Steve Haywood wrote: "in 1984 ... the [Barton Swing] aqueduct ... IIRC it was left open to give priority to the Ship Canal ... When was the latest you would have crossed the aqueduct and had to wait for it to swing in your favour rather than just cross it like now?"
We have crossed in 1977, 1978, 1985, 1992, 1998, 2004, 2007. The principle of priority to the Ship Canal has been the same since the Ship Canal was completed - clearly a bad idea to have a ship wait for the aqueduct and miss a tide, particularly as it takes so long (15mins?) to complete a 'swing'. But I don't think it has ever remained 'swung' as the normal (default) position. The 'Overnight' procedures have changed over the years, though: Nov1982 WW reports that the new 9am-5pm (7day-per-week) restriction was to begin on 26th of that month: they reported local boaters saying "the point remains that the Bridgewater Canal was in existence and had its own crossing of the Irwell before the Ship Canal was constructed and this restriction of use of the older navigation is felt locall to be unacceptable". MSCCo claimed flexibility would be possible, but I don't suppose returning it to the Bridgewater would ever have been a morning-priority in the absence of boats, but afaict, no more was it the procedure to allow a barge across and then swing it again, until a ship needed to pass. In a WW article July1985, John Fletcher says "_Nowadays_ the aqueduct is closed to Bridegewater ... _overnight_, so engineers don't have to work nights." (_my emphasis_). Of course it also closed for its usual fortnight maintenance session in the autumn each year.
