Double Track Triangles

alan2 · Post by **alan2** » Mon Aug 19, 2002 10:03 pm

Here Is a view of one I made.

To do this I used 10D End pnt pieces, default. and 4 pieces of Dynamic track.

1000M 10D curves, default. Mostly default.

Alan Heath.

There is somewhere a tutorial on single track triangles, think it's 10dRgtpnt.s 10dendpntrgt*8 (roughly) 10DYpnt 10Dendpntlft*8(Rough) 10Dlftpnt.

gopher · Post by **gopher** » Mon Aug 19, 2002 10:28 pm

alan2 · Post by **alan2** » Mon Aug 19, 2002 10:39 pm

Now you Mention it I have not. Yet, Will tommorow, is half past 11 now.

Alan Heath

pitleyfalley · Post by **pitleyfalley** » Tue Aug 20, 2002 11:01 am

Cool are you building Tywyn then? If so could you do the Talyllyn's Wharf as a Static exhibt sort of thing, so you can see it as you drive past?

Cheers Chris

Barden · Post by **Barden** » Thu Aug 22, 2002 3:09 pm

I built a single track triangle and as I had also built left and right double junctions I considered the double track triangle but rejected it. Double junctions look good but the curved pieces (dynamic) can give passengers a rough ride.
I brought in a double track branch from the W to join double track main runnning N to S. The main is straight throughout the junction which is all on level terrain.
The branch converges to single which then forms the triangle. The two legs join the main where there are crossovers to allow up & down traffic.
All west bound traffic on the main is diverted onto passing loops pending clearance to proceed.
All pointwork is 10d as I wanted manual control throughout (no 5d rght.man!).
I slapped on a 15mph limit for W bound traffic through the junction. From a standing start this is about all you will reach anyway.
I use 10m str where necessary but 2x10 would give more time to switch points.

JohnEyres · Post by **JohnEyres** » Thu Aug 22, 2002 6:05 pm

I have a single track junction at Parkside and only needed a short straight piece of dynamic track. I have a one/two track triangle at Earlestown as two sections are double connected with a usual junction but the west curve is single off to Liverpool. Its just a case of aligning the junction end which is seperated. No need for fancy bent twisted dynamic track.

gopher · Post by **gopher** » Thu Aug 22, 2002 7:07 pm

Barden · Post by **Barden** » Sat Aug 24, 2002 3:15 pm

Using the setup previously described I had no problems with my activities which use all possible routes through the junction. There are no gaps as all standard pieces fit perfectly.
Did`nt BR opt to use crossovers instead of double junctions on many routes as they found them cheaper to maintain. ?

jcjmann · Post by **jcjmann** » Sat Aug 24, 2002 9:15 pm

I managed a double track triangle. If you're going from W to a N-S line work out the angles between the points ie if you're using 10d points at both ends you'll need 70d of curve between to get the 90d. Find the largest radius curve of 70d that will fit between, then use straight dynamic track to connect, but you'll need to experiment with the length of the first bit of dynamic track. I find that at the double junctions, make sure they will connect to a standard A2t straight, so that you know the angles are equal.......I've just reread this and I'm not sure it will make sense, but I know what I mean.

Atomic Systems