Abstract: An apparatus for applying a single-component or multi-component adhesive to a ballast bed of a stretch of rails in a rail path, includes a container for the adhesive and elements for conveying the adhesive for application are mounted on a supply vehicle which can be driven on, or adjacent to, the rail path. The adhesive is guided from the supply vehicle with a hose having a one nozzle. The apparatus further includes a trolley that can be temporarily coupled and secured to a rail, and can be moved in a rail-bound manner at a desired and uniform speed independently of the supply vehicle. The trolley supports a boom on which the nozzle is mounted, so that a defined depth of penetration of the adhesive can be maintained by the apparatus at a uniform running speed of the trolley and defined flow rates of the adhesive depending upon the characteristics of the ballast bed and spray pattern.