Originally posted by moca:
A lot of Russian-made tanks have this ability to create a
smokescreen by injecting diesle fuel into some gadgets or
something. I've read that in many places but don't know if this is
more effective than smoke dischargers.
Generating smoke in this manner is a (relatively) simple matter
of injecting diesel fuel into the exhaust manifold in a controlled
amount. Off the top of my head, I know that the Chally 2 and M60A3
can do this ... seen it on video. I'm sure the complete list is
likely to be much longer than that.
The difference between smoke from diesel smoke generators and smoke
grenade launchers is a matter of time and obscuration
qualities.
Smoke grenade launchers fire their grenades off in a pre-determined
pattern. The grenades explode a few metres above the tank, much
like one of those fireworks air-burst. The resultant dispersed
smoke pellets produce a dense screen that totally cover the firing
platform in a couple of seconds. Smoke generators OTOH take much
longer to produce an effective screen for the emitting tank, mainly
because it is producing smoke from a single source instead of from
hundreds of dispersed pellets. Think of the smoke grenades you used
to chuck around and how long it took to produce effective
concealment.
Smoke grenades also typically use a phospor/rubber compound as
their active ingredient and this generates a screen that works not
only in the visible spectrum but also in the IR spectrum,
effectively concealing the platform from thermal sights. Diesel
smoke OTOH only works in the visible spectrum.
I have seen MBT's with about 6 or more smoke dischargers on EACh
side of the tank turrets. So three is quite modest.
I have also seen AFVs/IFVs with only 3 or 4 launcher per side.
The ACV-S, BMP-3 and CV9040 comes to mind.
What matters most is not how many launchers there are per-se but
rather how the launchers, the size of their grenades and firing
patterns achieves total coverage for the firing platform.
I'm sure that the SAF and STEngg have taken this into account and
are satisfied with the pattern/coverage they are getting from their
smoke grenade launchers. On a side note, the AMX-13 only has 2 per
side (?) but given that it is essentially AFV/IFV sized, this is
about correct ... ? 
Are there heat-seeking anti-tank missiles? I think there are,
and if I'm not wrong, they are fired from aircrafts. If there are
indeed heat-seeking AT missiles, then would it be useful for these
dischargers to fire flares to confuse such missiles - like on
aircrafts?
There are Imaging Infra Red ATGMs, the Javelin and Spike (in
fire-and-forget mode) comes to mind. They are not heat seeking per
se, as in they do not home into the brightest heat source like the
AAMs of old. Instead the operator "shows" a picture of the target
in the IR spectrum (for day/night operability) and the missle homes
in on the IR image that matches what it was given. As such, flares
do not so much confuse as obscure the image seen by the
missle.
There are also wire guided ATGMs that rely on the IR return from
the missle to provide guidance. These too have counter-measures
built in to prevent bright IR sources from confusing the return
from the missle to the guidance unit.
