RandallW wrote:Double stack clearances are Plate H (20' 3" vertical clearance), a full 3' 3" higher than Plate F (17' 0" vertical clearance).
Yes, while results may vary, that's exactly where I'm coming from when watching that video, to my eye seeing a decent chance for that 3'3" of clearance and if not, pretty close, using the cars' side hand-holds as a point of reference and toward the perspective of looking up from below as the cars pass under the bridge.
I'm also considering as to possibilities that within the context of earlier overhead clearance needs, soon into the progression ~19'6' clearance projects began including doing ~20'6" where it could be easily accomplished and toward longer term plans.