M48 Patton series in obat12

[Basileus Ioannis]

Hello team -

Again, couldn't find this topic discussed previously, please ignore if it is a dead horse...

Plans for the medium tank T48 drawn up by December 1950; first pilot T48 built December 1951, one year after design completed. LRIP began April 1952, full rate began by 1953; early production not fitted with rangefinder, so in January 1953 the Army said if gunner's direct sight telescope was installed then could accept for training purposes only (not to be sent overseas). 893 T48s built by 27 March 1953, standardized as M48 2 April 1953; most early production tanks had to be sent back to be modified extensively before they were acceptable.

Aircraft Armaments M1 cupola with enclosed .50cal commander's MG approved for production August 1953. Driver's hatch was enlarged by December 1953, and new M1 commander's cupola fitted by June 1954. Army revises descriptions 25 October 1954: small driver's hatch tanks with external .50cal MG cupola standardized as M48, large driver's hatch tanks with M1 cupolas as M48A1; 1805 large hatch tanks built with old cupola were retrofitted with M1 cupolas. M48A1 approved for overseas shipment on preferential basis. By the end of 1954, about 7000 M48 series (around 3200 T48/M48, 3800 M48A1) built by Chrysler, Ford, and Fisher Body Division of General Motors.

New fuel injection engine and enlarged fuel tanks improve range; with new Cadillac Gage fire controls, becomes M48A2 by October 1955, American Locomotive contracted November, production authorized December. While Chrysler, Ford and GM continue M48A1 deliveries, ALCO begins producing M48A2s; by the end of 1956, 2500 more M48 series (around 2375 M48A1, 125 M48A2) were built. This brings M48A1 production total to around 6175.

By January 1957, Chrysler contracted to build M48A2s; combined production rate 900 per year, 75 per month. During 1958, Chrysler develops metric fire controls with coincidence rangefinder replacing stereoscopic; standardized January 1959 as M48A2C, with 1344 previously built M48A2s converted to new standard. Production apparently ends by June 1959 after 11703 M48s were built (around 3200 M48, 6175 M48A1, 2328 M48A2/A2C), with the bulk of M48A2/A2C production exported to West Germany; coincidence RF and metric FC from M48A2C installed in new XM60.

Apparently only armored cavalry regiments, the two infantry divisions in South Korea, and a few CONUS battalions received the M48A2/A2C, one of which (1/77AR, 1BDE 5ID(M)) took them to Vietnam in July 1968, reequipped in-country with M48A3s about a year later. Last M48A3 equipped unit, 2/11 ACR, departed Vietnam 6 April 1972; most runners handed off to ARVN, units rotating Stateside were eventually reconstituted with M60A1s.

XM60 pilot production begun at Chrysler July 1959, full rate production of M60 on 22 April 1960, with 2205 built by October 1962 when production switched to M60A1. Meanwhile, Anniston and Red River Army Depots retrofit diesel engine of M60s into M48A1s to produce M48A3s, delivered from February 1963 to late 1964; Army receives 600, Marines 419. By 1965 no M48A1s in active duty units. On 14 April 1967, BMY contracted to convert 578 more M48A1s in storage into M48A3s, delivered by 1969; M48A1 to M48A3 conversions total 1597. After 1972, all active duty Army tank units equipped with M60 series, reserves have M48A2C/A3 or M60.

Anniston Army Depot up-guns M48A3s with 105mm gun, called M48A5; 2 delivered June 1975, 3 in July, 496 from October 1975 to December 1976, total 501 M48A3s converted to M48A5. In August 1976, 2 M48A1s in storage were converted to M48A5 standard; low profile Urdan cupola with M60 7.62mm MG replaces M1 cupola, previously produced M48A5s later retrofitted. Full rate conversions began October 1976, and by March 1978 708 more M48A5s were completed. Conversions continued until December 1979 for a total of 2069 M48A5s produced (501 from M48A3s, 1568 from M48A1s). All but 140 M48A5s were for the reserves or export: 2ID in South Korea replaced their M60A1s with M48A5s June-July 1978; M60 7.62mm MG on commanders cupola replaced with M2HB .50cal HMG on these tanks. These M48A5s would be replaced by M60A3(TTS) by mid 1985; M48A5s in reserve units replaced by 1990.

Therefore, recommend availability:

M48 Patton - ?/53 to 12/60 (radio code 91, for training only)
M48 Patton - 1/57 to 12/72 (UC 102 for reserves)
M48A1 Patton - 1/55 to 12/62 (radio code 90 or even 92)
M48A1 Patton - 1/63 to 12/64 (radio code 91)
M48A1 Patton - 1/57 to 12/72 (UC 102 for reserves)
M48A2 Patton - 1/57 to 12/59 (radio code 91, FC 15, speed 17*)
M48A2C Patton - 1/59 to 7/69 (radio code 91, FC 15, speed 17*)
M48A2C Patton - 1/65 to 12/76 (UC 102 for reserves)
M48A3 Patton - 1/64 to 4/72 (radio code 91 or UC 15 w/canister)
M48A3 Patton - 1/73 to 12/84 (UC 102 for reserves)
M48A5 Patton - 6/78 to 7/85 (radio code 91, with .50cal AA)
M48A5 Patton - 1/76 to 12/7? (UC 102 for reserves, w/.50cal AA)
M48A5 Patton - 1/77 to 12/89 (UC 102 for reserves, w/M60 AAMGs)

* AVI-1790 fuel injected gasoline engine gross HP 825, gross torque 1670 lb.ft. vs AV-1790 carbureted gasser gross HP 810, gross torque 1610 lb.ft.; AVDS-1790 diesel had lower HP but more torque than either gasser, although one vet wrote about M88A1 diesel vs. M88 gasser that the diesel had lower performance

note: after their withdrawal from service, 500 M60A2s had their turrets replaced with M48A5 turrets; the resulting M48A5E1 was fielded by reserve units 1/82?-12/89 (stats basically identical to original M60, but with 2x M60 7.62mm AAMGs)

This is all I could glean from Hunnicutt, Mesko, and Zaloga, as well as the excellent olive-drab.com site. If you have more accurate info, please advise. Thanks,

John

[DRG]

I'll put this info in the files to investigate next year. We skip some models as being irrelevant in game terms. I know some would prefer we include every last version of any tank for "accuracy" if it doesn't have any significant changes that would affect game play we skip it which is why the A1's were ignored as were the A2c's. Also affecting when models are available is the ammo ( or gun in the game ) which complicates things further when establishing when units are available and that can eat into the remaining unit slots if I let it so this involves more than just a couple of start or end date changes and I'm too busy with other issues ATM to do any more than copy the info to the list

[FASTBOAT TOUGH]

First Don will look into your information no worries there. I submit this to illustrate his point through my own learning curve a couple of years ago. Should you want to do so...go to the FASTBOAT Patch Page Thread Pg. 1 Post #3 MBT items A1. USA/M1A1 SA and A3. USA/M60A1 RISE and all the Posts of Pg. 2 that dealt with these two inputs. I look deeper now in the game and more so since after having to take in account the slot limiting OOBs in the game. Had the same issue with the BRADLEY I think in the same years submission, submitted 3 or 4 and got 1, but good enough for me as it accomplished my overall goals in the end.

Regards,
Pat

[Suhiir]

I'll second Don and Fast.
I find it practical to ignore certain models, speed up or delay new ammo variants, or increase the passenger capacity of a vehicle slightly in order to reduce the total number of equipment slots used in an OOB.

P.S.
Since you apparently discovered a treasure trove of info on the M48 series tanks I personally would be very interested in anything you find concerning USMC (OOB #13) usage.

[Basileus Ioannis]

Thank you Don, Pat and Suhiir, I appreciate your consideration and all the work you all put into SPMBT; the detail level of this game far outpaces its humble SSI beginnings, and your hard work shows. I mean, while running my brief playtest just now, I had a tracked vehicle get stuck in a rice paddy...another, a wheeled vehicle, wouldn't go into mud terrain so the passengers dismounted to continue on foot. That, gentlemen, is meat and potatoes details that certainly satisfies the appetite.

Suhiir, re: obat13 USMC use of M48s, here's what I've got so far: per Hunnicutt's PATTON, pilot T48 #6 was delivered to the Marines; since pilot #5 was delivered in November 1952, that must be the earliest date #6 was delivered. A photo of pilot #6 appears in Jim Mesko's M48 Patton In Action, with small drivers hatch and cylindrical blast deflector.

A website history of the 1st Marine Tank Battalion indicated that the Marines got only enough M46 Pattons for the 1st Marine Division in Korea, but CONUS units had to wait for the M47; photos in Hunnicutt show Quantico testing M47s by February 1953, and when the 3rd Marine Division deployed to Japan in August 1953, they had M47s. 1st Marine Division left Korea for Camp Pendleton in early 1955; it is possible that the Marines only picked up enough M47s for the 2nd and 3rd Divisions and the Force level battalions, and the 1st was reconstituted in early 1955 with M48A1s, leaving its M46s in Korea, but I don't have written data to the effect. It is also a given that the 2nd Marine Division had M48A1s by the time they deployed to Beirut in July 1958. The website also listed total M48A1 acquisition at 421 tanks, 419 of which were dieselized in 1963-64.

Lacking further M48A1 deployment info, I can extrapolate based on parallel development of the M67 flamethrower tank; Hunnicutt goes into considerable detail on this, starting with the T66 prototype based on the M47 hull (the turret was scavenged from the T42 tank program, and had the pistol port on the left side of the turret which was eliminated from the M47). The sole T66 was produced under Army Chemical Corps auspices, as well as the subsequent T67 pilot based on the hull and turret of the M48 with small drivers hatch, external .50cal MG, and no track tension idler wheel; photos of this pilot undergoing tests at Aberdeen are dated November 1953. The flame gun M7-6 mounted in an M48A1 turret was standardized on 13 October 1954, and the Marines ordered 56 complete T67 tanks, 17 T7 flamethrower turrets to be fitted to redundant M48A1 hulls, and the pilot T67 was rebuilt to M48A1 standard (larger drivers hatch, M1 commanders cupola, track tension idler wheel installed) for a total of 74 flame tanks. T67 standardized as Flame Thrower Tank M67, and T7 turret standardized as Flame Thrower Tank Turret M1 on 1 June 1955.

So it can be deduced that at some time between October 1954 and June 1955, the Marines were receiving M48A1 Pattons. Since M48A1 production apparently ran until the end of 1957, the fact that 3rd Marine Division was reequipped two years later might indicate they were second hand Army tanks acquired after production to make up a shortfall in the initial procurement.

The only changes I might recommend in obat13 availability:

012/531 M47 Patton - 8/53 to 7/59 (so they don't appear during either the Korean or Vietnam wars)
007/013/532/635 M48A1 Patton - 4/55 to 11/64

The ENSURE 202 mine rollers for M48A3s weren't deployed until late in the Vietnam War; photo evidence is dated 1970, and only 27 sets were deployed. The earlier Larruping Lou, ERDL I/II and Birmingham rollers were experimental and never fielded.

John

[Basileus Ioannis]

Thanks Pat, I can see the extensive work you did in your Patch thread. I don't know how you keep up with developments in so many nations, I have difficulty with just segments of one!

Re: M60A1(RISE/Passive), per History of the Shillelagh Missile System 1958-1982 by DeLong, Barnhart and Cogle: in February 1978 DA decided to phase down the M551 and replace it with the RISE/Passive with new ammo. The swapout began with 11ACR from June 1978, 2ACR was reequipped from September, then USAREUR DIVCAV units from December 1978 through March 1979. CONUS based cav units received RISE/Passives from April 1979, completing the Sheridan swapouts in all cav units during FY80 (I found no reference to 2ID Sheridans being swapped out with RISE/Passives, so they probably received M48A5s instead).

I had thought most M60A2 battalions were reequipped with M60A1s, but production rates and known phaseout dates seem to indicate that at least some of the six battalions in USAREUR received M60A3s instead. Per History of the Shillelagh Missile System:

Reduction in force ordered by DA April 1979

1/32AR, 3AD - 5/79 (received all 54 M60A3s at once)
2/68AR, 8ID(M) - 6/79 to 8/79
2/64AR, 3ID(M) - 9/79 to 11/79
3/33AR, 3AD - 1/80 to 3/80 (had catastrophic gun breech failure July 1979)

Was originally planned to leave two battalions in USAREUR until 1987, but decision to phase out the M60A2 was made February 1980, accelerated phaseout ordered May 1980

1/37AR, 1AD - 6?/80 to 8?/80
3/64AR, 3ID(M) - 9?/80 to 11?/80

The last two above may have received 11ACR's M60A1(RISE/Passive) pending availability of M60A3(TTS) for 1/37AR, M1 for 3/64AR. Phaseout of M60A2 completed during FY81, which leaves the one battalion at Fort Hood being the last, probably during spring 1981, most likely with rebuilt M60A1(RISE/Passive).

By December 1979, M60A3(TTS) appear to have been test-fielded by 1/10CAV, 4BDE 4ID(M); after a six month evaluation, 11ACR began to be reequipped from July 1980, a mere two years after receiving M60A1(RISE/Passive). 3/8CAV, 8ID(M) was apparently next, in December. In the first five months of 1981, four regular tank battalions appear to have received the TTS, I am not sure which division but I'm leaning toward 3AD, followed by 2ACR starting in June. Three more DIVCAVs received TTS before all six tank battalions of 1AD were reequipped from February to November 1982. Four remaining battalions of 8ID(M) appear to be reequipped from December 1982 to May 1983, with 3BDE 1ID(M) aka 1ID(FWD) being one of the last USAREUR units reequipped by July 1983 (the latter per www.usarmygermany.com). TTS fielding to CONUS must have begun at this point, with 2ID in Korea receiving theirs by mid 1985. Per REFORGER 1986-1993 by Tankograd, the latest photo evidence of M60A1(RISE/Passive) use by active duty units was by 1BDE, 1ID(M) during REFORGER 86.

While this has been culled from multiple sources, some of the dates and units are educated guesses, so if you have more definitive info then please let me know, thanks

John

[Suhiir]

Basileus,

The USMC was equipped exclusively with M4A3(105) Shermans prior to Korea. However, they had enough M26 Pershings in storage to reequip the most of the 1st MarDiv with them prior to sending it to Korea.

My info has the 1st MarDiv replacing it's M26 Pershings with M46 Pattons mid 1952. And by March 1955 they'd been replaced my M48A1's.

I had indications the M47 was available as early as October 1951, but that info may be inaccurate.

Good info on the conversion of the M48A1's to M48A3's. I knew some weren't converted but I think all but 3 out of 421 is close enough drop the M48A1 by 1964.

My info is the USMC got M67A1 Zippo in 1957 and those were upgraded to M67A2 in 1965.

The USMC gets a lot of its armor 2nd hand from the US Army. So it's not so much a shortfall in the production of M48A1's but having to wait till the US Army replaced theirs.

"The ENSURE 202 mine rollers for M48A3s weren't deployed until late in the Vietnam War; photo evidence is dated 1970, and only 27 sets were deployed.
The earlier Larruping Lou, ERDL I/II and Birmingham rollers were experimental and never fielded."

I'm assuming from what you say there were no mine roller M48A1's at all?

[Basileus Ioannis]

Hi Suhiir -

You're right, per T-34-85 VS M26 PERSHING Korea 1950 by Zaloga, on pp.46-47 it states that the Marines had received 102 M26 Pershings from the Army, and all but H&S Company continued using the M4A3(105)s for training, the crews cycling through H&S Co to keep current on the M26; the rest were indeed in storage at Barstow depot. A Company, 1st Tanks was the only active company of the battalion, so they had to scramble to collect experienced tankers from around the country to reconstitute the entire battalion. They got 27 M26s loaded on LSDs for the trip to Pusan, 22 for A Co and 5 for the regimental AT platoon (H&S Co crews filled out the AT platoon). They didn't send any floaters, and 90mm ammo was tight...a situation exacerbated by partial flooding on two LSDs (different source, may have been the 1st Tanks history site), the well decks suddenly began to flood while the ships were under way, and several tanks with 90mm ammo on board were flooded. The tanks were dried out and cleaned, but the ammo on those tanks were ruined and had to be replaced.

The earliest photo evidence of USMC M46s I found was in Hunnicutt's PATTON, dated 23 November 1951; others are seen "ridge running" during the winter of 1951-52. Other sources were more vague, saying they were reequipped "after the Chinese spring offensive", which was in late May 1951. The front line stabilized on the Jamestown-Missouri-Minnesota line by November 1951, and the Army took the opportunity that month to reorganize their tank units to the 69-tank standard battalions, and organizing regimental tank companies that were missing, so it is likely that the Marines took that opportunity to field M46s. Somewhere I had read that the Marines only received 80 M46/M46A1s, which is barely enough for the division...if true, then I assume that UNC took care of maintenance float? Not likely...

Since 1st MarDiv retrograded from Korea around March 1955, it is most likely that they were reequipped with M48A1s after returning to Pendleton.

M47 production was insane...while production nominally began June 1951, they didn't enter testing until late August, and that ran for a year. The early deliveries didn't even have the rangefinder installed, just like the T48s. While few automotive bugs were found, the problems were mostly related to the turret fire controls...it was designed to use an IBM gun stabilization system, but DA deleted the stabilizer and didn't redesign the FC to compensate...it took a year to work those bugs out. Meanwhile both Detroit and ALCO were cranking out incomplete tanks at a combined rate of around 350 tanks per month (estimate 210 Detroit starting October 1951, 140 ALCO starting late January 1952).

Re: M67, the Marines got the M67 based on the M48A1, the Army got the M67A1 based on the M48A2. The M67 was standardized on 1 June 1955, the M67A1 on 8 January 1959. M67s had .30cal coax MG; the M67A1 had 7.62mm M73 coax, improvements to the gun shield, and Cadillac Gage fire controls. 35 Marine M67s were authorized for dieselization late 1961; one pilot conversion at Detroit arsenal included upgrading the turret to M67A1 standards (coax, gun shield, FC), was designated M67E1 on 1 February 1962. M67E1 standardized as M67A2 on 25 June 1962; 73 remaining M67s converted at Anniston to this standard in parallel with M48A3s. The Army put its 35 M67A1s in storage by 1963, replacing them with cheaper M132 Zippo tracks; they were given to the Marines and dieselized to M67A2 standards by 1968, but they retained the three track return rollers, the M67/M67A2s had five. So the Marines received a total of 109 flamethrower tanks.

Re: mine rollers, that's what I gather, only experimental mine rollers were being tested on M48A1s, none fielded. After WWII, they scrubbed the Aunt Jemima mine roller and all flails and plows. They actually tried mounting several rockets on the glacis of tanks, with the jet blasting downwards, but it raised too much dust and wasn't very effective. During the Korean War, they sent this comb-shaped monstrosity called High Herman with 25 one-ton spoked disks to be fitted to the M46, but the thing weighed 36 tons, the mounting arm got in the way of the main gun firing forwards, and it tended to blow the final drive on the poor tank. So by 1953, they revised the mounting to two arms, and reduced it to 16 disks individually articulated, eight in front of each track, called Larruping Lou. Later reduced to 12 disks, six per track, this weighed 20 tons and didn't kill the final drives as much. But by May 1954, DA wanted a lightweight expendable roller, so US Army Engineer and Research Development Laboratory (ERDL) came up with two individual arms with a steam-roller-like solid roller in front of each track, called ERDL I. While effective, they replaced the solid rollers with four individually sprung tank road wheels, called ERDL II; this looks a lot like the ENSURE 202 that got fielded. DA contracted with Birmingham Fabricating Co to make the ERDL II, but they increased the number of road wheels to six per arm, twelve total. Now there was a concern that these lightweight rollers weren't providing sufficient ground pressure to set off antitank mines, so Lockley Machine Company came back with big solid drums with spikes on it, with arms that would shift more of the tank's weight on the rollers, but that tended to overstress the rear suspension on the tank, and was too expensive and not expendable. When the Vietnam War began, DA went back to the Birmingham roller, redesigned the mounting arms, and it was accepted under the Expedited, Non-Standard, Urgent Requirement for Equipment (ENSURE) program as the 202nd article, so called ENSURE 202. It was of limited effectiveness, so disappeared after the war while they studied captured Russian KMT-4 mine rollers the Israelis got from various Arab armies. This was tested on M60 series tanks, and finally fielded along with the track-width mine plow during Desert Storm as the Battalion Counter-Mine System.

John

[Suhiir]

On further research it seems the USMC got their first M47s in 10/1953 and only kept them until mid 1959.

Seems that as far as the USMC was concerned the if the flame turret was mounted on an M48A1 hull it was an M67A1, if mounted on an M48A3 hull it was an M67A2. The USMC never used the M48, M48A2, or M48A5.

I know the USMC was still using M4A3(105) dozer tanks in Korea. Haven't dug into the Korea-Vietnam era tho.

Also post WW II the USMC got some armor off a scrapped heavy cruiser and made up some armor kits for bulldozers. I understand the stuff was so heavy the suspension had a life expectancy of hours. But, since they were only really concerned with clearing beach obstacles I guess that was acceptable.

In the 80s they got some armor kits for the D7 dozers from the Israelis.

Of course there was the M728 engineer tank with it's dozer blade.

Don,

It'd probably be a major pain in the rear but perhaps gasoline fueled tanks should have their survival rating reduced by one as opposed to diesel fueled.

[FASTBOAT TOUGH]

That gasoline issue was a major problem with the SHERMAN M4A1 that had the Continental Radial Engine. They were noisier and certainly a death trap when a ruptured line ignited. The tankers were happy when the M4A2 came out with the General Motors 6046; 12 cylinder (6/engine), 2 cycle, twin in-line diesel. The diesel was a little quieter and more reliable and they knew they wouldn't get cooked off by fuel when hit. Of course that still left the armor and ammo issues but, in the long run survival rates were better with the M4A2 and as other models became available. It should be noted that the M4A3/4 would revert back to gasoline (Vee gas.) engines. There was no M4A5. And the final production M4A6 went back to a diesel engine the improved Ordnance Engine RD-1820; 9 cylinder, 4cycle, radial diesel. So to a degree I can see the point you make at the end of your last post.

Regards,
Pat