Large Scale Central

Draw bridge for doorway?

Track and Trestles
#1

Has anyone built a lift bridge? How have you addressed the lift mechanism? weights? springs? drum pulleys? My limitations are; one side will have a track platform but should stay open above the track to doorway height, the other side can be used floor to ceiling.

At the ECLSTS there was a nice drawbridge on display. Building one at the entrance to a room with 3-way open close switches and lifting from three feet to six and a half seems to be a simple engineering feat. This will permit access to the living/dining great room for family or One Gauge get-togethers.

Specifications:

One yard/meter free span.

Metal construction (?).

Opens quickly.

Sensors to detect train is not positioned at the bridge.

Power shut off and good conductivity connection across the span.

Single track.

#2

There are easier and more reliable ways i.e. build it the same way as a door to swing open in the horizontal.

#3

Dear David,

Here are some ideas if you have access to old MR mags.

If you have a club nearby, they usually have a library or a member that collects them.

Your public library system might have access to old copies, too.

In a pinch, I can get you back through 1995…

I like the first listing’s magnetic idea.

I also like the idea of spring loaded nails that pop up between the rails after you lift the section away, to prevent cars from rolling off into the abyss…

Hope this helps.

Sincerely,

Joe Satnik

Build a magnetic lift-out bridge
Model Railroader, December 1999 page 97
Latches secure this removable connection across an aisle
( BENCHWORK, BRIDGE, “DARNABY, BILL”, HINGE, LIFTOUT, MR )

Build a swinging gate for easy access; an alternative to the duckunder
Model Railroader, March 1998 page 94
( BENCHWORK, BRIDGE, HINGE, “HOOVER, GARY”, MR )

Swing bridges solve layout entrance problems
Model Railroader, March 1994 page 112
( BENCHWORK, BRIDGE, “DOYER, JACK D.”, HINGE, MR )

A drop bridge for the MR&T - bridging between two layouts
Model Railroader, July 1990 page 78
( BENCHWORK, BRIDGE, HINGE, MR&T, “ODEGARD, GORDON”, MR )

Bridge Basics 4: Deck bridges and moveable spans
Model Railroader, October 1988 page 100
Article also published in Model Railroad Bridges & Trestles Book icon, page 21
( BASCULE, BASICS, BRIDGE, DECK, “RUSSELL, HAROLD W.”, TRUSS, MR )

The near-perfect bridge, hinge spans walk in access
Model Railroader, November 1984 page 100
( BENCHWORK, BRIDGE, HINGE, “SOLOMON, STEVE”, MR )

#4

One of the larger clubs in this state, who shall remain nameless to protect the guilty, had a bascule type bridge so the elder statesmen of the group did not have to duck under the layout to enter. It even had a cutout switch that stopped all power to the layout so that the forgetful among them would not send their consists into the abyss.

They used this layout as their demonstration layout at shows and so on.

The cutout switch never failed, including the time the first battery powered locomotive ran on the layout.

Oh, the horror! Oh, the humanity!

#5

Events like described above are a terrible mix of funny and sad…kinda like suppressing laughter at a funeral!!!
dave

#6

David,
That was built by the club I used to belong to
http://www.svgrs.net/default2.html

#7

The ABTO modules group has a draw bridge that we use to get into the modules “loop”. The modules were built by Eaglewings Ironcraft. Sorry no good picture availabel of it. See http://www.eaglewingsironcraft.com/