Vehicle Protection

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In the previous post on this theme I looked at mobility factors but if a military vehicle is to have any utility on the battlefield it must be protected from enemy.

Threats

Threats to a vehicle, and by definition, its occupants come from many sources.

MINES and IED’s

The need to protect vehicles against mines is hardly new but in numerous conflicts the improvised mine, or IED, has been effective and deployed in increasing quantities. Sophisticated off route mines that employ explosively formed projectiles are a dangerous threat and difficult to defeat.

IED’s are complex because of the many variations, some may use commercial explosives or surplus munitions and others may use home-made explosives. They may be linked, have anti tamper devices, command or victim initiated with the trigger being some distance from the charge. The charge may even not be buried but in a vehicle on the side of the road.

This complexity makes them difficult to defeat.

DIRECT FIRE

Vehicles may need protection from small arms up to large calibre anti-tank rounds, RPG’s, anti tank missiles and air delivered weapons.

Although showing small arms ammunition only the 1 million frames per second video below is fascinating

The video below shows the effect of a typical man portable anti-tank guided weapon, the Javelin.

and, a 120mm tank round

Direct fire can produce significant spalling on the inside of the vehicle

Spall Effects of spalling

INDIRECT FIRE

Typically blast and shell fragments from artillery

FIRE

Molotov cocktails are still surprisingly effective and with the increasing proliferation of knowledge about how to create high burn temperature mixtures coupled with a greater likelihood of operating in hybrid conflicts in urbanised areas fire should be seen as a key future threat.

NBC

Although seen as a lower likelihood it is still critical for armoured vehicles to be protected against the impacts of nuclear, chemical and biological weapon systems.

ELECTRONIC

Electronic attack may be increasingly important and future vehicles begin to rely more and more on electronic systems for sensors, weapons and even propulsion.

Mitigation

To mitigate the effects of the threats highlighted above is a complex business. Ignoring the active means of defence, shoot them before they shoot you, vehicle protection is essentially passive in nature and even if we take the so called active protection systems in account they are still passive in so much that they are initiated in response to an attack.

ARMOUR

Steel, aluminium and advanced ceramic composite armours continue to develop, greater protection and decreased weight being the goal. Fabric armours are also an interesting recent innovation and highly advanced materials like graphene show great potential.

For lightweight vehicles composite materials offer an excellent blend of protection and low weight. DSTL and NP Aerospace have developed CAMAC EFP system that instead of using conventional ceramic tiles, packages small hexagonal ceramic segments into a resin matrix that is said to offer much better performance.

Segmented Ceramic Armour
Segmented Ceramic Armour

An earlier development that looked at composite armour was the DERA/QinetiQ and Vickers Defence Advanced Composite Armoured Vehicle Platform (ACAVP) that used a Fox turret and Warrior running gear mounted on a complete composite hull.

The so called plastic tank was the world’s first monocoque armoured vehicle chassis that used composites instead of metals for load bearing and protection. Advantages included a 15% reduction in weight, reduced thermal and radar signature, improved protection and resistance to corrosion (especially in salt water)

QinietiQ Plastic Tank and inflatable fascine
QinietiQ Plastic Tank and inflatable fascine

At 24 tonnes it had frontal protection against 30mm AP and 14.5mm protection elsewhere. It is now in the Tank Museum which is somewhat ironic given that it was designed to meet a future 18-25 tonne reconnaissance vehicle, the £6 million ACAVP being a precursor to TRACER.

The demonstrator was designed around a central mission module with driver and commander sitting side by side.

More details here, here, here and here.

Developed by Corus, BodycoteDSTL, QinetiQ and the University of Cambridge, perforated Super Bainite steel armour not only improves ballistic performance it reduces weight, comes in at a fraction of the price of conventional armour steel and provides a sovereign production capability.

The UK now has its own onshore supply of high-performance armour steel, thanks to a UK invention and a new manufacturing agreement.    Known as super bainite, the new armour steel has been developed to have outstanding ballistics properties and, in tests, it has performed better than ‘normal’ steel armour.    The Ministry of Defence has signed a licensing agreement with Tata Steel to manufacture the steel in the UK.    Showcased at Defence and Security Equipment International (DSEi) today, the material was invented and developed in the UK, with production ear-marked to take place in Port Talbot, South Wales. Under the agreement the steel will be turned into seven different items, including perforated armour plates that could be used on future frontline armoured vehicles.
The UK now has its own onshore supply of high-performance armour steel, thanks to a UK invention and a new manufacturing agreement. Known as super bainite, the new armour steel has been developed to have outstanding ballistics properties and, in tests, it has performed better than ‘normal’ steel armour. The Ministry of Defence has signed a licensing agreement with Tata Steel to manufacture the steel in the UK. Showcased at Defence and Security Equipment International (DSEi) today, the material was invented and developed in the UK, with production ear-marked to take place in Port Talbot, South Wales. Under the agreement the steel will be turned into seven different items, including perforated armour plates that could be used on future frontline armoured vehicles.

Flash Bainite makes some very bold claims, stating that it is cheaper, lighter, higher performing and easier to work with than conventional aluminium armour.

To disrupt the molten jet produces by shaped charge warheads DSTL has been investigating electric armour

Upon impact, an explosive warhead shoots a jet of hot copper into the target at several miles per second. Capable of penetrating over 1 foot of solid steel armour, this simple weapon can destroy a modern armoured infantry combat vehicle or tank. Few vehicles could practicably carry the weight of armour needed to resist such impacts, so the MOD’s scientific arm, the DSTL (Defence Science & Technology Laboratory) has been charged with developing a lighter solution.

The result is an Electric Armour system that DSTL claims will reduce the effect of impacts by such projectiles to almost zero.

Developed at DSTL’s R&D facility in Fort Halstead, Kent, the system consists of an outer skin – made from an unspecified high-strength alloy – that can be rapidly electrified to several thousand volts.

When hit by an RPG, the incoming copper jet has to pass through the electrified layers.

DSTL’s Professor John Brown explains how it works: ‘the high speed copper jet is virtually instantaneously dispersed by the powerful fields generated by the so-called ‘Pulsed Power’ System carried by the vehicle. Any residual debris is absorbed by the vehicle’s ordinary armoured hull.’

In a recent demonstration to high level British Army and MOD Customers, an armoured personnel carrier equipped with the system was subjected to repeated attacks, some from point blank range, and suffered only cosmetic damage.

Professor Brown says that the system, which weighs only a couple of tonnes, has a protective effect equal to carrying an extra 10 – 20 tonnes of steel armour

Defence Science and Technology Laboratory (DSTL), testing electric armour on an armoured personnel carrier at one their test range facilities.
Defence Science and Technology Laboratory (DSTL), testing electric armour on an armoured personnel carrier at one their test range facilities.

There would seem to be a considerable number of obstacles to overcome to make this militarily practical and resistant to simple countermeasures.

The fundamental problem with exotic composite armour is that they become prohibitively expensive.

Applique armour is simply armour that is ‘added’, or up armouring.

If one looks at pictures of almost any modern military vehicle it will be obvious that up armouring is extremely common.

Warrior Infantry Fighting Vehicle
Warrior Infantry Fighting Vehicle
Warrior MICV  with Increased Armour (WRAP2)
Warrior MICV with Increased Armour (WRAP2)

Modern developments in this area include not only the materials but also how they are applied, modular or tuneable protection kits can be used to tailor protection to suit the threat environment, assist with transport and allow easier replacement in the field.

Used since the emergence of shaped charge warheads spaced armour is a typical add-on for older vehicles vehicles.

The newer rod and bar configurations of the familiar cage armour seeks to physically disrupt the warhead.

The British company Amsafe Bridport produce a lightweight version of spaced or offset armour called Tarian. Amsafe are a traditional manufacturer of aircraft cargo nets, they make the largest cargo net in the world for the A400 for example and in conjunction with DSTL,  created Tarian.

Tarian protection CVR(T)
Tarian protection CVR(T)
Tarian on Heavy Equipment transporter
Tarian on Heavy Equipment transporter

Tarian was developed as a UOR for the princely sum of £500k and is a blend of different materials encapsulated in a fabric skin. It is fire proof and offers some ballistic protection in addition to high levels of RPG protection. Tarian is currently used on the Oshkosh Heavy Equipment Transporters and has been tested on a number of other vehicles.

Tarian quickshield
Tarian quickshield

Tarian QuickShield is a rapid replacement kit for damaged or missing bar armour, because it is so lightweight it can be carried as part of a vehicle’s standard equipment and is no in service with the MoD.

The latest version is called Tarian Extreme that has been extensively tested and is said to be 90% lighter than traditional steel bar armour, just as effective capable of being easily repaired in the field and much cheaper.

Amsafe have an agreement with ST Kinetics to use Tarian on its vehicles, the Bronco or Warthog as shown below

Tarian has huge potential, not just for vehicles and forms part of the Textron TRAPSnet system.

With possibly the exception of fabric armour, applique armour adds weight, sometimes a lot of weight. If a vehicle is not designed to accommodate this weight mobility and reliability will adversely suffer.

FRES Scout, is designed to deal with this potential weight growth, a clever move.

SHAPING

Shaping or sloping can increase protection against direct fire and blast effects.

The familiar sloped front and sides of armoured fighting vehicle is designed to increase the effective thickness of armour and present a glancing surface to projectiles.

To protect against mines and buried IED’s V shaped hulls deflect the blast up and around the vehicle rather than providing a flat surface for the blast to act upon.

Deep V shaped hulls has many disadvantages and one technique that is being investigated is to use a chimney to channel the blast wave, no I have not been on the sherry.

Vehicle blast chimney
Vehicle blast chimney

A recent Marine Corps Times article said the following;

While the tests’ results remain classified, DARPA officials say the blasts indicate a Humvee equipped with the structural blast chimney provides the mandatory survivability level required of an M-ATV, the lightest version of the military’s mine-resistant ambush-protected (MRAP) vehicles. And it does so at almost half the weight.

Not a universal panacea the Hardwire LLC blast chimney is at least a promising alternative.

SACRIFICIAL COMPONENTS and ABSORBTION

Designing components so that they come away in response to blast, for example, reduces resistance to blast and reduces the likelihood of a large under body explosion flipping the vehicle over. Although the vehicle may be rendered unusable its occupants survive.

Blast absorption matting is commonly used on the floors of armoured vehicles.

SPALL LININGS

Spall linings are designed to protect the vehicles occupants from high speed fragmentation caused by direct fire.

Because they are generally made from aramid, spun glass and other spun or woven fibre materials they provide a great deal of additional protection for only a modest increase in weight and cost. Spall linings are also mostly fire resistant.

DSTL are active in the field of armour research and last year, in conjunction with Ricardo, developed a new lining material;

Spall liners are an arrangement of molecularly manipulated polyethylene, the same material used to produce supermarket carrier bags. The polyethylene is spun into a fibre and compressed tightly; the units feel similar to dense wood, albeit lighter with far higher resilience to ballistic stress.

These were subsequently tested on the Foxhound light protected patrol vehicle.

The materials used in spall liners are also combined with other material to form integrated protection panels.

SEATING and INTERNAL FITTINGS

The careful arrangement of pedals, controls and various internal fittings does not have a great deal of bearing on vehicle survivability but has a significant impact on the survival of its occupants. Blast protected seating that insulates the seat from the vehicles floor, suspending the seat from the roof, has also seen a much greater use.

ENVIRONMENTAL MANAGEMENT

Filtering chemical, biological and radioactive particles is a simple method of protecting a vehicles occupant’s. Operating inside an enclosed vehicle in high or low ambient temperatures can be debilitating and rapidly inhibit effectiveness so heating and air conditioning are essential.

ELECTRONIC COUNTERMEASURES

Active electronic countermeasures are used to prematurely detonate or defeat the trigger mechanisms of mines and IED’s, it is an area that the UK is seen as a leader in although by going low-tech and employing simple pressure plate systems enemy forces can simply negate the many millions spent on these systems.

ACTIVE PROTECTION SYSTEMS

Active systems have tried to create a step change in protection against direct attacks by reducing the need for heavy armour.

A number of systems exist or are in development

Of course, every countermeasure has a counter countermeasure!

SIGNATURE MANAGEMENT

Specifically for direct attack, if the vehicle cannot be seen it cannot be shot at, so visual, thermal, electronic and sound signature testing and reduction is an essential part of a vehicles protection matrix.

The BAE Systems Adaptiv IR Camouflage system has recently been demonstrated

Although less exotic the Saab Barracuda signature management system is relatively cheap and in widespread use.

Even RF signature reduction on electrical and electronic connectors and enclosures plays a part.

DEF STAN 59-411 covers electromagnetic compatibility.

FIRE SUPPRESSION

Moving to diesel and away from petrol was an obvious means of fire protection but active fire suppression systems are still widely used in engine compartments to protect against oil mist fires and explosions.

External fire suppression is likely to be seen as important when operating in urban areas.

Standards

Testing is a hideously complex subject to many international and national standards.

The most commonly known is STANAG 4569, this describes Protection Levels for Occupants of Logistics and Light Armoured Vehicles.

The version was released in 1999 and the second revision in 2004 which included fragmentation, grenade and mine blasts.

The levels are described as;

Level 1

Kinetic Energy

7.62 x 51 NATO Ball (Ball M80) at 30 meters with velocity 833 m/s

Grenade and Mine Blast

Hand grenades, unexploded artillery fragmenting sub munitions, and other small anti-personnel explosive devices detonated under the vehicle.

Level 2

Kinetic Energy

7.62 x 39 API BZ at 30 meters with 695 m/s

Grenade and Mine Blast Threat

6 kg (explosive mass) Blast AT Mine:

2a – Mine Explosion pressure activated under any wheel or track location

2b – Mine Explosion under centre

Level 3

Kinetic Energy

7.62 x 51 AP (WC core) at 30 meters with 930 m/s

Grenade and Mine Blast Threat

8 kg (explosive mass) Blast AT Mine:

3a – Mine Explosion pressure activated under any wheel or track location

3b – Mine Explosion under centre

Level 4

Kinetic Energy

14.5x114AP / B32 at 200 meters with 911 m/s

Artillery

155 mm High Explosive at 30 m

Grenade and Mine Blast Threat

10 kg (explosive mass) Blast AT Mine:

4a – Mine Explosion pressure activated under any wheel or track location

4b – Mine Explosion under centre

Level 5

Kinetic Energy

25 mm APDS-T (M791) or TLB 073 at 500 meters with 1258 m/s

Artillery

155m High Explosive at 25m

Other related standards include STANAG 2920, EN 1523 and EN 1063.

Complimenting STANAG 4569 is the NATO RTO-TR-HFM-090 test methodology for determining Protection of Vehicle Occupants against Anti-Vehicular Landmine Effects. This seeks to look at the occupants not the vehicle.

View the full (and very complex) document here

These should be seen as starting points, not the end of the conversation.

For example, the Foxhound is reported as only having Level 2 protection but given the complimentary design of all the features I think it would be arguably a better place to be than for example, an older design at a similar level.

It should also be noted that availability plays a key role in survivability, if a vehicle is not serviceable because it takes too long to repair or maintain then it doesn’t matter what its protection level is.

Defence Science and Technology Laboratory

The MoD’s DSTL has an active materials research programme run by the Materials and Structures Technology Science and technology Centre (MAST STC) whose objectives are to support in the long term;

  • Collaboration
  • Maximising impact
  • Innovation
  • Maintaining the UK Defence materials capability

It is an area in which the UK has a strong reputation; Chobham and Dorchester armour were of course developed in the UK.

Its current targets are as expressed as;

Critical materials capabilities: Maintain a UK defence materials capability, including the sovereign Low Observable materials capability, areas where UK industry is not committed to continue supporting but are required for sovereign reasons and ensuring UK sources of strategic materials for defence.

Value for money: with reduced funding, materials are needed which are cheaper, last longer, are more reliable whilst maintaining or improving performance.

Support to current platforms: Providing improved materials, knowledge and materials advice to help sustain current defence capability

Future threats and opportunities: Develop novel materials with performance beyond current requirements to meet future requirements. Reduce technical risk in current and future platforms

Work Package 3.1 is for metallic and ceramic structural and protection materials.

Work package 3.2 is for polymers and composites structural and protection materials.

Read more here and here

Trade Offs and Trends

It is obvious but worth saying anyway, in order to mitigate threats one has to implement a range of solutions. Those solutions invariably lead to the need to trade increased protection with other capability areas.

Implementing a V shaped hull to protect against mines and IED’s will generally increase the height and centre of gravity of a vehicle, thus making it less mobile and more likely to have to be driven through vulnerable areas, increasing the chance of it being attacked.

Increasing armour thickness to protect against direct fire will increase weight and thus require a more substantial engine with its increase in fuel consumption, this increase in fuel consumption means putting people who provide that extra fuel into harms way.

There are areas on the margin where improvements can be had for minimal cost but in general every action has a reaction.

A market survey carried out by Defence IQ last year showed that the vast majority (90%) of responders believe IED’s will be a significant future threat with Heavy Machine Guns and RPG’s following closely.

One day, vehicle designers may well have to deal with laser beams and plasma rifles but that will be no more complex than it is today!

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Jed

Nice summary boss :-)

I think I may apply for some patents on my anti-plasma rifle ideas…….

Dominic Johnson

Has anyone watched that first one high yet?

Wstr
Wstr

Another advantage of Tarian Extreme or similar, over their metal bar/rod equivalents is in the extraction of personnel (e.g. following an IED strike or vehicle rollover). Damaged bar armour can get really messed up and jam side exits in the closed position.

IXION

The Blast chimney idea is at real WTF moment….

As Ian Dury observed

‘There aint half been some clever bastards……’

Brian Black
Brian Black

So what ever happened to ‘plastic’ tanks? Not the ACAVP specifically, but armoured vehicles generally.
ACAVP was a decade ago, and in that time fibre and plastics technology has continued to advance – particularly in aviation where ever larger and more complex components are being made. It seems as though there are some obvious advantages to plastic tanks, but they’re not exactly popping up everywhere.
Is there something inherently wrong with the idea of plastic armoured vehicles?

Observer
Observer

@BB

They’re weak against plastic planes. :P

wf
wf

@BB: I think the main reason is that shock loadings for IED’s can cause large structures to delaminate, which could be somewhat catastrophic. Steel has it’s disadvantages, but ductility isn’t one of them. I can remember various test programs re tank gun barrels that were partly made of carbon fiber: they were structured so that the CF only accepted hoops stresses in one axis as much as possible

IXION

BB

In a word heat.

(See early comments I made about f22)

Polymer resins can have all sorts of advantages or properties but all commercial polymers melt at much lower temperatures than steel and many less than aluminium. Indeed some (including Kevlar) really do not like ultra violet (sun) light.

Its no good being all light hard and corrosion resistant if Mk1 Molotov cocktail does for you.

So I do not think we will see an ‘all plastic’ vehicle, until very high – like 1000- 1200 degree c temperature stable polymers or other materials (eg Japs have done huge amount of work on ‘flexible ceramics) come about. When they do big time commercial benefits will accrue equivalent to the changes brought about by the invention of the blast furnace and mass produced steel.

IXION

wf

I wonder if ‘Plastic tanks’ would require a repair by replacement policy.

In effect a major IED strike or AT Missile hit could require the removal of all mechanical components and re fit to a new ‘boat’ hull.

In fact de-lamination can help with shock absorption one of the drivers in the uses of composites in helicopters has been their ability to absorb energy in part through de-lamination leading to ‘ crashworthy’ helicopters. (Not that revolutionary fibreglass crash helmets have done the same for years.

So plastic tanks could actually perform better that a steel hull against pure blast…

Mark
Mark

What you want is carbon nanotube reinforced polymer. Should do the job

Observer
Observer

On a more serious note, plastics are inferior to “steel” protection generally due to material density. With a denser material, heat jets and penetrators have to work harder to break through the armour. Plastics also tend to be bulkier for the same amount of protection, though lighter.

On the other hand, modern armour really isn’t 100% metal, it is a mixture of steel, plastics and even nylon, so you could say the “plastic tank” got intergrated into the metal one.

BTW, think the “holding the RPG round away from the hull” explanation is a bit wrong. IIRC, a heat jet is about 3x shaping cone diameter, the 2-3 inches away from the main armour won’t depreciate much of the force of a meter long stream of metal.

How cage armour actually works is in 2 ways, one, an RPG uses the outer cone of the RPG warhead as part of the firing circuit, hitting cage armour forces the outer cone into the inner metal one, causing a short circuit and a dud. It also compresses the inner “cone” that shapes the penetration jet. Since penetration is a multiple of the cone diameter, crushing it makes the cone much smaller, hence screws up penetration.

IXION

Observer

Right on all counts but..

Hollow charges all have there own ideal stand off distance for maximum effect. Depending on many factors:-

Cone Diameter at the front
Cone length
Whether it is a cone or a ‘trumpet’ shape
Material used as liner (seriously believe it or not Gold would be about the best)
Set it off usually a minimum of 1 ft away form the target armour does seriously degrade the penetration.

The warhead will be designed to use some of the penetrated materiel, as part of the cutting cone of gas and material cutting through the rest; it’s why some missiles sport long prong like probes at the front to get the ‘right distance’.

Barr armour messes that up for all the reasons you have given but also because is can set the missile up ‘too early’.

BTW often heard that US invented idea with chain link fencing in Vietnam. In fact Germans used it in late WW2.

Wstr
Wstr

@ixion

‘..I wonder if ‘Plastic tanks’ would require a repair by replacement policy…’

Love to see the policy instructions with that:

Thank you for your repair request, a full pallet packing wrap is being airlifted to you along with a stepladder and a return address label.
Please ensure you request a proof of shipping receipt from the RFA when handing over.
If a repair is not cost effective we may replace the item. Please note that as we don’t hold any spares this may result in a newer model and the procurement waiting time is currently 25 years.
Thank you for choosing ACME-Airfix for your warfighting needs.

Observer
Observer

@IXION

Most of the time, the optimum distance is measured in inches, and holding the warhead back 2 or 3 inches won’t help much. As you said, 1 foot. However, cage armour is not set up 1 foot away. The “hold away” distance is such a miniscule fraction of the penetration path that it doesn’t really work. Ironically, an RPG direct hit may actually cause less damage then as the distance between warhead to hull is below the “optimum” distance. The key defeater of the warhead is still the dud fuse and deforming the blast cone, causing the penetrator to form a “frisbee” instead of a sharp pointed needle.

The “probe” in front of a round is not a penetrator former, it’s called a fuse extender and it is often used to change a HESH warhead from a direct contact AT weapon into a standoff blast warhead to incread blast damage to structures. See MATADOR and MATADOR AS.

Observer
Observer

Oops, my bad.

Apparently MATADOR is a bad example. It DOES use a standoff fuse for penetrator formation with HESH as anti-structure instead.

The other “pointed” AT rounds I can find references to indicate the point actually carries a tandem charge to defeat reactive armour.

Wstr
Wstr

@ Ixion and Observer

The RPG as standoff [explosion] armour is stated in some many sources that it persists. The primary defeat mechanism is to disable the round by either crushing the warhead so the shape charge can’t form effectively or by short-circuiting the conductive cones so the fuze will not fire.
Standing off the explosion is very much a secondary last resort mechanism if it hits the slats. With a functioning round having 350-750mm RHA penetration on the most common variants; the typical standoff distance from the hull makes survival marginal, even with the protection of additional armour and allowing for some dispersion of the jet in the air gap).
The trick is in the design, if the primary defeat mechanism was to explode the round you would use a solid sheet (like WW2 bazooka plates) or if punching holes to save weight, then utilise a checker board pattern to increase the surface area and likelihood of a solid contact. Instead the slats with as few as possible supports are there to -decrease- the chances of a hit and try to trap the round between slats, for the effects mentioned above.

Wstr
Wstr

Reread my last and felt it should be clearer that I was agreeing with both of your main points (-didn’t we have a working edit feature in the past TD?-). It is amazing how many sources talk about cage armour as if it is simply glorified weight-saving spaced armour and not, what it is, which is a evolution specifically tailored to the RPG threat.

Observer
Observer

Yes, the “standoff” thing is pretty much an urban legend repeated so often it is taken as truth.

The other one is HEAT uses heat to penetrate armour.

Wstr
Wstr

@Observer Forgot about the HEAT=heat myth. By the same token I’m just waiting on a future Wikipedia entry that describes a HESH round killing a vehicle crew by drowning them in Robinsons Orange Concentrate. :)

Observer
Observer

@Wstr

That would be a biological weapon won’t it? :)

TD:

Maybe- Shaped charge warhead works by crushing a cone shaped inner oglive into a needle nosed penetrator and firing it into the target at high speeds. Cage armour crushes the sides of the cone, interupting the formation of the penetrator. For some older RPGs, cage armour also interferes with their fuses, shorting them out and preventing detonation.

How’s that?

IXION

I am not going to turn this into an argument!:-)

I agree with almost every thing you have said Observer and WSTr. The crushing pof the warhead etc IS the primary function.

I did have a slip of the keyboard over the 1 foot distance. The optimum stand of distance differs as I said from warhead to warhead.

The probe at the front of some missiles can be for several uses the 2 main ones are.

1. A small precursor charge to detonate reactive armour.
2 (Sometimes combined with 1) a fuse designed to set of the main warhead at exactly the optimum range.

The few inches of space; (the Israeli’s unsurprisingly did a lot of work on this and found the best practical distance was about 50 cm); is not the main effect of bar armour*, but it does have a surprising effect. In short every little bit helps!

* In the 60’s the Sweds did a lot of work on this and surprisingly came to the conclusion bar armour was rubbish!

Talk about counter intuitive they decided the best thing to do was to cover the tank in Jerry cans of Diesel!

Observer
Observer

@Ixion

I can see how the Sweds came to that conclusion. If you were looking at slat armour as simple spaced armour, it really doesn’t resist anything other than improve spall protection with the air gap messing up shockwave transmission (HESH warheads).

And don’t knock the diesal, it does act as reactive armour of sorts.

IXION

I cant find my original copy of their unclassified report, but the Sweds said something like, that in many cases the Bar armour was effective, but that in almost the same number of case hits that were not going to be effective, were nicely set up to penetrate by the same armour! so over all no score draw..

I am only aware that the Sweds came to this conclusion not sure anyone else has . If its true then the bar armour everyone is sporting in Afghan is just so much extra weight!

Likewise the diesel thing has been shown to be effective,n i believe the Israeli’s modified M113 by putting fuel tanks on the outside as well. And FMc’s upgrade of M113 did likewise.

Wstr
Wstr

@TD Sorry to leave you hanging – Friday’s siren call of the pub! I see Observer has made a stab at new words.

Nay probs on the edit-less commenting system, not a big issue I was concerned it was just me, what with moderation also being flagged for the first time in ages. Turned out that latter part was all me – reentered a new (and incomplete) email address following deletion of all my browser cookies; so you’ll have another moderation request today – sorry!

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