Imagine this scenario: A case packer loading 25 cases per minute consistently jams several times a day.
Each time, the maintenance team follows the specific lockout/tagout (LOTO) procedure, locking out each isolation point before clearing the jam.
This entire process can take 15 minutes or more including restart time, meaning at least 375 cases are left empty during the downtime.
Multiply that by how many times the machine jams each day or week, and you get a significant amount of money being left on the table.
Wouldn't it be nice if you could clear those jams, or perform other routine, repetitive and integral-to-production maintenance tasks in a way that didn't cut into productivity like full LOTO does?
Fortunately, such alternatives to LOTO do exist, and they are supported by OSHA. They can offer productivity gains while also helping to keep employees safe.
Outlined in OSHA standard 29 CFR 1910.147, alternatives to LOTO are allowed for maintenance tasks such as minor tool changes and adjustments, and for other minor servicing activities provided the alternative measures provide protection as effective as LOTO while under exclusive control of the employee.
ANSI/ASSE standard Z244.1 also allows for the use of alternative measures in place of LOTO for tasks that are considered “routine, repetitive, and integral” to the operation of equipment during production.
These alternative protective measures safeguard machines without having to completely cut off power, allowing workers to service a machine.
This can help improve safety by reducing the incentive to bypass traditional LOTO procedures, and improve productivity by allowing maintenance and operations professionals to perform tasks in a fraction of the time.
Taking the alternate route
Effective alternative protective measures are a combination of safety technologies and procedures – including rigorous risk assessments. The risk assessment should be a thorough review of every mode of operation, and every point of interaction between humans and the machine.
It should also evaluate if the alternative protective measure, such as an interlocked barrier guard or e-stop, will provide protection that is as effective as LOTO.
Let's go back to our original example of the case packing machine that's experiencing frequent jams. With alternative protective measures in place, the maintenance crew can quickly implement safeguards such as zone control to stop or slow production in a designated zone, quickly clear the jam, and get the machine back up and running within 30 seconds.
That's 14 minutes and 30 seconds of uptime being gained back and about 360 cases that can be packed – a significant improvement compared to traditional LOTO.
Implemented correctly, alternative protective measures can provide significant improvements in productivity while maintaining compliance and, most importantly, helping to keep workers safe.
Rockwell Automation will be speaking on alternative protective measures at two sessions during the Safety Leadership Conference next month. Learn more about the sessions and register for the conference here.
DISCLAIMER: Rockwell Automation always recommends users follow proper lockout-tagout procedures when performing service on equipment where no “company approved” safe alternatives have been assessed and implemented. Users must be sure that all maintenance and servicing procedures are safe, effective, and fully tested for compliance with all applicable standards and regulations and in accordance with best practice.
Published August 15, 2016