I recently built a Central Valley 1902 HO bridge. I am rather new at this - getting back into MR after some 50 years. I reviewed the Videos that Jeff from CV posted on their website and found them very helpful and especially liked the ability as recommended to leave the truss section unattached with glue so it can be removed. I did some testing and found out that with considerable weight on the bridge, ie two engines, the deck would wobble and deflect downward significantly. After some head scratching I determined that the deck load should be transferred to the truss probably in two ways. The truss, in prototype version has the criscross members which are under the deck to bear on as well as the joint between the truss verticals and the deck main cross bearers. Well if we do not glue the truss to the cross bearers then all that is left to carry the load is the very little engagement that the cross bearers have with the truss horizontal girder. And due to tolerances when the truss is sitting on that little lip it is not touching the lower x-plates. So when a heavy load enters the bridge it is likely to spread the truss width just enough to disengage the cross bearers and then the truss drops to the x-plates allowing deflection and movement.
So I made a non-prototypical mod that when painted is virtually unnoticeable but eliminates the above problem.
I added some short .060" styrene plates under each Truss vertical section along the inside of the girder with some .020" styrene shims underneath to fill the space between the girder flanges. These plates now fit well into the deck cross bearer undercut and allow the load to be transferred to the truss. It was worth the deviation to maintain the removable truss.
Since I am apparently not well enough schooled to include photos I will email one to whomever requests it.
John....
John...