Posted on 03/12/2010 7:16:12 AM PST by C19fan
They didn’t if it was pressurized. It’s called Caisson’s disease
They discovered that they had to depressurize slowly, just like modern day divers.
America’s closest equivalent to the Brunels were the German immigrant John Roebling and his sons and grandsons. Responsible for the Brooklyn Bridge (1867), workers (and Roebling himself) were badly injured by the ‘bends’ when coming up from the pressurized footing-construction caissons extending below riverbed level. They shortly rigged up decompression chambers to combat the problem.
cool , bookmarked
I gotta plead ignorance. Is that guy named Brunel?
Mark Brunell-QB
Yes, but this was like 30-40 years before Roebling. It was the Roebling case that made me wonder. Maybe the Thames, not being very deep, was not far enough down to create as hazardous a situation.
OK, I’ve been reading about this all afternoon, rather than working. I think the reason they didn’t experience it is that they weren’t breathing pressurized air. The caissons on the Eads and Brooklyn bridges were closed at the top and air was pumped in, which was also the mechanism by which the castings were brought out the center tube, called the “muck tube, i.e., the muck tube sucked the castings out. Apparently muck is a combination of mud and rock, which I never knew. I thought it was mud that sucked.
Brunel was also instrumental in the building of the Crystal Palace.
You may be right about the Thames tunnel construction not being pressurized.
There are stories of polluted water and gases forcing their way into the tunnel. That suggests that they were working at essentially ground-level atmospheric pressure.
On the other hand they must have been 100 feet below the surface, and that would mean significant hydrostatic pressure to hold off with the sliding-form system (invented by the elder Brunel) without assistance from air pressurization.
Yeah they had a lot of trouble with methane gas getting in and catching fire, but I don’t think they had the knowledge or ability to pressurize the whole tunnel at the time, which probably saved many lives, though it didn’t help the construction time any. The methane got in because apparently the bottom of the river was essentially a bog of sh!T... err, sewage from hundreds of years of the thames being used as a toilet.
Now, Downstream they got the wonderful tidal flushes.
Some of the older guys at work and I have had conversations along this line.
I read some of the report of the building of the Los Angeles Aqueduct.
That whole project was paper and pencil, careful planning and thinking, etc. And within cost and under budget. The sections of pipe were manufactured back east, then shipped to the aqueduct project, and all the pipe lengths and rivet holes lined up — just one of the amazing features.
You can download the report here. Over 300 pages, but it has pictures.
http://books.google.com/books?id=7yIWAAAAYAAJ
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Thanks hennie pennie. |
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