steam shovel

from The American Heritage® Dictionary of the English Language, 5th Edition.

• noun A large, steam-driven machine for digging.

from The Century Dictionary.

• noun A digging-, dredging-, or excavating-machine, driven by steam in its own engine from its own boiler: usually mounted on a car to run upon the rails of a track and used in mining, canal, and railway work. Called steam-navvy in England. It is essentially the same as the dredge, but is operated on land instead of from a boat. See cut at excavator.

from Wiktionary, Creative Commons Attribution/Share-Alike License.

• noun An industrial machine designed to effect a shovelling action through steam power.

from WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.

• noun a power shovel that is driven by steam