Duckunder to a Lift Up

I haven't seen a lift bridge wiring[OGR DVD #11,Barrett in the Backshop has one].

I have a drop section with dual tracks and it is just wired from/at the hinge end. Common wire to outer rails and Hot to Center rail will energize railpower for the length of the bridge.  No need to wire from both ends since the layout proper itself should be wired at the other end[unless you are trying to wire the other side of the layout proper from the hinge side proper???].

This Drop Section is recycled from a former layout which had an arrangement of lever switches to protect against accidents. But although I initially ran wires up and over the door casing[and under the carpet] to the other side of the 9x16 loop for kill switches, relays, etc, eventually I decided to do nothing except use the master layout kill switches when the drop section is down. 

If you have a loop like I do, both ends receive power from the buss wiring under the table.  Power to the lift up is as Dewey did above.  There is no interlock using this method.

However, if it the non-hinge side has no access to power then you must either transmit it via the bridge with additional contacts (or a plug) that are closed when the bridge is in place or run bypass power feeds across the gap.  My lift-up section is across a doorway so I could run the power leads up the wall and over the door jam.

It basically comes down to how much effort you want to put in to overcome the inconvenience.

Jan

I recommend a Switch & relay at each end to kill power to the approaching tracks. Far less costly than a locomotive on the floor nose first.

If you need help wiring that e-mail me.

You might want to click here and read up.

https://ogrforum.com/t...22#13960184938708822

I posted mine down the page a little, but you might want to skip down even more and read about wiring......and why you should put a disconnect on the unit.

I only put up my layout at Christmas and did not think I would need it. Wrong.

Here is why...

https://ogrforum.com/t...04#12129987958270504

Good luck, mine worked well for months last Christmas. Greg

i hope you aren't planning on lifting the entire 93" length.  that would be a massive amount of weight to counterbalance.  i would suggest cutting a 3-4 foot section out and creating your lift bridge somewhere near the center of that stretch.

to bridge the gap with wiring, you can always run wire down to the floor and create a protective threshold to contain the wires as they run to the other side of the bridge.

when planning a lift bridge once, we also talked about interlocking relays to prevent anything from falling into the bridge gap when raised, but finally decided against it.  1) many coasting drives would not stop in time anyway  2) non coasting drives stopped abruptly would cause too many derails 3) in one direction there would be no problem anyway as a train would hit the lifted bridge.

members that were really nervous about it would tend to run in the non-fatal direction, however in about 8 years of operation the number of disasters were in the single digits, most of those caused by the owners themselves (yes, you had to see it to believe it).

good luck...gary

The old March 2010 photo below shows, as Jan notes above, one method to get power across openings for bridges, drop sections and lift outs. The blue flex conduit over and around the door casing enables extension of the railpower bus all the way around the layout loop and back to the power center. It also contains control wire runs for operating Tortoise switch motors and switchstand lights as well as extra power runs and feeds for lighting, accessories and bridge power lockouts if desired.

hey Dewey, ...the drop down (v. lift) bridge looks like it would be a lot simpler to implement on the hinge side, but could you show a little more detail on how the locking side works?

have to say that locking out the entire layout (v. only a length of the track close to the bridge) would probably be the best way to go for a home layout.  with a club layout where people were repetitively entering and leaving, this wasn't an option.

thanks...gary

Gary

Re: The  "locking" side of a hinged Drop section.

Photos below of adjustable strike plates for receiving the Transome Catch spring-loaded 'strike' [latch] when the hinged Drop Section closes. Plates can be shimmed for tweaking or removal of shims if necessary. Strikes normally land with 1/8"-3/16" bearing on receiving plates and can be affected by any drastic change in humidity that might swell or shrink the wood framing. I have been able to maintain about 50-60% humidity and have experienced no appreciable change or problems.

Photo of wood walkway across bridge also shown.

I heard that one guy avoided the lift out or hinged section by having an extra high crossing and a low chair on wheels.  Instead of ducking he would sit on the chair, wheel himself under and stand up on the other side. 

Nathan

I use an old foot ottoman with wheels at duck unders instead of a lift bridge.  Also comes in handy when working under the layout wiring etc.