M4A1(75)s produced by Pacific Car & Foundry
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 M4A1(75) with small hatches. Please visit this page to do so.
Pacific Car & Foundry of Renton,
Washington produced 926 small hatch M4A1(75) Shermans from May 1942 through
November 1943. PCF was the only West Coast manufacturer of Sherman tanks, &
as a consequence of geography, a lot of their M4A1s served as training tanks at
various bases in California, while others were sent across the Pacific to fight
the Japanese. Very few WW II photos or combat reports show PCF built Shermans in
use in the European or Mediterranean Theaters of Operations.
Production Order T-3144 : 801 M4A1s
manufactured (May 1942 - August 1943) : Serial Numbers 3005 / USA 3060572
through S/N 3805 / USA 3061372
Production Order T-3332 : 125 M4A1s
manufactured (August 1943 - Nov 1943) Serial Numbers 3806 / USA 3061373 through
S/N 3930 / USA 3061497

A view of the assembly line at the start of production on April 21 1942.
The lead tank is the pilot, serial number 3005. PCF was stated to have
introduced the 1-piece differential housing at Serial Number 3007, so the second
tank shown here is most likely 3006. PCF used the E4186 one piece housing
exclusively up until August 1943, at which point they transitioned to the later
E8543, sharp nosed housing. Note that the early direct vision hulls seen here
were drilled out for the twin fixed machine guns. These had been eliminated from
the original Sherman design before production commenced at PCF, and the few
units produced with the holes would have had them filled in at the factory or
before shipment overseas.

Click on the pictures for larger size
The photos above show the pilot model, Serial Number 3005, USA 3060572, the
first and only unit accepted in May 1942. It arrived at Aberdeen Proving Ground
in early June. It is thought that about the first 50 units were made with direct
vision and the M3 type suspension. Unlike Lima Locomotive and Pressed Steel Car,
PCF did not produce any M4A1s with rotor sight turrets or the M3 type
"pepperpot" exhaust. Note, however, that the lower rear hull plate of 3005 was
configured for the early exhaust, but the holes were blanked off. As these are
the only photos we know showing a PCF M4A1 with turret lifting rings in the
"high" position, we must conclude that their use was very limited. The same can
be said of the drivers' hatch handles which can be seen in the "earliest"
position, mounted off center and on an angle. Also of interest is the non
standard barrel clamp for the .50 cal. machine gun.
Serial Number 3005 was evaluated and used to test various modifications,
including a 76mm gun installation in the original M34 gun mount. In this APG
photo dated August 4 1942, one can also see a few other modifications that
became standard on later production Shermans. A small "L- bracket" has been
added to the glacis between the drivers' hoods. It was mentioned that crews had
some difficulty climbing on to the Sherman. In order to provide a little extra
traction, this bracket was added to production in the Fall of 1942. Note that
the siren has been moved to the glacis from its original position on the left
front fender, and is protected by a brush guard. This modification was
introduced into production in Spring 1943, but, for some reason, seems to have
been limited to M4 and M4A1 model Shermans. Crew members were suffering injuries
from falling hatches, and this tank has been fitted with a positive hatch
locking mechanism. This modification was factory installed on all hatches
starting in the Spring of 1943, and kits were supplied for retrofit at Tank
Depots and in the field.
Click on the picture for larger size
Photos and documents indicate that a
good number of M4A1s from early PCF production were shipped to the Desert
Training Center in California. The above is dated October 22 1942, and shows 5
PCF M4A1s alongside a battalion's worth of M3 and M3A1 Lee Medium
Tanks. Sherman production commenced even though
the builders mentioned that they had not received all of the necessary drawings,
and were experiencing delays in procuring a few parts. Unlike some of the other
manufacturers, PCF was able to obtain 50. cal. machine guns from the start. We
suspect that they fabricated and added the non standard barrel clamp seen here
and on the pilot. Note that only the 5th M4A1 is equipped with the standard
commander's blade sight.
Click on the picture for larger size
The above shows 6 tanks arriving by rail in Rice
California, September 1942. The lead tank can be seen to be USA 3060599, which
would have been accepted in August; overall, the 28th unit produced. The return
rollers of the M3 bogies can be said to be in the "late" configuration, as they
have been raised about an inch by the addition of a spacer (1). Note the
presence of the standard cast air scoops (2), as opposed to the fabricated type
seen on some of the first Lima and Pressed Steel Car M4A1s. The missing tail
light guards are thought to have been introduced in September. Unlike the
previous photo, most of these tanks are equipped with the standard MG barrel
clamp (3) and commander's blade sight (4). Some tool fittings are "still"
missing from the upper rear hull.
A front view of the same scene. These tanks appear to
have been sealed with duct tape, one of the truly useful inventions of the time.
The appearance of the hull lifting rings (1) seen on early Pacific Car M4A1s was
quite distinctive. For want of a better term, we refer to these as the "blocky"
type. While most early Shermans had the head lamp plug holders mounted parallel
to the glacis, PCF mounted the one on the right side (2) vertically. We refer to
this as the "up / down" configuration. "Counting heads" evidence suggests PCF
continued this practice until June 1943, at which point both plug holders were
mounted vertically. Note the absence of fitting for the bow machine gun dust
cover. The lead tank is equipped with the first type of M34 rotor shield (3),
and the gun shield lifting rings (4) are in the "outboard" position.
Close up views of the "blocky" hull lifting
rings. These castings appear to have been used exclusively by PCF from June
1942 until February 1943. We suspect they were designed by Pacific Car and
produced at their foundry, since their caster's logo, a "P in a circle,"
can be seen on the rear unit. They can serve as PCF recognition
features when seen in period photos or on surviving M4A1s.
Newly designed hull lifting ring castings became available
to the builders in January 1943, and PCF appears to have introduced them at that
time. They replaced the "blocky" type completely by February, and were used to
the end of production in November 1943. These became the standard type of
lifting ring castings for all new production Shermans starting at the beginning
of 1944.
Click on the picture for larger size
The factory photo above is useful in that it shows a few transition points.
The lead tank has M3 type bogies, while most or all of the succeeding units are
equipped with M4 bogies. The fourth tank in line has the later upper hull
casting where direct vision was replaced with the elongated drivers' hoods. The
bow machine gun dust cover fitting and tail light guards have also been
introduced on these tanks. This photo was part of a series taken by the Seattle
Post-Intelligencer. They were not published in the paper, perhaps due to
security concerns. The photos are dated 1943, but we would judge that the scene
above was filmed in August or September 1942. Courtesy of the Seattle
Post-Intelligencer Collection, Museum of History & Industry: http://www.mohai.org/
.

The APG photo on the left above is dated March 7 1942, and shows the T6
pilot modified with machine gun dust cover fittings. The fittings were simple
steel rods bent to shape. A number of snaps were attached to the rod, and these
held the canvas dust cover. The MG dust cover became standard on Shermans by the
Fall of 1942, and all of the builders, with the exception of PCF, used steel rod
fittings.
PCF apparently came up with an alternate, metal strip design. We have found
no documentation for this, but noticed these strips on a few surviving M4A1s,
all of which were made by Pacific Car. While not easily apparent in most period
photos, the strips can be discerned in a few high resolution shots, such as the
USMC photo, above right.
As a
matter of minutia, we offer the photo above which was part of a
September 1944 report on Tank Arsenal Proving Ground Project No. 291,
featuring a redesigned bow gun dust cover and fastening ring. As can be
seen, the fastening ring was made of a metal strip similar to that used
by PCF. However, it was mounted vertically and was perhaps a bit taller.
The open section at the bottom of the standard fastening ring was
closed up, creating a sort of enclosure. While the test results showed
that the redesign was better at excluding "dust and dirt from the
machine gun," it was not significant enough to warrant replacement of
the existing set up.
As noted earlier, Pacific Car introduced tail light guards at about the
same time as the dust cover fitting. The guards used by Pressed Steel, Lima
Locomotive, and PCF are shown above. Each shape is unique, and can help
identify the maker of an M4A1 when seen in period photos. Surviving M4A1s must
be viewed with some skepticism, since the original guards might have been
damaged, and replaced with something non standard during remanufacture or
restoration.

The US Government financed construction of a modern
electric steel furnace foundry at the Renton plant (inset). It is stated that
PCF made its own gun mounts, and also provided some to other manufacturers. The
M34 gun mounts seen in the photo above feature the later type of rotor shields
with the cast in extensions that provided the gun with greater protection
against bullet splash. The lifting rings on the gun shield are in the "outboard"
position, and, in what appears to be another quirk exclusive to PCF, are welded
on at an angle.
The photo on the left above features a D50880 M34 gun
shield with the Pacific Car & Foundry caster's logo, a "P in a circle." The
right side view shows how the gun shield's lifting rings were welded on at an
angle. Modelers might note that Sherman gun shields generally sat a little proud
of the turret's surface. Photos courtesy of Chris Hughes.
Click on the picture for larger size
The M4A1s seen above were photographed on
the Pacific Car Test Track in the Fall of 1942. As evidenced by
the unit on the left, these tanks were built at the transition point
where direct vision gave way to hulls featuring the elongated drivers' hoods.
However, note that the later hull Sherman "still" has the M3 type bogies, a
fairly uncommon combination, but further evidence of the transitional nature of
the introduction of changes. PCF began production using the T41 rubber block
tracks that can be seen on these tanks.

An M4A1 wallowing through the mud at the test track in
early 1943. Japanese conquests in Asia created a rubber shortage which compelled
the Ordnance Department to employ some steel track alternatives. The T49
"interrupted parallel bar" tracks that can be seen on this tank are the most
common type seen on PCF Shermans made in 1943. This tank is equipped with the
improved M34 rotor shield with the cast in extensions (1), the "L-bracket" step
(2) and fittings for the spot and signal lamp (3). "Counting heads" suggests
that PCF was the first manufacturer to incorporate the spot light on its
Shermans in December 1942.

A rear view of Serial Number 3206, a December 1942
production unit. Continental Foundry & Machine, East Chicago (C-H logo) was
stated to have been PCF's primary supplier of hull and turret castings. However,
the turret of this tank bears the caster's logo of Scullin Steel (1), an
alternate turret source for PCF. The square type of Vortox Air Cleaners (2) are
most commonly seen on PCF built Shermans. Note the rounded transition piece (3)
that joined the lower rear hull to the belly plate. Lima Locomotive also used
lower hulls with this configuration.
"Big Snafu" of the 15th Armored Regiment, 6th Armored
Division was photographed at Camp Cooke, California in early 1943. This tank
features early pattern M4 bogies with the asymmetrical track skids. Note that
the bogies have received the "Roller Bracket Spacer" modification (inset). The
use of steel tracks created a friction problem involving the track skid, which
was remedied by the addition of a spacer that elevated the return roller by
about an inch. It is thought that PCF was the first manufacturer to incorporate
the spacer into production in early 1943. All Sherman production started out
using the M3 type of drive sprocket seen here. At the beginning of 1943, Lima
and Pressed Steel transitioned to the solid or "plain" sprocket, while PCF
continued to use the M3 type throughout production.
The periscope gun sight was found deficient, so
the Ordnance Department designed a new gun mount that incorporated a direct
sight telescope. A mock up (above) was photographed at APG on June 22, 1942. The
sides of the rotor shield were extended to protect the telescope (1) and the .30
caliber coaxial machine gun (2). Designated "Combination Gun Mount, M34A1," the
new design was released for production on October 16, 1942. Most changes to the
Sherman were introduced "with obsolescence." This permitted the manufacturer to
use up supplies of the old parts, even as the new parts were introduced into
production. The addition of the direct sight telescope was deemed so important
that the M34A1 was initially released "without obsolescence," with a cut off
date of January 15, 1943. The manufacturers could not obtain all of the parts
necessary to meet such a rigorous deadline, and ultimately, the M34A1 did not
completely replace the M34 gun mount in Sherman production until the end of
April, 1943.
As noted earlier, Pacific Car produced its own gun mounts.
This gave them a certain advantage regarding the introduction of the new design.
One Army document states that they introduced the M34A1 at Ordnance Serial
Number 3351. Another gives the figure as 347. Serial Number 3351 would have been
the 347th PCF M4A1 accepted, so both figures reference the same tank. PCF
assigned Manufacturer's Serial Numbers to its tanks, and we believe that they
were exact build sequence numbers. In any case, the figures provided indicate an
introduction date of mid February, making PCF one of the first builders to
institute the change. Photos show that the company used M34A1 gun shields in
both the early and late configurations.
A number of the first PCF Shermans to be equipped with the M34A1 gun
mount were shipped to the 6th US Army in Australia in the Spring of
1943. The 1st Marine Tank Battalion was reorganizing there after
Guadalcanal. In May, A Company replaced its Light Tanks with 24 of the
Army's M4A1s. The photos above show Marine tankers training on the
Mornington Peninsula, Victoria, Australia in July, 1943. The shot on the
right is entitled "Marine Tank Hero" and captioned in part, "A
superstitious Marine commanding Tank No. 13 is Sergeant Earl Mowery who
won the Navy Cross on Guadalcanal." Note the PCF style taillight guard
on Sgt. Mowery's Sherman.
Click on the picture for larger size
Company A of the 1st Marine Tank Battalion is thought to
have been the only USMC unit to use the M4A1 in combat. Above they are shown
landing on Cape Gloucester, New Britain Island in late December 1943. The heavy
T49 steel track was hard on the Sherman's suspension, but the cast in "grousers"
were considered to be asset in the difficult terrain encountered on the islands
in the Pacific. In general, steel tracks were the preferred type in the PTO,
since roads were primitive or nonexistent, and the campaigns were relatively
brief. In the vastness of Western Europe, with its modern road system, rubber
tracks were preferred.
Marines on a mission to capture the air strips near Cape
Gloucester, December 29 1943. Tank 6, which can also be seen in the previous
photo, attempts to negotiate the muck of a jungle trail. The head lamp plug
holders can be seen to be in the "up / down" configuration peculiar to PCF up to
June 1943. Marine Shermans in particular are rarely seen with the head lights
mounted. The lights were stored inside, and the light sockets were sealed with
plugs. A small chain attached to the plug holder secured the plug against loss.
The chain on the driver's side appears to have been broken on this tank.
Click on the picture for larger size
The 1st Cavalry Division's 603rd Light Tank Company also reorganized and
reequipped with M4A1s while in Australia. The photo above is dated April 22
1944, and shows tanks of the 603rd supporting the 162nd Infanty Regiment, 41st
Infantry Division in Hollandia, New Guinea. "Sad Sack" which can be seen to be
USA 3061012 (circled in red) was accepted in March, 1943. Despite a government directive to
change to white, PCF appears to have continued to paint the USA Registration
Number in blue drab throughout production. While many field modificatons were
available in kit form by this time, priority was given to Shermans slated for
the D-Day invasion, and the 603rd's tanks appear to be "as built."
Click on the picture for larger size
"Sad Sack" was photographed again in June 1944 on Biak Island. Note the
early version of the M34A1 gun mount, which included lifting rings on the gun
shield. The hull lifting rings seen here and in the preceding photo, are the
later type. PCF completed the transition to these by February 1943, most likely
just before the introduction of the M34A1 gun mount. To date, we have not come
across a period photo showing a PCF M4A1 built with both the M34A1 and the
"blocky" hull lifting rings.
Click on the picture for larger size
There are quite a few of photos of the M4A1s of the 603rd Tank Company and
Company A, 1st Marine Tank Battalion. Almost all of them have features
associated with Pacific Car. Above, a last look at a couple more Shermans of the
603d Tank Company, photographed on Wakde Island, May 17 1944. The lead tank can
be seen to have a pair of round, non-standard, objects (springs?) right by the
drivers' hatches. These may represent a field expedient modification,
installed to protect the crew from hatch injuries. The "official" positive hatch
lock and equilibrator spring modifications are stated to have been factory
installed at PCF starting in late April 1943.
A number of modifications
were introduced in production in April & May 1943. Serial Number 3645 was
accepted in June 1943, and was the subject of an Inspection Control Test at APG
in August. Positive hatch locks were introduced in late April, and can be seen
on the drivers' and commander's hatches (1). Sand shields were stated to have
been factory installed by PCF starting in late May. The M34A1 gun shield can be
seen to be the late type, which did away with the exposed right side flange and
the lifting rings. Photos suggest that PCF received consistent supplies of the
Federal Electric Model 160 series siren with the distinctive "V for Victory"
grille (2). 3645 was probably one of the last units to be built with the siren
mounted on the left front fender, and the head light plug holders in the "up /
down" configuration.