Japanese Railway signalling system

[stevej]

G'day, Unfortunately I do not speak Japanese. I am attempting to understand the various railway signals and signs that I have seen in You Tube video clips.

I presume that the pentagonal shape signal/sign that appears near to level crossings is associated with level crossings. There does not appear to be any indication exhibited.

So, I presume that an indication would only appear if the level crossing protection was not functioning. Though, the proximity of these signals/signs would not provide much braking distance at high track speed. I have also seen another signal incorporated, an alternating pair of vertical yellow lights. This I presume indicates that the level crossing protection is functioning.

I am also perplexed by the position of running signals on curved double track, being outside the opposing track. I presume that this is to provide visibility on curved track.

I do wonder why such a signal is not placed in between the tracks, though possibly insufficient clearance would occur in such placement. However, with the location outside the opposing track, visibility might be prevented by the passing of an opposing train.

Is there an identification to distinguish between controlled (absolute) and automatic (permissive) signals ?

Finally, on single track, does the tall post with white top and red cap indicate the location of level crossing circuits ?

I will appreciate any responses.

Steve.

 

 

[bikkuri bahn]

Each railway has its own system for level crossing indicators. In general, a white light will indicate a crossing working normally with no obstructions. If there is a malfunction or obstruction, a red flashing signal will activate. Trains are restricted to 130kmh for this reason.

 

Railways in Japan don't bother with the absolute/permissive rigmarole. All trains use some form of ATS/ATC/ATO. Red means stop and you don't and can't pass that red indication.

 

This may be of interest discussing Japanese signaling practices from a Dutch perspective:

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

[Kiha_120]

G'day, Unfortunately I do not speak Japanese. I am attempting to understand the various railway signals and signs that I have seen in You Tube video clips.

I presume that the pentagonal shape signal/sign that appears near to level crossings is associated with level crossings. There does not appear to be any indication exhibited.

So, I presume that an indication would only appear if the level crossing protection was not functioning. Though, the proximity of these signals/signs would not provide much braking distance at high track speed. I have also seen another signal incorporated, an alternating pair of vertical yellow lights. This I presume indicates that the level crossing protection is functioning.

I am also perplexed by the position of running signals on curved double track, being outside the opposing track. I presume that this is to provide visibility on curved track.

I do wonder why such a signal is not placed in between the tracks, though possibly insufficient clearance would occur in such placement. However, with the location outside the opposing track, visibility might be prevented by the passing of an opposing train.

Is there an identification to distinguish between controlled (absolute) and automatic (permissive) signals ?

Finally, on single track, does the tall post with white top and red cap indicate the location of level crossing circuits ?

I will appreciate any responses.

Steve.

G'day !  I believe you will find the pentagonal shaped sign with white lights are distant/repeater signals, typically used where sighting is problematical.

5 white lights vertically indicate next signal will be green/clear

"  lights diagonally indicate 'caution' 

"  lights horizontally indicate 'stop' at next signal.

 

 

I could well be wrong here, but from the countless hours I view through the windscreen of various Japanese trains ( all vicariously unfortunately ) this is the conclusion I have come to.

STOP PRESS !    Ooops !  No I AM wrong - I'm thinking of the circular boards

Edited August 11, 2015 by Kiha_120

[kvp]

The idea behind the obstruction detection system is that in case of a malfunctioning gate, the fault is indicated locally and the top speed of the line is lowered. In case of an obstruction, the preceeding signal should fall back to stop (red). With a malfunctioning gate, it's still possible to cross with the trains, but they have to go slower on the whole block and drop to a walking pace at the gate so they can proceed on sight. The indicators are required in case there are more crossings in the block so the drivers can know which one is faulty. (the european practice is to drop all signals to stop, then lift this restriction with a very slow, 15 km/h speed restriction on the whole block, regardless of its length)

 

Signals usually are not really placed in positions that would be normally blocked by another train, so they are either mounted high enough or they are meant for full bidirectional running on a double track line, so it's possible that both tracks have signals for both directions.

 

ps: The round signal repeaters with the lights in three possible positions are taken from american practice, while the colored lights are similar to european practice. (and are very similar to the early 20th century swiss practice, including the shape of the signals and light configurations)

[westfalen]

Wikipedia has a good page on Japanese signalling, in fact the second image on the page is of the pentagonal obstruction indicator.

https://en.wikipedia.org/wiki/Japanese_railway_signals

 

The 'Block Signal' section describes the difference between controlled and automatic signals.  Automatics have a number plate counting down toward the next controlled signal.  The rules allow a train to proceed at 15kph after stopping for one minute although the article says that many operators now treat all signals as absolute.

 

I can't say I've ever seen bi-directional signalled double track in Japan, so if there is a signal facing the wrong way it is probably for the other track but placed on that side for sighting reasons.

[SuRoNeFu 25-501]

Wikipedia has a good page on Japanese signalling, in fact the second image on the page is of the pentagonal obstruction indicator.

https://en.wikipedia.org/wiki/Japanese_railway_signals

 

The 'Block Signal' section describes the difference between controlled and automatic signals.  Automatics have a number plate counting down toward the next controlled signal.  The rules allow a train to proceed at 15kph after stopping for one minute although the article says that many operators now treat all signals as absolute.

 

I can't say I've ever seen bi-directional signalled double track in Japan, so if there is a signal facing the wrong way it is probably for the other track but placed on that side for sighting reasons.

It seems that the portion of San'yo Line that owned by JR Kyushu (where the portion itself is the Shimonoseki - Moji that runs through the Kanmon Tunnel) uses the "bi-directional signalled double track" concept, because when a maintenance work is carried out inside the tunnel, it means that only one track from the double track that is usable (as this tunnel handles very busy train traffic). With this, it requires both tracks to have bi-directional signalling system being installed, to allow the deployment of bi-directional traffic pattern during the closure of one track for regular maintenance work in the tunnel (it can be maintaining the track, or the tunnel itself). This is called as "単線並列区間", which literally means "two single track running side-by-side".

 

Slightly off-topic: this is also the reason why both tracks have overhead line dead section warning sign located before the entrance of Moji station from the tunnel (^_^)v

[westfalen]

I knew someone would know of somewhere, there is always an exception to the rule.  The most used phrase in the Queensland Rail rule book is 'except when'.

[stevej]

G'day, and thankyou everyone for the responses to my question. I have downloaded the linked files.

I now have some understanding of the Japanese signalling situation. Especially in regard to the pentagonal shaped obstruction signal for level crossings.

I have also now seen another level crossing signal indication, a circular head with two vertical yellows. Yes, I had noticed the adaptation of the Pennsylvania RR position light type signals.

These being utilized in Japan as repeating signals for running signals. The multiple use of independent running signals for junction turnouts is intriguing.

A single turnout being by double head, as in USRR practice. I continue to be amazed by the location of various signals on double track. I acknowledge the need for visibility on tightly curved track.

But, I have now seen a position light repeater attached to a nearby building well beyond the opposing track. With the short block signalling, the scene can be crowded with both running signals and level crossing signals.

All located in different positions. I presume that incab signal system is employed for hectic double line routes. The appearance of running signals that pulse, fully extinguishing at intervals, in intriguing.

I presume that this facet is designed to delay bulb burnout. However, at high speed , a running signal may be approached while actually extinguished.

Here we did have a flashing yellow subsidiary signal being for Shunt Ahead purposes. The flash cycle did not result in any long period where the lap was extinguished.

Plus, a Shunt Ahead was utilized at low speed. Subsequently, pulsating indications were implemented here in running signals. However, these pulsating indications do not fully extinguish, but pulse in intensity.

130 kph is indeed a stunning feat for narrow gauge commuter rail operations. It was proposed to raise the maximum road speed for the Waratah suburban sets in Sydney to 130 kph.

But, this was ridiculous and not implemented due to all other suburban sets restricted to a maximum of 115 kph. Yes, it is becoming obvious that the various Japanese railway companies had adapted slightly different signal variations.

I have seen two versions of the shunting signal, two horizontal yellows (possibly whites), the other by one white and one red horizontal.

The latter being similar to the Queensland Railway leading position light signal used at turnouts. The Japanese version being ignored during main line running, obviously only utilized during shunting.

Non motorized points possessing a Switchstand adapted from USRR practice. The more Japanese rail infrastructure that I observe, the more intrigued that I become.

Thankyou for the responses.

Steve.

[westfalen]

We had a thread a while ago about the pulsating signals, I think we came to the conclusion that it was due to mismatching of the frequency/frame rate of the camera used and that of the signal's power supply rather than the actual signal pulsating.  On a trip a couple of years ago a friend and I both took video of the same signals and they pulsated in one but not the other, at the time we were videoing neither of us noticed the signals pulsating and as we are both train drivers it is something we probably would have noticed.

 

We've been running 140kph commuter trains up here on the Gold Coast and Springfield lines for a few years now.

Edited August 14, 2015 by westfalen

[katoftw]

LEDs pulsate on camera.  Have a look at any destination board on the front of a train in videos.  Or tail lights on cars in videos.  9 of 10 times you'll see the pulsating.

[marknewton]

The only way you'd get a Waratah to run at 130kph would be to motor downhill with a tailwind. :)

 

Cheers,

 

Mark.

[stevej]

G'day, and thankyou for your additional responses. I had given thought to the pulsating signals as being a cause by camera frame rate. However, when I have seen that artefact previously, it has been a rapid flicker.

This pulsation seen in three video clips that I have grabbed, is a very slow cycle and the signal lamp does fully extinguish for a definite period. Decreasing in intensity as it becomes extinguished. I forget which particular video

clips that I have seen this artefact as those are at home. But, I do remember that one clip ended at Osaka station. I had also thought that perhaps this pulsation may have been due to a power surge in the signal supply. But, I have seen

this artefact in three separate clips now. Otherwise, all of the other clips that I have downloaded from You Tube do not possess this pulsating artefact. I have never been in the cab of a Sydney Waratah emu, so don't know how they perform.

115 kph was fast enough for me. While working down in Tassie on the narrow gauge, maximum speed was 60 kph. And, there was not much of that. You get to see plenty of the countryside rolling past at the average train speed of 40 kph.

I do remember the LED type signals introduced in the Sydney Metrop. Those at night time were VERY bright. LED light signals are now common here in NSW, but I have not been able to shoot any video from the cab for many years.

So, I don't know if those LED lights flicker on video tape. I naturally prefer the traditional semaphore signals that we had here in NSW. Those had grace and style.

One recently encountered Japanese signal indication has me intrigued. The previous signal exhibiting Green, the subsequent signal being a three head plus lower position light repeater at a diverging junction.

All three of the main signals exhibited Red, while the position light repeater displayed three verticals (next signal clear). This particular indication does intrigue me.

Steve.

[bikkuri bahn]

If you can actually give us links to the videos showing the indications, it would help alot in explaining things.

[stevej]

G'day Bikkuri bahn. Yes, I must in future write down the particular video clip title in which I find something of interest. I have found one of the video clips today featuring the pulsating signal indications.

Wakayama to Osaka by weegee99.

https://www.youtube.com/watch?v=NBPOIyXEt0Q

I am still searching for the clip featuring that diverging junction signal bracket. I download video clips from You Tube here at the local library. And, view them at home on my media player.

I have also found an interesting web site featuring Japanese railway signal and track diagrams. http://railwaytrackdiagrams.web.fc2.com/index.html

Unfortunately, I am not able to find a diagram key to explain the various signal symbols used in the diagrams.

And, naturally, I am unable to understand the Japanese text.

Thankyou for your respone.

Steve

[Ochanomizu]

Hello,

 

The pulsating signal is simply the phasing of the light with the frame rate of the camera.  A blinking signal in Japan blinks at a 1s cycle.  Ie: 0.5s on, 0.5s off.

[westfalen]

The pulsating effect in your video is the same as I mentioned my friend and I got on video on the Keikyu Daishi line a couple of years ago that appeared on video from one camera but not the other and neither of us noticed visually at the time we were filming.

[stevej]

G'day Ochanomizu and Westfalen, Thankyou for your responses.

You have confirmed that the signal pulse is caused by the particular camcorder frame rate. I am happy to know this as I did think that should the signals actually pulse as viewed, that would be most odd.

I have also now found the particular triple head junction signal in which I believed all three indications were red. In the video clip, Tokyo to Otsuki.

I have taken a screen capture on the computer and the middle head does actually show a yellow indication. The appearance of all three displaying red is probably due to the lower resolution of my media player. Plus, from the screen capture, it is obvious that the yellow indication is at a different location within the head. This I did not notice when viewing the video clip via my media player.

Steve.