Hi machorne, I have read your post on the hybrid brick-cast iron linings for the Great Northern and City Line (pasted below). I would be interested in the actual geometry of the section, i.e. thickness of the masonry lower half etc. Do you know where I can find this info? Are you aware of any published articles that describe this? Many thanks
You mentioned the following in your post:
"When the Great Northern & City was built (it opened in 1904), it was shield driven and entirely lined with cast iron and cement grouted in usual way. As each section was driven forward, the lower cast iron segments were removed in short sections and replaced by a number of rings of brickwork; the cast iron so recovered was then used elsewhere. The tunnels are therefore cast iron (top half) and brick (lower half). This is probably unique, but gave rise to much quieter running than wholly in iron."
You mentioned the following in your post:
"When the Great Northern & City was built (it opened in 1904), it was shield driven and entirely lined with cast iron and cement grouted in usual way. As each section was driven forward, the lower cast iron segments were removed in short sections and replaced by a number of rings of brickwork; the cast iron so recovered was then used elsewhere. The tunnels are therefore cast iron (top half) and brick (lower half). This is probably unique, but gave rise to much quieter running than wholly in iron."