In the early 30s necessity for cargo transportation has increased significantly, new roads and cities were built. Mack released one medium and two heavy-duty versions of the B range. The Model BM (1932-1941, 3030 pcs.) is the medium-duty model with carrying capacity of 3-5 tons; the Model BQ (1932-1937, 327 pcs.) is the heavy-duty model with carrying capacity of 6-8 tons and maximum speed of 40 mph (there were also three-axle versions); and the Model BX (1932-1940, 3032 pcs.) is the heavy-duty model of the first Mack's truck with a sleeping compartment for long hauls.