The hydraulic cylinders allow the Rail Foot Thimble to securely grip the base of the rail section to accurately guide it into place.
A special mechanism automatically withdraws the rollers a precise amount and locks the hydraulic cylinders as the rail is lifted. In this way the rail is made free running and damage due to welds and rail defects is lessened.
Rail cannot be released from the Rail Foot Thimble without first lowering it – a unique safety feature in rail threading devices.