Yobs placed rotten wooden sleepers on the railway line near Heysham which were hit by a train.
British Transport Police were patrolling near the scene on August 8 when the accident happened.
A spokesman for British Transport Police said: “We received a report that a train had struck railway sleepers placed on the line near Heysham Port station on Monday, 8 August at around 1.50pm.
“Luckily they were rotten and didn’t cause damage.
“The service was briefly stopped but no delays resulted.
“Anyone who has any information regarding the incident should contact us on 0800 405040 or text 61016 quoting reference 284 of 8/8.”