FOPS is an acronym for Falling Object Protection System. These are fitted to construction plant and mining machinery were there is danger of objects falling on the operator from above. They are different from ROPS which is a frame to stop the operator being crushed in event of a roll over accident. In modern machinery the two systems are often combined with the cab structure rather than being a separate structure over the cab.
Machines such as excavators are fitted with an additional heavy metal frame over the cab with thick bars to stop object hitting the cab. in some applications (mainly demolition) the can may be fitted with 'bullet proof' glass to protect against flying fragments (this glass is a multilayer laminate) instead of the normal toughen glass fired in vehicle that shatters on impact.
Modern cabs often combine FOPS and ROPS in the cabs basic structure. but machines fro special applications then have separate cab guards fitted to the windows for additional protection on jobs such as forestry or demolition work.
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