The bridge was double track in the true sense of the word, even after the 1951 resignalling which had a double track connection from the Scarborough branch right across the platform tracks to link to the goods yards on the avoiding line. There were at that time no less than 4 bays serving the Scarbo' line!
The Scarbo' link to the goods yards and to the high-number platforms was removed during simplification in 1974. Further work took place in 1988 as part of the preparations for ECML electrification. It is this revision which introduced a short length of single line shortly before the bridge (coming from Scarbo') which eliminated the previous facing and trailing cross-overs, thereby saving on two points! It was also this work that cut the bays back from 4 to 1 plus a siding accessed from the Scarbo' line.
There is a lot of detailed information in "Britain's Rail Super Centres- York" written by Ken Appleby and published by Ian Allan in 1993. (ISBN 0-7110-2072-8)