Talk:Seikan Tunnel

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This article is part of WikiProject Trains in Japan, an attempt to better organize information in articles related to rail transport in Japan. If you would like to participate, you can edit the article attached to this page, or visit the project page, where you can join the project and/or contribute to the discussion.
A fact from this article was used in the "Did you know" section of Portal:Trains on May 22, 2006.

In case you were wondering, the DYK was "...that the Seikan Tunnel (connecting the islands of Honshu and Hokkaido in Japan) is currently the longest railway tunnel in the world, and will be until the new Gotthard Base Tunnel (Switzerland), with a length of 57 km (36 miles), is opened?--Commander Keane 13:23, 22 May 2006 (UTC)

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[edit] Stability question

Just wondering how the dynamite effected the stability of the rock - compared with boring? CustardJack 15:24, 6 May 2005 (UTC)

It is a good question, and I'll answer it as best as I can with my limited knowledge.
By "boring" I'm assuming you mean Tunnel Boring Machine (TBM). As the article suggests TBM was abandoned due to the high variabiliy and fagility of the rock. (TBM's are best used in rock with uniform properties, rather than the varying strata, soft and fissured rock found in the Seikan.) Since the rock made a TBM difficult to direct and caused damage to the TBM, a more direct (but slower) approach of blasting and picking was used (Picking was used in the worst rock conditions). Blasting and picking can be targeted and optimised for each different situation encountered along the route, so a safe level of stability can be achieved.
An example of the advantage of blasting as compared to TBM in the Seikan tunnel was the use of different cross sections in different rock stability situations. Because of blasting's targeting ability, in the worst stabilty situations along the tunnel route (mid-way along the Strait) instead of the traditional circular bore made in one pass from a TBM, a circular cross seection was blasted in 4 sub cros ssections. First two small circular bores, then the rest in two goes (top drift and bottom drift). Naturally, with steel/concrete reinforcement put in place after each of the four passes, blasting proved a much more stable option than TBM. --Commander Keane 4 July 2005 20:50 (UTC)

[edit] Removed link

I removed the link to a Babelfish translation of the Japanese external link. Here are samples of the Babelfish translation:

"This adapter unit did from the tunnel and the bridge and the earth laid etc., as for operation of main island one the Japanese railroad constructive public corporation Morioka branch office, as for the Hokkaido one the Sapporo branch office, as for the blue 函 tunnel blue 函 constructive bureau constructed."

"In the blue 函 tunnel, in order for the seawater not to exert adverse effect on the concrete slab track, the corrosion resistance in sea water moderate heat Portland cement is used, as the crack crack does not occur, the special throb which introduces prestressing is used."

I'm putting the link here so interested parties can find it; it doesn't seem clear enough for a general readership.

[edit] Safety

Given the designed in safety factors of the Channel Tunnel, are the Japanese sure that the Seikan Tunnel meets acceptable safety limits ? One would assume so, however it can't be missed that this tunnel is only one tunnel, whereas the Channel Tunnel is 3 tunnels, one a specific safety tunnel. Does anybody know the Japanese view on this ?--jrleighton 12:13, 9 February 2006 (UTC)

I'm interested too, I might have a dig around for some info although I'm not sure if this sort is published. Keep in mind that when constructed the Seikan had:
  1. A pilot bore (small diameter)
  2. A service tunnel (larger diamter, I'm sure of it's current usability)
  3. The main bore
So it's comparable to the Channel Tunnel.--Commander Keane 12:23, 9 February 2006 (UTC)

[edit] Ideas for expansion

  • Inundations (safety and pumping stations))
  • Grouting procedures
  • Constructions procedures (steel ribs, cross section selection)
  • Images of the cross sections, top and side views of the entire tunnel

--Commander Keane 00:06, 17 May 2006 (UTC)

  • Current passenger and freight usage and its market share compared to other modes Softgrow 00:17, 17 May 2006 (UTC)

[edit] The fate of Yoshioka-Kaitei

Hmm. JRTR says the station was "demolished", but ja-wiki merely states that it's no longer served by scheduled traffic (定期列車の停車がなくなる). Who's right? Jpatokal 16:27, 18 May 2006 (UTC)

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