Submitted by Loretta Sorensen
Keith Bolsen, professor emeritus at Kansas State University, says very emphatically that, “Silage avalanches happen… believe it!”
Bolsen has spent years working with the feedyard industry in the U.S. to raise awareness about the safety hazards found around bunker silos and silage piles. He can share one story after the other about employees, nutritionists or bystanders having a near-miss incident or being injured in a silage avalanche. Many survivors have shared their stories with him. But not everyone lives to talk about their experience.
“An avalanche happens without warning,” Bolsen said. “In a fraction of a second, part of a silage face can silently break off and fall. It can be deadly for anyone located beneath it.”
Taking samples from a feed-out face is a common practice in feedyards, but one that can quickly lead to tragedy. Mac Rickels, a nutritionist in Comanche, Texas, had done this many times without any trouble. But one day, after taking a sample from a 32-foot high feed-out face, Rickels was standing about 20 feet away when 12 tons of silage collapsed on him.
“His chest hit his knees with such force that it shattered two of the bones in his leg,” Bolsen said.
Fortunately, a farm employee saw what happened and pulled Rickels out of the silage. Later, Rickels said he didn’t hear or see anything before the avalanche hit him.
“He acknowledged that he had become complacent about working around silage because nothing ever happened, until that one time,” Bolsen said.
Bolsen, who regularly visits dairies and feedyards, says he sees far too many 20- to 25-foot high feed-out faces in bunker silos and silage piles. It’s common sense to realize that a silage face that exceeds 20 feet tall is far more dangerous than one that is only 12 to 14 feet tall.
“A necessary part of my job is collecting silage and high-moisture grain samples,” said Al Kruse, a beef cattle nutritionist from Sterling. “In the spring of 1983, I was collecting a sample of high-moisture grain sorghum in a bunker silo at a feedyard. I had performed this task hundreds of times before and never thought about being in any danger.”
As a feedyard employee and Kruse approached the feed-out face, it suddenly collapsed and buried Kruse. Fortunately, the falling grain didn’t hit the employee. The heel of Kruse’s boot was exposed, and the employee pulled him from the ensiled grain.
“I sustained only minor injuries and spent 24 hours in the hospital for observation,” Kruse said. “The ‘buddy rule’ saved my life that afternoon.”
No silage pile is completely safe. Tulare, Calif., dairy nutritionist Doug DeGroff pulled samples from a 12-foot face, then turned to walk to his pickup.
“The sun basically went out,” DeGroff said. “I couldn’t see any light and the feed covered me completely. I knew what was happening before I hit the ground. The entire face fell on me, about 20 tons of silage. I remember thinking, ‘I don’t want to die here today!’”
Fortunately, DeGroff was able to brush the silage away from his face and call for help.
“A nearby dairy employee pulled me from the pile,” DeGroff said. “I am blessed to be here, and everything works. I am physically, mentally and spiritually healthier today than I was on the day of the accident.”
DeGroff thought feed-out face looked safe from every angle, but he was wrong.
Richard Porter, owner and manager of Porter Cattle Company in Reading, Kan., thought his pickup should be safe when he parked it about 12 feet back from the face of a bunker silo that was about 14 feet high.
“While I was standing about 30 yards away talking to an employee, the silage collapsed,” Porter said. “It hit the hood of my truck hard enough that you could clearly see the outline of the air cleaner.”
Porter’s experience supports the recommendation to stay much further away from a silage feed-out face than the face’s height.
Suffocation is generally the cause of death in a silage avalanche. Anytime someone works alone around a bunker silo or silage pile, an avalanche can be especially deadly because, once buried in several feet of silage, chances of surviving the avalanche greatly decrease within just a few minutes.
Undercutting a feed-out face by digging into it with a loader bucket usually creates a dangerous overhang of silage that can break loose. This scenario is common when the height of the silage in a bunker or pile is greater than the loader can safely reach.
“If a loader must be driven close the feed-out face in an over-filled bunker or pile, the buddy rule should be strictly enforced, no exceptions,” Bolsen said. “Silage samples should be obtained from a loader bucket at a safe distance from the feed-out face.”
Vehicles should be parked at least three times further from the feed-out face than its height. Any time a new silage crop is packed against existing silage, clearly mark the point where the two silages join, and use caution when the feed-out face approaches the joined area.
Bolsen recommends posting warning signs around bunker silos and silage piles to remind workers and any bystanders of the unseen dangers posed by the silage feed-out face. The sign should read, “Danger! Silage Face Might Collapse.”
If a bunker or pile is located in a remote area, the perimeter should be fenced and a sign posted saying, “Danger: Do Not Enter. Authorized Personnel Only.”
To reduce the risk of an avalanche, avoid filling bunker silos and building drive-over piles to excessive heights. Never work or stand closer to a feed-out face than three times its height and take care not to become complacent.
Bottom line. Never think an avalanche cannot happen to you.
“Accidents are caused by unsafe behavior or conditions due to the actions of people,” Bolsen said. “There has never been an unavoidable silage-related fatal accident. Learn all you can about silage safety practices and make them part of your daily routine.”
The only thing predictable about silage-related accidents is that they have and can result in serious injury or death. Bolsen offers some simple steps that can help silage safety become a reality in feedyards.
“Start with a plan and have written silage safety guidelines that are posted in break rooms or other areas where employees meet. The guidelines should be clear, consistent, and easy to understand. A hard copy of them should be made available to all employees,” Bolsen said.
Secondly, hold regular meetings with the silage team, which would also include chopping, packing and covering contractors. The meeting should include discussion of safety expectations in the feedyard’s silage program.
Thirdly, use zero tolerance when enforcing silage safety guidelines, and reward all employees for safety compliance and accident-free time periods.
Four common hazards encountered when managing silage in bunker silos and piles at feedyards include:
• Complacency/not paying attention
• Entanglement in machinery or equipment
• Exposure to silo gas (nitrogen dioxide)
The long hours of harvesting, transporting, filling, packing and covering silage in bunkers and piles increase the risks of fatigue, drowsiness and even illness.
Bolsen believes the following guidelines help minimize the risk of fatigue and promote a safer workday.
Employees should get a good night’s sleep, because tired machinery or equipment operators are more likely to make mistakes than operators who are well-rested.
The silage team should be properly sized to perform all tasks safely. Periodic breaks of 15 to 20 minutes are effective in keeping employees alert. Everyone should carry snacks and plenty of water. It is important to stay hydrated.
“Employees should always be alert, pay attention to their surroundings, and avoid distractions,” Bolsen said.
Bolsen had his own silage accident 45 years ago.
“I found out about silage safety the hard way late in the afternoon on Saturday, June 16, 1974. We were making dough-stage wheat silage at the K-State Beef Cattle Research Farm,” Bolsen said. “The silo blower plugged for about the eighth time that afternoon, and I started to dig the forage out of the throat of the blower.”
The PTO shaft was making one more very slow revolution. Zap! The blower blade cut the ends off three fingers on Bolsen’s right hand.
“When I pulled my hand from the throat of the blower, I knew I had made a terrible mistake,” Bolsen said.
Years later, looking back at why his accident happened, Bolsen said, “I was tired, frustrated, in a hurry, losing the harvest window, and was not paying attention.”
In conducting an Internet search for a safety presentation at a 2018 international silage conference, Bolsen found 18 fatal silage accidents worldwide over a two-year period where the victim was entangled in the front of a forage harvester.
Fifty-year old Peter Santini was chopping whole-plant corn for silage at his Harmony Township, N.J., farm seven years ago. It was a ritual he knew well. His father, Frank Santini, was working with him.
Their teamwork had roots in generations of tradition, on a farm that has been in the family for 80 years. About 5:15 p.m., Frank left briefly to get his son some supper. When he returned, he found Peter trapped in the forage harvester. He was attempting to fix the machine while it was running and was pulled into it. He was pronounced dead at the scene.
In the event that inspection or service work is needed for silage equipment, engines should be shut down and keys should be removed from the equipment to ensure someone doesn’t accidentally start it. Cutter heads must come to a complete stop if they need to be adjusted or unplugged.
“Machine guards and shields should always be kept in place to protect the operator from rotating shafts, chain and v-belt drives, gears and pulleys, and rotating knives on forage harvesters, silage wagons, and silage feeding equipment,” Bolsen said. “Exposed blades of a silage defacer pose a serious entanglement hazard. Never approach defacer blades while the machine is in operation. Never attempt to adjust, repair or unclog any machine while it’s running.”
Silage gas — nitric oxide — can be produced during the first few weeks after a forage is ensiled. Nitric oxide changes to nitrogen dioxide — NO2 — when it contacts oxygen. Nitrogen dioxide, which can accumulate in and around bunker silos and silage piles and livestock housing and open lot areas, can be fatal to humans and animals.
“Even brief exposure to NO2 can produce sudden death,” Bolsen said. “It’s a reddish-orange to yellowish-brown, heavier-than-air gas that smells like a laundry bleach. The highest levels of NO2 typically occur during the first 24 to 72 hours after the forage is ensiled. However, dangerous levels of the gas can persist for up to three weeks.”
Anyone who experiences even slight throat irritation or coughing around a bunker silo or silage pile must move to fresh air at once. See your doctor immediately if you suspect that you have been exposed to nitrogen dioxide gas.
“If a feedyard’s silage program isn’t safe, then nothing else about it really matters,” Bolsen said. “After all, the most important goal at every feedyard is to send all employees home safe to their families every day.”