The Hydro Express: Take a train trip back in time to the Blue Mountains

The restored 1950s diesel locomotive 4201 and its six heritage carriages stand waiting at Central's Platform 1.

Attired in my midnight blue flapper dress, boa and sequinned headband, I board the deluxe GMS lounge carriage, a first-class, steel-bodied sitting car built between 1936 and 1938. It's the plushest of the accommodation on offer for a two-hour trip to the Blue Mountains village of Medlow Bath, on the train christened the "Hydro Express" for the day.

The swanky GMS lounge has upholstered seating for 30 people, rosewood panelling and the somewhat new addition of an enclosed observation car. I'm lucky to be sitting next to Wendy Moy, wife of Mike Moy who owns the carriage and lovingly restored it with his son over many years.

The GMS is the rear carriage – dare I say "caboose" among these rail enthusiasts, probably not. Wendy's in her civvies; however, many of the 255 passengers on board have frocked up in Gatsby-style gear to celebrate the last day of the Roaring 20s Festival and all that Jazz, an annual event in the mountains.

I wander from carriage to carriage, from the exclusive lounge car, through the two Edwardian-era premier carriages with their individual compartment-style seating, and on through three standard-class carriages to the front of the train as we hurtle through Sydney's western suburbs and on to the mountains. As I open heavy doors and brace myself as we swish and sway, I pass ladies in their finery, a few gents in spiffing suits and fedoras and meet singer Greg Poppleton serenading passengers in the front carriage. Poppleton is a well-known swing band leader and key performer at the Great Art Deco ball held in Katoomba's Carrington Hotel during the festival. Today, minus his band and old-style megaphone, he's singing tunes of the 1920s and '30s to a rapt and certainly captive audience as he moves from carriage to lounge car.

On arrival at Medlow Bath, we're met by a troupe of dancers doing the jitterbug and as we're about to walk over the railway bridge and Great Western Highway to the Hydro Majestic hotel, the heavens open. The dancers keep up their moves and everyone else picks up the pace, making a dash for the hotel as a sumptuous high tea awaits.

Depending on what class fare is booked, passengers take a seat in either the Wintergarden Restaurant with views over the Megalong Valley or the equally beautiful Majestic Ballroom, which has the most intricate patterned ceiling set off with dazzling chandeliers, but no view. After filling up on delicate sandwiches, cakes and scones and taking an optional history tour of the recently re-opened 1904 property, folks are back on the train and heading home again. There are more snacks on the train, delivered to the seats if the top carriages are booked, and time to snooze or to wander between railcars to view photos of old trains and NSW country scenes of yesteryear.