British Transport Police have urged parents to warn their children about the dangers of the railway following the incident on the tracks near Healey Mills Depot in Ossett at the weekend.
The group were seen on the tracks near to Engine Lane at around 3pm on Sunday, around an hour before the driver of the 3.05pm Bradford to Kings Cross service reported striking a wooden sleeper which had been placed across the tracks in the same location.
No-one was injured and no damage was caused to the train.
A BTP officer later discovered a number of items, including the sleeper, had been placed on the tracks and there was damage to parked vehicle nearby.
Police are now stepping up patrols in the area.
Inspector Caroline Farrow said: “The last thing our officers want to do is knock on someone’s door to tell a parent their child has been killed or seriously injured as a result of messing about on the railway.
“The railway environment is extremely dangerous and trains, which can be silent, travel through this area at speeds of over 90mph.
”Please make sure your children are aware that the railway is an incredibly dangerous environment and remind them to stay away from the rail network, it’s not a playground.
“Those children seen trespassing may believe they can place things on the tracks before a train comes, however trains travel extremely fast and all it takes is for them to slip or trip and they will not be able to get out of the way in time. Children need to understand that what may seem to them as a fun or a game can be deadly to them and others.”
The warning comes following a renewed appeal by the BTP to stop children trespassing on tracks.
Statistics show young people are twice as likely to trespass at this time of year as in the winter. In the last year there has been a 25 per cent rise in the number of reports of trespass over the summer in the Yorkshire region.
Insp Farrow added: “We’re doing all we can to keep young people safe by patrolling areas where we know they’re likely to trespass and prevent them from doing so. However, we cover thousands of miles of track and we cannot tackle this issue alone.
“That is why we are urging parents and young people to heed this warning and take a reality check when it comes to trespass. It’s not a game: they are real tracks, with real trains and real life consequences.”
Vicki Beadle, community safety manager for Network Rail, said: “The railway is not a playground and mindless acts like this could have life threatening consequences not just for those who are trespassing on the railway, but for the passengers travelling on board trains. I am urging parents to know where there children are, especially during the final days of the school holidays, and to make sure they know the dangers of playing on the railway.”
Anyone with any information should contact British Transport Police on 0800 405040 or by text on 61016 quoting reference 296 of 21/8.