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Constructing a Liftout Bridge

3614 Views 14 Replies 10 Participants Last post by  Brian Considine
Am about to construct one to the section as shown schematically below;

Are there any basics in constructing one? I would appreciate any ideas of how to proceed.
Couldn't find anything on the web.


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I would say that it's quite dependent on your baseboard construction. I'd think of the lift out section very much like a modular baseboard section and keep to the ideas used there.

I'd build the bridge as a dropped down section in a box shape, the only difficulty I can see is going to be getting the alignment of the tracks right over the joins - I've had some difficulty when the section over the gap isn't straight.
The important thing is to keep the rails lined up so I would look at using baseboard dowl's mounted vertically & "over centre latches to keep the bridge in place. Electrical can easily be sorted using some plugs/sockets of your choice.

I would also lay the track in place as if the section was perminant & only after test running cut the actual rails with a very fine & sharp razor saw.
Hi Baykal,

I think it is a two step process.

First you need to build the framing and make sure it goes in and come out easily and that it can be sequred in exactly the same plave every time. once you have got it operating to your satisfaction in relation to the opening and closing then lay track over it and cut the track, rather than trying to fit the track hust over the length of the bridge section.

Hope this makes sense.


Hi Erkut,

Ifv you intend to have the section as a lift out rather than hinged two battons to support it should do the job as here another batton to lock into the cut out on each side running the length of the board there will locate it correctly everytime for track alignment, yes get the lift out in place lay the track and then cut the track either end hope it gives you some ideas the supports would need the angles to be cut to fit in.

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Guys thanks for all the ideas.

I have found this example from Brian Lamberts site, slightly scrolling down the page:

The most important part seems to be the spacer blocks where you mount the hinges a very useful tip.
Have lot of head scratching to do.

My mate Colin has a lift out section. He has the normal mechanical bits for the crude alignment but the precision comes from the electrical plugs and sockets at each end. He manages to get four tracks aligned without the need for fishplates every time !
Here is what I have in mind with the spacers and hinges:

The electrical part doesn't worry me a bit ( can't believe I'm saying this ). What worries me is the aligning of the track

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There's also the swing out gate option as shown in the bonus PDF on the Model Railroader online magazine.
It is easy for very slight movement in the hinge or the stops the other side to cause misalignment of the track especially where they meet at a very acute angle. I would try to adapt the bridge so that the tracks are cut at right angles (or nearly so) even if this means that the bridge needs to be a little longer. The tendency for tracks to misalign will be greatly reduced.

I say this from experience as I have something similar across an entry point into the middle of my layout. My tracks don't cross at right angles but not too far from it because they are on a large radius curve and the bridge is only about 18" or 45cm long. I have had to use tight hinges and make the bridge come down into tight stops so that the track alignment is acceptable.

Good luck with it. Robert.
Robert, thanks for the advice, I'll need that luck.

***Hi Erkut

The best way is to simply avoid hinges altogether - they introduce a quality and engineering problem that need not be there in the first place as the removeable bit isn't exactly heavy anyway, and is probably safer put somewhere rather than being left vertical like an awaiting guillotine :) .

Just use two pairs of proper baseboard alignment dowells each end and it MUST be perfect each time with no hassles.

Good alignment dowells aren't easy to get (They are NOT the same as that UK ebay seller has - his are sloppy compared to proper dowells).

Bromsgrove has these in UK and I have them here in AU. (I can post an image if you need it). Have the all male sides on the baseboard supports, the females set into the removeable bit.

Have a microswitch each end that controls the power to a small section before the removeable bit, set so that when the removeable part is out, the track power is off.

The Microswitch should be set into the baseboard supports for the removeable section - dead easy to do well. (I am talking standard mains voltage low cost Microswitches - these microswitches can be bought with a long alloy trigger that is easy to bend to suit the switching need. If you have problems sourcing them I can help)

If its a separate bit that is dropped in and taken out, the blend to the scenery can generally be better too... as hinge rotation doesn't need to be accommodated.

When you do the scenery, finish the surface up to where the removeable bit drops in and then cover the edge with platic cling wrap film (like food is wrapped in).

Place the removeable bit where it goes then do the ground surface with it in place. If you use a thin coat of epoxy or fibreglass resin with plaster mixed into it for the final edge area instad of just plaster it will be hard and not break/chip off.... remove the plastic when dry and the surface will be perfectly continuous.


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Richard thanks for all the info.

Dowells seems to be the solution then.

Now back to my bench and start planing drawing the plan.

QUOTE (Brian Considine @ 2 Feb 2009, 11:08) <{POST_SNAPBACK}>I would also lay the track in place as if the section was perminant & only after test running
, and securing the rails either side of the prospective cut,
QUOTE cut the actual rails with a very fine & sharp razor saw.
Don't rely on track pins and sleeper webbing to hold the rails in place. They need to be soldered to something, e.g., copper clad sleepers, the heads of small brass screws or the purpose made thingys that Guagemaster(?) sell for the job.

Also, think about what will happen the day you forget to put the bridge back and then run a train off the edge, or how to prevent it!

QUOTE (SPROGman @ 3 Feb 2009, 15:23) <{POST_SNAPBACK}>, and securing the rails either side of the prospective cut,

Of course, silly me forgetting that bit !

QUOTE (SPROGman @ 3 Feb 2009, 15:23) <{POST_SNAPBACK}>Also, think about what will happen the day you forget to put the bridge back and then run a train off the edge, or how to prevent it!

Bin there, done that, fitted cutout switch afterwards.
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