drop bridge for a walk through ?

You need to use some good tight hinges at the hinged end and put a pair of pins for the flopping end of the bridge. I've also seen V blocks of steel or aluminum used to get the horizontal alignment right with the blocks bein adjustable for the vertical alignment. A latch will keep the bridge down unless you want it up. The spring type is the best as this will keep the bridge locked down positively to the stops.

-- Why isn't there an Ozone Hole at the NORTH Pole?

To stop a re-run in model form of the Central of Peru's Chaupichaca bridge disaster, install a micro switch on the abutment at the non hinge end, and wire this to track sections of suitable length on each side of the bridge. When the bridge is up, these sections will be dead. Perhaps even a small push button on-off switch could be used. Regards, Bill.

How about just placing a wedge barrier on the track before opening the bridge?

Jim Stewart

When we had ours we used two of the sliding bolts you might find added to a house door ( the smallest we could find) to lock the bridge in the correct place.

For our electrical connectivity, we used 25-way connectors between the two, but we made no provision for trains running off (and surely enough, one did).

I'd imagine the best way would be with the push button switches as someone else described with isolating sections. To ensure it's automatic though, I'd put the have the bridge rest on the swiches whilst down, that way the cut-off is automatic. Switches attaches upside-down to the underside of the drawbridge would control the isolating section on the hinge side, and swiches attached to the base where the bridge rests would be the correct way up and control the isolating sections on the gap-side .

(Obviously the weight of the bridge shouldn't be entirely supported by the switches or they'll wear out quickly)

Hope this helps..

Craig

"A Drop Bridge for the MR&T", by Gordon Odegaard, Model Railroader July

It may be available on MR's website (I haven't checked). If you send me your snailmail address, I'll mail you a photocopy. Drop the first (or second) 'w' in the fromaddress.

HTH

how about steel or brass pins and plastic funnels at the corners for alignment and adding a microswitch that cuts power to the adjacent track segments when the bridge is not seated properly