Dn 679 is a frog of type 49E1, grade 1/9, radius 300 m with welded rail ends.
Solid cast frog is made of high-manganese steel in accordance with EN 15689 with four welded rail ends. For welding rail ends, a stainless insert of the special metal alloy is used. Welding of rail ends is carried out on the open-type butt welding machine under special technology. To fasten the frog to the pads, Skl12 elastic clip or other fastening is used to ensure the reliability and safety of operation.
It is quite common design among the European railway workers which is used both on station tracks of the main transport and on subways.