Wish I had an answer for this one... so many things you could do with several sizes of curved girder bridge. Enough to fit a quarter circle of O36 would do nicely. I've needed this for several projects, but ended up working it out of the design because all the custom solutions I found looked amateurish--and they were still better than what I could have come up with.
Could also use a curved girder to protect against or manage derailments on tight curves. O27 curved girder would likely have saved many locomotives from cement floors over the last hundred years.
