Slab waggons are designed to carry large uncut slabs of slate, often internally within quarries. The most common form is flat waggon (often referred to as a sled) where the slab is laid horizontally on wooden runners and chained to the wagon. A less common form is the vertical slab waggon, where two slabs are chained to an A-frame mounted on the wagon; this form of slab wagon was most famously used on the Corris Railway though other lines such as the Ffestiniog Railway also had examples of this type.