MSHA's Accident Prevention Program
"Stopping Conveyors in their Tracks"
Conveyor rollers have been developed that are designed to prevent a belt from running backwards down an incline in the event of a belt break. The rolls contain internal braking elements, which are activated by reverse movement of the roll. The number of rolls required depends on the incline, load, and belt characteristics, but generally about half of the carry side rolls are replaced. The braking components are not normally load bearing, so additional friction at start-up and during operation is insignificant.
From a safety standpoint, stopping a fully loaded conveyor belt from running backwards could reduce hazards caused by material being thrown from the belt or piling up at the bottom. Damage to structures at the bottom of the conveyor could also be reduced or eliminated. The rolls would also add additional protection over a backstop, since backstops do not function unless the head drive moves backwards, which does not normally occur when a belt breaks.
For information on manufacturers that are known to MSHA to have such products available, contact MSHA's Applied Engineering Division at 304-547-2303 or e-mail zzMSHA-InnovativeProducts@dol.gov.