🚀 go-pugleaf

Graham Moore wrote:

> I've got a very busy route and I'm trying to double up the amount of tracks 
> (double the capacity, right?), but the configuration isn't going too well.
> 
> Has anyone seen a tutorial about with a 4 track system? (2 in each 
> direction).

I'm guessing you have probably solved this yourself or got bored in
the month since you wrote that as I can't access the screenshots or
saved game you posted links to, but I've only just started reading the
group again. I'll give you my take on it, but feel free to ignore it!

For most situations, normal double track with regular signals is fine.
Sometimes you need additional tracks - the usual pinch points are
stations, junctions, long bridges and tunnels, uphills, and where you
have mixed speed traffic.

If you build a standard 4-track station with 2 up lines and 2 down
lines, allowing all trains to choose between either line, that is
usually sufficient for a through station. The only time you might want
more is if there are a lot of stopping trains, regularly filling both
platforms, _and_ non-stopping trains that then have to wait for them.

Junctions - can be easy or tricky, depending on the junction layout.
One key point is to make sure that trains going round sharp bends or
uphill completely clear the mainline first by providing a relief line
on the approach to a junction.

If you have uphill sections that significantly slow down your trains,
build a relief line on the hill - it needs to start just far enough
back that trains clear the junction then slow down on the hill, and
needs to carry on beyond the top of the hill to give trains time to
speed up again. Assuming all trains have similar speed profiles, treat
the two lines as equal, with regular signal spacing along both of
them.

If you have mixed speed traffic, you will do best to either provide
two completely separate running lines - one fast and one slow - with
little or no link between them. If the lines do have to merge at
junctions or stations, use signalboxes to separate the trains
afterwards.

If none of that applies and you are still short of capacity, you may
need to quad-track your whole line. If you can divide the traffic
roughly in half in some way, do that, and keep the two halves entirely
separate. If not, at the start of the double track have two-way
signals and a slightly longer signal block than usual to ensure that
trains take alternate lines. Don't provide connections from one line
to the other other than where absolutely necessary, because every link
has the potential to bring trains into conflict and thus reduce
capacity.

Please note that none of the above takes path-based signalling into
account.

-- 
                          Stevie D
    \\\\\       /////     Bringing dating agencies to the
   \\\\\\\__X__///////    common hedgehog since 2001 - "HedgeHugs"
___\\\\\\\'/ \'///////_____________________________________________