George Henderson,Thanks for the corroboration. Ah the heady days of the 37 trolley! There is in fact part of a gravity feed railway still in existence under the city. I say part because it was unfortunately transected by the new metro lines in two places.(Haymarket and Greys Monument) This ran from Spital Tongues down to the staithes below the Milk Market and was underground the whole way. During WWII it was used as a bomb shelter and a number of blast walls were built across the tunnel. There was an access point in the grounds of the Hancock Museum from which one could walk the upper reaches although it was bricked off at the colliery end. Further details can be got from the Newcastle Societiy of Antiqities
Minstrel