LAV-75; Stingray; M8 AGS

[Raellus]

I've read that the M1128 MGS carries 18 rounds of ammo for its 105mm gun. That really doesn't seem like a whole lot. I'm pretty sure on that episode of Lock 'n Load that I mentioned, they said 8 rounds in a magazine between the commander and gunner but I may have misheard. I'm sure all concerned would prefer to carry more rather than less ammo and would do what they could to make this happen.

[Legbreaker]

Consider that it usually only takes one hit from a large cal cannon to destroy the target. Consider also that 20 shots is likely to last a long time on the modern battlefield since it first shot hits are now the norm.
Just a few decades ago, the "bracketing" method developed by the British in WWII was really the only way to go - you fired long, you fired short, then once you'd assessed the range correctly, fired your kill shot (hopefully).
Ranging machineguns first introduced in the Centurion (I think) made the job a bit quicker and easier, followed by coincidence rangefinders, etc, etc....

[ChalkLine]

Still, 18 shots is not a lot on a wheeled gun system that is intended to move fast and cover a lot of ground. If it was a tracked infantry support weapon I could see it being useful as they tend to be placed on haulers for road marches.

Of course, who in T2K has ever fired off 18 main gun rounds?

[Legbreaker]

For that matter, who in T2K has ever fired off 18 single rifle shots in the one engagement?
Not many is my guess...

[Raellus]

True, fellows, but consider the matter of resupply. 18 rounds in one engagement is indeed a veritable cornucopia of heavy-duty firepower. 18 rounds stretched over 3-4 engagements, though... not so much.

When operating far out in front of logistical trail, cut off by an enemy envelopment, or, say, after the TDM takes multiple links out of the supply chain, 18 rounds is going to go pretty fast. I bet the vehicle crews and the unit commanders are going to be wishing for more ammo carrying capacity in their light tanks/AGSs.

[ChalkLine]

Originally Posted by Raellus

True, fellows, but consider the matter of resupply. 18 rounds in one engagement is indeed a veritable cornucopia of heavy-duty firepower. 18 rounds stretched over 3-4 engagements, though... not so much.

When operating far out in front of logistical trail, cut off by an enemy envelopment, or, say, after the TDM takes multiple links out of the supply chain, 18 rounds is going to go pretty fast. I bet the vehicle crews and the unit commanders are going to be wishing for more ammo carrying capacity in their light tanks/AGSs.

No worries mate, we'll store the extra ammo on the outside of the hull

[Legbreaker]

Originally Posted by Raellus

I bet the vehicle crews and the unit commanders are going to be wishing for more ammo carrying capacity in their light tanks/AGSs.

Very true. Shame the majority of vehicles are designed in peace time with the assumption that there actually will be a supply chain...

:S

[pmulcahy11b]

Originally Posted by Legbreaker

What date are you looking at the A4 variant being produced?

20 ready rounds seems quiet good for what is essentially a light combat vehicle. Late in the war, a larger capacity in both fuel and ready rounds is likely to be less important although it would certainly make sense if several years of peace were available to further develop the vehicle.

IIRC, it comes in sometime in mid-1996 (Word 2002 just takes way too long to open; excuse me for not looking right now, but there's no "looking real quick" with Word 2002 on Vista). The 20 rounds are in the autoloader; another 16 would be beside the driver and just behind the turret basket.

With the 750hp engine, the LAV-75A4 turns out to be practically an armored equivalent of a race car, without a giant fuel consumption, and even with the heaviest applique armor package. The armor is nothing to write home about, but I "replaced" some of the aluminum armor with aluminum/ceramic sandwich armor. This considerably lightened the vehicle while slightly improving the protection level.

[Targan]

Originally Posted by pmulcahy11b

I haven't statted out the A4 completely yet (it'll will probably be finished by the end of the day), but my offhand guess is that the A4 will end up 1-2 tons heavier than a LAV-75. The original LAV-75 used a 650hp gas turbine; I replaced it on the A4 with a 750hp diesel (I put "a modified form of a Caterpillar heavy tractor engine" and gave the engine a name that sounds like a Caterpillar engine, but is not actually used by the company.

In my post which resurrected this thread a few weeks ago I mentioned the engine used in the M8 which is a 6 cylinder diesel closely related to the HEMTT's engine. I'd go with that engine or something very similar.

Ah what the heck, I'll just quote myself from that post:

Originally Posted by Targan

I have discovered during some reading that this is only partially correct. The suspension and track system contains elements from the M113A3, the M2 Bradley and some M8-specific components. The hydromechanical transmission is from the Bradley but the engine, the 6V-92TA 6 cylinder Detroit Diesel, has 65% parts commonality with the 8V-92TA 8 cylinder Detroit Diesel used in the M977 HEMTT truck. The Cadillac Gage Stingray and Stingray II light tanks actually use the M977 HEMTT's 8V-92TA engine as well.

[pmulcahy11b]

Originally Posted by Targan

In my post which resurrected this thread a few weeks ago I mentioned the engine used in the M8 which is a 6 cylinder diesel closely related to the HEMTT's engine. I'd go with that engine or something very similar.

I thought of doing that, but that engine is physically a bit too large. The 850-hp Caterpillar diesel engine I based the fictional engine on is physically a little smaller than the gas turbine that is in the LAV-75.

[Legbreaker]

What role is the M-20/LAV75/etc supposed to have? How the vehicle is intended to be used (pre nukes, not post) is going to have a great impact on armour protection, speed, etc.

For example, a scout vehicle is likely to be lightly armed and armoured, fast moving and probably amphibious. If the M-20 was intended for light units (airborne, leg mobile, etc) to have some basic armoured support, then speed isn't likely to be of high importance.

I like Targan's idea of using the 6V-92TA 6 cylinder Detroit Diesel or perhaps the 8V-92TA 8 cylinder Detroit Diesel. Makes sense to use something already in production (would certainly help the supply chain), but availability could be a problem with these other vehicles also needing them.

Obviously size of the engine bay as Paul mentions is a limiting factor also unless we're looking at rebuilding the hull as well (not something likely to be done after the nukes).

[Webstral]

Great work, Paul. Thanks for putting in the time and effort. Without refuting any of the observations so far, I’d like to add a couple of notes.

[Paul, you mention a 36-round capacity for the design but a 20-round capacity for the autoloader. Does this mean that the autoloader carries 20 rounds while 16 more rounds are carried in elsewhere in the hull, or is 20 the maximum number of rounds the design can carry because of the autoloader?] Paul, you answered this while I was working. Thanks.

What is the impact of the (possible) new hull on the manufacturing process? What is the impact of the new hull, if any, on the other components? Commonality is a virtue, as is making the most of the existing assembly lines. I have no idea how difficult it would be to resize the hull, but I think the decision-makers at the top would make this an important consideration.

I agree with others that the crews are going to want as much ammunition as possible. How great a weight the Pentagon attaches to crew preferences is an open question. An encouraging point, however, is that with increasing use of computers in designing AFV, the engineers have been increasingly inclined to bring in crews to provide feedback even before the first models are constructed. If the A4 is being designed in late 1995, crew feedback may play a major role. By this point, it shouldn’t be too hard to round up a few disabled Chinese veterans and some American crews.

As for the intended role of the Ridgway (I’m throwing my voice behind this moniker), the US Army Vehicle Guide (v1) tells us that the original LAV-75 was organized into light tank/assault gun battalions. Light tanks might be used for reconnaissance, but assault guns are definitely not intended for that role. Traditionally, light tanks play a tank destroyer role (albeit a light tank destroyer in most cases) and a fire support role. By definition, assault guns are infantry support weapons first, anti-tank weapons second. Obviously, troops will use the Ridgway in whatever capacity it can serve. However, it’s the big brass who set specifications and create TO&E. We should look as well at the formations that have been issued the LAV-75 in the TO&E: five light divisions (one battalion each), an airborne division (one battalion), and a motorized division (two battalions). If we see the light divisions operating in roughly parallel modes to the heavier infantry divisions of the National Guard (42nd and 43rd being good examples), then we might see the LAV-75 filling the role of the divisional tank battalion for a motorized (not mechanized) infantry division. Yes, I know this is a bit of a stretch. Still, the basic idea is that a tank battalion offers the division commander a heavy-hitting force in case he finds himself up against a mechanized opponent or just needs some muscle to tip the scales. Pack this thinking aboard aircraft, and you have a possible interpretation for the LAV-75 role.

Although speed is not typically a value associated with assault guns or tank destroyers, we might see the Pentagon wanting an agile light tank in that single divisional tank battalion. A fast AFV with the firepower to tackle everything but the very best Bloc tanks can be moved from place to place on the battlefield very rapidly. Alternatively, a fast assault gun quickly can be moved from place to place across a two-brigade light infantry advance.

Therefore, it seems to me that the Pentagon would prioritize agility over increasing the 36-round capacity. If the Ridgway is operating in close coordination with the infantry, resupply will be a lot easier than if the Ridgway is supposed to be out in front.

9th ID is a bit of a mystery to me. It may be that there are two battalions so that one can remain under divisional control, while another is split up among the brigades. Or there might be another reason entirely. I’m at a bit of a loss, so I’ll stick to what I understand and opine that the A4 is supposed to act like an air-transportable tank within the light divisions.

Of course, the Pentagon is going to be influenced by how things have been working out for the Chinese. If the motorized/light infantry divisions with a single tank battalion are seen to have been cost-effective in the Far East, the whole concept will be much more attractive than if the Chinese equivalent of the 25th ID has been used in a fashion that is doctrinally similar but has been waxed anyway. Lots of variables here. Mind, it’s probably not possible to do anything about the TO&E of US Army formations in the time allotted anyway. The Pentagon isn’t likely to want to be caught flat-footed by an unexpected escalation of the Sino-Soviet War; a significant reorganization might not be in the cards.

Webstral

[Legbreaker]

Originally Posted by Webstral

Mind, it’s probably not possible to do anything about the TO&E of US Army formations in the time allotted anyway. The Pentagon isn’t likely to want to be caught flat-footed by an unexpected escalation of the Sino-Soviet War; a significant reorganization might not be in the cards.

My thoughts exactly. It's doubtful there would have been enough time to reorganise and retrain whole units so it's more likely older vehicles would simply have been replaced on a 1 for 1 basis as the new M-20/LAV became available. Crews would probably be drawn from reinforcements and draftees rather than veterans. As it's highly unlikely that the full complement of M-20s would have been supplied, it's probable than an armoured battalion would still consist of say 3 companies of the older vehicle and just one of the M-20.

It's also possible that the M-20 was only issued to one or two divisions, with other divisions having to wait their turn to receive them (and due to the nukes, never seeing them).

For ease of supply and maintence I'm for the second choice. To allow for them to be encountered pretty much anywhere, the first choice is probably the better.

[Raellus]

As for role, once again I'd like to bring up the Sturmgeschutz III comparisons. Originally designed solely as an infantry support assault gun, the Ausf F version, with a long-barreled 75mm gun, was soon found to be a valuable AT asset and increasingly served in that role as German MBT production lagged behind that of the Soviets. By the later stages of the war, they were pretty much being used as de facto tanks.

I see the LAV-75/M20 intended to fill a similar role to the Stug III Ausf F: infantry support, SP AT gun, and, in a pinch, MBT.
From what the V1.0 U.S. Vehi Guide mentions about it, it sounds like the LAV-75 was originally designed primarily to provide direct fire support to light and airborne/airmobile infantry units and provide them with some organic mobile AT capabilities above and beyond their usual Jeep and Humvee-mounted TOWs and man-portable ATGMs.

As for ammo carrying capacity, I would think that a vehicle designed to serve behind enemy lines (82nd Airborne) or with light or motorized infantry divisions- all of which don't have quite as extensive a dedicated logistical infrastructure as a Mech or Armored division- would need to carry plenty of its own ammo into battle or risk running out at a very bad time. 36 sure is a lot better than 18. By my calculations, it's TWICE the ammo!

[Raellus]

Once again, in order to reconcile our M20 Ridgway with established T2K canon...

Originally Posted by Raellus

There's an intriguing bit of canon that could justify our little project. On page 40 of the v1.0 U.S. Army Vehicle Guide, in the plate description for a 9th Infantry Division (Motorized) LAV-75, it states,

"As it happened, the LAV-75 proved admirably suited to the 3-73rd's [of the 82nd Airborne Division] mission and, with a few alterations, was adopted [emphasis added]."

I'd like to propose that those "few alterations" included a new, 105mm-armed turret, side skirts, and lugs for ERA.

Said "alterations" would then have been retrofitted to existing vehicles and incorporated into new production.

[Legbreaker]

It appears to me (and I could well be missing something obvious) that the LAV-75 (and M8) were passed over in favour of M1s, M2s and M3s as well as a number of other less widespread vehicles. Therefore, it's hard to say definatively which units may have received the LAV-75/M20.

Of course we do have the Sheridan as a precursor, but as it was phased out a little too early in our presumed timeline, and was only assigned to the 82nd Div anyway (I think)....

Perhaps new subunits (company size - battalion seems a bit big for my liking) are needed to fit the M20 (or M8) into the unit structure? :S

Ideas anyone?

[ChalkLine]

With a halt to MBT construction, it's likely that other divisions would have heavy and light armour units as more divisions were raised.

[Jason Weiser]

Here's another item to support Rae's hypothesis. The M20 is going to be going into engagements, even with the 105mm, where it will be routinely outgunned by enemy MBTs..yeah, I know, the M20 has no business taking on MBT as a matter of course, but like the TDs of WWII, since when does one always have a choice in this matter? Frontally speaking, a 105mm is going to knacker anything less than a T-72, anything more modern than that, that's where it might get a bit squirrly. So, a second or third round from said 105mm as a quick followup against Mr. T-80 is a damn good thing IMHO.

[pmulcahy11b]

For better or worse, here it is:

http://www.pmulcahy.com/best_stuff_t...never_were.htm

I await your comments and corrections.

[Targan]

Excellent Paul. Great work.

[Legbreaker]

Not bad at all.

Do the early models really warrant +4 fire control though? Early to mid 80's US MBTs appear to have only had around a +3...

Another point worth considering is would the US really allow high tech fire control systems to be included in the vehicles sent to china and possibly captured by the Soviets?

[pmulcahy11b]

Originally Posted by Legbreaker

Not bad at all.

Do the early models really warrant +4 fire control though? Early to mid 80's US MBTs appear to have only had around a +3...

Another point worth considering is would the US really allow high tech fire control systems to be included in the vehicles sent to china and possibly captured by the Soviets?

Well...

1) The fire control system of the LAV-75 was well ahead of its time, with a very advanced ballistic computer that was loaded with software to match, a pulse coded-beam laser rangefinder, sensors to take into account weather, temperature, and barrel droop and a bunch of little sensors that were tied together by the computer to give the gunner an excellent chance of a first-shot hit. This is a big part of what scuttled export sales.

2) Good point...and I don't have an answer for that one. Someone help me out here!

[Dog 6]

WOW


Good job Paul!

[Raellus]

Thanks, Paul! Outstanding work.

I'd really love to run a little battle sim pitting a handful of M20 Ridgways against a Soviet or PACT armored division c. 2000 (T2K) and see if I could stop them. I know that a lot of folks here don't like the Eastern European Sourcebook but the Czech Mate scenario, replacing the M8 AGSs with M20s would make a good foundation for such a war game.

[Webstral]

Paul,

Great work! Wonderful attention to detail.

Webstral

[Targan]

It has occurred to me that another possibility for improving the anti-armour capability of the LAV-75 could be to bolt one or two ATGM launchers to the outside of the turrets. Thats what they did with the cavalry versions of the Bradley didn't they?

I'm not suggesting that we change what has already been decided among us for the LAV-75A4/M-20 Ridgway (because I think it rocks), but might the Chinese and or US Army have a few ATGM-armed variants floating around? I don't know how hard it would be to fit the electronics required (that might stop my idea cold for all I know) but it seems to me to certainly be easier to bolt on a (manually reloaded) ATGM launcher than to replace the entire turret, auto loader and magazine with a 105mm version.

[ChalkLine]

Originally Posted by Targan

It has occurred to me that another possibility for improving the anti-armour capability of the LAV-75 could be to bolt one or two ATGM launchers to the outside of the turrets. Thats what they did with the cavalry versions of the Bradley didn't they?

I'm not suggesting that we change what has already been decided among us for the LAV-75A4/M-20 Ridgway (because I think it rocks), but might the Chinese and or US Army have a few ATGM-armed variants floating around? I don't know how hard it would be to fit the electronics required (that might stop my idea cold for all I know) but it seems to me to certainly be easier to bolt on a (manually reloaded) ATGM launcher than to replace the entire turret, auto loader and magazine with a 105mm version.

It kinda depends if the vehicles are shipped before or after the missile drought starts to take hold. I can see the first series having a Javelin on it, as it's a fire-and-forget missile that fits in well with its mobile role, but after that the launcher may be deleted due to a lack of munitions.

[Targan]

Originally Posted by ChalkLine

It kinda depends if the vehicles are shipped before or after the missile drought starts to take hold. I can see the first series having a Javelin on it, as it's a fire-and-forget missile that fits in well with its mobile role, but after that the launcher may be deleted due to a lack of munitions.

I totally agree with that. I'm not suggesting that the missile armed variety would have been produced in large numbers. I'm thinking that they would have trialled a few different options including the 105mm armed conversion and an ATGM armed conversion.

It may have even been that early on the ATGM armed variant might have been more appealing (because on the face of it it would be an easier conversion) but the 105mm version ended up being the preferred option because of the missile drought.

There may have even been several different ATGM armed variants, a Javelin-armed one for the US Army and maybe several different options for the PLA (TOW II, Javelin, some European or even Soviet-derived ATGM packages).

[StainlessSteelCynic]

I'm personally inclined to think that any ATGM version for the PLA would be wired for Sino/Soviet missiles or older Western systems, for a few reasons (or more simply, fitted with a hardpoint to allow a Chinese launcher to be mounted so that it can be fired by a crew member from the hatch - much in the same manner as the Milan on the Marder).

1. While certainly wanting to help the Chinese reduce Soviet numbers, would the USA really want to give them current (for the timeline) ATGM technology? Especially when the Chinese already have their own versions of Soviet ATGMs in service.
2. If using a Western ATGW why not supply an older (obsolete?) system, this would provide a way of disposing of older generation missiles that are still "reasonably" capable of tackling Soviet armour without sacrificing newer technology (that the Soviets may capture in the field and reverse engineer, think of Iran's F-4, F-5 and F-14 aircraft after the fall of the shah).
3. The West already has an idea of how Soviet and NATO ATGWs work against the others armoured vehicles because the Arabs and Israelis have provided plenty of examples (and to a much lesser extent, so have other wars in Africa) so they wouldn't need the Chinese operational experience so much.
4. If the Soviets are causing trouble, wouldn't you want to keep all your most capable gear ready for your own use, just in case they start to wander into your neighbourhood?

Just some thoughts...

[ChalkLine]

Originally Posted by StainlessSteelCynic

. . . snip good points . . . just some thoughts...

Once again, it sort of comes down to when the LAVs go to China.
I think canonically 'Tank Breakers' go to China in the early phase. Of course nowadays we know that the Chinese are the world's worst technology thieves, and giving them a GPS isn't a good idea. Giving them a Javelin just means your enemies, the PRC aren't shy about selling your technology to your enemies, are going to be zapping you with cut price versions of your own weapons.

During the next phase of the war, when there's a general engagement with the USSR, the seized stocks of weaponry could be mounted on export vehicles.

After that phase, well you won't be giving weapons to anyone. Every vehicle, every captured weapon, all will be needed for your own people.