European lancelet (Branchiostoma lanceolatum). (After J. E. Webb, On the populations of Branchiostoma lanceolatum and their relations with the West African lancelets, Proc. Zool. Soc. Lond., 127:131, 1956)
Comparison of the boom, dipper handle, and dipper for (a) conventional power shovel, (b) hydraulic backhoe, and (c) hydraulic front shovel. A typical lower frame, crawlers, and machinery frame are shown for the hydraulic shovel.