Job Safety

January 10, 2005

Fatigue Issues in the US Army

Fatigue in the military is a major cause of errors. The following article from Soldiers Online Magazine ( provides an insiders view. I am surprised with the the study results that soldiers can maintain accuracy even when sleep-deprived. I need to see the results. However, obviously, other target related abilities are impaired. This will require more investigation and I would be interested in readers’ views on this.

Story by SSgt. Alan Moore
With troop strength down and contingency missions up, the Army’s need for around-the-clock operations is greater than ever. With the sophistication and lethality of today’s weapons, scientists at the Washington, D.C.-based Walter Reed Army Institute of Research warn that danger lurks in drowsy eyes. Consider this true story from research files: During Operation Desert Storm a platoon of Bradley fighting vehicles was rumbling across Iraqi sands. Epitomizing the fighting doctrine: “if it’s in front of us, it dies,” the platoon had just decimated a column of Iraqi personnel carriers.

The Bradley platoon, in a staggered line crossing the horizon, advanced to the enemy graveyard. While navigating through the smoldering wreckage, two Bradleys on the right of the line accidentally veered slightly off course. The vehicles’ crews spotted two Bradleys on the opposite end of the line and, thinking they were still looking forward, opened fire on their comrades. In short order, both targeted vehicles were reduced to chunks of metal not much larger than an office desk.

“The crews were very lucky,” said Dr. (Col.) Gregory Belenky, the Army’s leading expert on sleep management. “They miraculously escaped without a scratch.” The incident was a classic example of what can happen when soldiers suffer sleep deprivation. For more than a decade, Belenky has been studying the issue at the Walter Reed Army Institute of Research, where he is director of the Neuropsychiatry Division. Belenky said determining how much sleep a soldier needs to function effectively might not only reduce friendly-fire incidents, but could be the difference between victory and defeat. “The real question is ‘effectively’ for what?” he said. “This is not an Army where soldiers load flintlock muskets, stand in rows, firing toward the enemy. If that were the case we could get by on very little sleep.”

When soldiers go to the field, the burden of sleep deprivation seems to be as heavy as their rucksacks. For example, soldiers of XVIII Airborne Corps are on a short string for deployment. Within 18 hours after notification, they’re in theater and conducting continuous operations. At that rate it could be 36 to 48 hours before some soldiers sleep. A lack of sleep takes an immediate toll on troop alertness, said Dr. (Maj.) Daniel Loube, assistant director of the Sleep Disorder Center at Walter Reed Army Medical Center. “If you take normal young adults and sleep-deprive them about an hour and a half, just one night, their ability to stay awake drops by 20 percent,” he said. “If you consistently sleep-deprive these people an hour and a half each night, their sleepiness increases 35 percent.” Capt. Thomas E. Hiebert, who commands a long-range surveillance detachment at Fort Bragg, N.C., said that after three or four days of continuous operations, the pace really starts to get to soldiers. “Even after 36 hours of no sleep, soldiers get edgy, decisions are probably not as well thought out as they should be.”

The good news, said Belenky, is that sleep deprivation doesn’t impair physical strength, endurance or coordination. “Soldiers can shoot just as tight a cluster with the M-16 after 90 hours awake as they can when well-rested,” he said. The bad news is that decision-making, logic and the highest mental functions are the most degraded by sleep deprivation. It boils down to what Belenky calls the temporal envelope, or the amount of time in which a correct decision must be made to avert catastrophe.

“The speed with which you acquire and process targets is critical, especially in armored operations,” he said. “If you see the enemy first, you can kill them. If they see you first, you’re history.” Belenky’s research indicated that as soldiers get progressively sleepier, they maintain accuracy, but they take longer to engage targets. “Once you exceed that temporal envelope, the other guy sees you and — boom — it’s over.”

When soldiers are sleep-deprived, they lose their place in the battle and get confused about where they are and what they’re doing. They lose their grasp of the tactical situation, and that’s how “fratricide” can happen, Belenky said. There are no warning signs. “For a period of time, you don’t see all that much change in performance with people who are sleep-deprived,” he said. “Everything seems to be going okay, then suddenly there’s a disaster.”

According to the U.S. Army Safety Center at Fort Rucker, Ala., one of the best ways to head off sleep deprivation is by developing and keeping to a unit sleep plan. The 82nd Airborne Division’s CSM Steven England said a sleep plan must start from and be enforced from the top down. “If leaders don’t plan well, if they don’t have a rest plan, it jeopardizes lives and mission accomplishment,” England said. “I know in the 82nd we stress the importance of a well-thought-out sleep plan all the way down to the squad and team level.”

Sometimes leaders and key decision makers don’t enforce the sleep plan enough on themselves, said Capt. Joe Clark of the 1st Bn., 17th Cavalry at Fort Bragg. “They make sure the trigger-pullers are getting enough sleep, but they push themselves to the max,” he said.

During training rotations, Clark said he saw some key leaders make decisions that they might not have made were they well-rested. “They were on their last legs; they had been awake for more than 36 hours,” he said. “That’s the time when the people around them need to say, ‘Look, sir, you need to get some sleep for your own good and the good of the unit.'” Some commanders think that by shortchanging themselves sleep they can get more work done. For a day or two they can, but after about three days of limited sleep they’re actually getting less done even when they have more time to work, said Belenky. And by tweaking the delicate balance of slumber versus labor, they are courting disaster, he warned.

It is possible to get by on minimal sleep. Students in Ranger School at Fort Benning, Ga., average 3.2 to 3.6 hours of sleep per night during the grueling 58-day course. “In terms of survival, three hours’ sleep is fine if none of your decisions are critical,” said Belenky. “To be able to think and plan, most people need eight hours to be at 100 percent.” Belenky and Loube cautioned against suggesting that commanders and officers need more sleep than their soldiers. “I don’t think it has to do with officer versus enlisted,” said Loube. “It depends more on how technical your job is, and how much decision-making skills are a part of your job.”

The infantryman has command and control problems too, said Belenky. “They are every bit as complex as the corps commander’s, just smaller in scope,” he said. “In fact, if you really look at the temporal envelope, an infantryman has a lot less time in which to be making these decisions.” Sometimes intense and repetitive training helps soldiers conquer critical moments, even though they may be sleep-deprived. “That’s called automatic behavior,” said Loube. “The more a task is repeated, the less decision-making is involved and the better the task will be performed with limited sleep. There’s no doubt about that. It has been well established in studies over the last 10 years. That goes for doctors, truck drivers or soldiers.”

In addition to training and implementing a strict sleep plan, some soldiers said the answer is to work when the mission demands it and sleep as often as possible. Give soldiers 10 minutes of wait time, and they’ll turn it into a nap. Catnaps are great, said Belenky. “Anything more than five minutes of sleep, and you begin to accumulate benefit. If you get 30 minutes of sleep, you’re better off than not getting any,” he said. “In fact, sixteen 30-minute naps are almost as good as eight solid hours.”

Fortunately, soldiers have turned catnapping into an art form. They can sleep through just about anything, anywhere — standing in a foxhole, on a bumpy ride in the back of a Humvee, or in the belly of an ear-thumping CH-47 Chinook. The challenge is for leaders to develop and implement sleep plans that will recharge soldiers and still enable them to accomplish the mission.