Original URL: http://www.theregister.co.uk/2007/10/18/goat_burst_stoppage_diver_submarine_outrage/

Bubbly billygoat-bursting boffinry brouhaha at MoD

Caprine-fizzing experiment moratorium outrage

By Lewis Page

Posted in Science, 18th October 2007 14:32 GMT

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.

As for just where the safety line is to be found in various kinds of pressure-change situation, the answer is that nobody really knows. Different organisations use different rules even for fairly cut-and-dried up-and-down dive profiles. Once you get into whipping someone up fast out of the deep sea and then quickly pressing him again in a chamber before he fizzes to death, well, that's relatively unknown territory.

But you'd like to know all about it, because one day you might have fifty or a hundred submariners exiting a doomed sub at depth and zooming up to the surface in their escape rigs. If you're on the rescue ship at the surface, compression chamber at the ready, you need to know what pressure to put them to, what gas mix to give them - what treatment will save the highest percentage. This isn't the kind of thing you want to be finding out on the job.

Goats, apparently, are relatively close to human physiology in this area. As the Herald notes, the unlucky caprines have been experimented on under pressure since 1905.

"Critics say that the data collected from thousands of experiments over more than a century should be more than sufficient to justify ending live testing and provide a base for computer simulations," adds the paper.

"The French navy has already abandoned its own live-test programme in favour of more humane methods."

On the other hand, helium certainly hasn't been in use for a century. Neon and hydrogen mixes are more recent still. Trimixes, with more than one inert component, are also quite new-fangled. Compression-chamber therapeutics is a field you would reasonably describe as being in its infancy - it wasn't that long ago that the Royal Navy could normally offer nothing more than pure oxygen or air in most of its operational chambers.

There's plenty of useful stuff still to learn - knowledge to be gained which could save human lives. How many lives, though? And how many goats would have to die or suffer to save those future divers, submariners etc.? How many goats would you torture to save one human? Does it matter if they get made into a tasty stew afterwards?

It doesn't stop there. Will there really be any divers and submariners in future? Won't it all be robots?

Maybe not, as a lot of key robotics tech - high bandwidth two-way wireless comms and satnav, for instance - doesn't work underwater.

The MoD told the Herald that its top people "are investigating a range of options for submarine escape and rescue, and life support, including and excluding animal experimentation. Any plans for further experiments using goats are subject to the findings of this review."

The Animal Liberation Front (sample quote: "the Boston Tea Party raiders did not consider themselves terrorists") said: "We call on QinetiQ to halt these experiments and hand all surviving animals over to suitable animal protection groups."

Deep waters, these. (Ah, thank you; it looks cold outside. My taxi? Ready for a fast getaway, you say?) ®