Hydraulic hose lines between an inner rail and an adjacent outer rail of a lift truck mast are reeved within a hollow chain guideway. Opposite ends of the chain are fixed to vertical channels; one channel is mounted to the outer rail and the other, to a center support of the inner rail, with the lowermost portion of the chain looped between the channels. The distance between the chain portions seated in each channel provides an unobstructed operator viewing window. Elevating the inner rail causes the chain to progressively separate from the outer rail channel and engage the inner rail channel while lowering of the inner rail causes the chain to separate from the inner rail channel and engage the outer rail channel.