The incident - which happened on August 27 at 8.48am - has been unknown to the public until independent regulator the Rail Accident Investigation Branch released a report on the government website last week.
The train, carrying a crew and 25 passengers, was travelling from Huddersfield to Sheffield at a speed of 20mph when it struck the stabiliser, south-east of Penistone station.
The stabiliser legs had been deployed as the lorry’s crane was being used to lift portable toilets onto its flatbed.
Central Rail Systems Alliance (CRSA) had been responsible for the work being carried out on the line - and had confirmed with the haulage lorry driver that the vehicle was in the right place - before the train approached and struck the lorry’s front-nearside stabiliser leg,” the report said.
“The driver then sounded his horn to give a warning but hadn’t seen the stabiliser legs, so carried on accelerating.
“As the train got closer the driver noticed the leg was close to the track and applied his brakes, striking the lorry five seconds later.
“The stabiliser was damaged, as well as the front and side of the train.”
None of the train crew, passengers or workmen with the lorry were injured in the incident but the accident ‘has raised important safety concerns’.
The report said the accident ‘demonstrated the importance’ of workers within the railway following procedures - particularly when supervisory staff aren’t present - and organisations having a clear understanding of the requirements when work is taking place with road vehicles on the line.
A controller of site safety (COSS) was required to be there but while the CRSA member of staff held a personal track safety competency (PTS), no-one who held the COSS competency was at the site at the time of the incident.
“No part of a road vehicle should be allowed within two metres of any line on which a train might approach,” the report added.
“In this case, however, one of the lorry’s stabiliser legs was much closer than two metres and was in fact foul of the nearest running line.
“After the train came to a stop, the driver made an emergency call to report the accident.
“The train was later moved to Barnsley, from where the passengers were able to continue their journeys.”