A long time ago in a galaxy far away; there was a packing plant across the Red Cedar river from a corn plant.
Maintenance departments of both plants were rivals, for unknown reasons.
Maintenance department at the pack had built a trough from old conveyor bottoms mounted at an angle deemed to be "close enough for gubmint work." Said trough was aimed at the corn plant. An oxygen bottle (from a "gas wrench) projectile was put in place on the trough.
A suitable maul was located, and the burliest mechanic was selected as the ignition wielder. The intent being to quickly and forcibly knock the valve off the projectile, forcing the escaping gas to propel the crudely aimed projectile over the river to the corn plant.
Fortunately, the terrorists at the pack were caught just before launch... And the barrage of mortar was never to be.
There are pictures, I have seen them.