ROPS, or rollover protection structure, are cabs, frames or bars that protect operators in the event of a rollover. According to Consumer Reports magazine, in 2007 there were 61 deaths and 15,000 reported injuries on zero-turn mowers. The most common scenario attributed to zero-turn mower death is the mower overturning and the operator being crushed beneath it. ROPS is designed for use with a seatbelt, to protect the operator when the mower is in use.
Operators sometimes lower their ROPS to ensure that they can get under low-hanging vegetation or around tight turns—but in these cases the risk of the operator is significantly increased. While it’s important to ensure that ROPS and the seatbelt are in use by all of your operators, there are also other ways to protect against the event of a rollover. The Occupational Safety & Health Administration (OSHA) offers a risk assessment for what equipment should be used on different terrains.
- 0° to 15° slope – riding mowers or tractor mowers are approved for these areas
- 15° to 22° slope – tractor mowers are approved for use on these areas
- 22° and up slope – these areas are mowed with string trimmers, push mowers or specialized equipment; specialized equipment can be riding mowers intended for use on slopes
- Within 5 feet of a drop-off – a buffer zone is maintained; only string trimmers and push mowers can be used inside this zone
Zero-turn mowers should not be used on any sort of slope that the operator is unable to back up on when the cutter deck is down. They also should not be used with slopes that are wet from rain or watering because the slick grass makes it harder for the mower to maintain traction. Mowers should also be used at a steady and consistent pace, because making turns or adjustments at high speeds only increases the chance of a rollover.
The majority of zero-turn mowers are now outfitted with ROPS or operators have the choice of attaching it. Any mower that offers ROPS should not be used without it. While sometimes it may slip operators' minds, they should always ensure that before they begin mowing, that ROPS is engaged and that the operator is using a seatbelt.
Sometimes there could be a need to fold the bar down, such as when mowing around trees with low-hanging branches. If that is the case, a good approach might be to first mow those areas with the bar folded down (as long as you're on flat terrain), and then raise the ROPS back into the proper "up" position to finish mowing the rest of the property.
Information taken from these sources: