If you were a member of the Red Army around mid-1943 or so
and you wished to remove a building,
or maybe half of a city block which offended you,
you could do a whole lot worse
than to call upon the services of an SU-152.
Now by September ’43 work had started on producing
a successor to this vehicle.
The prototype was produced in October
and it entered production started in December of '43.
That vehicle was the ISU-152
and we’re back in Padivoko
to have a look at the one right behind me.
Now compared to its predecessor,
it took a couple of little lessons.
It had a different steering mechanism,
it had different sights
and most importantly it also had a fair bit more armour,
almost 90mm compared to the 60mm of its predecessor.
We'll have a look in this in the normal matter,
outside first and then we’re going to have a hop inside.
I think I’ll fit in this one,
it looks like the crew compartment is big enough.
The ISU was of course built on the IS series of heavy tanks.
Early production versions would have a cast nose plate, such as this one.
Later versions would have a welded one.
Now you can tell just how early this particular vehicle was
by again looking at the serial number
which is engraved both on the front slope as well as the driver’s visor.
If you have a look, the first three numbers are ‘241’ which is the object code.
The next number is the digit ‘4’;
It means 1944 was the year of manufacture. 03; March.
The next couple of digits, which are 154,
indicate this was the 154th vehicle of that type to roll off the production line.
Another point to note though: this is a modernised ISU.
Items such as the grilled in headlights,
they were a post-war modification.
We’ll see a couple of other changes
from the original configuration as we walk around.
Other things you see on the front of the vehicle,
firstly of course, the horn, got to have that,
and for close-in defence
it was possible to shoot your personal weapons out of two little portholes.
One of which was welded over on this side,
the one on the right-hand side still remains.
Tow hooks, lots of spare track link and, of course, a big gun.
As we go a little bit further around the side,
this is another post war modification,
this little rack here for a tool kit.
These little notches, for lack of a better term,
are mounting points for a canvas cover
if you wanted to put one over the mantlet.
Now this brings us to the armour.
As mentioned, superior to that of the SU-152.
Frontal plate; 90mm at 30 degrees.
The two side plates for the cabin are 75mm, angled
on the vertical plane at 15 degrees
and they are also angled inwards on the horizontal plane.
Going a little bit further back again, indicator light, pioneer tools.
As we move further to the rear, external fuel stowage.
The vehicles came with four 90 litre external tanks.
Now unlike some other vehicles, like the T-34,
these external tanks were part of the fuel system.
There was piping between the tanks
which would come forward
and enter into the internal fuel tanks.
Now there’s a catch:
these are not the original external tanks.
As near as we can tell,
these are air compressor tanks which got mounted
and pressed into service.
The running gear is lifted straight from the IS.
There are six pairs per side of steel road wheels.
It’s solid steel, no rubber tires,
although, I am told there is rubber on the inside,
in a matter similar to Conqueror or some of the German all-steel wheels.
They’re mounted on torsion bar suspensions, each of which,
of course, has its own independent arm,
with a bump stop to stop the arm from going too far
and snapping the torsion bar.
Idler wheel looks very similar to the road wheel,
although I am told they are slightly different.
The track links are 650mm wide,
and are of a fairly simple cast construction.
Unlike a lot of other vehicles the Soviets had,
all the links here are identical.
They all have a single centre guide.
Single pin construction,
all the pins are held in place by means of a clip and washer.
Track tension, simple old school type.
There is a simple thread system.
You remove a locking plate, you get a big wrench, turn the thread,
it’ll move the idler forwards or backwards
and hey, presto, your track is tensioned.
Coming around to the back of the vehicle, again
we maintain the slope aspect of the rear armour.
Possibly a little unnecessary.
There are multiple ways of accessing the interior.
Now, you have, for routine maintenance,
these two hatches here, which will access the transmission.
An interesting feature of note,
which you don’t see often on Soviet vehicles,
is rubber pads for when you open it up.
It’s not going to slam on the metal.
If you have to do a little bit more major work,
undo the bolts on the outside of this panel here.
Again its rubber sealed, torsion bar on the hinge
comes out easily enough.
And if you have to do some very significant work,
there are lots more bolts and you can take off the entire back panel.
The fuel tanks, another post-war modification.
It is hypothesized possibly off a T-72, not original.
Further down, tow hooks, and there are marker lights such as here.
As you come around the left hand side,
another post war modification is the location of the log.
Now on the Russian forum it keeps coming up,
why is this guy always talking about the log as if it’s something interesting?’
Well, because it is! Only you guys have them.
Now for those of us in the West, who don’t know what the log is for,
it’s for un-ditching, or if you get stuck in mud.
You chain the log crosswise at the front of the track,
you go forward with the track a half a track length.
That should give you enough traction to get out of the mud
or off the high centre, or whatever it is you’re on.
Put the log back on its side, and away you go.
Finally, just above the left side third road wheel, you have a hatch here.
This is for easy loading of the ammunition
so you don’t have to hoist 152mm rounds all the way up to the top
and all the way back down again.
When you climb up to the engine deck of the ISU,
it’s very similar to most of the other vehicles of the time.
Very heavily armoured, air vents on the side,
big cooling vent at the rear for the transmission compartment.
Unfortunately, the little dome here, common to the IS series,
which is for the coolant system,
it kind of gets in the way of where you want to sleep.
But, at least you can get two people sleeping on the back deck here,
not too bad, should be nice and warm if the engine has been going around all day.
Underneath the engine deck, if I open it up, is going to be the V-2IS.
This is a heavy armoured deck. I mean, fortunately as you can see
there is an access plug here so you can access the coolant reservoir
without too much difficulty, without having to lift the whole thing up.
The V-2IS itself is a 520 horsepower diesel.
It has a multi cyclone air filter.
In cases of starting in extreme cold weather
there is a heater in the air filter itself.
So it sprays fuel in, there is a high voltage spark plug.
That starts to ignite the incoming air to make it nice
and warm to make it easier to start.
The coolant system also has a wick heater of its own,
also powered by the diesel, that heater not only heats the coolant,
so that it’s not frozen when you try to start the engine,
but it also is the crew compartment heater as well.
Combine this with the compressed air starting system
and this is very much a vehicle designed to operate
and survive in cold weather environments.
So I’m going to drop the cover right now,
hopefully without breaking my back.
The armoured concept extends,
like a lot of Soviet Tanks, to even the oil and fuel filler caps.
You get your square wrench, you do a lot of unscrewing,
fortunately we’ve already loosened this
and you can just see how thick this piece of metal is,
just to access this fuel filler down here.
Two exhausts, one on each side.
As you can see, it deflects sideways right over the fuel tank.
On the plus side, it’s diesel,
so it’s probably not going to do any harm.
There is a lot of negative thought
about the concept of an external fuel tank
and in reality it’s not as big an issue as a lot of people say it is.
For starters, it’s probably empty by the time you get into battle
if you haven’t already ditched it.
Secondly, if it’s a full tank,
it’s not going to ignite, because there is no oxygen to do so.
If it does get perforated,
and the fuel does leak out from the side,
it’s burning on the outside of the tank if it’s burning at all,
otherwise it’s just on the ground.
It’s not such a huge problem.
Alright, if you look at the back of the superstructure,
large two piece hatch on the loader’s side makes ingress, very, very easy.
The top obviously folds forwards and the back folds down.
Now it’s a little bit stiff on this model so, I’m cheating.
You can see how thick the hatch is.
This is not a lightweight device.
Held in place by a couple of clamps here.
Again, the back of the tank, sorry, Assault Gun, 75mm.
Quite thickly armoured. Put the tanker bar down.
As you move farther to the right,
there is a third port here for personal weapons,
a submachine gun and you could put a pintle up here for a machine gun
which could be operated by crew sitting on the back.
Or, because the breech operator’s hatch is on a ring,
it is possible to simply swivel the gun around to the front
and the breech can operate the machine gun that way.
Now the crew are quite well equipped with hatches.
In addition to the large loader’s and the breech operator’s hatch,
at the front right the Commander has his own and front left the driver has his own.
Just to the front of the driver’s hatch, you’ll see a small, little port.
That’s for the driver’s fuel tank,
he has one of his own and top centre is an armoured housing for a ventilator.
So, that’s it for Part One, for Part 2 of course, we go inside.