Walthers truss bridge - double stack clearance

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Gloriousnse
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Walthers truss bridge - double stack clearance

Post by Gloriousnse » Mon Jun 10, 2013 9:07 am

Hi all, i'm building a Walthers truss bridge - see: http://www.walthers.com/exec/productinfo/933-3012 - for use on a module, these used to refer to having double stack clearances, but interestingly I notice both the blurb and instruction sheet have been re-written without that reference!

My problem is that it doesn't appear to properly clear a doublestack with 2x 9'6" containers with Walthers bridge track in use. What I would refer to as 'scale' combinations of boxes foul the girders, and if somebody should happen to try and use a pair of Athearn 40' boxes with 'feet' under the floor then it doesn't fit at all - similarly i'd be concerned that any container stack not properly located would also collide...

Limiting the stock that can use it would be one way forward (I think it would only be limiting it to an 8'6"+9'6" max container combination) but i'm reluctant to do that for a module as it would impose a restriction beyond the basis spec that would be hard to police.

So - has anyone else run across this issue with the kit - and did you manage to come up with a clever way to solve it?
Martyn Read

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Re: Walthers truss bridge - double stack clearance

Post by Mike_R » Mon Jun 10, 2013 10:55 am

I think I've read where the prototypes have had this problem, it is normally the area above the portal that is the problem. They alter these areas to add clearance.

I have cut notches in some of my tunnels to clear double stacks and auto carriers.
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Re: Walthers truss bridge - double stack clearance

Post by Gloriousnse » Mon Jun 10, 2013 11:23 am

Not sure this will cope with notching...

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DSC_0086 by GloriousNSE, on Flickr
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Re: Walthers truss bridge - double stack clearance

Post by Gloriousnse » Mon Jun 10, 2013 11:26 am

Might have a way forwards if I can get the sides off without destroying it - I can then insert packing pieces at the bottom of the sides, and that will lift the sides and the top upwards...

That's (IIRC) something like 14 major glue joints to try and break though...
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Re: Walthers truss bridge - double stack clearance

Post by Mike_R » Mon Jun 10, 2013 12:08 pm

I think they fit a new portal top, that is as strong but narrower, probably easy as most of these bridges are quite old and welding and material techniques have improved.

This firm does such work http://www.osmoserailroad.com/whatWeDo_BR_S.php. This appears to be one of those http://www.osmoserailroad.com/whatWeDo_ED.php
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Re: Walthers truss bridge - double stack clearance

Post by Gloriousnse » Mon Jun 10, 2013 3:59 pm

Ta Mike - that might be an interesting solution...
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Re: Walthers truss bridge - double stack clearance

Post by Gloriousnse » Tue Jun 11, 2013 10:38 am

Okay....dissasembly not possible at this stage without causing serious damage. For anyone else building one of these that needs the extra clearance, my suggestion is that before you attach the side girder assemblies to the 'deck' sub assembly you make a modification to mount them higher up than designed, I think with some careful additions to the lower edge of the sides and a bit of packing you can gain something like 4mm fairly simply and without fundamentally changing the look of the bridge.

As that's not an option - I think however I can modify the upper girders, keep (and maybe even improve on) the 'lacyness' of it, and end up with good clearances.

I think if I cut away the central part of each cross brace, leaving the diagonals (on the left in the image above) and the upper flange in place, plastruct do thinner truss girders, so I would then glue two of those (one in front, one behind) to the upper flange - i'd also add plastruct truss girders to the X bracing, which at present is just thin plate, this should give something as strong as the present arrangement, but substantially thinner.

Hmmm....
Martyn Read

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