The HAVr C10 Siege Tower, or simply Imperial Siege Tower, was an Imperial heavy assault repulsorlift vehicle as fearsome as an AT-AT walker.
For firepower it had two heavy blaster cannons and two twin medium blaster cannons, as well as having nearly impenetrable armor. It floated about three meters above the ground on powerful repulsorlift engines. It was crewed by 6 people and could hold 12 passengers as well as 800 kilograms of cargo while going at a maximum speed of 90 kilometers per hour.
One such siege tower was deployed on the forest moon of Endor during the Battle of Endor, where a group of Rebels came across it thanks to Major Perrn's warning. The Rebels noticed a weak spot in the tower's armor; the armor around the repulsorlift engines (located beneath the tower) was weaker than the rest of the vehicle. Thanks to this weak spot, the group took out the tower before it could join the battle at the shield generator.
Sources
"The New Republic Campaign: The Battle for Endor from the PCs' Perspective" — Polyhedron 90 (Unlicensed)
