A Pacific National coal train has derailed in the Upper Hunter less than two weeks after an unmanned train operated by the same company ran away unmanned.
The Australian Rail Track Corporation (ARTC) confirmed it was notified of the derailment just before midday on Monday and was working to clear the tracks after initial investigations.
It is understood the lead wheel of a loaded Pacific National coal train came off the tracks at Ardglen Loop, a section of line between Scone and Tamworth just north of Murrurundi.
Pacific National confirmed one of its trains was involved in an incident at the Ardglen Loop on Monday.
A spokesperson confirmed six wheels on the lead locomotive derailed as the train was pulling up and all locomotives and wagons remained upright.
"There were no injuries to the train crew and the train was safely secured," he said.
The incident resulted in temporary disruption to rail traffic through the area, with services to the Gunnedah Basin resuming on Tuesday.
"Pacific National notified the relevant authorities, including the Office of the National Rail Safety Regulator, and is cooperating fully with the investigation into the incident," the spokesperson said.
Pacific National said determining the circumstances of the incident will be a matter for the investigation process.
"Safety remains Pacific National's highest priority.
"We continue to work closely with rail infrastructure managers, regulators and other stakeholders to ensure the safe operation of our services across the network, including in the Hunter region.
"We will consider any findings and recommendations arising from the investigation and take any actions that may be required."
The derailment follows a runaway train incident on July 25.
A fully-laden, unmanned Pacific National locomotive took off during a crew change at Camberwell and reached speeds of up to 90km/h.
It travelled about 10 kilometres before coming to a stop near Glennies Creek, at Nundah Bank, about 1am.
The Newcastle Herald understands the incident was triggered when the locomotive's onboard computer detected a fault with the braking system and brought the train to a stop.
Two crew members had stepped outside the locomotive to try to rectify the fault when it suddenly took off, leaving one crew member stranded on the train's 11th wagon as it began moving.
The runaway 10,000-tonne train's speed as it rolled downhill prompted the network operator to issue an emergency warning to other trains in the area.
"If the XPT was coming in the other direction it would have been wiped out," A source familiar with the incident said
The rail corridor was closed for several hours, with the incident stopping coal and passenger movements for about 36 hours to allow investigators to gather evidence and assess the circumstances before normal services resumed.
"There were no injuries to our crew or any members of the public, and there was no collision or derailment," a Pacific National spokesman said at the time.
Pacific National notified the Office of the National Rail Safety Regulator (ONRSR) and ARTC network control, and ONRSR confirmed it was investigating.
The July runaway prompted the North Sydney Transport Association (NSTA) to call on Pacific National to review and strengthen its safety procedures.
NSTA called for the operator to introduce additional operational requirements, including ensuring crew members do not exit locomotives or trains in operational environments without another authorised person present and on board where practicable.
"Rail safety relies on layers of protection. While incidents like this are obviously quite uncommon in this day and age, every opportunity to improve safety procedures, especially on non-passenger networks, should be taken seriously," NSTA president Lachlan Steenson said.
NSTA's head of the commission in the Newcastle Region, Sylvia Duong, said operators should not be relying on chance to keep heavy rail operations safe.
"Operators shouldn't have to rely on luck when it comes to the safe operation of heavy rail. Ensuring workers, in such a freight-heavy region as the Hunter, have appropriate support and backup when performing safety-critical duties should be a priority across the industry," Ms Duong said.
The association also called for greater transparency from freight operators regarding safety reviews following significant operational incidents.
The Ardglen Loop section of track, on the Liverpool Range grade between Murrurundi and Werris Creek, has been the site of previous Pacific National derailments.
They include a 2015 incident in which 19 wagons derailed near Kankool after a loaded coal train failed to apply sufficient braking on the descent.
Correction: A previous version of this story published August 11 stated: "A source familiar with the incident said the runaway train had come close to a head-on collision with a passenger service."
ARTC has since clarified there were no passenger services in the area at the time of incident.
"ARTC takes safety on its network seriously and is supporting ONRSR in its investigation," a spokesperson said.
