I recall John Norwood's account of this blockage in one of his books. IIRC, he was critical of the mess it turned into, siting that many managers from the 1951 blockade had retired, and after several light winters, their replacements didn't respect the trouble that they were in until it was too late. IIRC, they had so many engines and crews marooned on the hill that they had to call in what engines were in Durango to cover.
12 degrees in Strasburg this morning, good weather to pull that book out and reread that chapter.