2 ms·
That is an early cost estimate and tunneling estimates are by far some of the most innacurate in civil engineering because you never know how much the geology w
by akiselev 10y ago
That is an early cost estimate and tunneling estimates are by far some of the most innacurate in civil engineering because you never know how much the geology will differ from what the estimate assumed. Construction on the first tunnel segment started a year ago and won't be complete until the 2020s so it'll take a while before the developer knows how bad the overrun will be on that section, let alone for the whole line.
- trome 10y agoSooo crunchy there, jeez! Tunneling isn't as unpredictable as you suggest, rail lines are often completed on time and under budget[1]. When you do crazy stuff like try and build the largest tunnel ever built with cutting edge technology and don't plan for failure[2], that is when things go bad. Luckily, rail doesn't need giant tunnels, tunnel boring machines for that size tunnel are a known quantity. 1 - https://www.ch2m.com/newsroom/news/new-seattle-light-rail-line-opens-ahead-of-schedule-and-under-budget https://www.ch2m.com/newsroom/news/new-seattle-light-rail-li... 2 - http://q13fox.com/2016/07/21/bertha-seattle-tunnel-project-223-million-over-budget/ http://q13fox.com/2016/07/21/bertha-seattle-tunnel-project-2...
- Animats 10y agoThey already have 40Km of tunnel open with trains running.