Crews of the American made medium tanks, now designated as "General Grants" are asking for as
much 75 mm ammunition as it is possible to carry. Seeking a total operational capacity
of from 80 to 90 rounds, they are prepared to forego 37 mm and Browning ammunition and also to
remove the front hull guns and mounting.
A plan has been worked out by the Middle East Engineers which will permit the following
| 75 mm|| || 81 rounds|
| 37 mm|| 80 rounds|
|.303 in||5000 rounds|
|.450 in|| 700 rounds|
Military Engineering has been cabled for stowage diagrams and details of the scheme referred to.
The British are considering the development of command tanks. These would be standard tanks
suitably modified to carry two radio sets, the armament being replaced by dummy equipment. Vehicles
of this nature are being considered for use as observation posts, for Royal Horse Artillery (completely
motorized) and field artillery units in Armoured Divisions.
(G-2 COMMENT: The Germans have command tanks. The British feel the need of them, not only as
command tanks but also as O.Ps for artillery supporting tank units.
The basic principle for artillery O.Ps is that the O.P. should be
in the same type of vehicle used by the supported unit. Therefore an
armored car is more suitable for artillery supporting an Infantry
Division. The American Scout Car has been used with success.)
No decision has yet been taken on the requirements for command
tanks. A description of the "British Crusader" tank modifications is
promised in the next technical report and drawings are being sent
separately by air mail. It is stated that the "General Grant" has not yet
been investigated in this regard.
Removal of the auxiliary turret on the "Crusader" tank has been approved
and this is being accomplished. The opening in the hull is being
blanked off and the space used for stowage.
The frequency of failure of the 8,500 pound springs in the suspension
of the American medium tank (General Grant) is becoming very high. Various
theories have been put forth to account for this, but none is
entirely satisfactory. The main reason appears to be that the springs
are not suited to the demands made upon them.
Three cases of failure of the big end bearing of the master
connecting rod have occurred. No explanation can be found for the
fractures. It is interesting to note, however, that a case of sudden fall
in oil pressure occurred in an engine while on the test bed. Investigation
showed an air lock in the oil suction line and it was necessary to
prime the line before the pump would deliver any oil. Users should be
warned that the system must be most carefully checked for leaks and that
the failure to get oil pressure on starting is probably due to an air
lock in the suction line.
A weakness in design which has been brought out as a result of the
investigation into fires is the considerable area which present designs
of fuel tanks offer to hostile fire. In future designs consideration
should be given to keeping fuel tanks as low and unexposed as possible.
(G-2 COMMENT: The proper protection of ammunition should also be considered.)
The P.8 compasses have proved to be quite indispensable to tanks, but they are not yet
sufficiently accurate to allow them to be used as a sole method of navigation. Apart
from leakage of fluid and breakages of the glass of the grid ring, no defects have
occurred in the same compass equipment. It is suggested that the supply of a metal
cover to fit over the compass would save damage. P.8 compasses are now being issued
with a brass cover which meets the point raised.
The engine oil tank on Crusaders is in two parts, interconnected by a small pipe. It has
been reported by units that it takes a driver up to one hour to fill it with oil, and
that the flow between the tanks is so slow that an impatient man is apt to assume that
both tanks are full when only the one into which the filler passes is really full. A
modification is being introduced by which an additional connecting pipe 2" diameter will be
run between the tops of the tanks.
(G-2 COMMENT: The oil system is also a source of much difficulty.)
During the recent fighting there were two cases of British Valentine tank drivers being
killed and collapsing over the gear lever. The remainder of the crew were unable to
remove the driver to get at the gear lever on the clutch and were unable to stop the
vehicle. A similar incident occurred in a British Matilda tank during
General Wavell's advance, although in this case it should have been possible to
disengage the clutches with the hand wheels provided. It is considered that
all Armoured Force vehicles should be fitted with a means for stopping the engine
from the fighting chamber.
A "dead man's switch" is fitted to most gasoline driven tanks. The question of
providing the British Covenanter and the American tanks with this switch is
(M/A Report, London, No. 47672.)