Sherman 75mm turret
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"
Synthesis / evolution of the 75mm turret
First D50878 turret as seen on the T6 Pilot
#1) The initial design of the Sherman 75mm turret can be seen on the T6
pilot (above). This turret featured a gunner's rotor sight
device, pistol ports with M3 Lee style protectoscopes on both the left
& right sides, the M3 Lee MG cupola, & a very
simple gun shield. Note that neither the turret, or the gun are
equipped with lifting rings.
"Low bustle" D50878 75mm turrets
# 5) Based
on feedback from the
using arms, a number of changes were introduced into production in
A direct sight telescope was added, & to protect it &
the coaxial MG,
the rotor shield was widened. The new configuration was
"M34A1 Gun Mount".
The first version of the M34A1 gunshield had
lifting rings & attachment flanges on the
top, bottom & right
side (left-side photo).
The final version of the gunshield eliminated the lifting rings,
moved the right side attachment points to the inside of the
thus dispensing with the outer flange on that side.
There were a number of
reports of crew injuries, because the original design
of the hatches (left side photo)
were not completely secured. Consequently, positive
mechanisms were introduced into production (circled in red) &
modification kits were
provided for depot & field installation.
A spot light (circled in red
on the center picture) was also introduced in early
1943. Many of the
earlier turrets that lacked the spot light & its
photo), had them retrofitted during later upgrades. The
shows how the spotlight was mounted on the fitting.
A portion of
the turret wall was very thin, to allow clearance inside the turret for the
power traverse. To protect this "thin spot", a patch on the right front of the
turret was introduced around Spring 1943, & modification kits were provided
for depot & field installation. The photo on the left shows the thin spots
on the interior turret wall, while the photo on the right shows one of the
6) Heretofore, all 75mm turrets had a pistol port on the rear
side (left-side photo). However, in April 1943 the Ordnance Department
to eliminate the pistol port as they considered it a ballistic hazard.
D50878 turret was redesigned without the port (right-side photo).
of the same redesign, the "thin spot" was remedied with what
modelers call the "cast in, thickened cheek" on the right front (circled in
red on the
left-side photo above),
thereby eliminating the need to weld on the turret patch. The "bump" of
the cast in, thickened cheek can be
seen right where "Cornouailles" is painted on the right-side photo.
One of the interesting
historical anomalies of French Lend Lease Shermans, is that some
have the application of the welded on turret patch on turrets that already
had the thickened cheek, & thus did not require it. "Valois", "Massaoua" &
"Chemin des Dames" are historical examples where the French unnecessarily applied
the turret patch to a turret that didn't need it. The patch is ill fitting as a
consequence; Massaoua (right-side picture above) shows a particularly poor fit. This was
surely done due to a language barrier misunderstanding.
feedback from the using arms about the elimination of the pistol port
so negative, that in July 1943, Ordnance voted to reinstate it. By
only Fisher, Pressed Steel Car & Chrysler remained in
production program. The builders that left the program appear to have
production with "no pistol port" turrets.
The "no pistol
port" turrets began to enter the production
lines in the summer of 1943 (see above), but in the meantime, factories
depots were directed to weld up any remaining pistol port turrets that
the pipeline. Here are shown 2 different types of weldings on
Photo study let us think that the
majority of US Army 75mm Shermans in the European Theater of Operations in 1944 had either a welded up or
no pistol port turret.
# 8) The
feedback from the using arms concerning the elimination of the
pistol port was so negative, that in July 1943, Ordnance voted to
Feedback also stressed the need for a loader's hatch, so once again,
turret was redesigned to include the pistol port as well as introduce
"oval loader's hatch." These turrets continued to have the
"thickened cheek" on the right front (all the items circled in red on
the photos above). Pressed Steel Car seems to have been the first
to introduce the D50878 turret with loader's hatch in late October 1943.
ones were low bustle turrets like the one shown above. As Fisher-built
pretty much disappeared to Lend Lease (hence some difficulties in photo
surviving vehicles study) , we can only observe that
loader's hatch appears to have
been introduced on M4A2(75)s very
late in 1943 or early 1944. There are a few pictures of Soviet big
M4A2(75)s with low bustle turrets with loaders' hatches, which are
Improved split hatches ("turret hatch D69993 with equilabrator"),
equipped with integral springs on the hinges appear to have
entered the production lines in November 1943, on low bustle
turrets. They equipped then the high bustle turrets. They replaced the older design shown on the left side photo.
bustle" turrets - From the D50878 turret to the
The 75mm turret rear profile
was raised a few inches to improve clearance for the larger drivers'
the later hull designs. This clearance change resulted in the "high
bustle" turret, with older turrets termed as "low bustle". These
are modelers' terms only, the Army would have referred to the turrets
vast majority of high
bustle turrets were produced with a new Part Number - D78461. However
in November 1943, when Pressed Steel Car transitioned to the high bustle
the evidence suggest they continued to carry the old D50878
Part Number. Without more data, we can only speculate that PSC
might have used between 300 & 400 low bustle, loader's hatch D50878 turrets,
and between 200 and 300 high bustle, loader's hatch D50878
Fisher Body used D78461
turrets on their M4A3(75)Ws right from the start in Feb, 1944. At
is not known if they used any high bustle D50878s as part of their
From counting heads, it is
thought that Chrysler transitioned directly from the D50878 low bustle,
pistol port turret to the D78461 high bustle in late November, 1943.
75mm turret (part number D50878)
75mm turret (part number D50878 or D78461)
Late "High bustle"
75mm turret (part number D78461)
# 10) As supplies became available
in late 1944, 75mm turrets were factory equipped with the commander's
cupola (left side photo). Modification kits were also supplied for
high bustle D78461 turrets have a bulge to better accomodate the
vision cupola (right side photo). This modification seems to have
turrets cast from November 1944 onward.
"Low bustle" turrets
11) Due to the critical
foundry situation, Fisher Body agreed to accept 300 used D50878 turrets
left over from the retriever conversion program. They were to be
current standards, with M34A1 gun mounts & turret patches where
loader's hatch was to be cut in. They were to be installed on large
M4A3(75)Ws at the rate of 100 per month starting in November 1944.
There are a
number of period photos of these, including some tanks with HVSS. Most
of them appear to have been equipped with the commander's all round
cupola. Perhaps a small number of them saw some combat in the ETO in
closing days. It's common knowledge that the low bustle turret caused
interference issues when mounted on a "big hatch" Sherman. However,
that didn't seem to have been a problem with all the low bustle, no
turrets on many M4 Composites. In any case, the Fisher docs mention
recycled turrets "would require flame cutting of some stock on the
rear corners of the radio bulge to eliminate interference with the
doors". These photos of a 1942 production Union Steel turret (S/N 871)
that was certainly recycled show hints of how some material was removed
the bottom corners of the turret bustle. The loader's hatch was also
It is thought that some more low bustle bustle turrets received the
upgrade in the early 1950s. In that case, the 75mm gun was replaced
with a 76mm.
These "upgunned" Shermans were sent out as Military Assistance.
The way to distinguish between a recycled D50878 turret & a
production D50878 with low bustle and loader's hatch is that the late
production will have a cast in thickened cheek, whereas the recycled
will have the armor patch on the right front (as shown above). Also if
serial numbers can be read, the recycled turrets will have much lower
numbers than the late productions ( the few late production turrets
have S/Ns in the 4000 & 5000 range).