Top Ten Tanks

[Vesku]

Blasphemy! It's Bruce!

[klanx171]

Whos Ian Dickenson then?

[Vesku]

Nothing to do with Iron Maiden, that's for sure.

[zeiss]

Are those ... petrol tins being used as standoff armor for the treads? :eek1:

It's all part of an "ingenious" anti-HEAT system. :whis:

"The design of the side armor with its partly external fueltanks and after the renovation and mofication (REMO) with diesel jerrycans along the sides, also meant that the Strv 103 had the best protection against HEAT rounds.
Tests showed that while a HEAT round would puncture and often ignite the diesel pouring out on the outside of the vehicle, the HEAT jet itself would start to dissipate in the diesel."

The front has a much more classic HEAT defense..

[seabolt]

"Tests showed that while a HEAT round would puncture and often ignite the diesel pouring out on the outside of the vehicle, the HEAT jet itself would start to dissipate in the diesel."

Wow, really? Given the relative concentrations of energy, that sounds about as effective as diverting a bullet by sneezing on it midflight. Meanwhile the intake filters get pawned by petrol smoke. But I'm far from an expert on the subject ...

[Imp]

"Tests showed that while a HEAT round would puncture and often ignite the diesel pouring out on the outside of the vehicle, the HEAT jet itself would start to dissipate in the diesel."

Wow, really? Given the relative concentrations of energy, that sounds about as effective as diverting a bullet by sneezing on it midflight. Meanwhile the intake filters get pawned by petrol smoke. But I'm far from an expert on the subject ...

Not an expert but should work for 2 reasons.
1) the speed the round is traveling at diesel is a solid, try watersking & falling off at 60MPH may as well hit the ground you bounce.
2) diesel is actualy a good explosive, hard to ignite but engines are very inefficent extracting well under half the power. Its used for major demolition work with regular explosives as trigger as its cheap & effective.
So you have got cheap as chips reactive armour deforming/diffusing the plasma cone before it crosses the space & reaches the armour.

Perhaps in the winter armys should start dusting there tanks off with sugar or flour, winter camo pretty explosive to, cake anyone :whis:

[zeiss]

But I'm far from an expert on the subject ...

Well, now you know to hide behind the container of flammable liquid in your next gunfight..

[seabolt]

1) the speed the round is traveling at diesel is a solid, try watersking & falling off at 60MPH may as well hit the ground you bounce.

A full can of diesel almost certainly is going to defeat a last-generation HEAT round in this fashion, functioning as spaced armor. It's also going to fireball (like in the movies, which is far less energy efficient than a proper explosion), drenching the vehicle in heat and smoke (all of that unused energy) and marking its location for the next 5 minutes (this is bad).

I can't fathom how this would be better than simply extending the metal grille from the front around the sides. This led me to think that maybe the fireball was supposed to impact a modern tandem-charge HEAT round. (These are the "TC" rounds in MBT that work wonders; look for them!) The fireball certainly would remain in process when the follow-on charge fired, but its relative force vs a few dozen grams of metal moving at 9000 meters per second would be laughable.

That said, I would suspect that simply acting as spaced armor vs older HEAT ordnance is the intended function. The AFV probably lacks space for proper internal tankage and the designers made lemonade from their lemons. I wouldn't want to be driving the thing in a real fight, that's for sure.

2) diesel is actualy a good explosive, hard to ignite but engines are very inefficent extracting well under half the power. Its used for major demolition work with regular explosives as trigger as its cheap & effective.

As mentioned, diesel just sitting in a can usually is a poor explosive. It refuses to vaporize properly under 120F/49C. (Diesel engines reduce the effective flashpoint via compression, but used to be notoriously hard to start in cold weather for this reason.)

A mostly empty tin of petrol or hot diesel can be an excellent explosive: Under perfect conditions, a single can of the size on that AFV could yield a bang as big as *360* sticks of TNT. (This is a makeshift fuel--air explosive.) But I doubt that's the idea, here. The hazard to the crew from a real explosion would be non-negligible. (This would be an excellent way to snap every neck among them, for starters.) I imagine those tins are kept either topped off or empty, nothing between.

So you have got cheap as chips reactive armour deforming/diffusing the plasma cone before it crosses the space & reaches the armour.

Well, it is cheap, but so's that metal grate on the vehicle's nose. And it doesn't peal off greasy smoke and suffocating heat ...

[Imp]

As I say no expert but knew someone that was & used to use diesel a lot in 50 gallon drums.

On these 2 points

It's also going to fireball (like in the movies, which is far less energy efficient than a proper explosion), drenching the vehicle in heat and smoke (all of that unused energy) and marking its location for the next 5 minutes (this is bad).
&
As mentioned, diesel just sitting in a can usually is a poor explosive. It refuses to vaporize properly under 120F/49C. (Diesel engines reduce the effective flashpoint via compression, but used to be notoriously hard to start in cold weather for this reason.)

My thoughts
firstly as you say acts to a degree as spaced armour.

It would be a shaped explosion the round hitting it but more importantly the speed of the plasma would massivly compress the diesel easily hitting flash point then being vaporised.
The blast would be centred on the area of pressure so the explosion would be aimed mainly at the plasma jet taking energy out of it & hopefully distorting it.

Any fuel that ignited did not blow up due to compression by the jet, stuff on edge will be vaporised before ignition. Diesel further out that misses the blast will ignite giving your fireball.
From a protection point of view this is fine as would not effect the plasma cone & is ignited by heat alone. The plasma is nearly twice as hot as the sun 120F???? thats why it melts through armour needing vapour to ignite easily probably not an issue.

Yes I have dirty black smoke need to change the filters but it will burn out quickly & we are still in one piece.

This would have little effect on the crew or vehicle the part exploding vs the round would send most of its energy away from the vehicle.
The part that ignites will be a minor blast in all directions & take the path of least resistance also mainly blowing outwards.
Actually placing blocks of explosive on the tank to do this has been around for years using jerry cans not as scientific or controlled but can see why someonethought to test it.

Same principal is used to blow up a drum of diesel stick the TNT where you want to aim the explosion.

[seabolt]

It would be a shaped explosion the round hitting it but more importantly the speed of the plasma would massivly compress the diesel easily hitting flash point then being vaporised.
The blast would be centred on the area of pressure so the explosion would be aimed mainly at the plasma jet taking energy out of it & hopefully distorting it.

I think at this point we're just stumbling over semantics for this effect. I think technically even this is going to be highly localized flash burning given a fuel that lacked oxygen prior to the trigger explosion, but whatever. I fully agree it would do the trick against a single HEAT effect.

The point remains, why? A metal grate would do the same thing with far fewer side effects.