How are things built in the sea? Harbour walls, oil rigs etc. How are the foundations put in place?

Answer 1

depends a lot on the depth of the water, etc. If it's shallow, they can erect something called a Coffer dam, which is a temporary dam around what they want to build, then pump out the water and mud, and replace with enough concrete until they reach teh surface of the water.
Another way is to drive pilings into the ocean floor, and place concrete on top of the pilings.
Many oil rigs are built elsewhere, and floated into position, and either sank to rest on the bottom if the water's shallow, or anchored to the ocean floor by cables if the water's deep.

Answer 2

you do know that there is land at teh bottom beneath the water, right? Well you either dam up the source so there is no water, You place stuff into the water until you have built the bottom up above the water,or you use diving gear to work beneath the water. After that its done pretty much the same way you do it on the ground

Answer 3

There are many different kinds of foundations -- anchoring to the sea bed, floating, flexible, etc. Depending on the depth of the water a choice will be made. I would recommend reading the following:

http://en.wikipedia.org/wiki/Oil_platform

Answer 4

walls i would presume not being an engineer myself, probably put in the steel foundations first then plug the concrete wall moulds strieght into the foundations? oil rigs are made on land there just platforms on giant legs i think

Answer 5

Cofferdams

Answer 6

They get some King geezer to sit on the beach. Or they bring out some other geezer from the bible, with a piece of wood to part the water.........

Answer 7

if the water is deep.. they just put up forms and pour cement underwater.. it will still cure.. the hard part is digging out the loose material and keeping it out of where you want the cement forms.

Answer 8

they make it and then they put it in the water... so its made before placed in the water.

Answer 9

God put them there "in the beginning"