Great Central bridge news.
 

Why do they need "extensive" ground surveys on the site where a previous bridge stood for over 60 years?

A new bridge will have to meet much more stringent safety and building standards than the original bridge did I suspect :)

They are planning to use the existing bridge foundations that still remain below ground, however they need to determine the condition of these, as they are quite old now.
All the best
Phil

The original bridge was built 1898 and demolished about 1973, the remains of the foundations will not have received any attention since then. That's 40 years now.

Regards, 62440.