Archive index
Fleet
The 4D prototype
Melbourne’s experimental double-deck train and its place in the Hillside fleet allocation.
A single prototype
The 4D was a double-deck suburban prototype. It appears in historical fleet summaries as part of the original Hillside allocation alongside Hitachi and Comeng stock.
Why it belongs in the archive
A fleet allocation records responsibility for equipment at a point in time. The presence of the 4D in that list shows how an experimental vehicle passed into the franchise era. The core suburban fleet continued to consist of single-deck sets.
See the fleet comparison for the trains that formed the bulk of everyday services.