Prototype blog comment on Japanese Signaling and design

[KenS]

I found this blog post completely by accident:

 

http://signalling.wordpress.com/2011/02/16/signals-are-key/

 

It's an English-language post describing a Dutch railway evaluation of how signaling and the related track design of Japanese railways contribute to their efficiency.  It's worth reading as a perspective on how track layouts on the prototype are designed.

 

I was particularly impressed by this comment: "In employing these different „system philosophies”, the potential for simplification and cost saving appears to be enormous. Compare Tokyo and Utrecht Central stations. Both have a similar number of platforms and a comparable role in the network. Tokyo Central has 28 points, Utrecht Central has 280! Both stations have uncoupled the main traffic streams to eliminate crossing moves as much as possible. At present Utrecht handles 60 train movements per hour, Tokyo handles 180."

[Martijn Meerts]

Tokyo Station is really straightforward if it comes to the trackplan. Most tracks are dedicated to certain lines, and there's nearly no need for a train to every switch to a completely different track.

 

Utrecht is a mess though, too many tracks for the traffic it needs to handle, and if something needs to change, they just add new tracks rather than adjusting existing tracks it seems ;)

[bikkuri bahn]

Very interesting blog post, thanks for linking to it.  The mention of bi-directional running rings true- it seems the common thinking is that it allows maximum flexibility, but here in Japan it's seldom if ever used on high capacity lines.  The emphasis (as anyone who has spent time observing urban rail operations in Japan knows) on railway operation here is throughput, and bottlenecks reduce that.  Now, as a railfan I love the intricate trackwork arising from use of crossovers, single and double slip switches and the like, but you don't see much of that here in Japan compared with Europe or even some US Eastern Seaboard railway operations.

 

Also interesting about the 40km/h speed limit in stations in the Netherlands- this certainly would slow down the flow of traffic.  Just think of the Yamanote and Keihin Tohoku Line trains at Tokyo Station- they arrive seemingly at near top speed and slow down after entering the platform area tracks.

[Martijn Meerts]

The 40km/h limit is not for all stations/train services. In fact, I've never been on a station where trains would slow down to 40 km/h.

 

What's funny though, with my father's layout we made it so that pretty much every bit of track is bi-directional. This required a LOT of additional turnouts, a LOT of additional occupancy detects, and a LOT more complicated setup in the controlling software. It is more interesting to see trains run both ways, and trains stop less often, but you can forget about running on a simulated time table (not that we're doing that ;)) .. I can see it costing a ton in prototypical operation though, without much gain.

[KenS]

One of the reasons to have bi-directional signaling is to allow fast trains to pass slow ones "anywhere".  That's particularly important when mixing freight with fast passenger service, but also important if trains may not keep exactly to schedule.  Japan gives up that capabilty, having strictly-scheduled passenger trains pass at stations with sidings, and either relegating freight to small windows between trains or late at night (which they can do given their small volume of freight) or building special trains for high-speed operation (most of their newer freight gear can keep up with 110 kph passenger trains, and the M250 can run with faster express trains).

 

In the west, I don't think Japan's solution would work without dedicated passenger rights-of-way, as freight is more common, and the speed disparity is (or should be) greater.

[marknewton]

Very interesting blog.

 

As for bi-di signalling, I could have done with it last night. Stuck behind a failed freight train - for 83 minutes. When you're on your way home around midnight that's the last thing you want. What really annoys me is that all the bi-di infrastructure is in place, it just hasn't been commissioned. Grrr! :angry3:

 

Cheers,

 

Mark.