A large metropolitan zoo maintenance employee may have disabled a warning light on a small train that derailed in 2009, sending 22 people to the hospital. The records are part of the evidence to be used in a February 2012 trial in which plaintiffs claim the zoo was negligent in its maintenance and operation of the train. According to records, a maintenance worker saw a co-worker remove the bulb to an emergency warning light about a year before the accident. She said he did it because he could not get it to work and wanted to avoid calls about it, since the brakes were working well. Records also show that a warning buzzer also had been disconnected, although it is unclear who was responsible.
The maintenance worker denied lying and denied disabling the warning light. He also testified that he never asked other employees to lie on his behalf, and said his co-worker was retaliating against him because she had been replaced as his assistant. The worker testified that he wanted to sidetrack the train and fix the buzzer and warning light but zoo officials wanted the train to keep running because it was making money. Both employees were fired in May 2010. Because the emergency warning light had been removed and the buzzer disabled, a supervisor who checked the train the morning of the accident admitted in a deposition that the train should “never have left the station”. After an investigation, the Department of Agriculture fined the zoo $37,000 and attributed the wreck to the poor condition of the equipment and inadequate driver training. Defense attorneys for victims say the disabled warning light and buzzer could have alerted the driver to problems. “To have safety devices go unfixed for at least a year shows gross negligence and reckless disregard for the life and safety of children and others,” said Ronald Hillerich, who is representing eight passengers. Zoo attorneys declined to comment.
Now for the hard part… we need to ask ourselves:
- Are our safety systems designed to be “fail safe”, meaning that if they are not fully operational the machine/equipment will not operate?
- Are our safety systems in an established preventive maintenance program that includes “functional testing” of the systems by trained personnel?
- Are our safety systems functionally tested on a prescribed time frame?
- Are the personnel who do the PM inspection on the systems have established procedures and protocols to follow to ensure the tests are being done properly?
- Are the personnel who do the PM inspections on the systems trained on the established procedures and protocols?
- Is this training on a refresher schedule to ensure personnel receive training on the procedures and protocols every X (period of time)?
- Does the established PM program contain an “audit” element where randomly selected work orders are audited to determine if they are being completed per procedure or being “pencil whipped” in order to make the “WO % Complete” numbers look more favorable?
- Has our facility conducted an “interlock audit” on the critical systems to identify interlocks/alarms that may have been “jumped out”?
The next time we are out in our plants and we walk by a control panel, or even just a single safety switch, and we see all the red, green, blue, yellow, lens covers, we need to ask ourselves:
- How would we know if a bulb was removed or burned out?
- Is there an audible alarm that goes with the visual alarm and is it functioning?
The scenario that happened at the zoo is NOT A RARE occurrence involving Safety Instrumented Systems. I can not count the number of times I have come across defeated interlocks, bypassed interlocks, and overridden interlocks and alarms. On annual basis we find workers injured because someone had “jumped out” an interlock with a simple wire and two alligator clips! The employee was using the interlock in lieu of locking out the machine and when they reached in the machine it cycled and they receive an injury! And folks, these alligator clip jumpers can “jump out” even the most complex safety system in a matter of a few seconds! Another failure of our safety systems is the following… Next time you get your maintenance team together, ask them to empty their pockets on the table. See how many of them have “operation key blanks” on their key chain. This is a VERY COMMON practice at facilities that use true safety switches that are “keyed” in order to make them more secure. These safety switches prevent items like paper clips, screwdrivers, string, etc. from being able to defeat the system. So instead, all the maintenance personnel have “operations key blanks” in their pocket so they can “bypass” the safety system in order to “trouble shoot” the problem. PLEASE NOTE: a properly installed certified safety switch will NOT allow this blank key to work, but workers have figured out how to bypass this and to trick the system to function with the blank key inserted into the switch!
Either way, whether removing a light bulb or using jumpers, we are BYPASSING a critical safety system! We should NEVER assume “our employees would never do such a thing”, as we are ALL HUMAN and thus we are ALL FALABLE! Instead we MUST have in place an audit system that will keep everyone honest. We should also have a written policy that forbids any employee from defeating a safety system and have in place a “permit system” to manage this when it is necessary. Audits need to be carried out by personnel OTHER THAN those who work on the systems and they need to be done on an ESTABLISHED, yet VARIED, time table so as no one will be able to manipulate the audit results. We should be able to identify all our safety instrumented systems as they should be established within our maintenance system already.
Bottom line… the zoo train accident should have NEVER occurred, nor should the situation that allowed it to occur been allow to exist for one year. We need to have management systems that are intertwined to ensure that personnel are properly trained, procedures are established, and audits conducted to follow-up on these system requirements. After all, when we ASSUME something, it just make an ASS out of U and ME!