Self Propelled Artillery: M109 replacements

[uk 75]

Another of my favourite what-if issues. The M109 self propelled
howitzer must rank among one of NATO's most successful weapons.
Apart from France it served the NATO countries well and was very
difficult to replace. In Britain and Germany replacements appeared
belatedly at the end of the Cold War (SP70 having failed) and the
US found that despite repeated attempts the best M109 replacement
was a new M109.

Was this lengthy career inevitable. Could the US, UK and Germany have
produced a better vehicle from any of the numerous projects?

 

[TinWing]

Another of my favourite what-if issues. The M109 self propelled
howitzer must rank among one of NATO's most successful weapons.
Apart from France it served the NATO countries well and was very
difficult to replace. In Britain and Germany replacements appeared
belatedly at the end of the Cold War (SP70 having failed) and the
US found that despite repeated attempts the best M109 replacement
was a new M109.

Was this lengthy career inevitable. Could the US, UK and Germany have
produced a better vehicle from any of the numerous projects?

You really have to make reference to a specific project? For instance, you could offer information on the SP70 or you could update your own XM179 thread if you have found any additional information.

http://www.secretprojects.co.uk/forum/index.php/topic,5157.0/highlight,sp70.html

 

[razor]

"US found that despite repeated attempts the best M109 replacement
was a new M109."

I dont think so the US was stuck with the M109 because the politicos would not come up with the funds to develop and acquire something better . Having said that the M109 was a outstanding bit of kit in its day especially as modified by the Germans

 

[Pioneer]

Hell, from an Army perspective that has no SPH/G (or the ability of ones 'top brass' and politicians to make an executive decision on choosing an appropriate system!) I would welcome and take a second hand M109A3G or M109A6 Paladin any day! (although I favour the lightweight and simplicity of the wheeled Caesar SPH system!!)

Every time someone has questioned the validness of the venerable M109, I often respond 'How many SPH have the Soviet`s/Russian`s fielded in the time of the M109`s life time?

The poor old M109 must be one of the most overlooked (yet overworked) weapons platforms in post WWII times.

Regards
Pioneer

 

[Abraham Gubler]

I'd hate to interupt this thread with reference to the *actual* US Army project to replace the M109. It was the XM2001 Crusader... and low and behold it has it's own thread:

http://www.secretprojects.co.uk/forum/index.php/topic,7316.0

 

[Colonial-Marine]

There was indeed an XM179 at one point, I don't believe it got past the design stage however and the program was terminated in December 1969.

Section 1: Introduction of this document has some references to the XM179 and it's predecessor.
http://www.dtic.mil/cgi-bin/GetTRDoc?AD=ADA301713&Location=U2&doc=GetTRDoc.pdf

Also I remember there being some article in an ARMOR magazine about a proposed 155mm self-propelled howitzer on the Abrams hull.

 

[Colonial-Marine]

Here it is. Not an official project but an interesting proposal regardless.

https://www.knox.army.mil/center/ocoa/armormag/backissues/1990s/1995/nd95/6chassis95.pdf

 

[DanielStarseer]

Here it is. Not an official project but an interesting proposal regardless.

https://www.knox.army.mil/center/ocoa/armormag/backissues/1990s/1995/nd95/6chassis95.pdf

Yeesh!
Yes, interesting, it is.
But supposedly holding 80 rounds of onboard ammo, plus a VLS bank of 5 SAMs?

That thing woulda surely cost more than any tricked-out Crusader.

What I didn't see concerning the SAM system was just how they were cued up (queued up?).
Some sorta retractable optical system?
Curious, because the Avenger (Stinger pods on Humvee) used quite a bit of kit (optics, FLIR) just to utilize a turreted Stinger launch system.
Even with VLS, this proposal certainly would've needed optics/FLIR on a similar level, meaning big and bulky for the time, not like many of these small UAV multi sensor "balls" like we have today (like these: http://www.gs.flir.com/starsafire/ )
(seeing as the Armor article is from 1995, prior to the "explosion" in UAV systems development like we have seen this last decade)...

 

[TomS]

That's pretty typical of designs that came out of Western Design (whioch I assume was pretty much Sharoni, Bacon, and a couple of consultants). They came up with a bunch of notional armored vehicle concepts in the 1990s, most of which were, to my eye, over-stuffed with features of questionable utility.

 

[Colonial-Marine]

That's pretty typical of designs that came out of Western Design (whioch I assume was pretty much Sharoni, Bacon, and a couple of consultants). They came up with a bunch of notional armored vehicle concepts in the 1990s, most of which were, to my eye, over-stuffed with features of questionable utility.

Yeah their "Future-MBT" concept also had vertical launched SAMs, a rear facing remote controlled Mk.19, and a number of other features that probably would have added too much complexity.

 

[Abraham Gubler]

Western Design (now part of the Meggitt group) are world leaders in automatic loading magazines and the concept designs offered in Armor during the 1990s are mostly about packaging a primary weapon system into an armoured vehicle in an innovative way. Things like the anti air missile and self defence grenade launchers were features added to illustrate the surplus volume and weight margins of their designs and because they were features the US Army armor community were toying with at that time in their forward look exercises. They were hardly central to the capability of their designs. The success of Western Design’s efforts can be seen in the XM1200 vehicle family were – very nearly – the US Army was adopting a medium tank with remote turret and an artillery platform based on a tank platform.

 

[Firefly 2]

There are a myriad of SPH projects out there. Given the US Army's continuing penchant for tracks I would say that a system like the French Caesar or Czech Suzanna would never be adopted. While a SPH based on the M1 chassis would make sense from a logistical standpoint ( common operability, limiting logistic needs, etc), and the fact that the French have proven that it is feasible to base a SPH system on a MBT design ( the AU F1), there is one option that would make even more sense from a financial standpoint: the German AGM. It would seem logical to an enthusiast such as myself to consider such a design when it can be integrated on a hull that is allready in common use, and likely less costly than the M1: the MLRS.

http://www.army-technology.com/projects/artillery/

I have no doubt that I'm overlooking things. Any criticism is welcome.

 

[Abraham Gubler]

There’s a lot more to it than tracks or wheels. The M109 has a lot more in common with the G6 than with a Caesar type gun on a truck. Which is really just a towed gun with a truck in place of the carriage which has advantages and disadvantages compared to a towed gun. In that the crew have to expose themselves to the elements to operate the gun and it’s a lot cheaper than a fully armoured SPH – wheeled or tracked.

If the US Army needs a long range 155mm gun over and above the current 39 calibre gun programs (M109 PIM and M777) then they can always resurrect the XM2001 Crusader and the XM297 56 calibre 155mm gun. But the big question is “if” because with the current operational need, precision guided shells and lots of MLRS the demand for a >39 calibre barrel is not very high.

Placing the SPH system on the M1 chassis was never seriously considered by the US Army – though the Crusader is an M1 class vehicle – however the current PIM project is effectively placing the SPH system on the Bradley chassis. While the hull will be retained from the M109 most of the automotive stuff (including the driver’s position) will come from the BFV.

 

[Colonial-Marine]

Western Design (now part of the Meggitt group) are world leaders in automatic loading magazines and the concept designs offered in Armor during the 1990s are mostly about packaging a primary weapon system into an armoured vehicle in an innovative way. Things like the anti air missile and self defence grenade launchers were features added to illustrate the surplus volume and weight margins of their designs and because they were features the US Army armor community were toying with at that time in their forward look exercises. They were hardly central to the capability of their designs. The success of Western Design’s efforts can be seen in the XM1200 vehicle family were – very nearly – the US Army was adopting a medium tank with remote turret and an artillery platform based on a tank platform.

I'm not certain the XM1200 family got as close to adoption as that. There was still a long way to go with the vehicles other than the XM1203 NLOS-C. And the major contractors have taken a lot of criticism for their performance across FCS.

Looking a photo of the turret assembly on the XM1202, what appears to be the ammo carousel does look similar to Western Design's configuration in their FMBT proposal. Do you know if they were directly involved in the MGV program? Or the M8 AGS and M1128 MGS for that matter?

 

[Abraham Gubler]

I'm not certain the XM1200 family got as close to adoption as that.

The US Army was hell bent on adopting them - just the new US Government pulled the funding - and they had received their XM type codes. Which is closer than a lot of other systems have come.

Looking a photo of the turret assembly on the XM1202, what appears to be the ammo carousel does look similar to Western Design's configuration in their FMBT proposal. Do you know if they were directly involved in the MGV program? Or the M8 AGS and M1128 MGS for that matter?

WD provide(d) the ammunition handling systems for the M1128 and the XM1202. The Crusader/XM1203 system is a BAES (aka United Defense, FMC) system. I don't know about the XM8 but from memory that was an in house FMC system. WD also have a neat automatic loader that fits in the M1's turret bustle (34 vs 40 rounds) that is talked about for the A3 upgrade allowing the third turret crew (aka loader/operator, assistant gunner) to focus on second channel of fire crewing.

 

[Colonial-Marine]

The US Army was hell bent on adopting them - just the new US Government pulled the funding - and they had received their XM type codes. Which is closer than a lot of other systems have come.

WD also have a neat automatic loader that fits in the M1's turret bustle (34 vs 40 rounds) that is talked about for the A3 upgrade allowing the third turret crew (aka loader/operator, assistant gunner) to focus on second channel of fire crewing.

I know the FCS concept had plenty of support from Army leadership but I imagine experience from Iraq may have swayed the opinions of some, especially involved in HBCT-related program management. Surely there were others on the military end of the program besides for DefSec Gates who wanted the MGV concept replaced by something heavier. However Gates intent on integrating MRAPs so heavily into our force structure has me thinking he had a different idea than whoever else supported cutting MGV.

IIRC an automatic loader was considered during the earlier days of the M1A2 upgrade program. Do you know if it was the same turret bustle located system then?

 

[Abraham Gubler]

I know the FCS concept had plenty of support from Army leadership but I imagine experience from Iraq may have swayed the opinions of some, especially involved in HBCT-related program management. Surely there were others on the military end of the program besides for DefSec Gates who wanted the MGV concept replaced by something heavier. However Gates intent on integrating MRAPs so heavily into our force structure has me thinking he had a different idea than whoever else supported cutting MGV.

That was all just spin. The XM1200 family in the iterations being designed in the years before it was cancelled had lots, lots of armour. In the high level configuration more armour all around the vehicle than a M1A1/A2 has in its turret front. Also there was a high ground clearance mod that provided plenty of under-belly protection. Because of its modular design the XM1200 could be scaled up and down for protection by need which means you drive a vehicle with light armour for training at home to save fuel and wear and tear and drive the heavy armour vehicle in theatre.

Unfortunately the combination of the constant attention on air mechanised nonsense and the lack of imagination amongst many commentators and leaders – “where’s the armour” “we add it on sir” “where’s the armour!” – lead to the creation of a myth that the XM1200 was a light armour vehicle. Then of course the desire to save a few 10s of billions by the Obama Administration lead to XM1200 being cancelled. But the new GCV is so heavily reliant on the XM1200 body of knowledge and two of the main bidders were the team for the XM1200 it will end up being very similar.

IIRC an automatic loader was considered during the earlier days of the M1A2 upgrade program. Do you know if it was the same turret bustle located system then?

This was associated with the new 120mm gun that could be re-barrelled with a 140mm tube. I doubt there would be any connection because the 120mm Compact Autoloader is designed around the single piece 120mm ammunition and not the two piece 140mm ammunition: so it wouldn’t be upgradeable.

http://mdswebmaster.com/UK/MDS2008/cms/images/stories/pdf/PD_120mm%20Compact%20Autoloader.pdf

 

[uk 75]

Colonial Marine

Thank you for the ref about the XM179 which shows how short lived the
programme was (from mid 1968 to December 1969).

The earlier XM138 lightweight unarmored self-propelled gun is pictured in sources,
but no artwork or descriptions of the XM179 appear. "High development cost,
unacceptable projected production unit cost, and questionable design complexity"
were given as reasons for the cancellation. Sounds just like the MBT70. Still, it
might have looked a smooth bit of kit.. Would be nice to know more.

Abraham Gubler

Of course the Crusader programme is well documented, as indeed are various 80s
projects for M109 replacements. However, what is interesting is that after the demise
of the Xm179 in 1969 there appears to be no US equivalent of the European ill-fated
SP70 programme for an M109 replacement. Does this mean that the US were waiting
to see if this would be worth joining? Or did US Industry in the period 1969 to 1975
simply rely on improving M109?

UK 75

 

[Abraham Gubler]

Short history of replacing the M109 in the US Army up to Crusader:

1969 service trials fitted with the XM185 long barrel (39 calibres) 155mm howtizer from the XM179 program leading to the M109A1 and the demise of XM179.
1979-80 the Enhanced Self-Propelled Artillery Weapon System (ESPAWS) study replaced by the Division Support Weapon System (DWS) study replaced by the Howitzer Extended Life Progam (HELP) leading to the M109A4 in 1983.
1985 Howitzer Improvement Program (HIP) considering the XM284 Modified Armament System (MAS) based on the L39 M185 and the Advanced Armament System (AAS) with either the L39 XM283 (based on the M198's M199) and the L58 XM282. The XM282 had a 27.8 litre chamber, which is even bigger than the G6-52's 25 litres, and could shot a base bleed round to 45km. The XM284 was chosen and with a new turret and a range of improvements fro the Human Factors Howitzer Test Bed (HFHTB) became the M109A6 Paladin with production deliveries from 1992.
1992 to supplement the M109A6 a less expensive upgrade with just the M284 gun and NBC system was developed called the M109A5.

 

[uk 75]

Abraham

Thank you for this comprehensive listing. Somewhere in a book called
NATO Mechanised combat equipment produced in the 80s are artists
impressions of the ESPAWS. I will try and dig them out.

Would still love to see if XM179 was as wayout as the MBT 70 and XM701.

UK 75

 

[Colonial-Marine]

That was all just spin. The XM1200 family in the iterations being designed in the years before it was cancelled had lots, lots of armour. In the high level configuration more armour all around the vehicle than a M1A1/A2 has in its turret front. Also there was a high ground clearance mod that provided plenty of under-belly protection. Because of its modular design the XM1200 could be scaled up and down for protection by need which means you drive a vehicle with light armour for training at home to save fuel and wear and tear and drive the heavy armour vehicle in theatre.

Unfortunately the combination of the constant attention on air mechanised nonsense and the lack of imagination amongst many commentators and leaders – “where’s the armour” “we add it on sir” “where’s the armour!” – lead to the creation of a myth that the XM1200 was a light armour vehicle. Then of course the desire to save a few 10s of billions by the Obama Administration lead to XM1200 being cancelled. But the new GCV is so heavily reliant on the XM1200 body of knowledge and two of the main bidders were the team for the XM1200 it will end up being very similar.

Interesting to hear another point of view about the GCV program. Many former tankers I have talked to were hostile to the whole concept. Mainly due to the belief that even with the modular armor it wouldn't come anywhere near the Abrams. I am sure all of it is classified, but it would be interesting to know just how much progress was made in terms of developing lighter and stronger composite armors. Do you happen to know if Raytheon's Quick Kill APS happened to survive the division/cancellation of FCS?

Judging from BAE's recent 53 ton (75 tons in it's heaviest configuration!) ton offering it looks like GCV is going to be rather removed from MGV. Or a similar vehicle but seriously scaled up.

 

[Abraham Gubler]

Many former tankers I have talked to were hostile to the whole concept. Mainly due to the belief that even with the modular armor it wouldn't come anywhere near the Abrams. I am sure all of it is classified, but it would be interesting to know just how much progress was made in terms of developing lighter and stronger composite armors.

While the technical detail of armour development is of course kept secret the type and quality/quantity of armour for FCS MGV was not. It was just under-reported and too late to change the conservative opinion that the XM1200s were thin skinned. Also the Kit or Levels armour approach enables the vehicle to be issued for training in a low level armour configuration and then upgraded when deployed on combat operations. This saves a lot of cost associated with maintenance, fuel etc by doing a lot of driving in the lower weight configuration. Of course however if the potential users see an image of their to be issued medium tank without the add on armour they naturally think the vehicle is thin skinned. As I said before all of the XM1200 vehicles at full armour level would have had 360 degrees protection higher than that of the frontal armour of the M1A1/A2.

Do you happen to know if Raytheon's Quick Kill APS happened to survive the division/cancellation of FCS?

Yes it did and its part of the MGV BoK incorporated into GCV.

Judging from BAE's recent 53 ton (75 tons in it's heaviest configuration!) ton offering it looks like GCV is going to be rather removed from MGV. Or a similar vehicle but seriously scaled up.

Weight is not an even benchmark for determining armour. The GCV entries are far bigger vehicles than the XM1200 because they have more volume consuming components like conventional transmission, manned turrets and are also required to carry more people inside them (up from 11 to 15?). Volume determines surface area and surface area determines the amount of weight needed to achieve a level of armouring. For example the Swedish S-Tank had basically the same type of gun, ammunition and level of protection and mobility as a British Centurion but weighed <40 tonnes compared to >50 tonnes because of its advanced lower volume configuration.

 

[moin1900]

Hi

Drawings of self-propelled howitzers: casemate, turreted, enhanced M109A2 designs and two foreign systems SP70 and GCT.

Artillery Systems Engineering Study (Concept Team Final Report) 1981
http://www.dtic.mil/docs/citations/ADA102819

 

[eshelon]

Two concepts of AFAS-C
sources:
(1) Army July 1987 (and Field Artillery December 1989)
(2) Field Artillery December 1989

 

[Pioneer]

Two concepts of AFAS-C
sources:
(1) Army July 1987 (and Field Artillery December 1989)
(2) Field Artillery December 1989

Ohoo....tell us/show us more please eshelon!!


Regards
Pioneer

 

[uk 75]

Usually my enquiries tease out a long lost picture but despite years of prodding and the fact that it is now 50 years ago nothing has appeared about the xm179 programme. Still live in hope.

 

[skylancer-3441]

ESPAWS

 

[skylancer-3441]

AFAS-C FMC

 

[jsport]

Thank you Skylancer.

Again according to the patents binary propellants now allow much safer propellant storage.

 

[jsport]

A mechanized assault's Intiative could be quickly diminished w/ an automatic 155mm SPG firing guided rds.

 

[sferrin]

 

[skylancer-3441]

photos and captions from IDR's articles on AUSA'88 and '89

 

[uk 75]

Thank you for finding these articles. I remember them vaguely from the time they appeared.
It is strange that in all these years the elusive xm179 has never been illustrated. Perhaps it was simply a standard M109 with a new gun.

 

[jsport]

Liquid Propellents discussed

 

[jsport]

A 25mm RGLP would easily been able to defeat tanks threatening the M-109 allowing it to operate much farther forward.

 

[drejr]

That little gun on top of the model is supposed to easily take out tanks?

 

[jsport]

That little gun on top of the model is supposed to easily take out tanks?

Research on RLGLP possible velocities would answer your question.

 

[drejr]

I wonder why we have this forum at all then!

In fact it wouldn't, because my question is about this specific gun. Were the program requirements for self-defense against tanks or did you infer it? There's nothing mentioning the capabilities envisioned in the text you provided. I'm somewhat skeptical since the self-protection gun would presumably use the relatively low energy density XM46 propellant developed for AFAS.

My own research indicates a 10-15% increase in potential muzzle energy for what are more commonly abbreviated RLPGs, which wouldn't seem to make cannons barely bigger than a .50 BMG into tank-killers. Especially with propellants designed for medium velocity howitzers.

 

[jsport]

I wonder why we have this forum at all then!

In fact it wouldn't, because my question is about this specific gun. Were the program requirements for self-defense against tanks or did you infer it? There's nothing mentioning the capabilities envisioned in the text you provided. I'm somewhat skeptical since the self-protection gun would presumably use the relatively low energy density XM46 propellant developed for AFAS.

My own research indicates a 10-15% increase in potential muzzle energy for what are more commonly abbreviated RLPGs, which wouldn't seem to make cannons barely bigger than a .50 BMG into tank-killers. Especially with propellants designed for medium velocity howitzers.

Yes 15% would not be worth the hassle of a new gun. Patents on Binary propellants (ie safe, as will only detonate when combined and compressed in a particular chamber w/ a particular electronic ignition) have come along. Minus hypersonic veliocities attained then there is no point and we are quite past that now.

 

[Foo Fighter]

When considering a hard kill of any military target like a tank, I would ask the question, why bother? The hardware does not have to be defeated, just the organic and electronic components within. A good sized shock wave will do that. A question, what effect would a moab have on a small to middling mixed armour force?