A cab over is a type of vehicle where the passenger compartment sits on top of the front axle. These vehicles typically have a vertically flat front due to the engine being located under the cab or even further back. Another term for these vehicles is cab over engine, due to the fact that the passenger compartment is often situated on top of the motor. Many trucks and vans use this configuration, particularly in Japan and Europe where specific regulations may encourage the design. Some of these vehicles have a tilting cab to facilitate engine access, while others include a removable engine shroud inside the passenger compartment.
The first cab over trucks were introduced around 1907, and the design became popular for a time in the 1930s. Regulations in the United States during that time period limited the overall length of a truck and its trailers, and the cab over concept was able to offer a few extra feet in trailer length. Similar regulations have driven the popularity of cab over vehicles in Japan and Europe. By moving the cab forward to the very front of the vehicle, more passenger or cargo space can be opened up.
Another advantage sometimes associated with the cab over is visibility. Since there is no hood to look over, the driver can often see the road much better. Disadvantages can include excess engine noise due to the driver sitting right on top of it, and a rougher ride for similar reasons. These vehicles also tend to have poorer aerodynamic qualities due to their broad, flat front ends.
Cab overs are sometimes referred to as being forward control, due to the driver sitting at the very front of the vehicle. This has been used both as a marketing term and a description of the way the vehicles are actually driven. Forward control has been used in passenger vehicles, freight trucks, and a variety of other military and civilian applications. Some cab over military vehicles include armored personnel carriers (APCs), rocket or missile launchers, and radio vehicles. Civilian uses may include crane trucks, fire engines, and dump trucks.
The first tilting cabs were introduced in the 1950s. This unique design can allow easy engine access. A tilt cab can actually make an engine easier to work on than it would be in designs where the cab sits further back on the body. Other cab overs have engine shrouds inside the passenger compartment that allow limited access.