Not the traditional steam-shovel type devices now pretty much entirely supplanted by backhoes and bucket loaders, the power shovels are more of a backhoe arm with the industrial-strength version of a classic Cyberpunk vibroblade on the end, for cutting smoothly through the asteroidal metal. They make the entire rock ring with subharmonics when they're in use and are a cast iron bitch to learn to use effectively, but a skilled operator can shave a rough-blasted cavern dead square and level, and as smooth as dressed stone. They get the name because chisels, which is what the cutting head resembles more closely than a spade, are not so much a part of the mining tradition.
The device of choice for the Pellucidarans, these are handwaved extensions of 'Danish tunnel boring machinery. In deference to generations of SF/F artwork, they frequently have spiral "drill heads" for their front ends, rather than the flat rotating cutter heads of their 'Danish counterparts. They also manage considerably greater speed, actually measurable in miles per hour rather than feet per day. Unlike conventional TBMs, though, Fennish moles do not produce an endless stream of crushed rock unless they are designed specifically for mining purposes; instead, they somehow melt and fuse the rock into the walls of the tunnels they dig.
Because of the considerable requirements of a mole in terms of both space and initial resources, they are not common in Fenspace proper.
A few moles produce neither scrap rock nor tunnels, instead traveling through the ground without disturbing it. There are two main variations on this mode of travel -- the first produces a moving "bubble" in which the craft resides, while the second actually phases through soil and bedrock. Despite considerable research, the mechanisms for both versions remain mysteries.
- Which makes them popular with some Gurren Lagann Fen.