FYI JMA Shinkansen bridges and tunnels

martinvk

since 10 Aug 2002
Since starting my own version of the Hiroshima - Okayama Shinkansen line, following a wonderful trip to Japan during which I had the pleasure of travelling on that segment, I have been using hirochi's JMA bridge and tunnel assets with great success. However, there is one behaviour that had me stumped until recently. When two segments, both placed in the same direction are joined, no problem. However, if they are placed in opposite directions, with the ends either facing towards each other or facing away from each other, the tracks will cross over, switching sides. for some reason JMA Shinkansen Bridge A is the only one that doesn't do this. All the others with two tracks (JMA Shinkansen Bridge B to Wx and tunnel A and B1) have this behaviour.
To overcome this, either use a section of Bridge A when joining to segments that are not placed in the same direction or use two pieces of JMA Shinkansen ATRACK Slab. If you place a short piece of support structure under the single track, it will not show.

An overview of the objects mentions above. Segments in columns 1 & 5 where placed left to right and those in columns 3 & 7 where place right to left. Columns 2 & 4 show the crossover behaviour. In column 6, are the JMA Shinkansen ATRACK Slab segments joining two facing segments.
JMAoverview.JPG


A closer view of the bridge and tunnel names as well as column 1 and part of 2.
JMAhigh.JPG

JMAlow.JPG
 
I've had that occur too and then got the bridge I was using to work okay but don't remember what I did to do it.

I don't remember if the asset is classed as track or a bridge and I'm not sure if that makes a difference or not.
 
I used a tiny piece of no-ballast rails as a buffer between the two sections that caused the twist. In one spot, I used a normal, 1-track (X2) steel bridge over an invented road.

Otherwise, I imagine it gives the passengers a thrill to be running a chicane. :p

Bill
 
Since the placement direction seems to be the cause of this issue, is there a reliable way to determine what direction an existing piece of track was placed after the fact?
 
Thought I had a solution but all it does is confirm the obvious.
trackdirectionarrow.JPG

The little track direction arrows show the direction each track segment was placed. For the ATrack, while interesting, there is no issue. For the others, while the track itself is not an issue, the supporting spline is.
While Bridge A doesn't have a crossover issue, Bridges B and C do. Their column B spline was placed right to left in the image and they show the crossover issue.
So, while the double track objects look symmetrical, they do have a direction which causes the crossover effect.

Is there a similar type of attached object for splines?
 
I use track-objects to check the direction. Signals should face right at me and ones that face the wrong way are on those sections I laid in the wrong direction with wrong being a relative thing.

There is a track direction tag. Is that useful for what you need, or is that something that tells the AI only to go in a single direction?
 
My new little track direction arrows show the direction I placed the track, even from relatively far away but don't do anything for splines which in the case of the Shinkansen tracks is what is causing the crossover issue.
I will have to be more disciplined and remember to always place those tracks / splines in a specific direction and stick to it in the whole route or work hard to remove those crossover issues.
 
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