The Old Quarry is located near the top of Stepney's Branch Line.
When Percy was sent to pick up the The Mayor of Vicarstown, Diesel tricked him into going to the quarry, telling him that the Mayor would be waiting there. Percy set off to the quarry, but became stranded when he ran through a section of flooded track which doused his fire. Diesel returned here to rescue him, but his generator went out when he went into the water. The Search and Rescue Team managed to find and rescue them.