Grunt: The Curious Science of Humans at War

by Mary Roach

  The risks are amplified when someone on your crew has been up for sixty hours. It has been an enduring unease of the military that the last people you’d want operating subs or fighter jets or automatic weapons are often the ones doing it: the persistently, catastrophically sleep-deprived.

  ___________

  * As someone for whom the phrase “top secret” has applied mainly to decoder rings and campy spy movies, I had to remind myself that these are actual security classifications. I found it hard to take seriously the sign on the chain stretched across the navigation room door saying, TOP SECRET—KEEP OUT. They may as well have added NO GIRLS ALLOWED. I saw a printer in the crew lounge labeled SECRET PRINTER. Secret printer!

  † Almost as good as this one, by Andrew Karam, in the cold war–era submarine memoir Rig Ship for Ultra Quiet: “Bug juice didn’t come in flavors, just colors.”

  Up and Under

  A submarine tries to sleep

  THE BEDS IN THE missile compartment are a recent addition. When the USS Tennessee got a technology upgrade, some years after the sub was built, extra crew were needed to serve the servers. This posed a problem, until it occurred to someone that there’s room for a bunk pan in the space between two nuclear missiles. The Trident II launch tubes—of which there are twenty-four on board—stand 45 feet tall, spanning all four decks of the submarine. The multifloor missile compartment is the least hectic place on board. It’s like the stacks in an old college library—a still, private place to put your head down and catch some sleep.

  Though not just now. “All hands awake!” The voice on the intercom is accompanied by an alarm, loud and insistent. Bong, bong, bong, bong. An annoying child with a stick and pot.

  “Simulate sending all missiles.” This is a lot of missile. Each Trident carries multiple warheads, each programmable to its own destination, with sufficient precision to, as I’ve twice heard it put, “hit a pitcher’s mound.” The ballistic missile submarines of the US fleet, fourteen in all, are a roving underwater nuclear arsenal. Along with missiles in underground silos and others on bomber aircraft, they make up the “nuclear triad” of US strategic deterrence. You would be crazy to nuke us, is the message here; we have more bombs than you have, and you can’t take ours out first because you’ll never find the ones on the subs. Ballistic missile submarines have whole oceans to hide in, and a nuclear reactor aboard to generate power and water, so they never need to surface for fueling. They can stay deep until the food runs out.

  The Tennessee’s second-in-command, Executive Officer Nathan Murray, invited me to join him in the missile compartment for the drill. (I sailed out to the sub with a group of prospective commanding officers going aboard for a practical evaluation.) We pass a row of sleeping spaces along one wall, some closed off with black vinyl curtains, giving them the look of bathroom stalls at certain punk clubs in the 1980s. Murray points out the bed of a young man who shares his space with the wall coupling for the fire hose. He was woken up last night for a fire drill, and now this.

  The Submarine Force has formally acknowledged that it has a sleep problem. Quoting Force Operational Notes Newsletter (Special Crew Rest Edition), “An individual’s sleep at sea is not protected, allowing administrative training, maintenance, and ‘urgent’ matters to routinely shorten or interrupt a person’s sleep. . . .” The crew of the Tennessee endure fire drills, flooding drills, hydraulic rupture drills, air rupture drills, man overboard drills, security violation drills, torpedo launch drills. They practice launching the missiles more regularly than some people floss. On one hand, you want the crew to be well trained. You don’t want to hit the wrong pitcher. On the other, you don’t want training and drills going on so often that the people tending the bombs and reactors are chronically sleep-deprived.

  In 1949, submarine schedules allowed ten hours a day for sleep. On top of their “long sleep,” half the crew took at least one nap. Starting in 1954, subs went from diesel to nuclear-powered engines. The result being that there’s a lot more to watch than a temperature gauge and an oil level. On the USS Tennessee, four hours’ sleep has been about the average.

  Before coming aboard, I spoke by phone with sleep researcher Colonel Greg Belenky (Ret.), the founder of the Sleep and Performance Research Center at Washington State University, Spokane. Belenky knows what happens when people go from sleeping eight hours a night to sleeping four or five. Their cognitive mojo declines over the course of a few days, whereupon it plateaus, settling in to a new, compromised state. The less sleep they’re getting, the longer their mental abilities deteriorate before they plateau. Which mental abilities? Most. Sleep deprivation shrinks memory and dims the network that sustains thought, decision making, and the integration of reason and emotion, Belenky said. “You know when you have a problem you’re working on and you give up? Then you get a good night’s sleep, wake up, and suddenly there’s your solution? That’s what sleep does. It returns the brain to its normal specs.”

  On submarines, the junior crew have it worst. On top of work and watch duties, they are preparing for “qualification,” a sort of submarine version of passing the bar: sixty-plus verbal quizzes on submarine components and systems plus practical tests on various elements of your particular sub—anything from taking the helm to using a fathometer to blowing a sanitary tank. “I’ll get three hours of sleep one night, and the next night none,” said a long-faced seaman studying dive hydraulics in the vaporizer haze of the Tennessee’s enlisted crew lounge. (Between the vaping, the zombie-apocalypse video-gaming, and some aggressive tabletop football flicking, a terrible place to study. Or maybe just to be middle-aged.)

  The seaman will tell you he’s fine, but Belenky knows he’s not. When people drop below four hours a night, they don’t plateau. Their abilities continue to erode until they end up at the point where sleep researchers have had to come up with special terms, like “catastrophic decompensation.” “Put simply”—and here Force Operational Notes shifts into typographic overdrive, simultaneously boldfacing, underlining, and italicizing—“failure to get adequate continuous sleep every day results in overly fatigued personnel who, in a matter of days, function at a deficit similar to being intoxicated.”

  Like drunks, the chronically sleep-deprived are doubly dangerous in that they’re poor judges of their own impairment. Jeff Dyche, a sometime research psychologist at NSMRL, now with James Madison University, told me about a study that showed that people who’d slept six hours a night for two weeks were as cognitively diminished as people who’d been up for forty-eight hours straight. Unlike the up-all-nighters, routine six-hours-a-nighters see no need for caution. They’ve felt mildly exhausted for so long it’s become their normal, Dyche says. “They’re like, ‘Ah, I’m used to it.’” I’ve been hearing a lot of this over the past two days. “I get four and a half hours and I’m generally okay for a twenty-four-hour period,” said a sailor pushing trash into an institutional-grade compactor that would work with equal efficiency on flesh and phalanges.

  Murray and the sub’s commanding officer, Chris Bohner, volunteered to try out a new watch schedule aimed at keeping crew better rested, both for their health—insufficient sleep having lately been linked to obesity, high blood pressure, diabetes, heart disease—and for everyone’s safety. It is not a simple undertaking. “I spend a very significant amount of time,” Murray says, “figuring out people’s rest.” Murray is a popular leader—in both manner and mien, a solid individual. You never see him slouch or lean or jut one hip. He stands steady and square on both feet, like a bag of mortar set down. His hands park on his belt, with an occasional sweep over his head, which he keeps closely shaved. The latitude of Murray’s hairline, like that of the submarine itself, will remain a secret to me.

  The problem is that things come up. People fall behind and schedules fall apart. The problem this week is me. Everyone’s work was interrupted because the crew had to spend four or five hours looking for a spot where the seas were calm enough to drop a gangplank between
the sub and the vessel we sailed out on.

  Part of the Navy’s challenge in dealing with undersleeping has been that somewhere along the line, it became a point of pride. At NSMRL I met a longtime submarine commanding officer named Ray Woolrich. “Marines sitting around in a bar,” said Ray, “will tell you how many push-ups they can do. Aviators will tell you how many g’s they can take. Submariners will tell you how many hours they stayed up.” Better to be exhausted than to gain a reputation as a “rack hound.”*

  For decades, military sleep research proceeded in lockstep, focusing less on getting sleep than on getting by without it. Study after study tested this or that stimulant on fliers, soldiers, sailors. Only recently has protecting sleep become a Defense Department priority. Current Army policy requires unit leaders to develop and implement a sleep management plan in theater. (Though in one small survey of soldiers returning from Iraq or Afghanistan, 80 percent had never been briefed on such a thing.) A turning point, according to Belenky, was the lengthening of the Army’s field training exercises (FTXs), the massive simulated confrontations that serve as a sort of practical final exam for soldiers. “At some point the doctrine folks had concluded that any war worth going to would probably last a week or two, so they increased the duration of the FTX from three days to two weeks,” Belenky said. Up to that point, there had been a tradition of staying up for all of it, in order to “look motivated and get a good evaluation.” Belenky recalls getting a call from a commander shortly after the change went through. “He said, ‘I need your advice on pharmacology. I need my boys to be able to stay up longer.’” Belenky figured the man was talking about a couple extra days. “I said, ‘How long do you want them to stay up?’ He said, ‘Two weeks.’ People actually tried to gut it out.” It was a vivid and no doubt fairly entertaining demonstration of the importance of sleep to military competence.

  History provides equally vivid demonstrations. Medical historian Philip Mackowiak compared eyewitness and officers’ accounts of Stonewall Jackson’s performance during a series of Civil War battles with the general’s opportunities for sleep, if any, in the days leading up to those battles. In 100 percent of the battles for which Jackson had had no chance to sleep in the three days prior, his leadership was rated “poor.” In the Battle of Gaines’ Mill, his chief of staff described him as “thoroughly confused from first to last.” His brigades were not merely “out of order”; “he did not know where they were.” The Battle of Glendale found Jackson “benumbed, incapable . . . of deep thought or strenuous movement . . . uninterested and lethargic.” At times during the Battle of Malvern Hill, Jackson “appeared to be almost a bystander.” In the midst of the Battle of McDowell, he was discovered napping.

  For every twenty-four hours awake, Belenky told me, people lose 25 percent of their capacity for useful mental work. Jackson was leading the charge (or not) on 25 percent of his waking best. I’m trying not to think about a man named Patterson in one of the Tennessee’s machinery rooms. He’d been up for 22 hours trying to fix the electrolytic oxygen generator, a large, pulsing metal-hulled molecule splitter. “Basically it’s a hydrogen bomb,” he’d said cheerfully.

  The longest Belenky has kept subjects awake is 85 hours—three-plus days—which is about the limit, he says. “They’re not,” he adds, “very useful to anybody.” There are people who claim to have stayed awake for 100 and even 200 hours, but because their brain waves weren’t continuously monitored, as Belenky’s subjects’ are, it’s impossible to be sure they weren’t microsleeping. The very tired can slip into Stage 1 sleep for a few moments, eyes open, carrying out some quasi-coherent version of whatever it is they’re up to. As anyone who has slept on an airplane knows, it’s possible to maintain muscle tone while sleeping—that is, until you slip into REM sleep, during which muscles relax. (When people fall sleep at odd times in their circadian cycle, they may enter REM early. Blame “early-onset REM” for the slack-jawed head-lolling that happens when you nap sitting up.)

  Soldiers, including Stonewall Jackson’s, have on occasion reported sleeping during night marches. If you’re tired enough, Belenky says, your brain appears to briefly dissociate—one part sleeping, another awake. There are birds and marine mammals that manage this regularly. Dolphins and seals are able to sleep unihemispherically—with one half of their brain. This is because the other half needs to attend to breathing, which in their case requires swimming to the surface for air. When geese and ducks sleep in groups on the ground, the birds on the outer edge will keep one eye open and the corresponding brain hemisphere awake, scanning for predators.

  From a military perspective, a soldier who could march or swim or look out for enemies while simultaneously catching up on sleep would be a desirable item. It fits right in with one of the goals of the military’s futuristically minded Defense Advanced Research Projects Agency (DARPA): “to enable soldiers to stay awake, alert, and effective for up to seven consecutive days without suffering any deleterious mental or physical effects and without using any of the current generation of stimulants.” This is why you’ll find the Defense Department on the sponsor lists of some of the basic research on unihemispheric sleep. If science could just figure out how the ducks do it, perhaps troops could be enabled—chemically or surgically, God only knows—to do it, too. Belenky scoffed. “We’re not even sure what triggers whole brain sleep.”

  That hasn’t stopped military organizations from fantasizing about it. I came across a NATO symposium on Human Performance Optimization that included a roundup of medical technologies that might be repurposed to optimize warfighters. In among the prosthetic limbs “to provide superhuman strength” and the infrared and ultraviolet vision–bestowing eye implants was this: corpus callosotomy to “allow unihemispheric sleep and continuous alertness.” Surgeons have on occasion severed this connector between the brain’s halves as a way of reducing the number of seizures in patients with severe epilepsy. Does this in fact change how these patients sleep? No, says Selim Benbadis, director of the University of South Florida Comprehensive Epilepsy Program and the author of a paper on the procedure. He added that there are infants with incompletely developed corpora callosa and they sleep normally and with both hemispheres at the same time.

  “They think a lot of harebrained things are good ideas,” Belenky said of DARPA. Yes, they do. The wish list also included “surgically provided gills.”

  “RELEASE OF nuclear weapons has been authorized.” It’s the intercom man again. Even in a simulation, it’s a sickening thing to hear. I look around at the sailors standing near. One untangles an extension cord. His face betrays nothing. A sailor seated at a control console blows his nose. “Is this what it would be like?” I ask Murray. “If it were the real deal? Would people just be calmly carrying out their tasks, blowing their nose . . .” The whole business is straight off my fathometer.

  Murray’s not playing this game. “If your nose is running, you blow it.”

  Two sailors hustle past, each holding a corner of what looks at a glance like some kind of Lotto ticket. It’s the code for the key box, the box with the keys to launch the missiles. Two people must have a hand on it at all times once it’s out of safekeeping, for the same reason some airlines, in the wake of the 2015 Germanwings suicide flight, require a second person in the cockpit.

  Were this an actual missile launch, I’d wager that adrenaline would keep the crew alert regardless of how long they’d been up. But the normal day-to-day routines of a ballistic missile sub are a good deal less invigorating. Most watches are just that: hour upon hour of watching. Watching displays, readouts, dials, sonar feed. It’s a worrisome mix: sleep deprivation, tedium, and large, potentially destructive items. “The Navy doesn’t want us to publish anything saying that these guys monitoring these nuclear reactors are falling asleep on watch,” Dyche told me. “But we know that’s happening.” Even awake, the tired are poorly suited for standing watch. When psychologists give sleep-deprived people a standard battery of cognitive task
s, their score on measures of “psychomotor vigilance”—paying attention and noticing shit—drops dramatically.

  I never visited the Tennessee’s reactor and its tenders, because I didn’t have security clearance for that part of the sub, but I did visit the torpedo room. There are four of them, massive as medieval battering rams. Sweetly (I guess), they are named for the torpedomen’s wives. I asked the torpedoman on watch when last a US submarine had had cause to fire a torpedo at another vessel. He thought for a moment. “World War II.” He’s the Maytag Repairman, ready for action in the extremely unlikely event it’s called for. The torpedoman’s watch is a checklist of inspections, walk-arounds, paperwork. Always with the paperwork.† Outside of the sonar shack and the Missile Control Center, much of the Tennessee remains charmingly analog. I looked around the missile compartment at one point and thought, tuba parts. The torpedo launch console has big square plastic buttons—Flood Tube, Open Shuttle, Ready to Fire—that flash red or green, like something Q would have built into James Bond’s Aston Martin. The missile compartment has similarly retro-looking panels of buttons. They provided the setup for one of the more quotable things Murray said to me—a line that, were fewer precautions in place, could have joined “Houston, we’ve had a problem” or “Watch this” in the pantheon of understated taglines for calamity: “I wouldn’t lean on that.”

  On an intuitive level, the prospect of marginally vigilant humans babysitting reactors, torpedoes, and weapons of mass destruction is unsettling. That the scene takes place in a vessel under hundreds of feet of water, all the more so. Statistically, however, the highest risk doesn’t lie in the nuclear reactor compartment or even, for that matter, in deep water. The biggest risk lies with the seemingly straightforward but in fact reliably harrowing task of surfacing a sub.