A rail fastening system for securing rails to rail ties in which an elastic fastener is used. The fastener has one portion which lies on the rail flange and a second portion which seats within a support secured to the rail tie. The fastener comprises a base portion which seats within the support and two tapered arms which are curved over the base so that the free ends of the tapered arms lie on the rail flange. The support is located adjacent the rail flange and a locking element fits between the rail flange and the support and is shaped to interfit with the support in a wedge-like relationship such that longitudinal rail movement acting on the locking element is translated into a lateral force to prevent longitudinal rail movement.