Tips for 90-Degree Alley Dockingby Tom PriceUpdated February 19, 2019
Contrary to what the name implies, alley docking does not mean pulling up to a dock in an alley. Alley docking actually refers to guiding a semi-trailer into a narrow space, or between two vehicles and a 90-degree angle. Alley docking a tractor-trailer can be difficult for a new driver to learn and sometimes frustrating for instructors to teach. Becoming an expert at the maneuver takes experience, patience and lots of repetition.
Positioning the Tractor-Trailer
Position the tractor-trailer so that the target of the alley docking maneuver is on driver's side. Although alley docking is possible from either side, doing it from the left side of the rig is preferable to backing from the blind, or right, side. Blind-side backing, especially using a road tractor with a sleeper, is next to impossible for most drivers. Ensure that the wheels of the trailer are slightly past the target of the alley docking procedure.
Jacking is the process of putting the tractor 90 degrees to the trailer and pushing the front of the trailer sideways. Begin jacking by turning the steering wheel all the way to the right before backing up the tractor. If you do not turn the steering wheel all the way to the right before starting the tractor in reverse, the tractor will actually push the trailer backward longer, possibly missing the “alley."
Chasing is the process of steering the tractor back in front of the trailer to finish the docking maneuver as the trailer reaches a 90-degree angle to the target. Begin to chase the trailer at a point approximately 15 degrees before the trailer is at a right angle to the target. Turn the wheel rapidly to the left while moving the tractor at a very slow speed. Time the chase maneuver so that the tractor and trailer are at a 90-degree angle to the target.
Take It Slow
Some drivers feel that they have to rush the alley docking maneuver because traffic may sneak up behind them or try to pass them while they are performing the maneuver. Going slowly decreases the possibility of a traffic accident. Go slow until the tractor is jacked at a 90-degree angle to the trailer. Push the front of the trailer over slowly to ensure not to overshoot the point where the tractor starts to chase the trailer.
If a team of two drivers is manning the tractor-trailer, have the co-driver get out and stop traffic. Have the co-driver assist the driver by watching the blind side of the tractor-trailer to ensure that the driver does not hit any unseen objects. A single driver should also try to enlist help from people at the building he is trying to back into.