Modular Collapsing Train Bridge - RC / PF tracks

[Murdoch17]

Mod note: Zombie-bumping this because of major updates to the structure and the possibility of really building this is pretty high. I hope this is ok.

This bridge was inspired by Bad Cop's Pursuit (set 70802) and the short section of railroad bridge included with that set. When I first saw it, I thought it would make a great play feature for a train bridge that is actually usable by trains.

Here is the result of all that working and reworking: 12 sections of PF / RC train track (It won't work with 9V, sorry!) with 1 section "failure point" plus 2 studs of space to separate the moving from non-moving items and allow the hinge to do it's job.

The track leading up to the "failure point" as I call it, is raised ever so gently at an angle of (at most) 1 1/3 bricks high per 1 section of track. (The angle of ascent / descent depends on which part of track you are on, but for the most part it's consistent.)

The design of the bridge is modular so that you can easily disassemble the bridge for transport. It disassembles into 2 lower ramp sections consisting of 4 tracks each and 2 flat sections placed onto plates with the 1 "failure point" module consisting of a hinged (on one end) two-track section in the middle.

The bridge when the track is safe to cross: the pins are inserted and it should be stable. Naturally, a very heavy engine will snap the Technic rods in half, breaking the bridge permanently. Thus you can only use this engine with Small engines like my 2-6-0 + it's consist, (AKA the Lone Ranger train) the My Own Train series engines, or something of comparable weight.

I don't think putting a articulated such as a Union Pacific "Big Boy" or even a non articulated Pennsylvania "T1" would look very good on this bridge, as these (among other large types) are longer than the bridge gap itself.

This is how it works:

Their are two hidden Technic rods under the track that should allow trains to pass by safely overhead. Pull the Technic connector and your bridge collapses. Lift the bridge up and move the rod back in to reset the bridge for the next adventure.

To give you a bit of perspective on this mode's progression as a concept, here is the original idea from February 2015. It was a lot more complex with two rods and two break points, plus in all likely hood it would not have held up well if carried with the flimsy base-plate underneath. Nowadays we have only one drop point and reinforced regular plates! (this model is not in the LDD file, and is just for demonstration purposes)

Updated LDD file for the newer bridge model: http://www.moc-pages...1472495977m.lxf

As usual, all comments are welcome, be they questions, suggestions, or complaints.

Thanks for reading!

Edited August 29, 2016 by Murdoch17

[lightningtiger]

Interesting idea 'Murdoch17'.....perfect for your own Seconds From Disaster !

Brick On LDD On 'Murdoch17' !

[Electricsteam]

That is awesome murdoch! You should see if you could make a longer version activated by a lever or something.

[detjensrobert]

Why wont this work with 9v? The tracks are the same size as the PF ones.

.

[Duq]

Why wont this work with 9v? The tracks are the same size as the PF ones.

I'm sure you can make it work for 9V. If you don't mind cutting a track section in half for the collapsing part of the bridge...

[Electricsteam]

I'm sure you can make it work for 9V. If you don't mind cutting a track section in half for the collapsing part of the bridge...

Maybe he could get some metal tape instead of cutting up some tracks?

[Murdoch17]

Interesting idea 'Murdoch17'.....perfect for your own Seconds From Disaster !

Brick On LDD On 'Murdoch17' !

Thank you, I used to watch that show a lot!

That is awesome murdoch! You should see if you could make a longer version activated by a lever or something.

That's a good idea, but LDD physics (specifically lack of gravity) might make that a bit of headache. I mean how much length could I put on the breakable section before it starts to bend under the engine's weight?

Why wont this work with 9v? The tracks are the same size as the PF ones.

.

I'm sure you can make it work for 9V. If you don't mind cutting a track section in half for the collapsing part of the bridge...

9V won't work because of the huge gap between the broken an not broken sections. I can't reconfigure it because without that gap, because if I do, the bridge won't break.

Edited February 24, 2015 by Murdoch17

[Murdoch17]

I am Zombie-bumping this because of major updates to the structure and the possibility of building in real life this is pretty high. I updated the post and pictures, instead of making a new topic altogether.

I hope this is okay!

Ain't no stoppin' this train now, mister. We's gone on the express train to the wil' blue yonder, getcher ticket ready.

(words by Scott Bourgeois, picture by me)

[Legotom]

Great idea. I didn't see this post the first time around so thanks Mods for bumping it up.

9V won't work because of the huge gap between the broken an not broken sections. I can't reconfigure it because without that gap, because if I do, the bridge won't break.

You could do it this way. You'd have to solder some link wires between the fixed and moving bits of bridge, which might be tricky without melting the plastic of the track. Or use two sets of 9v track power connectors to join the two sections, but that would be rather bulky and ruin the look of the bridge.