When you Think Safety, Think it Through

Devices and regulations intended to increase human safety abound. However, all of them present a safety risk themselves to some extent. It's essential to ensure that the cure is not worse than the disease.

Here are some examples of safety systems that backfired due to inadequate forethought of their designers.

The Thresher

The first U.S. atomic submarine to be lost was doomed by a safety mechanism. The atomic reactor control system had an automatic emergency shutdown system. Known as 'scramming', it resulted in all control rods being dropped into the reactor with an almost immediate collapse of the chain reaction, thus ensuring that the reactor could never get out of control. No manual override was provided. Once scrammed, the reactor required some five minutes for the chain reaction to rebuild to operating strength.

Unfortunately, the designers of this system failed to take into account that when a submarine is below a critical depth, it becomes heavier than water and requires its propulsion system to be powerful enough to overcome that negative buoyancy. The inevitable happened. During sea trials, the Thresher was below the critical depth when a pipe burst. The water leak was quickly contained, but the fatal damage had been done - the mechanism scrammed the reactor. The electrical power drive was inadequate to maintain depth. The sub sank below its ultimate depth and was crushed before the reactor could be restarted.

When you think safety, think it through.

The Concorde

The only Concorde to ever crash was lost by a safety mechanism. The plane was prone to blow its tires. If a tire blew during takeoff, the wheel might jam in the wheel well if retracted, so there was a mechanism that prevented the wheels from being retracted if a tire blew. There was no emergency override.

When the gear is down, the aerodynamic drag on the plane is much higher than when it is up. The designers forgot that this could doom the plane during takeoff if full power was not available. That was what happened. (It also appears that the plane was slightly above recommended weight for the runway and weather at the time; aviation accidents are rarely due 100% to one factor.) The debris from a blown tire punctured a fuel tank, and the resulting fuel leak disabled one of the four engines. The pilot did not have the option to override the 'safety' mechanism, and the plane had insufficient power to maintain altitude sufficient to reach Le Bourget airport, a few kilometers away. Even if the wheel had jammed, it could have resulted in no fatalities if the plane had landed gear up at Le Bourget. Instead, everyone was killed.

When you think safety, think it through.

The Austin Marina

During the 1980's, all sorts of technical contraptions were used in attempts to force people to use seat belts. One of these was installed on a car I had. It required that a person sit on the seat, and only then connect the seat belt, supposedly to prevent people from leaving the seat belt connected behind the seat. Otherwise, when the ignition key was turned on, a loud buzzer sounded. An elaborate coded wiring system was used to prevent the system from being bypassed.

The designers forgot that people other than full-weight adults ride in cars. My children were heavy enough to trigger the weight sensor. But, children are prone to get excited and bounce up and down, or to turn to one side to pass toys one to another. Every time one of them moved a muscle the weight sensor released, then because the seat belt was still connected, the buzzer went off. (This was before car seats for children.) The only way of driving that car safely with children was to drill a hole in the buzzer casing and inject epoxy resin so that the 'safety' system thought it was connected, but it made no sound to distract the driver.

When you think safety, think it through.

Speed Limits

Ontario Highway 7 is mostly two lanes and runs from Ottawa to north of Toronto. For many years, the speed limit on the road was 90 km/hr. Then, there were a few high profile collisions on the road between cars exiting from side roads too close to an oncoming vehicle for the latter to stop in time. The speed limit was reduced to 80 km/hr in the misguided belief that the frequency and severity of such collisions would be reduced.

The result is one of the most dangerous roads in the area for law-abiding drivers. Most drivers, long distance truckers and bus drivers in particular, simply refuse to drive 80 km/hr for over 300 km non-stop. Whenever they encounter a vehicle driving at anything like the inappropriate speed limit, they move up to with a car length of the 'offender' to scare them off the road. If that doesn't work, they lean on their deafening horns. Since usually the shoulders on this road are far too narrow and sloping for a car to take to them at full speed, and it would be lethal to slow down, the situation continues until there is an opportunity to pass, or the driver in front speeds up to 100-110 km/hr and remains there long enough to be able to get off the road safely.

When you think safety, think it through.

By the way, don't bother the Ontario Provincial Police with such things. They can't even be bothered acknowledging reports of such incidents. And, some ten years ago, when a tailgating driver tried to physically push my car off the road, the OPP officer to whom I reported the incident snapped that "people don't run into other people without a reason" and was going to charge me with causing an accident until I pointed out that I had a witness in my car. Then, he told me to get lost. However, if a Greyhound bus is involved, write Greyhound Canada - they do listen, and take action.

Nuclear Waste

All nuclear power plants produce materials that are intensely radioactive for tens of thousands of years, but that cannot be used to produce power in a reactor. Currently, such material is stored in pools of water to keep them cool, for without water cooling many of the materials would quickly heat to their ignition point and catch fire, which would spread radioactive material over a large surrounding area. If the water container were to crack, whether by earthquake or by deliberate human action, a disaster would inevitably follow.

For over half a century, governments all over the world have been approving the construction of nuclear power plants without any consideration of these disasters waiting to happen. Now, the Canadian government is proposing a next step - the transport of all such material to a single location to be stored so that it can be retrieved at will in the future.

There is a catch: no civilization on the face of this earth has ever lasted more than a thousand years without breaking down. Most have lasted less time. The only truly safe way to store material that is lethal to humans for periods far longer than a thousand years is to ensure that it safely survives a collapse of civilization.

There is such a system. It's simple too. Drill the type of hole that is drilled every day to explore for oil and gas, two kilometers (or more) deep. Drill it on the site of the reactor so there is no danger from accidents during transport. With suitable spacers to ensure that material will not accumulate to critical mass, lower the high level waste down that hole until the hole is full to within a kilometer of the surface, then fill that last kilometer with material matching the surrounding earth. Then, drill another hole that stays a safe distance away. Multiple holes can be drilled from the same location, as holes can be directed out in a radial pattern. Even if the material somehow did manage to concentrate enough to form a low level reaction, it wouldn't pose a danger a kilometer into the earth, no matter where in Canada the hole is drilled. The dangerous material would be unlocatable and unreachable by terrorists or anyone of similar bent. But, nuclear planners have never read Toynbee - the meltdown of civilization is not part of their consciousness.

When you think safety, think it through.

John Sankey
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