Safety Advice NRA21-08 - On Track Plant Machine / Crane Controllers



    Machine (and crane) controllers are required by the Rule Book to play an important part in supervising the use of on track plant.

    They are responsible for authorising movements, and checking that permitted speeds are not exceeded and that clearances between machines are maintained.

    They are also an important check on movements over level crossings, across points etc.

    Machine controllers should normally discharge their role on foot, accompanying the item of plant, and must use duplex communications equipment for open-channel communication with the operator.

    Some on track plant is equipped with a second seat. That seat may only be used by the machine controller while they are supervising movements if the seat is designed and installed to provide the machine controller with a clear view in the direction of travel.

    If the second seat does not enable the machine controller to have a view that is at least as clear as the operator, then the machine controller must discharge their role on foot and not ride on or in the machine.

    For Mobile Elevating Work Platforms (MEWPs), the machine controller must never ride in an elevated basket. This is because their role includes emergency rescue using the ground level controls should that be required.

    In certain circumstances (e.g. when movements are required over long distances), movements using ‘send and receive’ controls may be implemented where it has been shown to be safe by a risk assessment.

    Any ‘send and receive’ movements shall be controlled strictly in accordance with the Rule Book and Infrastructure Plant Manual.

    Only in these circumstances, where a machine controller is not required to control the movement, can supplementary seats without full visibility of the line ahead be used to convey the machine controller as a passenger.

    During the COVID pandemic, second seats in constrained, enclosed cabs must not be used as doing so compromises the social distancing requirements.


  • All those with machine controller or crane controller competence must be briefed by their Sentinel Sponsor on the limitations of not using second seats or riding in MEWP baskets detailed in this Safety Advice.
  • Plant Operations Scheme Representatives must check that on track plant operators and machine/crane controllers understand and are following the instructions in this Safety Advice and the Rule Book.
  • Site managers should use site safety checks to test that these instructions are followed.
  • Those planning worksites should consider traverse distances to and from access points for on track plant to make sure safe use does not require excessive walking distances for machine/crane controllers.

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