UK Defence Forum

mr.fred wrote:

RunningStrong wrote:How is that appliqué!?

It’s not part of the underlying structure. With an angle grinder and a bit of effort you could remove it and still drive the tank away.

If anyone started using an angle grinder on a vehicle to remove large metallic chunks of the vehicle it would immediately invalidate the Certificate of Conformity, unless it was covered by a mod strike modification. Which is by all purposes a modification to the core structure of the vehicle.

There are plenty of other items that are bolted onto a vehicle like stowage bins and access covers that aren't defined as appliqué. So to state that something that has to be irreversibly removed (because to re-apply would further modify the base structure due to hot-working the metallic components) is appliqué is incorrect.

mr.fred wrote: the rest absolutely applies

to applique

Luckily is is the wk end (and raining!):
Origin of reconnoitre From French reconnoître (obsolete spelling of reconnaître ), from Latin recognoscere (“to recognise”). Contrarily, there is also an obsolete 19th-century British English spelling reconnaitre (now reconnoitre ).

See what the Normans did (to us) .
Correspondingly, while the main population has (over the last hundred years, may be the latest influx is changing that) gained a lot in average height, the Normans have let go of Sandhurst only over that same period of time:
the average height of recruits has gone down by 4 cm

Aplique armour has some defects:

Shearing strain means an non lethal hit can mal-align panels, needing an angle grinder anyway! This means you have to replace the whole lot.

Aplique really doesn't like ERA. The shock wave will cause delamination. This has been seen in several conflicts and one of the reasons the Israelis moved from this to their APS systems.

It can really screw up stabilisers if the system wasn't designed from the outset to accommodate the fulcrum effects on the turret, due their increased bulk, and asymetric weight distribution (something the Russians learnt with the T72BM upgrade and the Germans have found out with L2A7).

Also, anything with a rail is a disaster when you get impact damage. The rails on the Leo engine pack are a real issue with combat damage and were a weak spot we identified for targeting if we ever had to come against one.

jimthelad wrote:Aplique armour has some defects:

Shearing strain means an non lethal hit can mal-align panels, needing an angle grinder anyway! This means you have to replace the whole lot.

Aplique really doesn't like ERA. The shock wave will cause delamination. This has been seen in several conflicts and one of the reasons the Israelis moved from this to their APS systems.

It can really screw up stabilisers if the system wasn't designed from the outset to accommodate the fulcrum effects on the turret, due their increased bulk, and asymetric weight distribution (something the Russians learnt with the T72BM upgrade and the Germans have found out with L2A7).

Also, anything with a rail is a disaster when you get impact damage. The rails on the Leo engine pack are a real issue with combat damage and were a weak spot we identified for targeting if we ever had to come against one.

A lot of issues are related to legacy platforms where appliqué and anti-RPG protection have been a UOR into theatre. Proper appliqué (which the new CR3 turret should be designed for, like AJAX) provides you with a host of options for the expected threat and future growth. Done properly, it also makes battle damage repairs a simpler task.

Yep look no further than the latest Merkava and Namer platforms to see how it is done properly on a new build.

RunningStrong wrote:

mr.fred wrote:

RunningStrong wrote:How is that appliqué!?

It’s not part of the underlying structure. With an angle grinder and a bit of effort you could remove it and still drive the tank away.

If anyone started using an angle grinder on a vehicle to remove large metallic chunks of the vehicle it would immediately invalidate the Certificate of Conformity, unless it was covered by a mod strike modification. Which is by all purposes a modification to the core structure of the vehicle.

Taking the mass of the armour off would impact the performance, but that’d be it.

https://i.redd.it/v0hlcmqag9411.jpg

There are plenty of other items that are bolted onto a vehicle like stowage bins and access covers that aren't defined as appliqué. So to state that something that has to be irreversibly removed (because to re-apply would further modify the base structure due to hot-working the metallic components) is appliqué is incorrect.

Quoting the standard again, the only other option for armour is:
3.17 Integral armor. Armor material used as part of a structure to perform a load-carrying or other operational function, in addition to ballistic protection. Also known as structural armor.

So it’s integral or appliqué, and Chobham/dorchester is not integral.

As for the work done, there are usually work instructions on how to do it.
I doubt that tanks with Chobham/dorchester are written off once struck, there’ll be a repair process to replace damaged packs.

ArmChairCivvy wrote:Origin of reconnoitre From French reconnoître (obsolete spelling of reconnaître ), from Latin recognoscere (“to recognise”).

Indeed! It was a tongue-in-cheek reference to George Dubya's alleged comment to Tony Blair that "The problem with the French is that they don't have a word for 'entrepreneur'.

mr.fred wrote: Taking the mass of the armour off would impact the performance, but that’d be it.

That's utter rubbish. Even appliqué changes the structural performance of a vehicle. You're bolting rigid steel plate/composite onto the structure FFS. Harmonic frequencies, rotational acceleration and deceleration, shock propagation, failure mechanisms.

mr.fred wrote:Quoting the standard again, the only other option for armour is:
3.17 Integral armor. Armor material used as part of a structure to perform a load-carrying or other operational function, in addition to ballistic protection. Also known as structural armor.

So it’s integral or appliqué, and Chobham/dorchester is not integral.

As for the work done, there are usually work instructions on how to do it.
I doubt that tanks with Chobham/dorchester are written off once struck, there’ll be a repair process to replace damaged packs.

You're referencing at Mil-Std in a UK Def-Stan discussion.

RunningStrong wrote:You're referencing at Mil-Std in a UK Def-Stan discussion.

Can you cite a Def Stan definition?
Because the US govt freely publishes most of their standards, they tend to be the de facto international standard.

RunningStrong wrote:That's utter rubbish. Even appliqué changes the structural performance of a vehicle. You're bolting rigid steel plate/composite onto the structure FFS. Harmonic frequencies, rotational acceleration and deceleration, shock propagation, failure mechanisms.

If the impact of removal is similar between your definition of appliqué and the MIL-STD, is it a meaningful distinction?
If your definition for appliqué is based on the use of temporary fasteners, would the use of one-way fasteners change the definition of the armour pack? If I were to attach it with a small seam weld?

mr.fred wrote: Can you cite a Def Stan definition?
Because the US govt freely publishes most of their standards, they tend to be the de facto international standard.

I wouldn't quote Def Stan on a public forum, no. It's not the "de facto" International standard. That would be STANAG.

mr.fred wrote:
If the impact of removal is similar between your definition of appliqué and the MIL-STD, is it a meaningful distinction?
If your definition for appliqué is based on the use of temporary fasteners, would the use of one-way fasteners change the definition of the armour pack? If I were to attach it with a small seam weld?

Rivets can be drilled and replaced with no impact to the material, which is not dissimilar to many security bolts used to hold armour on. Replacing an existing weld changes the composition of the surrounding metal work.

RunningStrong wrote:"de facto" International standard. That would be STANAG.

Indeed, but does it deal in definitions (rather than just protection levels)?

RunningStrong wrote:Rivets can be drilled and replaced with no impact to the material, which is not dissimilar to many security bolts used to hold armour on. Replacing an existing weld changes the composition of the surrounding metal work.

Putting a hole through a panel to accommodate a fastener changes its ballistic performance.

Depending on the material and arrangement you can arrange it so that a welded attachment has no impact on the appliqué or the structure behind it. Indeed most bolt-on appliqué systems are fitted to welded bosses, rails or studs which have no other purpose than mounting the armour. whether you drill and tap those or weld to them doesn’t make much difference to either side if it’s designed that way, except that the welded joint is stronger and much more difficult for passing ne’er-do-wells to remove in order to steal example armour packs.

Simple question then. How are the "Panels" of Dorchester amour fitted to the Challenger 2? Are there hundreds of hidden covered bolts holding it in so that it is removable or is it permanently attached? From being in and on a Challenger 1 I couldn't see any. My definition of applique armour was the add on packs like the Challenger 2 and Warrior TES sets. I know I keep mentioning the Merkava but again having been in and on a Mk III, the "Bolts" are clearly visible on the Armour blocks to allow the ready replacement in field workshops, and to allow new armour types to be easily added. To me the Armour on the turret of the Challenger 3 looks like its core structure has been covered in a shell rather then individual panels, with obvious cut outs for the Sights and Gun Mantle, etc.

mr.fred wrote:

RunningStrong wrote:Rivets can be drilled and replaced with no impact to the material, which is not dissimilar to many security bolts used to hold armour on. Replacing an existing weld changes the composition of the surrounding metal work.

Putting a hole through a panel to accommodate a fastener changes its ballistic performance.

Depending on the material and arrangement you can arrange it so that a welded attachment has no impact on the appliqué or the structure behind it. Indeed most bolt-on appliqué systems are fitted to welded bosses, rails or studs which have no other purpose than mounting the armour. whether you drill and tap those or weld to them doesn’t make much difference to either side if it’s designed that way, except that the welded joint is stronger and much more difficult for passing ne’er-do-wells to remove in order to steal example armour packs.

If you're going to say fixings effect armour, then you're aware that hot working armoured steel is also detrimental to the performance? That's from personal experience.

RunningStrong wrote:If you're going to say fixings effect armour, then you're aware that hot working armoured steel is also detrimental to the performance? That's from personal experience.

Oh absolutely welding affects any heat treated material. It’s worse with aluminium.
That’s why you can weld to mounting bars just like bolts are threaded into mounting bosses.

Right so I see the mounting brackets in the photo, but they are not for field replicable armour modules, which is how I see applique armour. However is applique is actually to mean any armour fitted over the core structure of an AFV either permanently or in easily replaceable modules than I accept that argument.

Good detail abt gun, engine, suspension
https://www.iiss.org/blogs/military-bal ... 224840faac

Good article but again the timescales that have been stated seem to be overly long to me. Is this just to match yearly funding to a work schedule? IOC is seven years away! with FOC three years after that and then around ten years service life. Mind you I doubt we will be replacing them around 2040, more likely to retire them without as new lighter, hard hitting and well protected platforms including unmanned take the stage.

Well, agreed. Is it about on-shoring?

Back to that IISS blog article, this bit I found most interesting ( the Danes field A7s with the version of the gun we will be getting now; not in 7 years time, as in '30 Oct 2019 — Krauss-Maffei Wegmann (KMW) has marked the beginning of deliveries to Denmark and Germany of the latest version of the Leopard 2'):
" One likely contender for Challenger 3’s ammunition is the KE2020Neo. By taking advantage of the higher chamber pressure the L55A1 can offer, Rheinmetall hopes to provide a 20% increase in performance over the current generation of 120mm smoothbore armour-piercing fin-stabilised discarding sabot (APFSDS) ammunition.

The L55A1 will also allow Challenger 3 to make use of programmable high-explosive ammunition such as the DM11, enabling airburst capability. Although this armament certainly represents a significant upgrade in lethality over the Challenger 2, the L55A1 is also fitted to the Leopard 2A7V MBT, already in service with Germany and Denmark."

The underlined part is pretty good progress towards the 50% that going for 130 mm would have given.
- none of the percentages have been calculated based on the rounds used now in the rifled gun
- I doubt we will ever get to see that comparison

I think it is safe to say that in my view the new ammo form the L55 will be superior to the CHARM APFSDU round and even more so the APFSDS one, given the higher velocity and length of the penetrator, without going into all the physics and stuff. What will be missed is the HESH, but a combination of the existing HEAT and the new programable HE round should compensate, though probably at greater cost per round.

There's also reports that there's an agreement to use the US depleted uranium ammunition and that the necessary minor changes to the gun are underway.

Long gun plus DU = best combo in world I would think.

Ron5 wrote:Long gun plus DU = best combo

Ich bin auch ein Berliner
... aber Du bist nicht Deutsch! Clearly

But thta is why I wanted to lift the 20% better penetration out of that text

The Idea of the L55 and the new Long Rod Penetrator APFSDS was to have a superior combo to the US Army's L44 and APFSDU pairing using tungsten rather than the more politically sensitive uranium. I mean no one else adopted DU Armour to the best of my knowledge.

Lord Jim wrote: I mean no one else adopted DU Armour to the best of my knowledge

Did you mean penetrator or armour? A few M1s were built with DU in the more vulnerable parts of the front half. An experiment not heard of since...