Welcome to European Tribune. It's gone a bit quiet around here these days, but it's still going.
A cubic meter of cement weighs something on the order of ten times as much as a cubic meter of water.

"A few tons per meter" is unlikely to cut it.

- Jake

Friends come and go. Enemies accumulate.

by JakeS (JangoSierra 'at' gmail 'dot' com) on Tue Dec 22nd, 2009 at 06:13:47 PM EST
[ Parent ]
Sorry for nitpicking, but
  1. cement is actually rather light, c. 1.5 t/m³;
  2. concrete is more dense, up to 2.5 t/m³;
  3. however, methinks the buoyant tunnel would be made of steel, which is much more dense than concrete: 7.8 t/m³.

*Lunatic*, n.
One whose delusions are out of fashion.
by DoDo on Tue Dec 22nd, 2009 at 06:24:42 PM EST
[ Parent ]
portland cement has a density of 1.44 (that is, m^3 of portland cements weighs 1.44 times that of a m^3 of water).  Concrete can go as high as 3 with very dense aggregate.  Are we talking about trainloads of cement here, because any load will be subject to the axle loading of the rails which sets an upper bound on the train linear density.

Or are we talking about the tube itself?  I was considering the tube to be made of steel alone, but now you mention it, a ferrocement design would be much lighter (steel has a density of about 8).  There are many ferrocement boats out there and ferrocement is lighter than concrete.

by njh on Tue Dec 22nd, 2009 at 06:27:27 PM EST
[ Parent ]


Occasional Series