
Tokyo lowers subway line underground in one night without service disruption - gregorymichael
https://www.youtube.com/watch?v=wIbZqqLra9k
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stevesimmons
I am always impressed by these kinds of meticulously planned civil engineering
works, especially when other similar sized projects can limp on for months and
months.

One of my favourite examples while growing up in Fitzroy in Melbourne
([https://goo.gl/maps/RzHa4MUWxuM2](https://goo.gl/maps/RzHa4MUWxuM2)) was
when a 1.6km stretch of a 4 lane road was completely replaced over one weekend
in 1998. What made it so impressive was trams running down the centre of the
road; the central two lanes had tram tracks embedded in concrete a foot thick,
with overhead power lines above. Replacing this all in a single weekend was
spectacular to see!

From memory, the timetable was something like:

* Friday 9-11pm - close the road, tow away cars still parked there, remove overhead tram power lines

* Friday 11pm to Sat 7am - jackhammer up the two central lanes of tram tracks embedded in concrete a foot thick (not much sleep for the local residents that night!)

* Sat morning - cart away concrete rubble

* Sat afternoon/evening - dig up two outer asphalt lanes, remove concrete curbs with footpath. Once each section of road was excavated back to its foundations, new tram tracks were placed in position with formwork for their supporting concrete.

* Sat evening/night - pour concrete around tram tracks and allow to set. Redo concrete curbs to footpath. Adjust height of drains and manhole covers in the two outer lanes.

* Sun early morning- eerie calm until concrete is hard enough to relay asphalt road lanes beside it.

* Sun afternoon/evening - lay two outer asphalt road lanes (grade base, spread gravel, compact, asphalt base layer, asphalt top layer)

* Sun night - reattach overhead power lines for trams, etc

* 3am Monday morning - paint white lines on road

* 6am Monday morning - turn on traffic lights. Fully open for traffic!

With work crews assembled from all round Melbourne, the full 1.6km stretch was
done in parallel, from start to finish in 57 hours. Zero disruption during the
working week!

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malloryerik
Am I overly pessimistic in thinking that this wouldn't happen in the United
States?

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mmagin
Not really. Both Japan and western European countries are much better at doing
big infrastructure affordably.

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whazor
Because there is less space and more people per square meter. There is more
money to avoid downtime.

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ericzawo
Anyone else from Toronto watching this and feel a sharp pain in your back? I
sure am.

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superjisan
This is beyond impressive. Kudos to the workers and planners.

