Breda LRV - Flexible gangway connections

Work continues on my Breda LRV project ...

So the correct term for the wiggly bit between carriages is "gangway connection". I'm not sure though if that applies on trams since there is no gangway? Anyway, I needed something to bridge the gap between the two halves, as this is obviously not the look I'm after:

Please forgive the cruel close up photography!

I've been pondering this for some months now, knowing that sooner or later I would have to tackle it. Luckily I came across a technique involving carefully folded paper in a magazine a while back and so didn't have to invent something myself.

Making folded carriage gangway connectors

1. First prepare some paper. I took a sheet of printer paper, cut two strips the width of the sheet, and one of them at the height of my carriage bodies, the other at the width of the carriages. I.e. one strip is for doing side-to-side, and the other is for doing up and down.
2. Now paint them underframe grey colour.
3. Next, glue the two strips at right angles, in a big L shape.
4. Now start folding. Simply fold one piece over the other. One strip will go across, the next down, the original strip will now fold back across the other side, and the other piece will now fold back up.
5. Once at the required thickness, glue the two strips together and trip off square.

This worked well, however I had a small problem in that I had a worm gear and drive shaft to straddle. So I cheated somewhat and after making up a cardboard jig, I taped my paper concertina to the deck of my laser cutter and slowly lasered out the middle of my concertina.

A little fine tuning later and it slipped over the drive shaft very nicely.

Looking good!

thoughts on paper gangway connections

There is no denying, the paper concertina looks fantastic. It also wiggles around and moves most wonderfully. However there is a downside to this technique. Because the paper is quite tightly folded and glued to each carriage end, it actually constrains the motion a little bit. The LRV is now slightly less keen to turn sharp corners, and when it does turn a corner, it concertinas together on the opposite side, so looks a little odd.

So perhaps next time I'll try one of these other techniques:

• http://www.djhweb.org.uk/class101.asp – a simple zigzag of paper, however look from above and you'll see straight through to whatever is underneath, something I wanted to avoid.
• http://callingallstations.co.uk/2014/07/14/how-to-improve-old-rolling-stock-part-3-gangway-connectors/ – two zigzags that slot into each other. Slightly better looking and better behaving I imagine, but still see-through.
• http://www.elginmodelrailwayclub.co.uk/2010/articles/corridor-connections/corridor-connections.html – an elaborate series of squares folded together and held in place with little tabs. Sounds fiddly but would be pretty quick to make up on a laser cutter. This would also avoid the issue of being see-through from above.

I won't change what I've done though, my LRV is a living test bed for different techniques :)