Bit of a query for you...

[andy2tanx]

Didn't really know who to ask this,
When a harbour is built how do they get the mortar to go off underwater?  Do they have special cement or what?  I know its a daft sounding question but I really wanna know!

[PaulC]

I'm no expert in these matters mate but as I understand it mortar goes off as a chemical reaction not a drying one so the underwater gig is not too much of a problem. I do believe you need underwater cement though. I'm told it's very funny if you tip it down someone's bog.

[Jay]

Of course the old way was to use what are called 'caissons' - basically upside down boxes withe the open end at the bottom. It was sunk and then the water was pumped out by increasing the internal air pressure. One side effect was that a number of workers who spend long hours working in this environment developed a strange sickness when they emerged back into the normal environment after their shifts. The unknown condition caused the men to bend over in strange contortions but it was also noted that the symptoms disappeared when they went back to work in the caissons. Sounding familiar yet?

No? Then perhaps the fact that a certain John Haldane was called in to investigate this phenomena may jog your memory?

Still no? He concluded that the 'sickness' was caused by the men working in over pressured environments. The men themselves, noticing the contorted figures of those affected had a rather apt name for the condition - they referred to it as the BENDS.

[Mr T.]

Hobby (formerly Comm Diver)'s yer man for this!!

He's been in a caisson (in full Comm Kit, Kirby Morgan lid, surface supply the works) when they filled it full of concrete to set a new canal wall (seen the photies) - literally encased/swimming in VERY quick drying cement. Bit of ring-twitch moment or what??

Also the construction workers who completed a number of stretches of the Channel Tunnel had to be brought out and put straight into a pot coz of the depth/pressure gig.

"Momma never told me it would be like this..." (come on, sing along!)

(Edited by Bren Tierney at 10:15 pm on Aug. 19, 2002)

[andy2tanx]

thanx fellas, now I can sound really bright at work when this gets chucked around.