On Thursday, when the temperature reached 42 in Warrnambool and 40 in Melbourne, both the 5.13pm and 7.13pm Warrnambool-bound services were about an hour late.

V/Line spokesman Brad Voss said heat restrictions capping maximum speeds at 90 km/h were in place because the temperature exceeded 36 degrees, which delayed services.

In higher temperatures, the steel railway tracks can expand in the heat.

“Over 36 degrees the speeds are down to 90 km/h,” Mr Voss said.

“What compounded the delays was we had two quite severe signal faults – one at Lara and one at Corio.”

Mr Voss said the 5.13pm service got stuck at Lara for the “best part of 55 minutes”.

He said passengers who believed the air-conditioning wasn’t working had forced a door open on once carriage, and some passengers had been “quite stressed and anxious”.

Mr Voss said the air-conditioning was working, but opening the door brought heat into the carriage.

Passengers on the later service had to catch a train to Geelong, then board coaches for the rest of the journey, which held them up by more than an hour.

Mr Voss said some affected customers had been in touch and V/Line would take care of them.

The disruptions continued on Friday, with six out of eight services between Warrnambool and Melbourne replaced by coaches for most of the journey.

Lara police Sergeant Greg Taylor said police had spent up to two hours preventing cars going through malfunctioning level crossings in the area on Thursday evening.

Standard readers shared their experiences of the disruptions on social media.

Annie Slattery she was one of the unlucky ones stuck on the train, but she said “the air-con was on and we were always kept up to date with what was going on”.

Many readers commented that it was better to be on air-conditioned buses than on the outdated Warrnambool line train carriages.