I was wondering if anyone knew how to calculate the minimum curve radius for a section of track that is going to be in a yard. Speed is not an issue, maximum tonnage will be 134t and maximum length will be 21m

Cheers

I was wondering if anyone knew how to calculate the minimum curve radius for a section of track that is going to be in a yard. Speed is not an issue, maximum tonnage will be 134t and maximum length will be 21m

Cheers

The max tonneage surely ought to be irrelevant.

The angle formed by the ends of the 21m long arc is however important.

FYI, the sharpest main line curve near ZigZag is 8 chains (160m).

FYI, the sharpest branch line curve on Oberon, Batlow, and Dorrigo lines is 5 chains (100m) with restrictions on class of steam locos to 19-class.

The 21m long siding curve would probably need no "transitions."

Presumably there are formula that convert the arc length L of 21m for a radius R to the angle A of the curve.

I was wondering if anyone knew how to calculate the minimum curve radius for a section of track that is going to be in a yard. Speed is not an issue, maximum tonnage will be 134t and maximum length will be 21m

I doubt anyone designs track from scratch. The various rail authorities use standards. The John Holland Country Rail Network standard is http://www.jhrcrn.com.au/media/2169/crn-cs-210-v1-3.pdf The ARTC equivalent is https://extranet.artc.com.au/docs/eng/track-civil/procedures/track-geo/Section5.pdf?260716

Speed is very much an issue, as is wheelbase, bogies or fixed axles. You may have to look at gauge widening. Look at the radii in turnouts, you said a yard so that will be a concern. Is it conventional ballasted track or concrete slab etc. In short, it depends. I assume with 134t you are talking 33.5 tonne axles so it looks like heavy haul or special wagons.

I doubt anyone designs track from scratch. The various rail authorities use standards. The John Holland Country Rail Network standard is http://www.jhrcrn.com.au/media/2169/crn-cs-210-v1-3.pdf The ARTC equivalent is https://extranet.artc.com.au/docs/eng/track-civil/procedures/track-geo/Section5.pdf?260716

These standards are living examples of "the devil is in the details." Frightening complicated.

Pity that they don't seem to mention turnouts.

In NSW the set of tangential turnouts is (CMIIAW) something like:

1:7.5 about 150m radius?
1:8.25
1:9
1:10.5 about 300m radius?
1:12
1:15
1:18
The V-crossings can be curved or straight.

I doubt anyone designs track from scratch. The various rail authorities use standards. The John Holland Country Rail Network standard is http://www.jhrcrn.com.au/media/2169/crn-cs-210-v1-3.pdf The ARTC equivalent is https://extranet.artc.com.au/docs/eng/track-civil/procedures/track-geo/Section5.pdf?260716

These standards are living examples of "the devil is in the details." Frightenly complicated.

Pity that they don't seem to mention turnouts.

In NSW the set of tangential turnouts is (CMIIAW) something like:

1:7.5 about 150m radius?
1:8.25
1:9
1:10.5 about 300m radius?
1:12
1:15
1:18
The V-crossings can be curved or straight.