or the serious Mek, a popular construction project is the Battle Fortress — a clanking, smoke-belching behemoth festooned with guns and boyz, alive with Grot riggers and whirring tracks. Typically twice as big as a battlewagon, and often even larger, a Battle Fortress is a mobile stronghold and artillery battery rolled into one. Like all Ork vehicles, there is no standardization, and Battle Fortresses can come in all sorts of shapes and sizes, but without doubt, the most popular sub-type is the Skullhamma.

The Skullhamma is a special type of Battle Fortress often built by Speed Freek Mekboyz. It has a supercharged triple-overpressure turbo engine that occupies a good deal of its hull. When a Skullhamma is moving at top speed, the supercharger kicks in and sends it hurtling forward, the front wheels or tracks lift off the ground and huge clouds of dust rise behind it. Orks find speed addictive; consequently, the crews of Skullhammas rarely disembark — they live, eat, and sleep on board, only getting off to crump 'eads.