Someone commented about tanks getting smaller. Silhoutte wise, I'd agree. I'm
not sure this is totally true though in mass. Or crew. You might drop 1 crew.
But a tank with fewer crew had better be mechanically more reliable and easier
to maintain. Part of the reason for a big crew complement is maintenance.
You realize there is a trend towards heavier ordinance? Some new designs (not
counting the ones loosely based around lasers or railguns) are talking
about 130-140mm main ordinance? Heck, they've got 105mm mounted on an
8x8 and I understand someone is working on (may be done) a 120mm turret for an
8x8 wheeled chassis. If these upgunned FSVs can carry that kind of ordinance,
a tank probably should be going bigger or nastier.
It'll be interesting to see if we ever get a Hammer's Slammer blower or tanks
are done away with in favour of other weapons systems. I suspect this
argument is a lot like the BB/Aircraft Carrier debates. Only time will
tell us what will actually transpire.
<PERPLEXED> BTW: What part of Jon's comment about "reply to me off list" did
all you
15mm-hungry gamers miss? Was the instruction too complicated? Not that
the list doesn't waste BW on other things from time to time, but Jon T
specifically asked for everyone to keep their replies off list and send them
to him....
</PERPLEXED>
> On Mon, 31 Jan 2000, Thomas.Barclay wrote:
> Someone commented about tanks getting smaller. Silhoutte wise, I'd
Ordinance size has increased to 125mm on the T90. The US and its allies which
prefer not to go the route of autoloaders (technical and manning reasons) are
stuck at 120mm, because that is about the limit of the size
round your average loader can heft around in the turret. Some ammo has become
two piece (the brit 120mm I think) so as to alliviate this to a degree,
however, that slows the loading time down quite a bit reducing the speed for
follow up shots.
One area this has pushed things is the development of liquid propellants
for the main gun. Thus you'd have a projectile that was inserted, close the
breech, squirt a given volume or weight of propellant into the chamber and
*BOOM*. This would make resupply a bit odd in that you'd transfer half of your
ammo load via hose rather than by hand through the
turret hatch. The big issue is the volatile nature of such a propellant.
In a message dated 1/31/00 1:21:59 PM Central Standard Time,
> monty@arcadia.turner.com writes:
<< One area this has pushed things is the development of liquid propellants
for the main gun. Thus you'd have a projectile that was inserted, close
the breech, squirt a given volume or weight of propellant into the chamber and
*BOOM*. This would make resupply a bit odd in that you'd transfer half of your
ammo load via hose rather than by hand through the turret hatch. The big issue
is the volatile nature of such a propellant.
> [quoted text omitted]
Seems to cry out for a binary system - where you have two liquids or
gases that are NOT volatile until mixed.
I would imagine that propellant would be supplied in insertable cartridge
reservoirs (i.e. 2x 10 gallon drums of Binary propellant) that way all the
resupply folks have to do is pop the armored hatch (breakaway in case of
mixing/explosion) and slide the liquid propellant canister into place.
> -----Original Message-----
> On Mon, 31 Jan 2000, Mike Wikan wrote:
> I would imagine that propellant would be supplied in insertable
I'd think that two hoses would be more logistically easy. One could fill
up at the POL stops and have less down time. Tanks are thirsty creatures,
filling up the propellant resovoir every time you gassed (diesel'ed,
Kerosene'd or whatever'd) up would make much more sense than having disposable
containers for the fuel. Another issue is the seal at the inside for your
"tank" of propellant.
I think the big problem with liquid propellants is leakage and how to remove
said propellant when a round has been loaded and needs to be unloaded.
The leakage issue is related to breach blocks. Most tank guns have a sliding
breach block which is sealed by the back of the casing (which is
usually the only thing not consumed from the firing, everthing else being
consumed). A liquid propellant would require a shift from a sliding breach to
a screw in breach at the least. The screw in breach at least allows for bagged
propellant and no casing. How well that would work against a liquid
propellant, I'm not sure, but perhaps it would work.
Removing the propellant would also be a tricky thing as there can't be any
residue left that would potentially ignite...
> Popeyesays@aol.com wrote:
> monty@arcadia.turner.com writes:
The main problem is to get them properly mixed when you want them to be. If
the mix isn't homogenous when you ignite it, you get rather
nasty variations in muzzle velocity (and through it accuracy, and - for
kinetic rounds - penetration). Lots of work is being done on this, but
very little real progress during the past several years that I've heard of.
Leakage can be an issue, but as long as no mixed propellant leaks out
there's no serious problem - which means that you'd want to mix your
propellant as late as you possibly can (ie, in the gun chamber). Since the
current sliding breaches are very nearly *gas*proof at extreme pressures (and
the cases where they aren't tend to be regarded as disasters, costing the tank
crew their eyebrows at least and their lives at worst), I don't think there'd
be much of a problem with a sliding breach for liquid propellants at low
pressures. You'd need to close the breach before you pour the propellant in,
but that's not a problem.
Removing residual propellant can be a problem, but it only becomes
serious if you fail to mix the binary propellant properly - if it is
correctly mixed, there won't be any energetic residues. Cooling the gun
chamber to stop residual *heat* from igniting the reaction too soon could well
be a bigger problem.
> The screw in breach at least allows for bagged propellant and no
I was under the impression that the M109 and the Challenger both use bagged
propellants rather than cased, and the ones I climbed around in last November
were definitely equipped with sliding breaches rather than screw ones <shrug>
Regards,
In a message dated 1/31/2000 10:45:40 AM Pacific Standard Time,
> Thomas.Barclay@sofkin.ca writes:
> You realize there is a trend towards heavier ordinance? Some new
Shure, but they should be getting bigger, but there comes a point were you
just can't get it any more combat effective, something about breach over
pressuring that I read about when doing a sci fair project on coil guns.
-Stephen
The Germans in the Second World War designed an anti tank gun where the
propellant was ignited in a separate chamber. Gases leaked into the main
chamber behind the round that was secured by a pin. When the pressure reach a
certain point the pin broke and the round was fired. This enabled a gun with a
much lighter breech and barrel to be used because it wasn't having to put up
with a powerful explosion.
Buck
> On Tue, 1 Feb 2000, Oerjan Ohlson wrote:
> > The screw in breach at least allows for bagged propellant and no
Ahh, well then perhaps my concerns were mistaken. Good to know thats the
case...