I hope I can fade a little more slowly. In those days, early to mid '60's, the Potrero Tower at Mission Bay Roundhouse and the Visitacion Tower, opposite Brisbane, had been consolidated into the Bayshore Tower and the the old electric machine was replaced by an old fashioned CTC type panel incorporating those other two plants which were activated by code pulses which you could hear over the speaker. Potrero had been electro-pneumatic and Visitacion was armstrong. When Bayshore Tower ended everything was moved to Fourth and Townsend. I don't know what happened after the demise of the old Fourth Street Tower and the advent of Caltrain.