A tram-train fly-over above the main railway at the Haymarket depot is a suggestion for bringing the South Suburban line back into passenger use as part of the Edinburgh tram network.
The idea is being promoted by ex-councillor and railman Lawrence Marshall, who has been campaigning for the re-opening of the line since the 1980s, as a means to avoid the impossible complexity of a tram service cutting across the main Edinburgh-Glasgow line.
Technically, if not financially, it should be feasible, given tram bridges already straddle the railway at Carrick Knowe and Edinburgh Park.
Lawrence got in touch after my recent comments about the potential for a revival and suggests an interchange at Cameron Toll where the tram could continue either on road to the Royal Infirmary or further along the South Sub loop to a Portobello station at Southfield Place, where it would meet the Borders Rail and other new train services.
The big drawback remains the limited tunnel capacity east of Waverley, for which he suggests doubling its size.
Who knows what the cost or practicality of boring a new tunnel through solid rock would involve and I doubt very much if either of us will ever live to see the day that happens.
A Haymarket bridge and Little France spur might be possible, but the issue would still be passenger numbers as, Gorgie excepted, the route snakes its way through areas too thinly populated to make it worthwhile.
Didn’t stop the first line, though.