wheel-tapper

wheel-tapper (plural wheel-tappers)

1. Alternative form of wheeltapper
   • 1939 July, Cecil J. Allen, “British Locomotive Practice and Performance”, in Railway Magazine, page 20:

     During the interval my friend, who was seeing me off, observing a wheel-tapper at his work, and having the incredulity which decides that there can be no practical outcome of this mysterious operation, asked me what did happen if the wheel-tapper discovered anything amiss.