Manufacturing Group pauses to reflect on lives of Hill and Overman, receive reminder on importance of safety

ARNOLD AIR FORCE BASE, Tenn. – A plaque bearing the names and images of John T. Hill and Alvin D. Overman now occupies a small space next to the bay door of Building 446 at Arnold Air Force Base.

The plate reads, “In Memory of the men who lost their lives in service to AEDC at the Model Shop.” Inscribed at the bottom is a date – December 10, 1971 – the day the lives of both Hill and Overman were tragically claimed by a silent killer.

Manufacturing Group employees at Arnold AFB gathered late last month to remember the lives of two of their own more than 45 years after their deaths, as well as to be reminded to focus on safety while carrying out potentially dangerous work at AEDC.

“Every day, about 1,600 employees here at AEDC come to work just like Mr. Hill and Mr. Overman thinking that they’re going to go home to their families in as good a condition or better than they came,” said Warner Holt, Test Operations and Sustainment contract group manager of manufacturing. “But the stark reality is that’s not always the case. We do have hazards out here that can kill.”


It was two weeks before Christmas in 1971 when Hill and Overman, along with another employee, were tasked with working in an offline furnace in Building 446, which is located just behind the Model Shop. This work required entering a pit area, otherwise known as a confined space.

“At the time, we didn’t have the technology that we have today,” Holt said. “We didn’t have O2 meters. We didn’t have the requirement to follow procedures. We didn’t even have a lot of the confined spaces marked at the time. So they were unknowingly in great, great danger.”

Hill, 41, entered the furnace first. He quickly fell unconscious.

“Just a few seconds after he entered the area, he was overcome by argon gas that he didn’t know was there,” Holt said.
Overman, who was serving as a lookout for Hill, observed his Model Shop colleague fall. The 51-year-old Overman reacted quickly, entering the furnace to assist Hill. Like Hill, he was unaware that argon gas, which is both colorless and odorless, had leaked into the furnace and settled at the bottom of the confined space. Also like Hill, Overman lost consciousness within seconds of entering the furnace.

Attempts to revive both men were unsuccessful.


The May 29 memorial, held on the site where the two Model Shop employees were killed, was coordinated by the Model Shop Safety Leadership Committee, and most of the details for the event were orchestrated by Tim Scott, Machine Shop planner/scheduler. Along with having the opportunity to reflect upon the lives of Hill and Overman, the time was used to hold a brief post-Memorial Day holiday stand-down, during which Manufacturing Group employees were urged to keep safety in mind and follow procedures, especially when entering confined spaces.

The deaths of Hill and Overman represent two of the 16 recorded deaths that have occurred at Arnold AFB since 1958, with the last occurring in 2001. In a memo sent to company employees just prior to the Memorial Day holiday, Cynthia Rivera, general manager for the TOS contract at Arnold AFB, pointed out these fatalities occurred on nine different calendar days, adding that seven of the nine days were within eight days of a holiday. Two of the fatal injuries were within six days of Memorial Day.

“Our Human Performance Improvement tools teach us that actively addressing error precursors can prevent accidents,” Rivera wrote. “Error precursors such as mindset, stress, distractions, and time pressure can all be present around holidays. We need to take the time to recognize these precursors and actively work to mitigate them to avoid injuries and equipment damage.

“We need to pay attention to our mindset and stress level. Observe if our colleagues seem distracted. Address it with them. Be aware of the time pressure that we, our customers, and the nature of our work place on us. This just adds to the stress and potential time pressure from external sources associated with holidays.”


The timing of the memorial was appropriate, as the AEDC Safety Focus for May pertained to working in confined spaces. Throughout the month, the Safety, Health and Environmental team conducted annual assessments of confined spaces, focusing on identifying such spaces and ensuring each is clearly marked with proper signage.

There are approximately 1,600 confined spaces across Arnold Air Force Base.
Those trained to work in and around confined spaces must meet requirements for entry into confined spaces, per SHE Standard B5. These include having the atmosphere tested by trained personnel, the documentation of a Confined Space Work Instruction or Permit for each active entry, adequate ventilation being provided, having retrieval/rescue equipment available at the entry point during active permit required entries, and confined space attendants maintaining continuous communications with entrants.

The deaths of Hill and Overman occurred less than a year after the Occupational Safety and Health Act was signed into law and more than 20 years before the OHSA regulation pertaining to permit-required confined spaces became law.

OSHA Standard 1910.146, which became law in January 1993, requires the testing of the air, development confined space permits to identify hazards in confined spaces, identification of spaces with signage, training for those involved in the entry process, standby emergency rescue, and other requirements in place at Arnold AFB today.

“Prior to the standard, we sampled the air because it was the correct thing to do to protect our workers,” said Bingham Bragg, Industrial Hygienist at Arnold AFB. “Through the years, technology improvements in monitoring equipment has also allowed better real-time measurement of atmospheric hazards that keep the workers safe. Where we used to have only an oxygen meter or LEL meter to evaluate atmospheres, we now have multi-gas meters that are able to measure other possible hazards such as carbon monoxide, hydrogen sulfide or nitrogen dioxide.”

Bragg added that recognizing the potential hazards in the space, following the work instructions, and being aware of one’s surroundings are most important to the safety of those involved.

“When I read where there has been a death in a confined space somewhere across the country, it seems to come down to someone not recognizing the hazard, having no training and not complying with OSHA,” he said. “OSHA regulations have become law to protect us from ourselves. When we follow it, we usually go home safe.”


During the memorial, Holt encouraged workers to pay close attention to the task at hand and not take shortcuts. He said employees should maintain a questioning mindset when carrying out their duties.

“If it’s in doubt, we don’t do the job,” Holt said. “And if we see something unsafe, we stop the job. We stop the work before somebody gets hurt or even worse, because it can happen.”
Ironworker Kevin Glaser also spoke during the memorial and led the group in a prayer in honor of Hill, Overman and other AEDC workers lost over the years. Both he and Holt said employees should strive to look out for one another.

“Let’s understand that we are our brother’s keeper,” Glaser said. “We do watch out for each other. That’s our responsibility.”

Doug Pearson, deputy general manager for the TOS contract, addressed the Manufacturing Group workers during the memorial. He asked employees to follow safety procedures and to always take the necessary precautions.

“From the company standpoint, there’s nothing that we do that’s worth your life,” Pearson, a retired Air Force pilot, said. “We’re not in combat. When I flew fighters, I wore a parachute over 1,000 times, every time I flew. I used it one time. Wear your hardhat. Wear your gloves. You many only need them one time, but that one time may save your life.”

Both Holt and Pearson also emphasized the importance of reporting and addressing “near miss” safety incidents. Pearson said doing what it takes to prevent relatively minor incidents may prevent more serious events from occurring in the future.

“If we put the emphasis on everything from papercuts to broken fingers, then perhaps we can prevent the next fatality,” Pearson said. “I would encourage you to do that.”
Pearson urged employees to take care of one another and to participate in briefs about the jobs to be performed, including discussions of potential issues and how to react should an incident occur.

“As many of you have heard me say, there’s probably nowhere so few people have such a distinct influence on our nation’s defense,” Pearson said. “From here, we decide and build the future programs that are going to take our sons and daughters into combat and, more importantly, bring them out safely. That’s a great contribution, and we need you here to do that.”



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