Large Scale Central

Lift up bridge questions

I am installing a lift up (as opposed to lift out) bridge to allow access to the centre of the loop.
It will be hinged at one end and aligned at the non hinged end with lift out rail clamps.
I am concerned that at the hinged end the rail on the bridge will foul the rail on the base when the bridge is lifted.
Has anybody done something like this and are there any tips/suggestions that could be passed on?

Look under Rick Marty’s Shasta Pacific build. He just did one like that with the hinges on top of the bridge.

Shasta Pacific

Thank you for the replies between the knowledge on here and on a UK site I have successfully made a mock up of the hinge/rail configuration and it works perfectly.

Now all I need to do is to think of a way to disguise the hinges or an explanation for why they are there.

i did not need it in the end, but i made plans and trials for just that.

my solution was to use inclined cuts on the rails.

Did a couple of these for my indoor line, though those are just boards, not bridges. Main thing is to keep the hinges well above track level - a good half inch or so. Installation was a bit of a pain - at least doing it solo - trying hold everything in place and out of the way while using the screw gun.

Korm Kormsen said:

i did not need it in the end, but i made plans and trials for just that.

my solution was to use inclined cuts on the rails.

Thanks Korm that is the effect I was after originally, now I am going back to the drawing board to revisit all the options.

The gap at the end was/is my biggest concern but this may ease my fears.

The incline on the hinge end may work for me with my Hillmans clamps at the other end keeping track in line.

What angle did you plan on using, 45 degrees or shallower?

Oh did I mention that it will be a double track bridge? Ben Hur has got nothing on me when it comes to productions.

Gap, here’s my hinge solution.

All good solutions. The key is to get the pivot point near or above the rail head which allows the gap to open rather than bind. I’ve done bi-fold bridges with two hinge points: Hinges on top at the beginning of the bridge, and underneath at the fold point. Old picture, but illustrates the idea.

What angle did you plan on using, 45 degrees or shallower?

45° should do the trick.

for double track i got a nice thing. a “gauntlet”. makes for interesting crashes.

the entrances are made from an LBG crossing.

description here: http://kormsen.info/bridges/trussbridge/

Korm Kormsen said:

What angle did you plan on using, 45 degrees or shallower?

45° should do the trick.

for double track i got a nice thing. a “gauntlet”. makes for interesting crashes.

the entrances are made from an LBG crossing.

description here: http://kormsen.info/bridges/trussbridge/

Hmmm the gauntlet sure is an interesting concept (https://largescalecentral.com/externals/tinymce/plugins/emoticons/img/smiley-surprised.gif)but I think I will pass on that one. (https://largescalecentral.com/externals/tinymce/plugins/emoticons/img/smiley-wink.gif)

I ended opting to use the method suggested by Korm with the hinges underneath the bridge.

Some pictures of the start of the bridge build, getting the hinges positioning just right.

I am using steel gate hinges.

The opening the will be bridged it is just over 1 metre wide.

(http://www.largescalecentral.com/FileSharing/user_3049/GAPs%20Pictures/Bridge%20Opening.JPG)

Checking the hinge height, the hinges will recessed into mounting block.

(http://www.largescalecentral.com/FileSharing/user_3049/GAPs%20Pictures/Deck%20Height%20Check.JPG)

Hinges from the top;

Closed

(http://www.largescalecentral.com/FileSharing/user_3049/GAPs%20Pictures/Hinge%20Top%20View%20Closed.JPG)

Open

(http://www.largescalecentral.com/FileSharing/user_3049/GAPs%20Pictures/Hinge%20Top%20View%20Open.JPG)

A small gap was required to allow the bridge to swing up but it is only slightly wider then the thickness of the deck board so it does not present a problem

(http://www.largescalecentral.com/FileSharing/user_3049/GAPs%20Pictures/Top%20View%20showing%20gap.JPG)

Will be following to see how this materializes.

The lift up bridge is finished!!!
From a concept put forth by Korm Kormsen who sometimes frequents this forum of putting the hinge under the track, as opposed to the convention of having the hinge joint above the track, to the finished thing has been a Ben Hur type production.
Trains can now cross the entrance to the firepit area with no problems.
Bridge non hinge end is located by using “Hillmans” lift out bridge clamps.
All that need to be done is to design and manufacture a safety device that stops trains from running off the edge when the bridge is open, I use battery power so breaking the track circuit does not apply, some form of physical barrier will be required possibly even a catch point.

More thought on the safety device is required, any suggestions folks???

(https://www.largescalecentral.com/FileSharing/user_3049/GAPs%20Pictures/Bridge%20Side%20View%20toward%20house.jpg)

(https://www.largescalecentral.com/FileSharing/user_3049/GAPs%20Pictures/Bridge%20Lenghtwise.jpg)

(https://www.largescalecentral.com/FileSharing/user_3049/GAPs%20Pictures/Train%20on%20bridge.jpg)

(https://www.largescalecentral.com/FileSharing/user_3049/GAPs%20Pictures/Hillmans%20clamps%20close%20up%201.jpg)

Looking good. Please post a few detail shots in the up position too!

Re safety device: The best is an electrical block on both side of the bridge that is automatically disconnected when the bridge is lifted. This can be accomplished with one or two momentary contact push button switches on the landing pad. Only need to break contact on one rail per track.

Personally, I am battery power, so I need a mechanical stop. I use a blue Aristo track screwdriver in a hole drilled into a tie and the bench. I learned the hard way that this device was required (https://www.largescalecentral.com/externals/tinymce/plugins/emoticons/img/smiley-money-mouth.gif)

Jon Radder said:

Looking good. Please post a few detail shots in the up position too!

Re safety device: The best is an electrical block on both side of the bridge that is automatically disconnected when the bridge is lifted. This can be accomplished with one or two momentary contact push button switches on the landing pad. Only need to break contact on one rail per track.

Personally, I am battery power, so I need a mechanical stop. I use a blue Aristo track screwdriver in a hole drilled into a tie and the bench. I learned the hard way that this device was required (https://www.largescalecentral.com/externals/tinymce/plugins/emoticons/img/smiley-money-mouth.gif)

I use battery as well so a mechanical stop is needed.

As the bridge leads to a sitting area with a firepit visitors will be using the bridge as well so something that is semi automatic will be needed.

I have considered a battery powered solenoid dropping a barrier but that would get a bit messy, so a lever system will be the best option I think.

Will take some pictures of it open when it gets a bit lighter.

Picture of the bridge open.

It does not open past 90 degrees, I made it like that so that it cannot be left open by mistake and someone must hold it open.

The landscaped sitting area is in the background when it is finished there will paths running around all the bench work and gardens between them and the firepit.

(https://www.largescalecentral.com/FileSharing/user_3049/GAPs%20Pictures/Bridge%20open.jpg)

Yes. some kind of mechanical lever would be good. The bridge itself creates the barrier on one side, but perhaps if visitors will be opening the bridge, some means of determining proper track alignment has been established on closing is also needed. Mechanical is still the best as it can not fail due to dead batteries.

How about something the person opening the bridge must engage that will not disengage until the bridge is seated properly?

Calling Rube Goldberg, Rube, are you with us?

Thanks for the pic. I would still like to see a close-up of the hinges in the up position when you can. No rush, I’m just curious as to your implementation.

A rube here,

If you split it in the middle, you automatically get 2 blocking sections.

Amazon.com: GUAngqi Stainless Steel Sliding Bolt Lock Thick Small ...

Above; high tech alignment device and lock…

so you want something mecanical?

well, this idea would be as mecanical as it can get.

a moveable buffer, operated by the weight of the closed bridge and a (lighter) counterweight.