Tokyu Toyoko line crash

[ToniBabelony]

Just last night, before closing down and running the last trains in heavy snow, at Motosumiyoshi station, a Yokohama Minato Mirai Y500 series (empty run) ran into a Tōkyu 5050 series (in service), injuring 20 and causing some pretty heavy damage: http://matome.naver.jp/odai/2139239528511158501/2139239552911321803

 

Fan made video with pictures:

http://www.youtube.com/watch?v=dtSSPxc58Lg

[miyakoji]

Looks like it telescoped a bit.  Did the snow obscure the signals?

[ToniBabelony]

Looks like it telescoped a bit.  Did the snow obscure the signals?

 

The Tōyoko line operates on an electronic ATC-P system, so probably the snow obstructed the sensors of the ATC-P and/or the emergency brakes on the Y500, that tailed the 5050, failed to make the stop in time.

[bikkuri bahn]

Once again, it's still too early to speculate, and unfortunately the news cycle is being dominated by Olympic gold news, but other news reports state both trains were carrying passengers, 80 people in the lead train and 60 in the following train.  Also, the first train had overrun the platform by 20 meters (one car length), though the reports don't clearly state whether the train reversed as is normal practice. Apparently due to the weather, trains were running at either 10 minute delays, or 10 minute headways, unsure which.  Details may likely change as the investigation continues.

[kvp]

Considering what is missing from both cars, this looks serious. It's lucky that noone died. Afaik the old JNR trains had separate cold and warm weather versions, with the warm weather versions used around Tokyo didn't have proper dehumidifier equipment in their brake system, so their brake lines could freeze up in sub zero temperatures. I don't know what type of equipment tokyu uses and can't really find much info on the Y500 either. Also, since atc-p is afaik magnetic, it can not be blocked by snow, so either brake problems or simply brake distance problems.

 

ps: Additional pictures, with the slightly damaged Y500 in the 3rd picture:

http://matome.naver.jp/odai/2139239528511158501

(it looks like the tokyu train was too soft)

Edited February 15, 2014 by kvp

[bikkuri bahn]

Both trains are essentially the same Tokyu carbody design.

[kvp]

I just wonder why did the motor unit and (afaik) the control trailer telescope on the same train (with the motor derailing) while the colliding Y500 suffered only very minor damage?

[lurkingknight]

It's probably not cold enough to freeze the fluid, especially with the amount of braking that's done in operation... we're not talking a cold train that's been sitting in -30C temps. Any hydraulic fluid in those systems is probably up to proper operating temperatures. Unless the actual friction material on the brakes is too cold.. but again... we're not talking extreme cold here. 

[westfalen]

A train's brakes are air rather than hydraulic so no fluid to freeze but if condensation freezes in the brake pipe it could block the flow of air.

 

If the first train overshot the platform would he be able to set back without authority, our rules in Brisbane are that we cannot set back onto the platform without the ok from train control that the section behind us is clear and we will not trip the preceding signal section. If the first train started setting back at the same time as the second passed the preceding signal protecting its rear the driver of the second train would not have gotten any warning that the section if front of him was occupied or at least have that warning reduced below the margin required to stop in time.

Edited February 15, 2014 by westfalen

[E6系]

Hello Mr westfalen,

 

I believe the brake lines are heated to prevent the condensation from heating.  But I rule nothing out until the investigation is complete.

[lurkingknight]

I had a feeling the brakes would be air operated, but again normally such systems have design features that are able to deal with the climate in the operational area. It just doesn't seem like it would've been cold enough. But then again as air decompresses it will cool and perhaps condensate.

 

Either way, train accidents like that usually end up a lot worse in terms of injury and loss of life, this one was very lucky.

 

It's always too easy to be an armchair expert on things like this, so I'd be somewhat interested in the findings of the investigation.

Edited February 15, 2014 by lurkingknight

[cteno4]

more coverage

 

http://www.japanprobe.com/2014/02/15/photos-two-trains-collide-on-toyoko-line/

 

http://mainichi.jp/english/english/newsselect/news/20140215p2g00m0dm023000c.html

 

http://blogs.yahoo.co.jp/stuff_4004mrgyou/54555782.html

 

jeff

[ToniBabelony]

Man, I'm the best bench-speculator! I should get paid for this... Or maybe be a broker or banker xD