Small and large hatch M4 Shermans Composites (Hybrid)
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."

The Chrysler Corporation manufactured M4(75)s featuring cast front ends joined to welded rear hulls. The US Army did not create a new designation in order to distinguish them from completely welded hull M4s; officially, all of them were "Tank, Medium, M4, 75mm, Dry." In period documents, such as unit rosters and even some Ordnance Dept. Test Reports, these were frequently misidentified as M4A1s. For convenience, we will use the popular term "M4 Composite." The British designated them as "Sherman I Hybrid." Chrysler produced 1676 M4 Composites from August 1943 through January 1944.

Production Order T-7903 : 580 tanks manufactured : Serial Number 44228 / USA 30100462 through S/N 44807 / USA 30101041 (August-December 1943)
Production Order T-7281: 698 tanks manufactured: Serial Number 58623 / USA 3098789 through S/N 59320 / USA 3099486 (November 1943 - January 1944)
Production Order T-10888 : 398 tanks manufactured  : Serial Number 59321 / USA 3031184 through S/N 59718 / USA 3031581 (December 1943 - January 1944)

In addition, evidence from surviving examples has recently come to light which confirms that the American Locomotive Co. also 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.
 
Production Order T-4305: 300 tanks manufactured: Serial Number 40305 / USA 3072902 through S/N 40604 / USA 3073201 (October - December 1943)


M4 composite    M4 composite
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The original Sherman design included both cast and welded upper hulls. In the rush to increase production, it was noted that cast hulls could be manufactured cheaper and faster than welded hulls, with "a large saving of welding rod and labor." However, in October 1942, it was concluded that while conversion to all cast hulls might be advantageous, it was not feasible under the current industrial conditions. In that same month, the Ordnance Department in conjunction with the Chrysler Corporation, began design work on a cast front end that offered a partial solution to the higher cost of the all welded upper hull, since the front is where a good deal of the welding man-hours were spent. Also, the front casting as shown above, was a fraction of the size of a complete cast hull, so could be produced by smaller capacity foundries.


M4 composite

Prototypes were often made using existing Shermans. In this case, Chrysler removed the original welded front section and retrofitted their new casting. Note the the absence of appliqué armor and gun travel lock, as well as the old style commander's blade sight, and the earlier one piece differential housing.


 M4 composite RN 30100471
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A "photo op" showing "The First (sic) Chrysler Built M4 Tank Shipped Aug 28th 1943." This tank can be seen to be USA 30100471, so while it may have been the first one shipped, we believe 30100462 was the first one built. Many improvments and modifications were beginning to filter into the Sherman production lines by August, and a number of them can be seen on 30100471. Note the factory installation of applique armor, gun travel lock with the corresponding "late" siren position, 2 inch smoke mortar, late E8543 differential housing, and the recently introduced "no pistol port" turret. On the other hand, periscope guards are not installed, and the bogies are "still" equipped with the straight return roller arms.


M4 composite

A photo of a small hatch M4 Composite (SN 44266, September 1943 acceptance) on display in Tennessee. It is one of only two known surviving examples. The early front end casting is similar in appearance to the small hatch M4A1, but includes a pair of ventilators by the drivers' hatches, such as were standard on welded hull M4s. The protrusion on the right front was used as an antenna bracket on the M4 and M4 Composite, whereas it housed a ventilator on the M4A1. 44266 was retrofitted with the E9 modification. While the "no pistol port turret" is appropriate, it is not original, as it was cast by Union Steel, which was not a supplier to Chrysler. The early M34A1 gun mount with lifting rings was not used by Chrysler either. Most likely all of these, as well as the commander's vision cupola, were added during a remanufacture in Spring 1945. Photo courtesy of Paul and Lorén Hannah.


M4 composite    M4 composite
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"Counting heads" evidence suggests that only about 50 small hatch M4 Composites were produced. Consequently, there are very few period photos of them. Above left a crew of the 499th Armored Field Artillery Battalion, 14th Armored Division poses during Tennessee Manuevers in January 1944. Note the applique armor patch on the turret. A few Composites, both small and large hatch, were made with earlier D50878 turrets with the "patches" and welded up pistol ports. At right is a rare "combat shot" of a small hatch Composite, serving with the 40th Tank Battalion, 7th Armored Division in Niedersorpe, Germany, April 7, 1945. Unfortunately, not much can be seen due to the extensive use of camouflage, but this tank appears to have extended fenders, which suggests it was a remanufactured unit. Although 75mm Shermans were no longer "required" in the ETO, a number of remanufactured jobs were shipped there in 1945 to make up for losses suffered during the Battle of the Bulge.


M4 composite

One of the deficiencies of the original Sherman design was the hazardously small size of the drivers' hatches. In February 1943, larger hatch dimensions were submitted, but it was found that "increased size not possible of application to present hull design." Development work was begun to reconfigure the front of the Sherman to accommodate larger hatches. Chrysler's cast front concept was used, & in May, the new casting was attached to a tank pulled off the line at Pullman Standard. This project was part of the "ultimate" redesign of the Sherman, which also included the introduction of the new 76mm turret as can be seen above.  By June, the Ordnance Department approved of making all subsequent welded hull Shermans as large hatch Composites. However, in that same month, Fisher Body submitted an alternate large hatch design that featured a single 2 1/2 inch glacis plate that was found to be ballistically superior. As a result, the cast front concept was abandoned except at Chrysler which had already made commitments and started production.


M4 composite

M4 composite

The M4 Composites that began to roll off the lines in September, 1943 were the first "large hatch" Shermans of any type. Improvements were added as they became available. Most of them appear to have been equipped with the new "upturned" return roller arms (circled). In November, Chrysler transitioned to the new high bustle D78461 turret that added a loader's hatch and reintroduced the pistol port. Above is a nearly as built, December 1943 production M4 Composite currently preserved in a private collection in the US. While the hand crank may be a reproduction, it is appropriate, since Chrysler appears to have introduced the simplified one piece design. Photos courtesy of Mark Holloway.


M4 composite    M4 composite

Chrysler started M4A4 production using side armor plates that had nicely beveled top edges (left). In July, 1943, the company transitioned to the use of square cut side armor plates, a practice already employed by most of the other builders. It is thought that, from August, 1943 to the end of production in June, 1945, all Chrysler Shermans, including the M4 Composites, were built with square cut side armor plates. Our example on the right, shows the Firefly Composite in Klein-Willebroek, Belgium. Modelers might note that on M4 Composites and welded hull M4s, the air scoops (1) are seen to sit ON TOP of the sponson plate, whereas the holes on cast hull Shermans were machined out in such a way that the scoops were flush mounted (inset).


M4 composite    M4 composite

At the outset of production, Chrysler M4s were equipped with the "original design" exhaust deflector (above left, but not a Composite). This had been added to M4 and M4A1 models starting in the Spring of 1943. In November, the Barber-Colman Increased Air Flow System was introduced. This featured an improved exhaust deflector that became standard on 1944/45 production M4s and M4A1s. However, those later models had upper rear hull plates whose lower edges went straight across, whereas all Composites appear to have been made in the earlier "cut out" configuration.


M4 composite    M4 composite

It would appear that Chrysler was supplied exclusively with the "square" type of air cleaners. The lower rear hull was constructed of armor plate with an angled transition piece joining to the the belly plate (outlined in red). Trailer towing pintles were standard on the Sherman series by the time Chrysler began M4 production, but they don't appear to have been factory installed on any of their Composites. Chrysler was directed to install the pintels on M4A4s starting in April 1943, but it was found that they bent up, making it impossible to open the engine access doors. Consequently, "It was immediately burnt off as many new tanks M4A4 as possible," and further installation was suspended. At the change over to M4 production, it is likely that Chrysler had trouble finding a supplier for the pintels, so that the Government gave them a temporary "pass." In any case, in period photos showing only the rear, an M4 without a towing pintle is likely to be a Chrysler built Composite. Right side photo of M4 at RAAC Museum, Puckapunyal, Australia, courtesy of Leife Hulbert.


M4 composite    M4 composite

Midway through their M3 Lee program, Chrysler designed and introduced the pressed metal type of bogie wheel. They used them throughout production on their VVSS equipped Shermans. Their distinctive drive sprocket (right) was also employed throughout, including HVSS production.


M4 composite    M4 composite

All large hatch Shermans had a U shaped ventilator between the drivers' hatches (above left). Note the little water drainage hole just below. The front contours of the large hatch M4A1(76) were very similar to the Composite's. However, the M4A1(76) was equipped with an additional ventilator next to the bow gunner's hatch, whereas this area was blanked off on the Composites, and could serve as an antenna location for a command tank.


M4 composite    M4 composite

M4 Composites were, and still are, often mistaken for M4A1s. If one can see it, the little "nubbin" (asterisked) in the center of the glacis is a sure indication of a Composite. Remanufactured tanks can be a challenge when trying to determine the "as built" appearance. It was noted that, 98% of the time, power trains didn't require replacement, but our example had its original replaced with one featuring a three-piece differential housing. The tank was also retrofitted with the E9 track modification, the modified M34 gun mount with "wing piece," commanders' vision cupola and the late armored housing for the gunner's periscope.


M4 composite
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Sand shields were mandated to be factory installed by the time Chrysler began production. This seems a waste, as most crews removed them. The little notch (item 1) seen on the sand shield attachment strip, might serve as a minor recognition feature, as it appears to have been exclusive to Chrysler's late production and remanufactured M4A4s, as well as their M4 Composites. Our example shows a POA-CWS-H1 Flamethrower Sherman of the 713th Tank Bn on Okinawa, June 1945. A Ronson flame gun replaced the main armament, and was "hidden" inside the 75mm gun tube. Note the overflow pipe emerging from the turret splash (item 2) - a Flamethrower Sherman recognition feature.


M4 composite
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The engine decks were in the typical pre 1944 M4 / M4A1 configuration, where each of the four main fuel tanks had its own filler nozzle. However, the Composites' engine deck lift handles (circled in red) were oriented front to back rather than side to side. The pioneer tools on our example are mounted in their "initial" positions. "Tokyo or Bust" of the 44th Tank Battalion was photographed in action near Manila on March 10 1945.


M4 composite
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An M4 of the 775th Tank Battalion, Luzon, April 1945. Blanket roll racks (item 1) were standard equipment on the "ultimate design" Shermans. This modification was charged to Tank Depots starting in late December 1943. As yet, it can't be confirmed if the racks were ever factory installed. It seems more likely that some Composites received them as they were processed through Tank Depots. Another item of interest is the "quick release towing shackle with handle" (item 2). These had been installed on the front from the outset, while the rear continued in the original Sherman configuration. The quick release used double towing lugs; it shows up on the rear in a small number of period photos, and on at least one surviving Composite.


M4 composite
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M4 Composites were produced at the time when Shermans were most needed overseas. The vast majority of them were sent to either Europe or the Pacific. Above right is C-10 of an unidentified unit training in the British Isles, April 26, 1944. USA 30100929 would have been accepted in October, 1943. This unit can be seen to have a "no pistol port" turret, and the "original design" exhaust deflector. The tools on the upper rear hull plate reflect the "initial" configuration. About a month later, the sledge hammer and wrench were relocated to the rearmost section of the engine deck. Note the absence of tool or fittings on the left rear sponson.


M4 composite
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"China Clipper" a veteran of the 68th Tank Battalion, 6th Armored Division was photographed in September 1944 while undergoing repair in a hangar near Nancy, France. Note that, like 30100929 shown in the previous caption, "China Clipper" has a "no pistol port" turret. Period photos suggest that most of the M4 Composites shipped to Allied Forces in Europe were equipped with the earlier turrets. Chrysler manufactured its own power trains. Throughout the M4A4 program, they had three piece differential housings. At the outset of the M4 program, Chrysler PTs were reconfigured with the late one-piece housings (Part Number E8543) as seen here.


M4 composite    M4 composite
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"Another Dinah" USA 3099241 (above left) of the 763rd Tank Battalion was photographed on Okinawa in April, 1945. By the Registration Number, this tank would have been about the 1026th Chrysler M4, and would have been accepted in November, 1943. Our "counting heads" method suggests that this was about the introduction point of the high bustle D78461 turret; i.e. about 1000 units would have been made with "no pistol port" D50878 turrets. In general, the introduction of changes was "with obsolescence." As the new parts began to enter production, the manufacturer continued to use the old parts until the supply was exhausted. So, for instance, another A Co. 763rd M4, USA 3099276 (above right), built 35 units later, can be seen with the earlier, low bustle turret.


M4 composite
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A pair of M4s of the 706th Tank Battalion in action in Agana, Guam, August 1944. The lead tank "Cognac" can be seen to be USA 3099305, indicating December 1943 acceptance. "Counting heads" suggests that this was about the point where the supply of low bustle turrets must have been exhausted. Note that "Cognac" has the crow bar mounted on the left rear sponson whereas the trailing tank "Cupid" does not. The crow bar appears to have been repositioned from the right to the left sponson in November, probably coincident with the relocation of the wrench and sledge hammer.


M4 composite
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The photo above left was taken in late July 1945 at the Manila Supply Depot. It shows a few Composites along with some "new" remanufactured M4A1(75)s. "Bloodthirsty" appears to be a combat veteran Sherman of the 44th Tank Battalion. The Registration Number is USA 30100748, indicating September 1943 acceptance. We've pointed out the "cast in thickened cheek," typical of D50878 "no pistol port" turrets as well as the later D78461s. The commander's cupola has the positive hatch lock mechanisms that were added to Shermans starting in the Spring of 1943. These were replaced by "turret hatch D69993 with equilabrator," which can be seen on the M4 in the foreground. The improved hatches had integral springs on the hinges, and appear to have entered the production lines at Chrysler in November.


M4 composite
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A Sherman Ic Hybrid of the Coldstream Guards, Guards Armoured Division photographed near Namur, Belgium December 25, 1944. The British received over 2000 M4(75)s as Lend Lease. A number of these were Composites, and photos suggest that quite a few were converted to Fireflies. The M4A1 was not acceptable for Firefly conversion because the rounded contours of the cast hull could not accommodate the arrangement of the Firefly's interior stowage. This was obviously not an issue with the Composites, and one of the converting firms mentioned that those with the D78461 turrets saved them a lot of time and effort since they already had loader's hatches.


M4 composite    M4 composite

Most surviving M4 Composites in Europe are Firefly conversions (Sherman 1c Hybrid), such as the example above on display at Klein-Willebroek, Belgium. It can be seen to have an earlier D50878 low bustle turret with applique armor and a welded up pistol port. One of the reasons for the introduction of the high bustle D78461 turret, is that the low bustle was stated to have caused some interference issues when mounted on large hatch Shermans. However, the majority of large hatch Composites were produced with low bustle turrets, and we have found no historical records that reported this as a problem.


M4 composite

The only other type of Sherman built in the Composite configuration was the M4A6. This was powered by a radial diesel that was even more massive than the multibank engine of the M4A4. Consequently, the M4A6 was assembled by marrying the large hatch cast front to the M4A4's longer hull. Although the initial contract called for 775 units, it was cut back to only 75, as the Government determined instead to increase production of Shermans powered by the Ford V8 engine. M4A6 production ran from October 1943 to February 1944. To date, no surviving examples have come to light.


M4 composite    M4 composite

Chrysler built Shermans have the Tank's Ordnance Serial Number stamped into the rear towing lugs. Should any readers have the opportunity to examine a surviving M4 Composite, we would greatly appreciate a report.


M4 composite

Some Chrysler built Shermans have been seen to have the Serial Number stamped in the driver's compartment, 6 inches (15 centimeters) left from the dataplate.


M4 composite    M4 composite

Along with the tank's serial number, we try to record the data about the large hatch front casting - Part Number E6289. This information is cast on the top, just behind the driver's hatch. Most of the examples examined have caster's logos indicating that they were produced by the American Steel Foundries East Chicago, Indiana plant. These have been seen to have part serial numbers with an "A" prefix. A few others have been noted with ASF-Granite City, Illinois logos, with "B" prefix serial numbers. "Counting heads" suggests that at least 300 more E6289 castings were made than would have been required by Chrylser. Although the historical documentation is pretty "emphatic" that only Chrysler made Composite hull Shermans, we have explored the possibility that another company made some using front castings that became excess after Chrysler's M4 and M4A6 contracts were terminated.


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

Another item observed on the few known ALCO Composites, but not on Chryslers, is the protective splash around the fire extinguisher housing (left). Also, while a few remanufactured examples have been seen with them, it would appear that Chrysler did not factory install the door stops on either side of the engine access doors, while ALCO did (right).


    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.


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