Does anyone know anything about the turning triangle or sidings at Dombarton?
Dombarton never had engine turning facilities; bank engines kept banking to the end of the 1 in 30 grade at Summit Tank, where there was a Water Tank (funny that) and a turntable to turn bank engines for the return trip to Unanderra or whereever.
Dombarton is on that 1 in 30 grade which is unsuitable for normal designs of crossing loops. Dombarton was built in IIFC 1940s, and learned from the fiasco of the (1920?) Boronia Refuge Loops half way up Hawkesbury-Cowan bank. The problem was that heavy trains could not restart on the 1 in 40. At Dombarton, trains restarted on (almost) level track.