It is helpful to have a brief history of London Underground when considering any aspect of its maintenance or future development. The system has developed over more than 100 years and only comparatively recently come ...It is helpful to have a brief history of London Underground when considering any aspect of its maintenance or future development. The system has developed over more than 100 years and only comparatively recently come under the control of a single organisation. This partly explains the complexity that has resulted from differences in construction between lines. A brief History is accordingly appended to this presentation as Appendix B. The recent History outlines how Tube Lines have come to be involved with London Underground and explains a little of the reason for our existence. We are required to maintain and improve London Underground assets. Our performance has to be measurable and it follows that we need to know the current condition "value" of those assets. A large part of London Underground's infrastructure is tube tunnels some of which have not been fully assessed since they were first constructed in the 19th Century. They used materials whose physical and durability properties were not, at the time, fully understood; and they were designed on a very empirical basis if they were "designed" at all. Some shafts and other elements of the Tunnel Asset appeared to have been forgotten or lost when the Public Private Partnership (PPP) instigation procedures began in earnest in 1998. A major part of our current maintenance programme is thus to ascertain and agree the current condition and extent of approximately 178kilometres of tube tunnel asset that we are required to maintain and improve.展开更多
文摘It is helpful to have a brief history of London Underground when considering any aspect of its maintenance or future development. The system has developed over more than 100 years and only comparatively recently come under the control of a single organisation. This partly explains the complexity that has resulted from differences in construction between lines. A brief History is accordingly appended to this presentation as Appendix B. The recent History outlines how Tube Lines have come to be involved with London Underground and explains a little of the reason for our existence. We are required to maintain and improve London Underground assets. Our performance has to be measurable and it follows that we need to know the current condition "value" of those assets. A large part of London Underground's infrastructure is tube tunnels some of which have not been fully assessed since they were first constructed in the 19th Century. They used materials whose physical and durability properties were not, at the time, fully understood; and they were designed on a very empirical basis if they were "designed" at all. Some shafts and other elements of the Tunnel Asset appeared to have been forgotten or lost when the Public Private Partnership (PPP) instigation procedures began in earnest in 1998. A major part of our current maintenance programme is thus to ascertain and agree the current condition and extent of approximately 178kilometres of tube tunnel asset that we are required to maintain and improve.