John Kennedy, the Canberra man named as the driver of the XPT diesel locomotive that derailed at Wallan, sent an email to Australian National University professor Clive Williams on February 3.

The 54-year-old complained to his friend about several train faults and how he had to manage malfunctioning trains.

"My last six Melbourne return trains have been very late or cancelled mainly due to train fault issues," the email read.

"Three of the six runs I was down to one engine, on another trip I had no 'speedo' and the only trip without a train fault was disrupted by the big derailment last week."

It is believed the derailment mentioned in Mr Kennedy's email relates to a freight train that left the tracks on January 29 at Barnawartha, about 200km north of Wallan.

Investigators from the Australian Transport Safety Bureau spent Saturday examining the scene of the derailment, and looking at the maintenance of the train and railway as well as signalling data.

It was reported the train was supposed to slow to 15km/h as it was diverted through a different part of track near Wallan station.

Some passengers from the XPT have said it was speeding when it derailed.

Professor Williams rejected these claims.

"He wouldn't have been speeding. He would only be doing that if the signage was incorrect or he hadn't been informed that the speed limit had been reduced," Prof Williams said.

"He was careful to stick to the speed limit, he wouldn't be speeding knowingly because that's not acceptable."

Work to remove the derailed train started over the weekend.

Three cranes were at the scene of the derailment early on Sunday, starting a wreckage removal process that will last at least three days.

The ATSB is to release a preliminary report in about a month, ahead of a final report in 18 months.

Australian Associated Press