The pivoting grinding assembly permits alignment of the grindstone parallel to stock rail for full grindstone to rail contact. A flexshaft can be connected for use of hand tools. Crosslevel variances in turnout geometry represent a common cause of wheel-climb derailments. It’s not unusual to find bolted or insulated joints within 30 to 40 feet of switch points. This is particularly true in signaled territory where insulated joints are used. Like any set of bolted joints, mud pumping can occur at these joints. This pumping can cause a crosslevel twist or variance over the truck centers of the car, such that as the rear trucks are traversing the low joint, the opposite diagonal corner on the leading end of the car may be traversing the point rail in a reverse move into the turnout.

Depending on the amount of twist, some degree of vertical wheel unloading will occur on the lead truck. At the same time that the wheel is loosing vertical load, the lateral forces on the point rail may be reaching a peak value. The lateral forces developed on the point rail are substantial. The point rail, typically a section of straight rail planed to a fine tip, represents an abrupt change in direction, causing excessive wheelset angle of attack and attendant high flanging forces. Any reduction in vertical load at this point, coupled with a high lateral force, will result in a high L/V ratio with a high probability of wheel climb.