British APC/IFVs, why doors and no ramp?

[Olof Larsson]

On 3/19/2021 at 2:59 PM, Rickard N said:

Swedish IFVs have "always" had hatches, and not power assisted either to the best of my knowledge. I think one reason is that it's quicker to get a hatch open than waiting on the ramp (unless you've parked at an angle I suppose). The Swedish army tested the M113 so the idea has been at least looked at.

/R

Well ramps sucks when being opened to far in deep snow. And doors are far easier to open and close manually as you never have to work against gravity.

[Loopycrank]

12 minutes ago, Przezdzieblo said:

I remember a news footage from 1991, from the beginning of land operation in Iraq, with US soldier slipping on Bradley's ramp and falling on his lower back in the front of camera. Maybe this hazard should be noted as a small disadvantage of designs with ramp

 

Think about this carefully.  On a vehicle with a door, there is a sudden transition from ground level to the height of the ground clearance of the vehicle plus floor thickness plus the height of the lip around the door.  There will always be a lip, by the way; there has to be to ensure adequate sealing against water and NBC junk.  The lip not only adds height to the distance the soldier needs to clear getting into the vehicle, it adds an inherent tripping hazard on the way out.



The fact that a person can slip on a ramp does not in any way imply that doors are somehow easier to navigate, or have any advantage whatsoever.

 

2 minutes ago, Stuart Galbraith said:

The reason why there is no missile on the vehicle is doctrinal. . It's like blaming an SLR for being single shot. A Bradley turret version was available, but the army didn't want it.

Why doesn't it fire on the move? Because it would cost too much for the MOD to replace the FV432 (ultimately it never did), and because the British Army fought from overwatch. It was designed for the quaint world of WW3 when all its targets were supposed to come to it.

Why does it use a Rarden, to keep commonality with Scimitar. The reason why the Rarden looks old fashioned, it is. It's one of the first ( think possibly the first) 30mm gun in a NATO ifv, from the early 70's. Should it have been replaced for warrior, yes. Does it matter? Not really. Anyone who prays and sprays with a Bradley probably shouldn't be in the gunners seal

Tell you what, have you read Richard Holmes Dusty Warriors? You should. It will give you a good feel for what the Soldiers liked and disliked about it on a deployment in Iraq in 2004. It might surprise you.

Forgive me for being cynical about the stated reasoning behind British military doctrine; there are multiple examples of cost-cutting features in their hardware being rationalized as being that way "for doctrinal reasons" as well as multiple examples of standards being revised to fit the performance of the hardware rather than the other way around.  Some documents to this effect were posted on the Ed Francis Discord a while back regarding the purchase of the Challenger II vice the Leopard II, and there are multiple examples of jiggery pokery with reliability numbers in Steve Raw's book on the L85.

Not including an ATGM on every hull of a vehicle that's ostensibly intended to face off against an army with a massive superiority in number of tanks is dubious.  ATGMs have no recoil (at least not that the vehicle designers need to account for), are extremely lightweight, and give an IFV a fighting chance against tanks, especially in an ambush scenario.  Not only that, but they are much better at destroying bunkers or other hardened targets than an autocannon.  The Bradley goes one better and has thermal optics, which the Soviets largely lacked.  A large-caliber gun is generally a better vehicle-killing weapon than an ATGM, but the cover of night will do a lot to even things out for the M2 against the godless hordes and their endless supply of tanks.

Not including an ATGM system that can be fired from under armor is also dubious.  A number of AFV design books from the period talk about how wargames and practical experience showed that mobility is not armor, but armor is definitely a kind of mobility.  That is to say, light, nimble vehicles cannot avoid being hit well enough to forego having armor.  However, in a large-scale war, the front lines are swept with enough artillery and small arms fire that not having adequate overhead protection to at least keep that out means that there are effectively large areas of the battlefield that a vehicle simply cannot traverse.  The large percentage of infantry casualties caused by artillery in WWII would tend to bear this observation out.  Given that, having to stick ones head out to operate an ATGM post stapled to the roof is a definite downside of the design, and that's before even considering NBC protection.

Speaking of "spraying and preying" is an obvious strawman.  The issue isn't that the clip-fed RARDEN lacks the ability to perform suppressive fire with its autocannon or maintain some arbitrary sustained rate of fire that looks good on paper and has no tactical value.  The issue is that it's feeding from three-round clips, and it has a two man turret crew.  Congratulations; you've managed to re-invent the same tactical problems that the T-34 had in 1941.

[Olof Larsson]

On 3/19/2021 at 7:31 PM, Loopycrank said:

Ramps allow easier egress and ingress by far.  This is one of those things where the fact that it's the overwhelmingly dominant design choice should be a clue.  M113 has a ramp.  CV-90 has a ramp.  Type 89 has a ramp.  Marder has a ramp.  Puma has a ramp.  Lynx has a ramp.  K21 has a ramp.  Redback has a ramp.  Hell, even Kurganets has a ramp!

It's not like there's a raging debate between two schools of thought on this.  There is an obviously correct design solution that everyone chooses given the chance, and not choosing it is conspicuous.

What's more, as I explained, the Warrior somehow manages to throw away the one, dubious advantage a door has by going with a power operated door that's just as slow, heavy and complicated as a ramp!

The Strf 9040 and CV9030 FIN and CV9030N has a door and no ramp. The CV9030 CH, CV9035DK and CV9035NL has a ramp with a door. The Kurganets has a ramp with a door, the Type 89 has a door, the K21 has a ramp with a door.

[Olof Larsson]

17 minutes ago, Loopycrank said:

 

Think about this carefully.  On a vehicle with a door, there is a sudden transition from ground level to the height of the ground clearance of the vehicle plus floor thickness plus the height of the lip around the door.  There will always be a lip, by the way; there has to be to ensure adequate sealing against water and NBC junk.  The lip not only adds height to the distance the soldier needs to clear getting into the vehicle, it adds an inherent tripping hazard on the way out.

Yes. With a door, you need to seal the door. With a typical ramp, you need to seal the ramp, and the door in the ramp, with all the mud, snow ect. that might end up on the inside of the ramp. And yes the "lip" can be a tripping hazard. If one behaves like a idiot and doesn't use it to step on, on the way in and out. And despite having spent all my military service after basic training on a IFV with a door and no ramp (CV9040) , I cannot recall, even seing a soldier trip getting in or out of the vehicle. Well excluding myself, slipping and spraining a ancle while walking down the sloping glacis. So I would be far more worried about soldiers slipping on a ramp (especially in wet and muddy conditions) than slipping getting in or out a door.

[Mighty_Zuk]

Ramps good

Doors gay

Why? When all else fails, it's a power club.

[WRW]

How are ramps operated?

Can they be operated manually?

[Stuart Galbraith]

10 hours ago, Loopycrank said:

 

Think about this carefully.  On a vehicle with a door, there is a sudden transition from ground level to the height of the ground clearance of the vehicle plus floor thickness plus the height of the lip around the door.  There will always be a lip, by the way; there has to be to ensure adequate sealing against water and NBC junk.  The lip not only adds height to the distance the soldier needs to clear getting into the vehicle, it adds an inherent tripping hazard on the way out.



The fact that a person can slip on a ramp does not in any way imply that doors are somehow easier to navigate, or have any advantage whatsoever.

 

Forgive me for being cynical about the stated reasoning behind British military doctrine; there are multiple examples of cost-cutting features in their hardware being rationalized as being that way "for doctrinal reasons" as well as multiple examples of standards being revised to fit the performance of the hardware rather than the other way around.  Some documents to this effect were posted on the Ed Francis Discord a while back regarding the purchase of the Challenger II vice the Leopard II, and there are multiple examples of jiggery pokery with reliability numbers in Steve Raw's book on the L85.

Not including an ATGM on every hull of a vehicle that's ostensibly intended to face off against an army with a massive superiority in number of tanks is dubious.  ATGMs have no recoil (at least not that the vehicle designers need to account for), are extremely lightweight, and give an IFV a fighting chance against tanks, especially in an ambush scenario.  Not only that, but they are much better at destroying bunkers or other hardened targets than an autocannon.  The Bradley goes one better and has thermal optics, which the Soviets largely lacked.  A large-caliber gun is generally a better vehicle-killing weapon than an ATGM, but the cover of night will do a lot to even things out for the M2 against the godless hordes and their endless supply of tanks.

Not including an ATGM system that can be fired from under armor is also dubious.  A number of AFV design books from the period talk about how wargames and practical experience showed that mobility is not armor, but armor is definitely a kind of mobility.  That is to say, light, nimble vehicles cannot avoid being hit well enough to forego having armor.  However, in a large-scale war, the front lines are swept with enough artillery and small arms fire that not having adequate overhead protection to at least keep that out means that there are effectively large areas of the battlefield that a vehicle simply cannot traverse.  The large percentage of infantry casualties caused by artillery in WWII would tend to bear this observation out.  Given that, having to stick ones head out to operate an ATGM post stapled to the roof is a definite downside of the design, and that's before even considering NBC protection.

Speaking of "spraying and preying" is an obvious strawman.  The issue isn't that the clip-fed RARDEN lacks the ability to perform suppressive fire with its autocannon or maintain some arbitrary sustained rate of fire that looks good on paper and has no tactical value.  The issue is that it's feeding from three-round clips, and it has a two man turret crew.  Congratulations; you've managed to re-invent the same tactical problems that the T-34 had in 1941.

 

The problem is, it is actually true. Ive a mid 1980's British Army Tank Commanders manual, and they were clearly going with overwatch, rather than the US doctrine of the entire force moving as an entity. And I still think overwatch is a better choice than driving the entire battalion battlegroup into an ambush.

The primary weapon of a Warrior was not, in my view at least, the 30mm. It was the infantry section, carrying the LAW 80 and the M72 LAW. The 30mm was there for fire support against infantry and enemy APC's and IFV's. It did that fine. Yes, im sure that cost did play a role in the choice of no stab , but if we had done that, we would be looking at a buy of half of the projected buy of something like 1048 vehicles. Even that, I suspect, would not have entirely replaced FV432 thinking about it. But in a military that was really given far too many things to do, it really was about the best that could be done.

The whole point of the ATGM platoon was to give Antitank support to the rifle companies. If they had integrated the missiles with the rifle companies, you would very likely have had a reduction in the rifle strength of the sections, something that I think had already lost a man with the transition from FV432 to Warrior. And looking at the conflicts Warrior was largely involved in, mainly peacekeeping or stabilisation operations, that was a fortuitiuous choice I think. As it was, they had vehicles that could operate WITH the Warrior companies, such as the Spartan or Spartan MCT, so Im not seeing it as a problem as there would always be a missile team operating in support. And as you pointed out yourself, there WAS a warrior with Milan, vehicles modified in 1991 to carry the milan sections at a speed that could keep pace with the other warriors by welding a Milan firing post on the roof. Was it an elegant solution, no. Did it work? Well it did see action and did apparently kill enemy tanks, so I guess it must have done.

[Stuart Galbraith]

48 minutes ago, Mighty_Zuk said:

Ramps good

Doors gay

Why? When all else fails, it's a power club.

Just paint 'please knock' in Russian on the door. And when the gallant lead element of World Socialism does that, you press open and squish the poor bastard against the mudguard.

My work here is done.

[Tim Sielbeck]

18 minutes ago, Stuart Galbraith said:

 

The problem is, it is actually true. Ive a mid 1980's British Army Tank Commanders manual, and they were clearly going with overwatch, rather than the US doctrine of the entire force moving as an entity. And I still think overwatch is a better choice than driving the entire battalion battlegroup into an ambush.

I think you're confusing the US with the USSR.  We also used over watch.  Bounding over watch when we thought contact was less likely.  

 

Where on earth did you get the idea that the US would go charging in so recklessly?

[RETAC21]

During this debate I was thinking about our own Pizarro, which went from a ramp in the prototype to a door in the production vehicles:

http://3.bp.blogspot.com/-VNR5Y_bdn3k/T1nIhnxhCTI/AAAAAAAABpY/6JFwhipZ0qA/s1600/PT1-Pizarro-Sevilla%2B%25281%2529.jpg

Affter troop testing, so I would guess it comes down to preferences, rather than their being an advantage one way or another. One advantage of the ramp I have seen quoted is that it would detonate a mine if opened over one, which will give a clue that the location is not a good one to disembark...

[Stuart Galbraith]

32 minutes ago, Tim Sielbeck said:

I think you're confusing the US with the USSR.  We also used over watch.  Bounding over watch when we thought contact was less likely.  

 

Where on earth did you get the idea that the US would go charging in so recklessly?

It was the 1996 edition of FM 17 15 'The Tank Platoon'. I admit its been some 2 decades since ive read it, but the impression I got at the time was that the US Army had largely moved from bounding overwatch to total force movement, primarily because of the Mobility of the Abrams and the Bradley I guess. That is pretty much how it happened at 73 Easting anyway, the Bradleys seemed to be only stopping to pop TOW's. Even in Team Yankee they seem to be doing pretty much the same thing.

[Ssnake]

FWIW, neither the Austrians with the Ulan nor the Spanish soldiers I talked to about the Pizarro seemed to have been unhappy about the door.

The Bradley ramp, I found incredibly noisy ... unacceptably noisy at night, I'd even say. But that sample may have been an outlier. The Marder's ramp seems to have been the least noisy one I have so far witnessed, as it doesn't even emit the solid CLUNK of arrestor hooks locking the ASCOD door in place.

I would however roundly reject the argument that a ramp could serve as a mine detector. The chance that you trigger a mine with the ramp before the first guy sets foot on the ground but that you don't detonate mines on the way to the disembarkation point is ridiculously small.

 

I admit that I would instinctively opt for a ramp for an IFV, but I think you can make engineering mistakes, or come to acceptable results irrespective of the door/ramp swing plane being in the vertical or horizontal. Obviously, all other factors being equal, a ramp gives a bit more clearance on entry/exit even if the dimensions are the same, unless the door opening angle is at least 90° - which becomes increasingly difficult to accomplish as the armor thicknesses increase. I would also suspect that the load bearing on the door hinges is less favorable than for those of a ramp, and that opening or closing, even if power assisted (which is a must these days) could be slower if the vehicle was parked with significant roll angle. It is unlikely that you would accidentally attempt to lower a ramp in a location where the ramp was blocked (would require an obstacle that sneaks up to you from behind, or a moronic driver backing up against a wall or something).

[Interlinked]

When the Swedes were evaluating the M113 as a technical case study for APC technology, they also evaluated ramps vs doors. Initially, an early prototype of the Pbv 302 was fitted with a powered ramp inspired by the M113 design, but the final production model Pbv 302 had two rear doors. They chose doors, because it permitted faster dismounting. 

https://www.ointres.se/pbv_302.htm

Quote

Inspirerad av M113 var prototyperna försedda med en nedfällbar ramp baktill, men det visade sig snart att avsittning kunde göras snabbare om istället två bakdörrar användes.

"Inspired by the M113, the prototypes were fitted with a fold-down ramp at the rear, but it soon became apparent that depositing could be done faster if two rear doors were used instead."

[Loopycrank]

On 3/20/2021 at 3:34 PM, Olof Larsson said:

The Strf 9040 and CV9030 FIN and CV9030N has a door and no ramp. The CV9030 CH, CV9035DK and CV9035NL has a ramp with a door. The Kurganets has a ramp with a door, the Type 89 has a door, the K21 has a ramp with a door.

Ah, you're right about the Type 89.  It appears to be two outward swinging doors.

 

The CV90 example suggests that it is not at all difficult to re-design for customer preference.

[DB]

I mentioned Ajax earlier, I think. There are two completely different door designs across the variants. It is of course derived from the ASCOD 2 platform, so is not entirely unlike Pizarro and Ulan

[Manic Moran]

Surely it seems to me that the first guy out will be out first with a door because it only needs to open a fraction of the swing, but that once the ramp is down, everyone else will be able to follow more rapidly?

That said, the Type 89 does seem the best of both worlds. I guess the other advantage to the ramp is that if you're lifting things heavier than a round of ammo (I'm thinking the 25mm, here, which is a two-man-lift) a ramp is probably a bit easier to go in and out of.

[DB]

Not certain, but I suspect that the mass and space take for a hydraulic system that raises a ramp is going to be higher than that for a door. Everything ns a modern AFV is weight limited to the point where they save weight at about the same expense pound-for-pound as combat aircraft.

[Ssnake]

You can just as well hoist it with a steel cable.

That being aid, hydraulic systems as such don't take up much space (that's why engineers love them if volume constraints are significant), and if you have a hydraulic system already, laying two pipes to operate the door isn't going to be a significant complication. The main argument against hydraulics is that they are horribly inefficient; about 40% of the energy input dissipate into internal leakage.

[Harold Jones]

If I recall correctly the 113 ramp used a cable.  Whatever the mechanism it seemed break often enough that seeing a 113 with free fall chalked on the ramp was not uncommon. The first time I saw one was straight out of training and I thought it was the name of the vehicle.

[Stuart Galbraith]

Well its a better name than Gavin.

[DogDodger]

1 hour ago, Harold Jones said:

If I recall correctly the 113 ramp used a cable.  Whatever the mechanism it seemed break often enough that seeing a 113 with free fall chalked on the ramp was not uncommon. The first time I saw one was straight out of training and I thought it was the name of the vehicle.

You recall correctly. The cable was dumped with the Bradley, however.

 

[seahawk]

I dot get the debate, in the end the question for the user is how big and easy to use the opening is. The only practical difference is that a ramp smoothens the hieght difference between the vehicle floor and the ground, a door does not.

[Mighty_Zuk]

Most APCs and IFVs today have sponsons at the rear, which prevents the use of a door, as it would limit the width of the hole and make it more difficult to mount and dismount.

And since the rear still has to be armored, opening or closing a thin and unpowered door would be awkward in certain angles.

http://3.bp.blogspot.com/_eQNPu6zzxaU/S7ehYoHHhVI/AAAAAAAAqVA/K6AbFa1s6mc/s1600/march2720102.jpg

And of course doors interfere with the exterior of the vehicle. If there are exhaust pipes or vents, tools, or anything that could bend and or break, it's best not to use a door that soldiers would just slam into.

Edited April 19, 2021 by Mighty_Zuk

[Interlinked]

Namer's issues are its own.

[skylancer3441]

On 3/19/2021 at 9:31 PM, Loopycrank said:

even Kurganets has a ramp

...same for T-15 HIFV, and front-engine version of BMP-3.

Edited April 20, 2021 by skylancer3441