So now weíre moving to the business end of the tank, the turret, and weíre going to
start with the commanderís hatch.
The M26 had known failings with the engine and the transmission, but another known failing
was with the commanderís hatch itself: Over rough ground it had a very unfortunate habit
of coming loose, swinging forward, and hitting the commander on the head.
In fact, so notorious was this that the manual of 1948 gave specific instructions for a ëfield
expedientí method of fixing this by drilling holes in the hatch system and installing a
cotter pin.
Another feature about the hatch is that it has a periscope mounting if you wish to install
a periscope and the entire interior is mounted on roller bearings with an azimuth scale so
that the commander could tell with great precision where he was looking in relation to the turretís
gun.
OK.
Letís go inside.
Once inside, the commander is seated in his traditional position behind the gunner.
He has a commanderís override, he can traverse the turret by use of this lever by pushing
forwards or backwards to traverse to the left or to the right respectively.
As you move around, he has six direct vision prisms to give 360 degree vision, and directly
to his rear is the SCR-528 radio set.
You will note that it is mounted lengthwise: In order to reach some of the further controls
he has to reach a long way back.
It is equipped with a mirror mounted to the turret interior to allow the commander to
see what it is he is doing.
So now we move to the gunnerís seat, to his direct front we have an M10 periscope.
This consists of two components: We have a unity sight here for just general observation
or really close range targets, and we have a x6 telescope to its right which is the primary
sight.
You will note it goes through the turret roof so you can observe while still in a turret-down
position.
To the left is mounted the M71 auxilliary telescope, this is a x5 sight with a fixed
reticle, and it is used in case the primary telescope is inoperable, or just simply to
make sure that the gun tube is clear of any obstacles because it is mounted low and co-axially
to the main gun.
The gun itself is the 90mm M3.
You will note there is an interior travel lock mounted to the turret roof.
Further to the left is mounted the coaxial .30 cal.
To the gunnerís direct front we have power traverse.
Now, the traverse only is powered, elevation is purely manual.
There is a linkage which goes from the handle to the electric motor down there, and then
the pump which is here.
There is a manual traverse, you release the brake and quite simply crank.
So further down, we have the elevation handle for the gun and behind it is the manual trigger
used in case of a failure of the electrical firing system.
This is the gear change lever, and what it basically is is the hydraulic or manual option
for the traverse, so up is hydraulic, and down would be manual.
Finally, down to the right is a turret lock which is used to stop the turret from traversing.
The loaderís purpose in life is of course servicing the guns.
The big one, the 90mm M3 is percussion fired and uses a manual breech, though the breech
block has been dropped from this particular gun.
To its left is a .30 caliber coaxial machinegun.
Behind this is the ready rack, and what this consists of is ten rounds of immediate-use
ammunition.
In the event that the ten ready racks are expended or there is a lull in combat, additional
stowage can be found in six compartments under the hull floor.
He also has, just behind him, a pistol port which can be used like so.
Weíre going into the driverís compartment.
Both the driverís and assistant driverís hatches are sprung with torsion bars, and,
of ourse, the seat has two positions, up and down.
So starting off with the right hand side, the most obvious thing is the fixed CO2 fire
extinguishers which can be activated from inside by pulling the pin and then down, there
is also another pull handle over behind the assistant driverís hatch.
Directly to the front is the master power box.
This has two options, for the 24 volt and the 12 volt systems.
The 12 volt is only ever used if you have a 12-volt radio, otherwise itís just ignored.
Power onÖ power off.
Moving further forward, brake release, and the instrument panel.
The panel components, moving from right to left, are pretty self-explanatory.
You have a fuel tank selector which determines which fuel tankís level is displayed on the
gauge.
All the circuit breakers, on or off, and the warning lights for the oil pressure and the
oil and water temperature for the transmission and engine respectively in the bottom right.
You have your amperage coming out of the generator, your tachometer, how many revs youíre pulling,
and you can turn on, and off, your personnel heater.
Differential oil pressure, the fuel cut-off is used to turn off the engine.
You donít actually turn the magnetos off, you just press and hold and the de-gassers
will stop the engine that way.
Turn on the panel lights for the instrument panel, and this is how the external lights
are turned on.
Speedo, oil pressure, engine temperature, and these outlets are used if you want to
attach an external flashlight or some similar device.
If you wanted to start the tank, what you would do is first of all make sure that Master
Power is on, then you would check your fuel tanks, and then open up the fuel cut-off valve
which is located down by your feet.
Ensure you are in neutral, turn magnetos to ëbothí.
Now, there is a ëboosterí lever here, but it is completely unused, itís just part of
the part number.
When youíre ready, throttle up your throttle with the hand throttle about æ of an inch,
and press and hold ëstart.í Hopefully the engine will now roar into life, and youíll
idle at about 1,000 rpm, then after the warm-up you drop it down to 600.
Now, it is possible if you canít get the engine to start by itself to tow-start the
vehicle; what you do is you get another tank to tow you at about 18 miles per hour, and
then you just drop it from high range down to low.
Of course, your magnetos have to be on.
The catch is that tow-starting can only be done if the engine is already warm.
There are three ranges.
The first only goes to 9 miles an hour, 18 in second, and the top range is 30 miles an
hour.
So, a couple of points to note about steering.
As the steering is conducted by application of the brake, there is no neutral-steer capability.
The tank must be moving forward in order to turn.
The turning radius is about 20 feet.
Something else is if you are doing a particularly tight turn, let it go forward and back every
now and then and that way it releases a bit of tension on the track, thereís less chance
of walking it off.
Lastly, the manual is very adamant that if you are not applying the brake, you push forward
on the levers all the way to the stops, and this makes sure that you donít have the brakes
riding, and that way theyíre not going to overheat back in the differential.
The driver only has one periscope, but at least it is rotatable so that he can get a
different field of vision depending on which way he wants to look.
Now, the assistant driver is referred to in the fire commands as the BOG, the bow gunner,
he has a complete set of driverís controls available to him and he can take over driving
the vehicle if required.
He also has the .30 caliber Browning machinegun to his direct front which is fired simply
by watching the tracers through the periscope in the assistant driverís hatch.
Pershing was not the most successful tank that the US ever designed.
However, the improvements in armour, firepower and mobility were such that it has to be considered
significant for those reasons alone.
With the issues with the transmission and engine particularly, the writing was already
on the wall by 1950 and the Korean war with the tanks due to be replaced in service by
M46.
That said, I hope you enjoyed your tour, and Iíll see you on the next one.