I've seen at least 3 other photos of completely different derailments of the 18 and one other derailment of the 17. None of 16, but at least one serious derailment of the 50. I am sure you are right Taylor that the new bigger engines found the soft spots, though some of the incidents shown in photos are actually after the mid 20 which can be assumed because the engines have the Rushton stacks. From the exploration I have done of the SVRy mainline I suspect there were many trouble spots where Spring thaw could have led to soft road bed. I don't believe I have ever seen a photo of a derailment involving 19 or 20 on the SVRy. I know 19 was on the point when it's pass. consist derailed, but the engine and tender as I recall were not.