Scaled Management Systems

Guard for metal spinning lathe


The flat belt drive on a metal spinning lathe was not guarded and an accident occurred when the operator was changing the belt speed while the machine was running down.

The machine was not guarded because of the need to regularly change the belt speed by hand. It was not practical to buy new machines with automatic speed adjustment.


To comply with legal requirements and to prevent more accidents, a fixed sheet steel guard was installed to prevent access to the belt drive system when it was operating at full speed or running down.

The guard has a number of features which provide safety whilst still being flexible enough to allow the operator to change belt speeds frequently.

Hinges in the middle of the guard allow half of it to lift up, thereby exposing the front or rear shafts. Hinges also run along the side of the guard allowing it to be flipped sideways to expose the entire belt drive system. The guards are bolted in position to prevent the guard being opened before the transmission stops. Because of the age of the machine it was not possible to install time delay interlocks.

The engineering changes were combined with instruction and training of operators.

Hierarchy of Controls:

Engineering and administration (SOP / training)


  • The guard makes work on the lathes and the changeover of belts safer.
  • It conforms to current legal requirements whilst allowing easy access when a changeover is necessary.
  • The guard design was introduced on the company’s remaining metal spinning lathes.
  • Employees and maintenance personnel improved the isolation, lock and tag-out procedures.