The Banjo Signal No. 140 would move the arm "STOP" sign back and forth across the RED light as a train passed by. This was accomplished with the use of a vibrating drum that rotated when current was applied from accessory voltage and this was activated from the weight of the train going over a No. 145C Contact that was placed beneath the track. This signal was available from 1954 until 1966, and there are no known variations.

An identical Banjo Signal was produced in 1970-84 by MPC (No. 2140), so collectors should check the bottom of this tower to see if it has the following inscription: "PART NO. 140-50 / NO. 140 BANJO SIGNAL / MADE IN U.S. OF AMERICA / THE LIONEL CORPORATION / NEW YORK"