Continuing our series of video tours, M103
is described, perhaps a little optimistically, in the manual as a heavily armoured, full
tracked, combat vehicle of low silhouette. Into this silhouette would fit five personnel,
including, notably two loaders. Now, the M103 did not have the greatest service
career in the US Army, but the Marine Corps took it for much longer. One of those trainee Marines was at the time
2nd Lieutenant Ken Estes, who grew over the years to become historian and author Kenneth
Estes, and heís here with me today to just go over the vehicle that is here at the Military
Vehicle Technology Foundation in Portola Valley, California. So, Ken, why is it that the Marines kept the
M103 program going, while the Army abandoned it? Well, as we know, the Army had several heavy
tank projects going on at the end of World War Two, but they lost both money and interest
in these projects, they petered out. The Marine Corps, though, maintained its requirement
for a heavy tank after the war. Basically itís because of our doctrine for
the amphibious landing, where we originally wanted light tanks of the Marine division
to land in the assault force, then be followed up and reinforced by medium tanks from the
higher headquarters, the corps level tank battalion would then continue the action inland. But when the Marine Corps went to all-medium
tanks in World War 2, that reinforcing tank battalion by default became a heavy tank battalion,
and so thatís what our doctrine and what our requirements called for in the late 1940s. We always wanted a heavy tank, and then when
we were written into the war plans by 1948 which put Marine divisions potentially up
against Soviet Army forces in the Persian Gulf, Western Europe, and Southern Europe
it became more of an imperative then for the Corps to have its heavy tank. We bought some M26s in the meantime, but these
were carried only as interim or substitute heavy tanks, they were not the heavy tanks
we wanted for the job. Now we jump to the Korean War then and we
have tank crisis of 1950 when all of us have World War 2 gear, and the Army prototypes
for the next generation, T41, T42 and T43, the light, medium and heavy tanks, are just
on the drawing board, and these are rushed into production. The M103 prototype was nothing more than a
wooden mock-up at the time. But these tanks were produced all between
1952 and 1953, and entered service as the M103. So this refutes, amongst other facts, that
the Marine Corps has always used Army hand-me-downs, the M103 was really pushed more by the Marine
Corps than by the Army into its existence OK, so youíre trained primarily in the M48. You come down to the motor pool for your M103
training, you look at this thing, what goes through your mind? ìWhat a heavy buggerî, and how slow it must
be, because being brand new tankers, we just wanted to go fast and furious and everything,
and we just thought this thing would be a drag. In the end, though, we could see that it was
a nice idea to have something this big and this powerful to back you up. Itís a little ironic that I find myself with
you here today and still writing books on the M103 because I was one of the biggest
teasers of the heavy tankers, always telling them that weíd have the battle done by the
time they showed up, and so forth. OK. Now letís go around, have a look at all the
components, and see what makes it work. The suspension on this tank consists of 14
pairs of roadwheels mounted on arms on torsion bar suspension. Each roadwheel arm has a bump stop to prevent
it from going too high, and there are friction snubbers on the numbers 1, 2, 3, 6 and 7 arms
to prevent rocking. Adjusting the track tension on this tank appears
to have been a convoluted process: You had to coast to a stop without the use of brakes
in such a manner that the track link would stop directly on top of the return rollers. So to go over the process, Iím going to bring
Ken back in. So Ken, what is it you have to do? OK, letís first look at the compensating
idler arm in there, youíll notice itís a six-sided barrel which actually rotates around
a thraded inner arm, and that extends and retracts the idler arm and creates and sets
the actual tension. So youíd first take a few turns off that
to make the track looser, then weíll grab a tanker bar, and with a couple of guys, get
in and lift the track up so we can put a one-inch wooden block on number 2 return roller. That done, weíll put a string tightly between
the tops of those two return rollers, and then weíd tighten or loosen as necessary
to get a 1/8 inch to 3/16 inch gap between the bottom of the track and that string. Thatís the correct setting and then we just
bend up and grab that piece of wood again, or just sacrifice it later when we drive off. Thatís how you get the track tension correctly
set. Whilst talking about the idler arm, you will
note that it is physically connected to the number 1 roadhwheel arm. As a result, when the roadwheel goes up, the
idler is pushed forward and down and this maintains track tension on the entire tack. So at the front of the tank, a couple of things
here. Firstly, this would be where the handles go
for the first and second shots of the fire extinguisher. Then we have the headlight assembly, we have
the service drive, blackout service, blackout marker, and there would be a small shrouded
light here called the blackout drive. So Ken, when is it that youíd use the one
versus the other versus the third? The service drive would be used administratively
at night when thereís no presence of the enemy or any tactical problem. Standard headlight, just like the same ones
used on trucks. In fact, we have the same high-beam/low-beam
switch for your left foot to use, just like in trucks. The identical light is here, but with a red
lens for driving under infra-red conditions. If we come over here to the hatch for the
driver, we see a position for a periscope there that is the mount for the driverís
infra-red scope. It actually has two eyepieces and it allows
you to drive in infra-red. The useful distance is only about 15-20 feet,
so you donít go very fast, and itís a very weird situation, you donít get a good sense
of depth perception or anything like that. Then thereís so-called blackout driving which
means you have a very small hooded light here illuminating again about ten or fifteen feet
of the ground ahead of you, and again, this is all done very slowly and very carefully. The blackout marker is for other people to
see you: These glow at very very low levels so that we can keep track of other vehicles
in the column, or if you want to position this tank at night by using a ground guide,
the ground guide can see the tank by using the blackout markers on each side and then
use a red-lens flashlight to signal the driver to move forwards, backwards, left, right,
stop. The groundguide is basically the guy with
the flashlight marshaling people which way to go. Right, and those markers then allow you to
do that without illuminating any other part of the action. OK, so here we are under the business end
of the 120 rifle, you have the bore evacuator and a strange little item on the end with
two notches on it. What is that for? Originally it was much larger because we had
two large holes about like ëthatí on either side, the idea being to have a blast deflector
that would vent some of the smoke of the muzzle to one side and not obscure our sights very
much, but it didnít work, so we cut it way back and we left those two notches there simply
as kindof a spanner tool edge to tighten it down. Its only purpose is to torque down on the
bore evacuator so that it wonít come loose during shock or firing. So while weíre here talking about the gun,
this is not the same 120 which was originally in the Armyís T34, is it? Well, thatís true. The original idea the Army had, at the suggestion
of the Army Ground Forces, was to abandon some of the wilder heavy tank schemes they
had, and theyíd take the well proven and well-known 120mm anti-aircraft gun, and put
that into a smaller more maneuverable tank. That became the concept. So the T34 tried that out, but when we went
to the 103 project, we made a much more powerful gun, greater chamber pressure, and a little
bit longer in the tube. This is actually the T123 cannon much improved
in ballistics and of course ammunition variety than you had in the original T34 prototype. And you have shot, HEAT, HE, anything else? And white phosphorous. Smoke. Uh-huh. OK, so moving along the sponson side, behind
the main stowage box, what we have here is the air filter housing. There is one housing on each side of the engine. Pull it open, pull this up, release the locking
lever, and give a good, solid pull. The filter itself, as you can see, itís made
of cloth, and what you could do is get compressed air, shake it out, blow it, and otherwise
clean out the air filter. Return it back into position exactly the reverse
of the way you took it out, lock it into place, close the compartment, and bolt it back into
place. On the rear left of the tank we have the external
telephone, sometimes also known as the Tank-infantry telephone. What will happen is that a rifleman who needs
support will come up to the left rear of the tank, drop down the hatch, pull out the handset,
push to talk. Invariably this was the signal for the driver
to put the tank into reverse and scare the hell out of the rifleman. Also to note, he could transmit off the radio
by the use of a pushbutton. The little red light on the top here was basically
the driverís way of telling the riflemen to come and answer the ëphone: He had a button
in the crew compartment, the little red light would light up red, and this would be the
signal for the rifleman to approach the tank. This is the fun partÖ. OK, here we goÖ now, weíre getting more
towards the business partÖ. All right, Ken, so what is it that weíre
looking at here? Well, we have the AV 1790 cubic inch diesel
engine. The intake air is coming from the inlet weíll
see in the turret, youíll show that, so outside air is coming through this tube into the air
cleaner that you demonstrated, the clean air is being sucked, then, by that turbine, you
can see the outer part of the turbine which is exhaust driven, and goes at pressure then
into the intake manifold of the engine. Thatís air supply. The fuel supply we canít see, itís at the
front of the engine with its own set of double-fuel filters. Notice here the quick disconnects for the
electrical connections, this engine can be taken out in about thirty minutes with a small
crane. We check the oil level here, we do the oil
filling in that connection there. On the opposite side of the engine we have
the same setup for the transmission oil. We can also see the top here of one of the
three fuel cells. These are aluminium, they conform to the shape
of the tank, and this allowed us to carry a total of 385 gallons in this tank as opposed
to a much smaller amount of gasoline in its predecessor. This little gizmo here is for a purge pump,
so that you can manually pump some fuel out from the bottom where you tend to gather corruptions
of various sorts to the fuel, iincluding water which is a nasty thing to have also, so you
periodically purge the fuel cells manually with a little pump of the impurities and garbage
that sometimes arrives in your fuel despite the fuel filters in both the supply truck
and in the tank itself. Of course, this is the diesel powered version
of the engine, why is it that the Marines moved from the previous petrol to the new
diesel? Well, the Marine Corps had a choice. It could go with the Armyís new M60, which
was a diesel medium tank or main battle tank, but we wanted to keep our fleet which we had
bought with hard cash some years before. So we took the chief M60 improvement which
was the diesel engine and backfitted it onto this tank and also the M48 medium. In the case of this tank, its operational
range went from about 80 miles in gasoline to about 300 miles on diesel, and 80 miles
on gasoline as we tankers know means that you go 40 miles operationally, then spend
the rest of your time trying to find a fuel truck to top you back of again, so it really
changed the nature of the tank force: It now had legs, so to speak, it had an operational
range that was useful. So what was it that the Marines had to assist
with the recovery of a vehicle of this size. Ah. We fixed that in the Marine Corps because
the only recovery vehicle we took after we got rid of the M4 series, the so-called ìShermansî,
was the M51, a heavy tank retriever, built on this chassis with an even more powerful
gasoline engine which developed a thousand horsepower as opposed to the 750 of this engine. It was quite a beast. And it was just as heavy as the heavy tank,
but it had a 50-ton winch and a 25-ton crane, and it was pretty much equal to the job of
recovering even this bear when it got buried or bogged down. So at the left rear of the engine compartment,
what we have here is the transmission oil dipstick and filler, which appears to be pretty
well equipped, and what we also can just see here is one of the steering wheel linkages
which, as the driver turns the steering wheel, applies or reduces power to the transmission. OK, well, that covers it for the engine deck,
weíll close it up and move on.
I've been watching it one and off while waiting on matches on test server, Managed to pause at this perfect point http://i.imgur.com/FRKWGQu.png
Part 2
Part 3
Dunno if anyone else has already seen them before, but they were new to me, and I'm pretty religious about checking the WoT website for new stuff.
I like Ken's commentary and input as a first-hand source of information on this tank. It'd be nice if Nick could get people who've actually operated the tank on the show more often.
I don't understand the point of having two loaders. From what he said, it seems the first gunner loads the projectile, then just gets out of the way while the second loader puts in the propellant, rams the whole thing in and then signals the gunner. The second loader is also apparently responsible for monitoring the gun counter balancing pressure or whatever it is.
So was somethibg left out? Or how can it even be worth having the first loader there taking up space?
It is always fun looking at older tanks and seeing how similar things still are.
In a modern Abrams tank, crew positions are similar. Controls are all pretty much in the same place. Dials, switches, gauges are identical. And by identical, I mean identical. Whoever made those dials and light switches is still in business because those are the same ones you will find in military vehicles today. The only problem is none of them work.
With the exception of a couple small things, someone trained on these could easily hop into an Abrams like it was nothing, or vice versa.