one of the most astheticly pleasing classic tanks:

Now does anyone know what those ridges on the Panther turret are for? Wondered that forever.

It's called Zimmerit. It's an anti magnetic mine coating, applied as sort of a paste in ridges to provide distance and reduced surface area. Ironic because only Gerry really used magnetic mines.

SilverMK2 wrote:Indentations are often used to strengthen large panels - a flat panel of a certain size when (say) a weight is placed upon it will tend to bend equite easily. A panel of the same size which has been produced with an indentation is a lot stronger, and will take a greater amount of weight before deforming.

This is why you see a lot of fuel canisters with these kinds of markings (see the excellent German "jerry" cans vs the crappy British versions during WWII), as they contain large weights of fuel and use comparatively very thin metal sheeting in their construction.

I have been looking for those amazing Jerry canes to strap to my jeep for ages, but they are obscenely expensive.

It's why cars have all those creases and shapes in their panels - they're called swage lines and make an otherwise flat thin metal sheet much stronger. It's also why medieval armour was curved and shaped, it made it much stronger.

Civil cars usually have rounded metal surfaces plus added edges that prevent it from bending easily. Military surfaces are usually straight to simplify production, standardization and repair. So military metal surfaces need these extra X to provide stability against bending (compare also a paper sheet with a VVVV folded paper sheet to understand why it is more stable).

Totally OT, but one thing I love about that photo is it really gives you an idea of just how massive these machines are if you haven't had the chance to see one IRL. Most photos don't really convey the scale of these beasts.

True that! I went found the Bovington tank museum last year and it was one WTF moment after another. And that was just the WW1 vehicles!

The Early WW2 - wtf!

Then the big Cats - wtf!

Then the Crocodile - wtf!

And that's just one 30 year period. Yeah tanks are cool, but we all know that!

Emerett wrote:
I have been looking for those amazing Jerry canes to strap to my jeep for ages, but they are obscenely expensive.

They're not that bad:

http://www.quadratec.com/products/12202_06_07.htm

You can also get them in blue (usually for water). Sure, you can get plastic cans for half the price, but they're not nearly as conveniently shaped for attaching to a vehicle.

farmersboy wrote:It's why cars have all those creases and shapes in their panels - they're called swage lines and make an otherwise flat thin metal sheet much stronger. It's also why medieval armour was curved and shaped, it made it much stronger.

And, more importantly, helped deflect weapons away from the user. Glacis plates didn't just come from tank design after all

The creases are the difference between a flat sheet of paper and corrugated cardboard. Its all about bending moments, section factors and shar forces...

SilverMK2 wrote:Indentations are often used to strengthen large panels - a flat panel of a certain size when (say) a weight is placed upon it will tend to bend equite easily. A panel of the same size which has been produced with an indentation is a lot stronger, and will take a greater amount of weight before deforming.

This is why you see a lot of fuel canisters with these kinds of markings (see the excellent German "jerry" cans vs the crappy British versions during WWII), as they contain large weights of fuel and use comparatively very thin metal sheeting in their construction.

Thanks for explaining that, Silver . For some reason, I didn't make this connection with the "X's". Now it clicks!

notprop wrote:It's called Zimmerit. It's an anti magnetic mine coating, applied as sort of a paste in ridges to provide distance and reduced surface area. Ironic because only Gerry really used magnetic mines.

Here's a cool blog post about modeling it on an IG vehicle:

http://necrodustdevils.blogspot.com/2008/08/hellhond-3-zimmerit.html

Where is that APC from and who makes it?

I'd like to grab one.

Yes I would like to buy some as well. Can anyone name the model and where to buy it?

Thanks

It's from here. Specifically the hybrid gun carriage system. Note that it's 15mm, not 28.