Electronic wire guidance is not the only guided forklift system available. Other systems include automatic guided vehicle (AGV) and rail systems.

 

Rail systems vs. EWG

 

Rail systems guide the forklift using the installation of a rail on each side of the aisle to keep the forklift straight. Because rail systems need to allow space for the rails, the aisles cannot be as narrow as with EWG systems, meaning that the increase in space is not as great.

 

Rail	EWG
Rack to rail (each side) 200mm Bracket to lift truck (each side) 25mm	Rack to lift truck (each side) 125mm
Total: 450mm per aisle	Total: 250mm per aisle

 
Using EWG systems results in a saving of 200mm per aisle over rail systems: 200mm over 20 aisles is four metres. This extra space can be used for another double row of racking resulting in even more pallet space. Rail guidance is also more expensive, costing between $200-$300 metre to install (including the bottom beam which prohibits storing stock on the floor), where electronic wire guidance typically costs between $40-$50 metre.

Guide rails are made from thick cold-rolled steel that comes into contact with the truck when in guidance. The weight of the truck (up to 9000kg) exerts force on the steel and deforms it over time. In addition the mechanical anchors used to hold the guide rails down to the floor may loosen with wear and result in the guide rails moving out of position. This may cause the truck to lose guidance if sections of the steel have been deformed. Rail systems may require regular maintenance to ensure that the rails do not come loose. 

 

Rail systems do not increase productivity as much as EWG as it is a lot harder to align the truck with the rails. This results in a loss of time and a lower through-put per cycle than with EWG systems.