A terminal tractor, known in the United States as a shunt truck, spotter truck, spotting tractor, yard truck, yard dog, yard goat, yard horse, yard jockey or mule, is a semi-tractor intended to move semi trailers within a cargo yard, warehouse facility, or intermodal facility, much like a switcher locomotive is used to position railcars.
Distinctions between a terminal tractor and a regular road truck are several and noticeable:
- A single-person cab offset to the side of the engine.
- A full-height, sliding rear door for easy access to trailer connections.
- A very short wheelbase, usually with a solidly mounted rear axle.
- A low-power diesel or alternative fuel engine, usually with an automatic transmission.
- A fifth-wheel coupling with an integrated lifting mechanism allows the semi-trailer's legs to remain in the lowered position during movement. 15 inches (380 mm) and 70,000 lb (32,000 kg) of hydraulic lift is typical.
- 12-gauge steel side wall cab construction with 1⁄2-inch (13 mm) steel floors for protection in abusive and dangerous work environments.
- 360-degree view to facilitate five to six moves an hour.
Since off-road versions do not have to drive on roads at highway speeds, a typical top speed is just 25 miles per hour (40 km/h). It is rare for these vehicles to be on highways, so it was very unusual when a pedestrian was accidentally struck and dragged by a yard truck at an intersection in Bellevue, Washington, in February 2014.
Autocar, Capacity Truck, Hoist Liftruck, Tico, and Kalmar Ottawa terminal tractors are manufactured in North America. Orange EV manufactures pure-electric terminal tractors in Missouri. Effenco manufactures hybrid systems that can be retrofitted on yard tractors. One of many European manufacturers is the Dutch company Terberg which has a US presence. Terberg has also introduced a fully electric yard tractor and an autonomous terminal tractor, the AutoTug.
Assignment and scheduling of yard trucks in order to load/unload containers to/from ship obeying the stowage plan is an important problem for port operators. Efficient and real time solution methods are required by practitioners.
- "Capacity Texas" (PDF). capacitytexas.com.
- Woman struck and killed by yard truck in Bellevue By KOMO Staff Published: Feb 24, 2014
- "Quick Spin: Orange EV's All-Electric Terminal Tractor". Heavy Duty Trucking Info. Retrieved 4 May 2017.
- Flexible ship loading problem with transfer vehicle assignment and scheduling "Transportation Research Part B: Methodological, 111, 113-134, 2018"
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