Hi Noel. The version of events that I gave is what happened and is supported by Dornan and Henderson in their account of NSW electric railways, written close to the events in the 1970s. The deckers came about because they couldn't for various reasons get more capacity out of the system so they felt that they would try instead get a bit more out of the trains while retaining the 8 car length as you say.

It would be difficult to roster the solution you suggest as mostly they're the same lines serving both inner and outer areas. About the only short-distance line you could preserve for single deckers in those days might be the Bankstown/Inner West loop.

Tony P

---InTramsDownUnder@..., <noelreed10@...> wrote :

The original Tulloch built double deck carriages were built to provide greater passenger capacity in a train which could use the existing city platforms. Expansion of the Sydney suburban area meant that commuters would need to travel well beyond the previous electrified lines which ended at Sutherland, Liverpool, Parramatta and Hornsby. The aim was to provide more seats for the longer distance commuters and to leave the single deck trains
for city and short distance commuters.
Noël Reed.