Lionel 153 Block Signal & Bascule Bridge

I thought about this; I have an original 313.  I am not sure if the wiring is the same on the new version but, the original can disconnect the center rail power if you isolate it a few track lengths from the bridge.  I the idea was to keep locomotives from going through the open bridge.  You will need a relay to control the signal.  The trigger will be the isolated center rail.  The normally closed (NC) connection will go to the green bulb and (NO) normally open would go to the red bulb.

The circled terminal is hot when bascule bridge is down.  You could power a relay (one normally and one normally closed contact) to drive the lights on your 153 Block Signal.

Thank you both very much.  Will look into getting a relay.

Ive been considering the same thing (postwar version).  I have the isolated track section and ive wired the green bulb to that lead - I am wondering if I can connect the red bulb to the bascule motor instead of using a relay. Your thoughts on this method?

@DrSteveDC posted:

Ive been considering the same thing (postwar version).  I have the isolated track section and ive wired the green bulb to that lead - I am wondering if I can connect the red bulb to the bascule motor instead of using a relay. Your thoughts on this method?

With bridge full up and motor not running you would have no light on your signal.  Relays are fairly inexpensive.

@Steims  I've ordered a relay. My bridge cycles up and then down with no stop in between.  I am assuming the postwar bridges work that way unless it has been modified.

The videos I have seen on the re-issue model shows momentary push button to raise full open then re-push button to send it closed.  The bridge remains full open if desired.  

@Steims  Got it, mine is a prewar version. I can attach a switch to power it off and leave it in the raised position.  But then you would have to lower it each time the train rolls around.  I am probably going to use the relay - will have a cleaner green/red cycle.  If i attach a lead to power the red bulb from the motor there would probably be a short time where both the red and green light were on. I certainly dont want to confuse the railroad engineer :-)