Abstract: An apparatus for the field milling of a pocket into a railroad stock rail to accommodate the precise nesting abutment of a switch point rail thereto avoids the necessity of milling such pockets under shop conditions and permits the use of Continuous Welded Rail (CWR) through railroad switches. The portable, self-propelled apparatus is adapted to the field milling of pockets into stock rails to accept the selectable placement of a movable switch rail therein and is powered by a portable power supply that may be either auxiliary or integral. The apparatus comprises components which are preferably fluid-powered. The apparatus clamps onto the stock rail and comprises a positionable milling assembly inclined at the angle necessary for milling the desired pocket into the stock rail. The apparatus moves the apparatus along the stock rail at a controlled speed whereby the milling head is fed along the stock rail during the milling operation.