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.

The American Locomotive Co. manufactured 150 M4A2(75)s from September 1942 through April 1943, as well as 2150 M4(75)s from February 1943 through December 1943. Evidence from surviving examples has recently come to light which confirms that ALCO manufactured some M4s with Composite hulls. So far, the data suggests that some or possibly even all of the 300 tanks of the final 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: 500 units, 150 M4A2(75), 350 M4(75): Serial Number 1405 / USA 3065484 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

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. This tank was on display for many years at the Ordnance Museum at Aberdeen Proving Ground in Maryland. When the Museum closed, it was moved to storage at Ft. Benning, Georgia, where it is no longer accessible to the general public. Of course, SN 1405 was built with a standard D50878 75mm turret. The 17 pounder Firefly turret seen in the photos was tested at APG & Ft. Knox, and later installed on this tank by the Ordnance Museum to create a Firefly display. SN 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 tested to destruction, 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 housings interchangeably up until about September, 1943. Color picture courtesy of Neil Baumgardner.


ALCO SN 1407    ALCO SN 1407

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, and 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). M4A2s were provided with rather simple exhaust deflectors (1) made up of pieces of formed sheet metal supported by a pair of brackets on the ends. The brackets are missing on this example, and the deflector is somewhat distorted. Note that the grouser cover blank off plate (2) is mounted flush with the armor. An interesting curiosity that is seen on both 1405 and 1407, and on a small number of other Shermans, is the cast in "bump" next to the bow machine gun (3).


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. Also evident is the repair by welding of imperfections in the differential housing and
rotor shield castings. (Photos courtesy of the APG Restoration Staff).


ALCO    ALCO

ALCO    ALCO

Photos showing the "bump" on a pair of Commowealth M4A2s, and two 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

A front view of the only other known surviving M4A2 with the "bump," as photographed by Jim Goetz. This tank, which was named "Sultan," served with the Polish Skorpion Regiment, and was assigned the British War Department Number T-145501. It was reported that on May 12, during the 4th Battle of Monte Cassino, T-145501 veered into a pile of anti-tank mines that had been hastily removed to the side of the road. This set off an explosive chain reaction which utterly destroyed the tank and killed the entire crew. These were the first combat fatalities suffered by the Skorpion Regiment, and in the action from the 12th to the 18th of May, the unit recorded the loss of 5 officers and 8 enlisted men KIA, 8 officers and 27 enlisted men WIA, with 3 Shermans totally destroyed and 8 damaged. Shortly after the battle, it was decided to leave T-145501 in place, and in May, 1946, the tank became the basis for a monument to the 4th “Skorpion” Armoured Regiment. In our view, it is one of the most unusual and poignant tank monuments in the world. Both Jim and our own Pierre-Olivier have closely examined this tank, and we can only conclude that its serial number has been lost to time. So who made this tank? Note the "bump" (1) along with the filled in holes for the fixed machine guns (2). As mentioned earlier, "the bump" has been seen on a few early production Shermans made by Pullman, Fisher, Ford and ALCO. An interesting anomaly seen on T-145501 is that the weld seams (arrows) have been ground down, so that they would disappear under a coat of paint. The only other surviving example we have seen with ground down weld seams is the first ALCO Sherman, Serial Number 1405 featured earlier. This practice would have been strictly cosmetic, completely unnecessary and wasteful of labor, so we had assumed it would have been very limited. For instance, photos of the third ALCO, SN 1407, also accepted in September, show the bump, but the weld seams stand proud of the armor, as was obviously the case with almost every Sherman made. So could T-145501 have been the second ALCO M4A2? Perhaps, but the machine gun dust cover fitting (3) suggests that this tank was made in October, 1942 or later. Also, although not apparent here, the little step between the drivers' hoods can be seen in period photos of T-145501, and counting heads suggests that the step was introduced in Sherman production in "late 1942." Also of note is that this tank has fittings for the foul weather hood (circled) on both the driver's and assistant driver's hatches. In any case, our best guess is that this M4A2 was produced by ALCO in late 1942.


ALCO RN 3065575

This Office of War Information photo is part of a series taken at the ALCO plant in Schenectady, NY,  and dated January, 1943. While described as "new M4 tanks," we believe "M4" was being used generically in this case, and would judge that these are actually M4A2s, since ALCO did not begin M4 production until February, 1943. Of interest is the mix of 1 and 3 piece differential housings, as well as metal and rubber tracks, suggesting the company received supplies of these components from more than one source. Note the factory installation of the bow machine gun dust cover fitting (1), an item that appears to have entered the Sherman production pipeline in October, 1942. The little step bracket (2) was introduced in "late 1942." These are not present on SNs 1405 and 1407 shown earlier, although the fittings for the driver's foul weather hood can be be seen on them, and oddly, on both the driver's and assistant driver's hatches. Double fittings (3) can also be seen in 3 of the tanks in the OWI photo. Perhaps ALCO mistakenly thought that a foul weather hood was going to be provided for the assistant driver as well? In any case, while the fittings were installed at the outset, it is thought that supplies of the foul weather hoods did not become available until late 1942. The tank furthest from the camera can be seen with a foul weather hood (4) partially installed on the driver's hatch. That same tank has the "bump," as evidenced by the rise in the dust cover fitting. ALCO appears to have chalked build numbers on its Shermans, and we suspect that the "117" seen on the unit with the 1-piece diff might be such, indicating December, 1942 acceptance. 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 RN 3065575

Period photos of M4A2s known to have been built by ALCO are rare, and our final example shows USA 3065575 about to roll off the assembly line. This OWI photo was likely taken by Howard Hollem on the same day as the previous image. By the Registration Number, this tank would have been accepted in December, 1942, and would have been their 92nd unit. We couldn't get a definitive read from the original 8 x 10 glossy print, but suspect that the number chalked on the side and circled might be 92. The M34 gun mounts seen on this and the unit behind, are the same as what is on Serial Number 1407 - "outboard" lifting rings (1) on the gun shield, and the first type of rotor shield (2) without the cast in "wing" pieces. The head lamp plug holders (3) are mounted parallel to the glacis. The bogie units feature the second or asymmetric type of track skid (inset), and the return rollers have been raised up an inch by the addition of spacers (circled).


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 variations of the bow MG socket. On the earlier configuration (left side photo), the bow MG is actually 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 armor 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 points, 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 hatch. Positive hatch lock mechanisms (1) with equilibrator springs (2) 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. The drivers' hoods are what are informally labeled "narrow" hood castings. The castings were about 18 1/2 inches wide, and were mirror images of each other with Part Numbers D77160A and D77160B, respectively. Note how  the front of the castings were rounded at the top. Although somewhat obscured by the applique plates on this and every other of the 24 surviving ALCO M4s we know of, the shape was tapered in such a way that it was "square-ish" where it was welded to the glacis.


M4 ALCO drivers hoods

As a matter of minutia, we would observe that we have been able to "climb on" at least 7 surviving ALCO M4s to find hood castings with the stylized "PL" logo indicating that they were cast by Pratt and Letchworth, a foundry in Buffalo, New York. Of interest is that the casting marks include "RECON" and below that a date "11-16-42." We have also seen these same casting marks on 2 M4A2s thought to have been made by Federal Machine & Welder. All have the same date, which would lead us to guess that RECON was not a foundry, and 11-16-42 was not a casting date, but that the symbols might indicate that the drivers' hood castings were "reconfigured" from direct vison to the elongated type by Pratt and Letchworth on November 16, 1942.

M4 ALCO drivers hoods

The photo above provides a close up of the little bullet splash that protected the drivers' hood hinge knuckles (outlined in red). At present, these pieces have been noted only on some ALCO M4s as well as some Fisher M4A2s with welded drivers' hoods. They were official parts that appear to have been introduced on ALCO M4s starting in April 1943. An ALCO drawing labels them "Guard, Hinge" and shows that they were welded assemblies made from "1/2 Armor Plate" with Part Number 8673287 for the right-side piece and 8673288 for the left. We have not been able to document the reason that these were not added to other manufacturers' Shermans.


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

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 military specifications called for one and one half inches of armor. We would note that we observed this "shortfall" on the first ALCO Sherman, serial number 1405, discussed earlier. 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. The photo shows M4 Serial Number 1765 (April, 1943) on display in Crestview, Florida. This tank was remanufactured in 1945 at which time it received the E9 modification (1). Note the weld seams (2) where the additional plate was affixed to the original, and the hole (3) in the additional plate for the engine crank. Photo courtesy of David Hobbs.


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, with the possible exception of Pullman Standard, 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 on display at the War Museum at Overloon in The Netherlands. 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. 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 using AFVs brought up 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 ALCO’s final Production Order. 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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