Name that doodad, greeble, keg of beer, or whatever.

I bought a bunch of Dirtside miniatures a while ago and I am in the
final
leg of my assembly line approach of making them tabletop worthy.  They
are
all from Geo-Hex and for the most part they are good minis.  The only
problem I had was a lot of the vehicles had so much flash on the back of
the hulls that it obscured any detail that was originally there.  I
ended
up filing a lot of the backs flat and gluing on bits of plastic card and
drilling holes to give them detail.  Anyone else had the flash problem?

Anyway, that isn't the reason I posted to the list.  A couple of the
miniatures I bought share the same hull. Namely the HELLBAT Grav SP
Gun-FWA06 and (I think) the SIMBAT Grav AA Tank-FWT42.	

The thing is that they both have a thing on the front that looks like a
55
gallon oil drum.  I am getting ready to paint both of them and that
detail
struck me as odd.  For those of you who haven't seen the miniatures I am
talking about or just want to play the home version of this game,
imagine a
grav tank with a soviet style external fuel tank bolted to the front.

The big question is what could they possibly be?  And, before you all
give
me a bunch of goofy answers, realize that I am looking for PSB
explanations
here.  I am fully aware of the possibility of sending a force in with
beer
kegs mounted onto the front of their tanks as incentive not to get hit
(as
if you really needed one).

Lurker First Class,

Ndege Diamond

(Who actually stays up late thinking about this stuff)