M4(75)s and M4A2(75)s manufactured by American Locomotive Company (ALCO)
Most of the information on this page is courtesy of Joe DeMarco. Note: some of the information on this page was compiled using a technique informally referred to as "counting heads." It is based on the ongoing study of period documents and photographs, as well as surviving Shermans. Due to the limited nature of available reference sources, some of the information presented here must be considered as "educated guesswork."

First of all, you have to identify the tank as being an M4(75) or and M4A2(75) with small hatches.

American Locomotive Co. manufactured 150 M4A2(75)s from September 1942 through April 1943, and 2150 M4(75)s from February 1943 through December 1943. Evidence from surviving examples has recently come to light which confirms that the American Locomotive Co. manufactured some M4s with Composite hulls. So far, the data suggests that some or all of the tanks of the last ALCO Production Order were built as large hatch Composites.
 
All Serial & Registration Number ranges given are interpolations. The authors would welcome more data concerning ALCO built Shermans.
 
Production Order T-1480 : 150 M4A2(75) tanks: Serial Number 1405 / USA 3065484 through S/N 1554 / USA 3065633
Production Order T-1480 : 350 M4(75) tanks: S/N 1555 / USA 3065634 through S/N 1904 / USA 3065983
Production Order T-3157 : 500 M4(75) tanks: S/N 3931 / USA 3065984 through S/N 4430 / USA 3066483
Production Order T-3646 : 1000 M4(75) tanks: S/N 24705 / USA 3033235 through S/N 25704 / USA 3034234
Production Order T-4305 : 300 M4(75) tanks: S/N 40305 / USA 3072902 through S/N 40604 / USA 3073201


M4A2 ALCO DV
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M4A2 ALCO DV

A late 1940s, along with a modern view, of the very first ALCO built Sherman, M4A2, Serial Number 1405 / USA 3065484 accepted in September, 1942. It is currently preserved at Aberdeen Proving Ground. Of course, 1405 was built with a standard D50878 75mm turret. The 17 pounder Firefly turret was tested at APG & Ft. Knox, & later installed on this tank by the Ordnance Museum to create a Firefly display. 1405 was delivered to APG with a one-piece final drive housing, but the tank was used to test "final drive protective shields." Presumably its original differential housing was destroyed, and it now has the three piece differential from the very first Pacific Car & Foundry M4A1, which was also a test tank at APG. In any case, ALCO Shermans used both three piece & one piece diffs interchangeably up until about September, 1943. Color picture courtesy of Neil Baumgardner.


ALCO SN 1407    ALCO SN 1407
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Two January 1943 views of the third ALCO M4A2 Serial Number 1407. Of note is the very early type of E4186 one piece differential housing, & the "bent rod" hull lifting rings. The M4 type of bogie units certainly appear to have been installed on ALCO Shermans from the start. ALCO began Sherman production relatively late, and these photos suggest that none of their turrets had lifting rings mounted in the "high" position (see the 75mm turrets page for further information). An interesting curiosity seen on a small number of Shermans identified as either ALCO or Pullman, is the cast in "bump" next to the bow machine gun on both 1405 & 1407.


ALCO SN 1405

ALCO SN 1405

Interior and exterior views of the "bump" show that this particular glacis casting was made to hold the twin fixed machine guns that were part of the original M4 design. The fixed MGs had been eliminated months before ALCO began producing Shermans, and one can see that the holes were simply sealed up by welding. (photos courtesy of the APG Restoration Staff).


ALCO    ALCO
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ALCO    ALCO
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Photos showing the "bump" on a pair of Commowealth M4A2s, as well as a couple US Army M4s. Note that in the few period photos showing the "bump" on M4A2s, as well as on the two known surviving examples, the tanks have direct vision. On the other hand, the two M4s, which are presumed to be ALCO built, are seen to have the later type of drivers' hoods. There are no known surviving examples of M4s with the "bump."


ALCO RN 3065575
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Our final M4A2 photo shows USA 3065575 about to roll off the assembly line at the ALCO plant in Schenectady, NY. This tank would have been accepted in December, 1942. Note the factory installation of the step bracket, as well as the bow mg dust cover fitting. The glacis pattern that can be seen is typical of ALCO up to mid 1943. Current evidence suggests that most or all of the 150 ALCO built M4A2s had direct vision. On the other hand, the authors have yet to come across a period photo or surviving example of a direct vision M4 that can be identified as ALCO.


ALCO front glacis    ALCO front glacis

The left-side photo shows the construction of the front glacis on earlier ALCO built Shermans. The red lines indicate the weld joints. Note that the "plate" that includes the bow MG was actually a casting, whereas the other sections of the glacis were armor plates. "With the bump" would be a variation of this early glacis pattern. In the right-side photo, the front glacis is made of a single armor plate, and the bow MG, hull antenna bracket and drivers' hoods are welded into it. Left-side photo courtesy of http://wra-tanks.blogspot.fr/


ALCO bow MG    ALCO bow MG

ALCO built Shermans have been seen with two variants of the bow MG socket. On the earlier variant (left side photo), the bow MG is part of a cast "plate," while on the later one (right side photo), the bow mg is a small casting that is welded into the front hull plate.


ALCO hull antenna bracket

The typical cast antenna bracket seen on ALCO built Shermans. Note how the bracket is welded flush with the glacis, a useful clue when trying to identify an ALCO Sherman.


M4 ALCO drivers hoods

The direct vision slots were considered ballistic weak spots, and it is thought that ALCO dispensed with them when they transitioned from M4A2s to M4s in early 1943. The modified drivers' hood casting featured an additional periscope in front of the drivers' hatches. Positive hatch lock mechanisms with equilibrator springs were factory installed on ALCO Shermans starting around May, 1943. These made the hatches easier to manipulate, and insured that they were locked in the open position, thereby avoiding injury to the crew. Tank Depots also retrofitted this modification to many Shermans.


M4 ALCO drivers hoods

Here is shown the little bullet splash protecting the drivers' hood hinge knuckles (circled in red on the photo). This part has been seen on some Fisher & ALCO Shermans. It was an official part that seems to have been introduced in Spring 1943. The reason this part was not added to other manufacturers' Shermans is unknown.


ALCO head lamp sockets    ALCO head lamp sockets

ALCO Shermans were equipped with the cast type of head lamp sockets used by most of the small hatch Sherman manufacturers. In the above photo of Serial Number 1405, one can see that a plug is partially installed into the head lamp socket. When not needed, the head lamps were stored inside, and plugs were provided to seal the sockets. Note the plug holder welded to the head lamp guard, which held the plug when the head lamps were installed. The plug holders were initially oriented parallel to the glacis, but later were repositioned to vertical, most likely to keep them from falling out. "Counting heads" evidence suggests that ALCO repositioned the plug holders to vertical about mid 1943. Also seen to good advantage in the above photo is what the authors informally refer to as the "bent rod" lifting ring as seen on many early Shermans.


M4 ALCO lifting ring    M4 ALCO lifting ring

Although the very first ALCO built Shermans had the "bent rod" type, they were soon replaced by "padded" hull lifting rings. These were castings with rectangular bases, which were also used by most of the other manufacturers.


M4 ALCO lifting ring    Cast hull lifting ring

ALCO appears to have transitioned to the use of the most common and final type of hull lifting ring castings at about the same time as the introduction of the second glacis pattern - Summer 1943.


ALCO glacis patterns


ALCO    ALCO

A few surviving ALCO M4s have been seen to have an additional armor plate welded to the upper rear hull plate. One theory about this anomaly is that ALCO may have begun production of its Shermans with upper rear hull plates that were only one inch thick, whereas the specifications called for one and one half inches of armor. Thus, the additional plate may have been required to bring the rear armor up to spec. If so, it would appear that the situation was corrected before the end of April, 1943.


ALCO    ALCO

Another "quirk" that has been noticed on a few surviving ALCO M4s is that the bullet splash protecting the air intake on the front engine deck section is fabricated from three pieces.  Other manufacturers of M4s and M4A1s appear to have used a one piece casting for this part. The authors suspect the three piece splash may have been used on all ALCO M4s. In the above photos, notice the vertical weld seams on the inside and outside corners of the splash. (Right photo courtesy of David Doyle).


ALCO

Examination of surviving examples of M4s & M4A2s known to be ALCOs, show them with lower rear hulls constructed of armor plate with an angled transition piece joining to the the belly plate.


Cookie

Cookie

These two photos show ALCO M4, Serial Number 24871 / USA 3033401 currently preserved in Ortona, Italy. This particular tank is said to have been a combat casualty of the 31st Tank Battalion, 7th Armored Division, put out of action during the Battle of Overloon in October 1944. The photos show the tank at its previous location at the War Museum, Overloon, Netherlands. This tank would have been accepted in July, 1943, and reflects the appearance of almost all US Army M4s and M4A1s in Northwest Europe during WW II. For the Overlord invasion, certain modifications were considered essential, and any Shermans that had been shipped to the UK without them, were directed to have them installed. Thus, in NW Europe, US Shermans will be seen almost without exception with M34A1 gun mounts, positive hatch locks & the entire suite of armor appliqué modifications. Readers are more likely to see unmodified US Shermans in the "secondary" theater of Italy, or in the 6th Army Group, since they invaded southern France from Italy (photos courtesy of Axel Recke).


M4 composite

During a Sherman spotting tour in South America in November 2013, our friend Jim Goetz examined a pair of M4 Composites that have Serial Numbers that were assigned to the final Production Order of the American Locomotive Co. (ALCO). These tanks are former British Firefly conversions that were purchased by Argentina in the late 1940s. The Argentinians re-engined and up-gunned many of their Shermans and labeled them "Repotenciados." Jim reported that the unit on display in Asuncion, Paraguay is Serial Number 40351, while the one in Olavarria, Argentina (pictured above) had Serial Number 40313 stamped on the left rear tow lug.


M4 composite    M4 composite

Jim examined other South American M4 Composite Repotenciados that had Chrysler Serial Numbers. It is to be noted that, on the few ALCO all welded hull M4s we have examined, the serial numbers are stamped "one on top of the other," and only on the left rear tow lug. That is what Jim found on the ALCO built Composites, such as seen with 40351 above left. On the other hand, Chrysler serial number stampings have been noted to be oriented "side by side," and present on both rear tow lugs. The Chrysler orientation can be seen on the right above, from the Repotenciado on display in Cordoba, Argentina. Also of note is that the two Composites with ALCO serial numbers were seen to have double rear towing lugs, whereas the Chryslers had only one.


M4 composite    M4 composite

A comparison of Chrysler-built Composites with the few known ALCO examples reveals some differences. The forward edge of the right front appliqué plate is rounded on the ALCOs, but cut on a straight angle on the Chryslers. The ALCOs feature the so called "plain" drive sprockets, whereas Chrysler used their own distinctive sprockets throughout Sherman production. Most Chrysler Composites can be seen to have the later "upturned" return roller arms. We believe that ALCO finished Sherman production using the earlier "straight" return roller arms. As mention previously, the "notch" in the sand shield strip appears to have been exclusive to Chrysler's late production and remanufactured M4A4s, as well as their M4 Composites. We suspect that the notched sand shields were adjustable by 11 inches, so they could fit equally on M4A4s, Composites & M4A6s. In any case, the few known ALCO Composites have unnotched sand shield strips. Right side photo courtesy of Frank Louw.


    M4 composite    M4 composite

In early 1945, Commonwealth troops in Italy received a number of Fireflies converted from M4 Composites (Sherman Ic Hybrid). The Polish 4th (Skorpion) Armoured Regiment is reported to have been issued a dozen M4 based Fireflies. The unit shown above, named POWAB, was knocked out on April 19, 1945 near Bologna. This tank has a number of ALCO features, such as the rounded applique plate on the right front (1) and the "plain" sprocket (2). Note the step bracket (3), which appears to have been omitted by Chrysler with the introduction of the gun travel lock. ALCO produced its last Sherman in December 1943, and it is thought that they ended production with the low bustle, no pistol port turret, along with suspension units with "straight" return roller arms (4). Chrysler Composites have a "notch" in the rear section of the sand shield strip (5), while ALCOs do not. Photos courtesy of the Polish National Archives.


M4 composite    M4 composite

Lance Sergeant Michal Krzywoszanski was a fitter attached to the Regiment's Light Aid Detachment. He took a few photos of POWAB as he and his crew salvaged useable parts from the tank. As mentioned previously, the towing pintel became a standard feature on Shermans by the middle of 1943, although they don't appear to have been installed by Chrysler. ALCO began adding them in April 1943, and one can see the pintel's faceplate (1) in the left side photo. In the right side image, note how the ventilator on the turret drains to the front (inset). This appears to be consistent with ALCO Shermans, whereas with Chryslers, it consistently drains to the rear. Photos courtesy of Chris Wroblewski.


M4 composite

This photo of POWAB highlights a few other features not typically seen on Chrysler Composites - the 3-piece engine crank (1), and the round air cleaners (2). One can also see that this M4 has double rear towing lugs (3). Photo courtesy of the Polish National Archives.


M4 ALCO serial number    M4 ALCO serial number    M4 ALCO serial number

ALCO built Shermans have the Tank's Ordnance Serial Number stamped into the left side rear towing lug. An unknown letter / number combination has been seen on the right rear tow lug of some. The collection of more examples might make it possible to decipher the meaning, if any.


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