MRO Today - Haul monitors in confined spaces

Haul monitors
Electronic personnel monitoring systems are a cheaper and safer way to protect crews working in confined spaces

by Barry White

Most deaths in confined spaces occur because no one knew there was a problem inside the space (hazardous atmosphere, heart attack, etc.), and when they found out, it was too late to get the worker out and save his or her life.

In a recent confined space accident in Illinois, for example, four employees were killed when highly explosive gas leaked through a faulty valve into the space. The attendant did not know of the change in the atmosphere, and only the fire and explosion notified him of a problem.

In another case, a worker doing routine maintenance in an airplane fuel cell died of asphyxiation. The cell he entered had been purged with a non-explosive gas. The gas lessened the hazard, but depleted the area of oxygen.

To try to prevent these dangerous situations, the Occupational Safety and Health Administration (www.osha.gov) issued the confined space entry standard (29 CFR1910.146). It requires monitoring of a confined space's atmosphere before an entry is permitted and continuous monitoring during the entry to be sure the atmosphere remains safe. In addition, an attendant must be stationed outside each permit-entry confined space, ready to help the entrant in the event of a hazard. The attendant must listen, communicate, warn the worker to exit the space if necessary and
call for help. He must never enter the confined space.

The concerns this regulation present for maintenance or production managers are numerous. The most significant one is cost. If a manager opts to station an individual outside each entry location, salary and benefits are paid for non-productive work.

In many operations, contractors are hired to perform maintenance in confined spaces. In these cases also, money is spent on hourly wages for a hole-watch person who does nothing other than stand outside a confined space to watch and listen.

Fortunately, there are proactive, safer and less expensive options for continuous personnel and atmospheric monitoring.

Technology to the rescue
Under the confined space standard, OSHA permits the use of an electronic attendant, if that equipment can perform the duties of a human attendant (listening, communicating, monitoring, etc.).

Workers entering confined spaces can be monitored by an electronic attendant that never rests, never leaves for the bathroom, never falls asleep, and is always there to watch and help.

In addition to permitting the use of electronic monitoring -- and here is where the cost savings can be appreciable -- OSHA permits the electronic monitoring system to monitor the well-being of more than one worker, so there is no longer the need for a one-on-one relationship between attendants and workers.

Some electronic systems used at large facilities monitor an entire confined space entry crew at the same time. Consequently, workers formerly used to monitor entries are freed to perform productive work.

The most effective systems operate by providing a small personal monitor that the entrant carries into the confined space. The personal monitor is a radio/computer device that constantly reports to a monitoring computer console located in the facility. The monitor can be used as far as two or three miles from the confined space. The most sophisticated systems are wireless.

How does it work?
Monitoring systems provide full-time radio communication between attendants and workers. The worker's personal monitor status is verified every few seconds to maintain a constant link.

At a predetermined time, a loud signal is sent to the personal unit. The signal requires the worker to respond (by pushing a button that says, "I'm OK"). The console attendant can contact an individual or any number of workers to communicate needed information or alarms.

An effective system can also be connected to a company's portable gas detection or other sensors to provide continuous environment monitoring. Readings are displayed on the monitoring computer's screen, and at the point where predetermined levels are reached, alarms are triggered. The worker is contacted and told to exit the space. The system fully documents all activities, such as alarms, and telemetry readings for analysis and reporting.

Conclusion
The value of these electronic systems is their constant monitoring, dramatic reduction in cost and increase in worker safety.

While such systems may not be cost-effective for small companies where there is seldom more than one entry being made at a time, often the reduction in risk in the worker's safety is worth the expense of installing such a system.

It only takes one fatality, one huge lawsuit or one large OSHA citation to cost much more than an always-alert electronic monitoring system.

Barry J. White is a former regional administrator and director of safety standards with Federal OSHA. In that latter position, his office wrote the confined space entry standard (29 CFR 1910.146). He currently serves on the board of directors to Safe Environment Engineering, creator of the Lifeline Monitoring System.

This article appeared in the August/September 2000 issue of MRO Today magazine. Copyright, 2000.