on Thu Apr 12 14:32:21 2012, in response to Re: Rush hour J to 9 Av, posted by Railman718 on Thu Apr 12 08:37:52 2012.
When I worked the road, the rule was that special services were not to be dropped. If a QB went bad on the stand at Stl, then an OK QJ (later M) was to have the signs changes and be used as the QB interval. The same was true at 95 St with the RR nassau specials. If a scheduled Nassau RR (called "RJ" by operating personnel after the original post Chrystie 4 AV/Nassau service) train went bad on the stand then a Bway RR was to be similarly converted to Nassau service which was easy at the time since all RRs were 8 X 60 ft cars at the time.