On 13 Jan., 09:57, Graeme wrote:


http://london.thesouthafrican.com/li...erground-and-i...

Didn't Brunel's sheild predate Gateshead?



Yes, but Gateshead machine permitted tunneling to be carried out at
far lower cost. This was due to the smaller bore diameter, and also
the construction of the tunnel itself. I believe Gateshead used pre-
fabricated tunnel segments rather than brickwork. These innovations
made tunneling affordable. Rememeber that the company that built
Brunel's Thames tunnel went into bankrupcy on account of the
escalation of construction costs, and that the tunnel wasn't completed
until many years later..