I do not know how the gentle slow was achieved, but there were 4 lines (and a central platform), so it was a similar problem. (thanks Falkor @sydenhan town forum for the extract).

Since we can no longer seem to present a united front on the closure of FH pools, I doubt there is the will power to push through a new subway project, when presumably half of FH would prefer it to be just bricked up, (or perhaps made into low cost housing)....