Wheelslip

Near-synonym: wheelspin

Source: wiktionary

The traction motors are connected in three parallel groups of two in series, and the mid-points of each pair of motors are connected together; the mid-point connection is used in conjunction with relays to form a device which is sensitive to wheelslip, thus leading to an improvement in adhesion.

Source: wiktionary

Minor changes to control gear include the provision of automatic wheelslip protection, since these units will be operated on lines with ruling gradients of 1 in 60 or 1 in 80. Wheelslip automatically causes the main generator field excitation to be reduced; the load regulator is forced back to minimum excitation and, if operating in one of the two stages of traction motor field divert, causes reversion to full field.

Source: wiktionary

Daily diagramming involves the single-heading of 1400-tonne trains over the northern banks, where wheelslip can be experienced when the rails are wet.

Source: wiktionary