A week after one of the biggest public transport timetable overhaul, rail passengers are taking more journeys than they would like on older "S-set" trains without air conditioning.
Dating to the 1970s, S-sets have been put to use in greater numbers on several lines to accommodate an extra 1500 weekly services introduced as part of the timetable changes.
A leaked Sydney Trains document shows an increase in the use of S-set trains during peak periods on the South and Inner West, Bankstown and Airport and East Hills lines.
The Inner West and South lines have the most during peak periods of the day with eight S-sets operating in the morning and six in the evening.
First rolled out in 1974, the S-sets are the oldest carriages in the Sydney Trains fleet.
And as the only trains in the fleet without air-conditioning, passengers find their journeys on them uncomfortable during the height of summer.
A spokeswoman for Transport for NSW said the S-sets would be relied on "to ensure we meet the ever increasing demand for our services".
The O'Farrell government had the option of ordering an extra 20 Waratah trains in 2013 but decided against exercising it, leaving Sydney train commuters stuck with the non-airconditioned carriages for years.
While the S-sets are now in greater use, they have not been distributed evenly across Sydney's suburban rail network. None operate on the North Shore, Northern or Western lines.
Labor's transport spokeswoman, Jodi McKay, said the greater concentration of S-sets on certain lines represented a "double whammy for Western Sydney commuters who face longer journeys ... sitting in out-of-date and uncomfortable carriages without air conditioning".
But a spokeswoman for NSW Transport Minister Andrew Constance said customers on lines serviced by S-sets would be the first to benefit when the new Waratah trains arrive next year.
Speaking to the Herald, several commuters expressed surprise and frustration at the impact of the timetable changes on their daily commute.
Rajeev Gupta, who travels to the CBD for work from Homebush, said he had to travel on S-sets on every trip since the new timetable was introduced just over a week ago.
"It's hot and humid - you hardly get a place to sit, and people are struggling," he said.
Enrico Somaschini, who travels from St Peters to Wynyard and faces a longer trip to work because of the timetable changes, said: "I don't know why but from Monday we've only had old trains."
Other commuters also said services were more crowded during peak periods.
Lauren Edwards, who commutes to Kogarah or St Leonards, said: "They've cut some trains and the ones that do come are over-capacity ... it's not improved it at all".
However, others had far less chaotic experiences with the timetable updates.
"I haven't actually noticed them, to be honest", said Alyssa Glass, of St Peters.