Bubbly billygoat-bursting boffinry brouhaha at MoD
Caprine-fizzing experiment moratorium outrage
The UK Ministry of Defence (MoD) has finally been challenged by animal-rights groups over a long-running programme of experimentation in which goats - among other animals - have been deliberately given the bends in decompression chambers.
Rather than a malevolent hatred of cloven-hoofed creatures, the tests in question were motivated by scientific inquiry into diving and submarine safety. Many trials have been carried out over recent decades at the Alverstoke research facilities in Gosport, formerly by the Defence Evaluation and Research Agency (DERA). The Alverstoke lab was deemed to be something the private sector would like when DERA was largely sold off under the name QinetiQ in 2001.
Your correspondent visited Alverstoke ten years ago in the DERA days, as part of the navy-diver training course, though we didn't see any goats getting bent (so to speak). The staff there were already well aware that their days of putting goats through aggressive decompression regimes were probably numbered. The prevailing view seemed to be that as soon as the animal-lib tendency found out what was going on, experiments would cease; and according to The Herald of Scotland, this has now (finally) happened.
The idea of the goat-bothering trials - and the many other trials using humans, or just test equipment - is to improve safety for people in hyperbaric underwater environments.
For those who don't know, whenever human beings (or animals) are subjected to greater-than-normal pressures - as when diving, or during submarine accidents - their body tissues move gradually into a different equilibrium with the breathing gas. Such gas has to contain a high proportion of inert constituents such as nitrogen or helium, as oxygen is poisonous at high pressures.
The inert gas gets absorbed into the body tissues over time, and lurks there like the bubbles in an unopened bottle of coke - which isn't a problem of itself. The snags come when the person (or goat) moves back to lower pressures, as in the case of a diver surfacing or pressure in a hyperbaric chamber being released.
The trick is to let the pressure down gradually, as if opening the coke bottle just a tiny crack. If you let the gas out of a coke bottle slowly enough, after a while it will have gone completely flat without a single visible bubble ever forming. Likewise, a diver who surfaces sufficiently slowly will have no problems.
But sometimes you need to get up out of the water faster than that. Your submarine may be in trouble, or maybe you need to clear up a minefield in a rush, or perhaps you don't have infinite supplies of breathing gas. So you speed things up a bit, and you start to fizz.
If the bubbles are small enough, that could be fine. But at some point, they start to cause problems in the body. They can make nerves and muscles act involuntarily, doubling up people's limbs (a classic "bend"). Moving on up the severity scale, they can knock out your vision, cause excruciating pain, fatal brain damage, paralysis, heart failure, etc.
Other things than fizzing body fluids can go wrong, too. If you inadvertently hold your breath under falling pressure, your lungs can burst. A minor puncture may not be a big deal, but a serious one can cause an embolism which will finish you before the bends get a chance. Just by way of extra toppings, if you aren't careful your eardrums can rip during a fast change; you can suffer inner-ear damage; your sinuses might gush fluid or blood; your guts can rupture - especially if you've been drinking coke; and if you're really unlucky and have a shitty dentist, one or more of your teeth could explode.
It's great, being a diver.
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