A lift truck comprising: a frame defining a main structural component of the lift truck; a pair of laterally spaced apart outriggers extending from the frame , each outrigger including at least one wheel; a vehicle controller for controlling at least one function of the lift truck (10, 110; a load handling assembly secured to the frame adjacent to the outriggers , the load handling assembly comprising: a mast assembly positioned between the outriggers ; and a carriage assembly including fork structure for supporting a load on the load handling assembly , the carriage assembly being movable vertically along the mast assembly and the fork structure being moveable laterally with respect to the mast assembly via a sideshift assembly ; wherein the load handling assembly further comprises an optical sensor structure that monitors for conditions wherein movement of the carriage assembly would result in contact between the load and at least one of the outriggers ; wherein the optical sensor structure comprises a pair of laterally spaced apart contactless optical sensors , each contactless optical sensor being located adjacent to a corresponding outrigger and monitoring a respective area (A 62 ) around the corresponding outrigger for a portion of the load to enter the respective area; and wherein the vehicle controller receives a signal from the optical sensor structure and prevents movement of the carriage assembly in a direction toward the at least one of the outriggers if the signal from the optical sensor structure indicates that such movement would result in contact between the load and the at least one of the outriggers , and wherein a portion of the load entering the respective area causes the vehicle controller to prevent movement of the carriage assembly toward the at least one of the outriggers . a frame defining a main structural component of the lift truck; a pair of laterally spaced apart outriggers extending from the frame , each outrigger including at least one wheel; a vehicle controller for controlling at least one function of the lift truck (10, 110; a load handling assembly secured to the frame adjacent to the outriggers , the load handling assembly comprising: a mast assembly positioned between the outriggers ; and a carriage assembly including fork structure for supporting a load on the load handling assembly , the carriage assembly being movable vertically along the mast assembly and the fork structure being moveable laterally with respect to the mast assembly via a sideshift assembly ; a mast assembly positioned between the outriggers ; and a carriage assembly including fork structure for supporting a load on the load handling assembly , the carriage assembly being movable vertically along the mast assembly and the fork structure being moveable laterally with respect to the mast assembly via a sideshift assembly ; wherein the load handling assembly further comprises an optical sensor structure that monitors for conditions wherein movement of the carriage assembly would result in contact between the load and at least one of the outriggers ; wherein the optical sensor structure comprises a pair of laterally spaced apart contactless optical sensors , each contactless optical sensor being located adjacent to a corresponding outrigger and monitoring a respective area (A 62 ) around the corresponding outrigger for a portion of the load to enter the respective area; and wherein the vehicle controller receives a signal from the optical sensor structure and prevents movement of the carriage assembly in a direction toward the at least one of the outriggers if the signal from the optical sensor structure indicates that such movement would result in contact between the load and the at least one of the outriggers , and wherein a portion of the load entering the respective area causes the vehicle controller to prevent movement of the carriage assembly toward the at least one of the outriggers . <EOS>