Faster than the wind, and perhaps he saved your life

kw: book reviews, nonfiction, biographies, scientists, safety, rocket sled experiments

There is a name you need to know: John Paul Stapp. If you have been in a car accident, it is likely that you owe your life and health to him. That is, if you were wearing a seat belt.

Step back about 70 years. World War II had just ended, and a young physician was wondering why so many military pilots were dying, when they didn't have to. During that war, getting shot down was a death sentence in one of two ways: you died when the plane crashed, or you died trying to exit the plane. After the war, ejection seats were found to be, far too frequently, tickets to oblivion. Their design was based on, at best, random guesses about the amount of stress the human body could survive, and the forces the aircraft frame could handle.

Dr. Stapp set out to gather accurate and usable data. What he did and how he did it are detailed in the first half of Sonic Wind: The Story of John Paul Stapp and How a Renegade Doctor Became the Fastest Man on Earth, by Craig Ryan. The second half shows what he, and the country, did as a result.

Before the 1940s, a smattering of centrifuge experiments had established that, with training and with minimal support from a flight suit, a fighter pilot could avoid blacking out at accelerations of about 6 G's. The G is a one-gravity acceleration force. If you weigh 150 lbs (68 kg), that is the force a mattress must apply to hold you up. If you and the mattress are put in a centrifuge and spun so as to apply a 6 G acceleration, the centripetal force the mattress (and the frame holding it) must now apply to hold you is 900 lbs (408 kg). When your body weight is spread out by a mattress, if the area of your body against the mattress is about 5.4 sq ft (0.5 m²), you'll feel a pressure of about 28 lb/ft² or 136 kg/m². That comes to about 0.19 psi. Now, multiply that by six, and you'd feel almost 1.2 psi. If your normal blood pressure is 120/75 (what doctors currently recommend, but maybe yours is higher), that 120 mm translates into 2.3 psi, and the 75 mm into 1.5 psi. So you can see that sustained acceleration of 6 G's tends to draw the blood in your body towards the mattress. If you are sitting rather than lying down, it doesn't take long for an acceleration of 6 G's to pull the blood from your brain, and you black out.

At this point it is all about sustained G forces. It makes sense that you could survive larger forces if they occurred briefly and were rapidly abated. Somehow, a factor of three became dogma, so that a brief acceleration of 18 G was considered the threshold of death. Yet, common observations of people surviving falls calls this into question. One of my brothers fell 20 feet out of a tree, landed on his back on the lawn, and had the breath knocked out of him. But he got up after a minute or so and was OK. Now, a grassy lawn is softer than landing on concrete, but it doesn't have much give. The main thing keeping this from being an "instant stop" (physically impossible) was the flexibility of the body, which squishes out briefly. I calculate that my brother's body touched the ground going about 24 mph (39 kph) and stopped in a distance of about 4 inches. That works out to a stopping force of 60 G's. If instead we allow him a little more flexibility to squishing, perhaps the stopping distance was 6 inches, and he experienced 40 G's. Either number is a far cry from 18 G's.

Over about a decade, Dr. Stapp used himself as the primary experimental subject (not the only one; he also used chimpanzees and on rare occasions, another volunteer) in rocket sled experiments. The rockets would get the sled going to some high velocity, and a braking system would then stop it over a prescribed distance. Here are parameters that might describe a typical experiment:

• Rocket acceleration: 4 G's
• Burn time: 4.6 s
• Burn distance: 410 m (1,340 ft)
• Peak speed: 644 kph (400 mph)
• Stop distance: 20.5 m (67 ft)
• Stopping time: 0.23 sec
• Average stop G's: 20
• Peak stop G's: 30 (measured by camera)

Early experiments were conducted with the seat on the sled facing backward, so the subject was pressed into the seat by the stopping forces. Experiments were also conducted with the seat in various orientations, including "butt forwards", to determine the forces of an ejection seat's kick-off blast.

Later experiments were conducted with the seat facing forward, and the subject exposed first to the wind blast, and then to deceleration against the webbing holding him into the seat. Dr. Stapp used chimps to determine the edge of lethality, though it turned out that they are much, much tougher than humans, so getting the calibration right for human experiments was tricky. With humans (mostly himself), he gradually raised the G forces and observed his own feelings and had doctors note what injuries he sustained. Thus, as time went along, the design of the seat was improved to avoid points that exerted extra forces and were causing injury. Over time these design changes were implemented in pilot seats.

The final, most definitive experiment was conducted with a chase plane flying above the rocket sled, to observe and film it from above. The pilot was astounded when the sled outraced the plane, reaching a top speed of 639 mph (1,028 kph), or Mach 0.9. This earned Stapp the title of "fastest man on earth" in a ground-bound vehicle. The title stood for about 30 years. During the deceleration, though, he sat forward-facing, getting the full wind blast, and being jammed against seat restraints with a crushing 45 G's, peak, during a stop that lasted less than 1.5 seconds. He was a mess when he was helped out of the seat. His eyes looked like pools of blood; he was lucky they had stayed in his head. It took weeks for all his sight to return. He had several broken bones. Though he had the ambition to go 1,000 mph, or at least Mach 1 (about 715 mph; authorities vary), it was not to be. He had advanced to Captain, Major, and was now a Colonel, and was moved by the Air Force command to a more administrative role. His sled, named the "Sonic Wind", was retired.

What he did next is the subject of the second part of the book. Dr. Stapp had performed his experiments, often against opposition, on a shoestring. He had to scrounge and cadge for equipment and apply verbal tricks to get some semblance of permission. Such skills were even more necessary after about 1956. He had long lobbied and clamored to Air Force brass about the safety, and its lack, in fighter aircraft and also transports. One result of his nagging was that many transports in war zones had the seats for the troops facing backwards. Then they were much more likely to walk away from a crash. But even during his earlier experiments he was also lobbying for the use of seat belts in automobiles.

By 1956, about 36,000 Americans were dying every year in automobile crashes. The population was about half what it is today, so in proportion, there could now be 72,000 auto deaths yearly, but instead, there are about 33,000. It took Colonel Stapp and his allies another 14 years to bring about the changes, primarily in laws, that have, since about 1970, saved at least 800,000 lives. Over the last 17 years, some of the difference is also due to airbags, something Stapp heartily approved of; he died in 1999, the year after airbags were mandated.

During his "lobbying years", he fought resistance in both government and industry against mandatory seat belt installation and use. The auto manufacturers were a lot like the tobacco lobby of the same era, denying that their products' quality had anything to do with the deaths that were occurring. Fortunately, there were at least aftermarket seat belts available, and many members of the public didn't wait for Washington or anyone else. Over a decade's time, sufficient statistics were compiled that a growing number of lawmakers became convinced of the belts' value, and in 1968, factory-installed seat belts were required by law. I remember an ambulance EMT who said he'd never unbuckled a dead body.

I bought my first car in 1967, a 1964 VW beetle. A couple of years later I bought a set of aftermarket 3-point lap/shoulder belts and installed them. Fortunately, Europe had been ahead of the curve, and though the car didn't have belts already installed, it did have threaded mounting holes, so the installation was easy. I have used seat/shoulder belts ever since. But growing up, we did many road trips, hundreds of miles yearly, in a big station wagon with no belts, and a mattress in the "back-back" for us boys to nap on. We were lucky.

Since 1984, one after another of the U.S. states has passed laws requiring seat belt use. Compliance varies, but averages 85%. Nearly all of those 33,000 highway fatalities in recent years, has come from the 15% who don't wear seat belts. In spite of the air bag in most vehicles, they either crash around inside during a collision, or are ejected. Driving in California with my brother several years ago, we saw an SUV hit the median barrier on the freeway, and the driver burst through the side window and landed on the highway almost in front of us, on his head. One of us (I don't recall who) said, "We just saw someone die."

Two things to remember about Colonel Dr. John Paul Stapp: He risked his life, incidentally becoming the fastest man on earth, to gather safety data; then he used those data and traffic statistics to practically crowbar the United States into becoming quite a bit safer as a place to drive or fly. Craig Ryan's exciting biography brings us the man and the stories, a portrait of someone to whom you just might owe your life.

Not just another questionnaire

kw: values, safety

Today a "safety perception survey" was initiated at my company. Though we were given three weeks to do it, I filled it out right away, to counteract my tendency to procrastinate.

I work for one of the safest companies in the world, and though I'd like to tout it, I have a principle of keeping its name out of this blog. The company shares a few best practices with the handful of companies that get named "safest in the world" in their industry or sector.

First and foremost, managers and executives have their bonuses tied to the safety performance of their units, as a multiplier, not an additive item. Poor enough safety performance can eliminate the "variable" from someone's "variable compensation". This does not stand alone, and indeed, could easily lead to many abuses if the company did not also have strong standards of ethics and of people treatment, with 360° feedback for both.

Secondly, there is frequent training and "safety meeting" feedback for all employees. Not only is every incident publicized, many near-misses are included. For example, if a piece of equipment malfunctions and there is a leak, whether of water of of something less innocuous, the reason(s) for the fault are studied with a view towards eliminating that kind of failure in the future. A stumble in the parking lot, that leads to a sprained ankle, may not lead to a loss of working time or production, but it is the health of the person, rather than productivity, that is the focus of concern. This is a lot better climate than the kind of thing we sometimes hear about, where somebody gets hurt and has a sudden need for some "vacation", so the time off doesn't count against company lost work time statistics.

Thirdly, we are encouraged to take care of one another, not in a nannyish way, but as colleagues who are also friends. Thus, if I am carrying too many things on the staircase, where a colleague might ask, "How will you hold the handrail?", I am more likely to get an offer of help carrying it, so we both have a hand free. I admit it takes time and practice to get used to this, but one comes to appreciate it.

A fine balance has to be kept. Too much paranoia about safety can impact productivity more than "permitting" a certain level of harm. But if there is this attitude, the "permission" will grow to unacceptable levels. Thus, the safety goal is always proclaimed to be "zero incidents", and we frequently hear, "We don't believe anyone should go home hurt." An attitude of watchfulness rather than fear is encouraged. It works.

Nobody is perfect, and the world is not perfect. With such a safety culture in place, however, we find that the most dangerous thing any of us does is to travel to and from the workplace. And that is also being worked upon…

No I am NOT killing myself

kw: articles, medicine, safety, sweeteners

For the record, I drink about a liter of Diet Pepsi daily. It is sweetened with aspartame. My doctor and others get on my case about that. Here is some 21-year-old news from Archives of Internal Medicine:

Safety of Long-term Large Doses of Aspartame

Arthur S. Leon, MD; Donald B. Hunninghake, MD; Catherine Bell, MBA; David K. Rassin, PhD; Thomas R. Tephly, MD, PhD

Arch Intern Med. 1989;149(10):2318-2324.

Abstract

---

• Safety of long-term administration of 75 mg/kg of aspartame per day was evaluated with the use of a randomized, double-blind, placebo-controlled, parallel-group design in 108 male and female volunteers aged 18 to 62 years. Subjects received either aspartame or placebo in capsule form three times daily for 24 weeks. No persistent changes over time were noted in either group in vital signs; body weight; results of standard laboratory tests; fasting blood levels of aspartame's constituent amino acids (aspartic acid and phenylalanine), other amino acids, and methanol; or blood formate levels and 24-hour urinary excretion of formate. There also were no statistically significant differences between groups in the number of subjects experiencing symptoms or in the number of symptoms per subject. These results further document the safety of the long-term consumption of aspartame at doses equivalent to the amount of aspartame in approximately 10 L of beverage per day.

This won't end the matter. People are going to believe what they want to believe, even my doctor, who claims to believe in "evidence based medicine", but only does so when it fits his prejudices. The article is sufficient for me.

What do you wear when you mow?

kw: safety

This picture was taken by a colleague, who passed it along via e-mail to all of us. The boot belongs to a construction worker who habitually wears his steel-toed boots when lawn mowing. It is a good thing he does so. He had an incident a day or two ago that resulted in a riding mower running over his foot. The mower blade ripped the steel toe out of his boot. Three of his toes were cut, but not too badly, probably by the steel toe as it made its exit. Had he been wearing sneakers, it is likely he would have lost all the toes on that foot. You can see where the blade hit the boot…

The average rotary mower has a five-to-seven horsepower engine, and the kinetic energy in the whirling blade is similar to a stick of dynamite. Riding mowers are roughly twice as powerful. Think about it the next time you mow barefoot.

Living in the mouth of a loaded cannon

kw: book reviews, nonfiction, safety, Alaska, avalanches

I've lived in California three times. I did my undergraduate studies at Cal State Los Angeles. When I did my graduate studies in South Dakota, one of my professors once said, "Visiting California is like walking in front of a loaded crossbow. Living there is like being tied to a chair in front of it." He was referring to earthquakes. I've been through a few, including one that rolled me out of bed at 6 am precisely (The "Sylmar Quake" that devastated areas of the San Fernando Valley). I've since moved out of earthquake country...relatively speaking, because there is nowhere on Earth that has absolutely no earthquakes.

I've also lived in tornado country, several parts of it, including the Buckle of the Tornado Belt, Stillwater, OK. I've seen a few, and once came close to being caught up in one. Tornadoes can be more destructive than any earthquake, over a much smaller area, but they give more warning of their imminent arrival. If you have a well-made storm cellar, you can ride out even the strongest tornado; though an F5 with 300+ mph winds leaves little but plowed land behind, it won't pull a good cellar out of the ground!

When I moved to Rapid City, SD, I was shown by a colleague how to recognize a flood-prone area. This was just a few years after the big flood of 1972 pretty much razed a downtown area. It wasn't hard to learn to recognize signs such as scraped bark and debris caught in forks, ten to twenty feet above ground. Early settlers only lived on the terraces above the floodplain, but later folks obliviously put houses anywhere they could afford a flat spot. Floods usually give some warning beforehand, and many arrive slowly enough to be escaped from...but not all.

An avalanche, more like an earthquake, arrives suddenly and is over in moments. Experienced observers can learn to predict that a certain place is likely to release an avalance soon, but too few people are experienced enough to see the signs of imminent danger. Each year, about 25 people die in avalanches in the Western U.S., and a similar number in Alaska, though the latter has a much smaller population.

Avalanches, like floods, earthquakes, and tornadoes, occur in certain places. One can learn to recognize an avalanche path. Mainly, it doesn't have many old trees at its bottom. There are even more signs of imminent risk, signs that "If you go there, you'll die." Jill Fredston and her husband Doug Fesler have taught avalanche awareness and avalanche safety courses for many years in Anchorage, Alaska. They codirect the Alaska Mountain Safety Center. They have no web site I can find, but www.avalanche.org/ has a list of courses, including theirs. Together they also consult with businesses and governments, when workers must go into a risky area. And, of course, they are called to many rescue efforts, and have helped dig out many victims...all too few were survivors.

Ms Fredston's new book, "Snowstruck: In the Grip of Avalanches," tells the story of her avalanche education and the growth of the center. She shows us the power of avalanches through the stories of people who've experienced them. Sadly, many of these died. Considering their immense power, and the suddenness with which they occur, the surprise is that anyone survives.

Having trained people in the vicinity, wearing a radio beacon, and having knowledge of how to anticipate (and thus avoid) an avalanche-prone area, plus knowing what to do if caught in one, can give you a chance at living. But only a chance. Few people live more than a few minutes once buried in snow that immediately refreezes to concrete-like consistency. It takes a quarter to half an hour to dig someone out of a four-foot burial, and such shallow burials are the exception, not the rule.

The book's amazing and sobering stories make it a very readable companion volume to the more authoritative Snow Sense that she and her husband co-authored. Where that volume is matter-of-fact, factual, this one is for the heart as much as the head. I felt the fear and despair of many of the victims, the anguish of their families, and finally the frustration of Jill and Doug with the apparent determination of the majority of fellow-humans to live in denial, as a terminal condition. There is no doubt, where avalanches are concerned, denial is fatal.