Steam & Excursion > Sun Kink on Durango & Silverton

Extreme Heat Buckles Durango & Silverton Narrow Gauge Railroad Tracks
KCNC
June 21, 2016

> DURANGO, Colo. (CBS4) – It’s not just roads that are buckling under
> Colorado’s extremely hot temperatures. Railroad tracks are also
> feeling the heat.
>
> According to the Durango and Silverton Narrow Gauge Railroad, the
> heat buckled tracks on their line on Monday. When it happens it’s
> called a “sun kink.”
>
> “We repaired it last night. We had to get our trains back. Crews went
> out early this morning to assess that the repairs were satisfactory
> and we were running our normal three train schedule today. We don’t
> anticipate any further sun kinks this summer,” railroad spokesman
> Christian Robbins said in a statement.


ARTICLE with photo and D&SNGRR statement:

Extreme Heat Buckles Durango & Silverton Narrow Gauge Railroad Tracks

I also saw on Fox News weather report Durango is in the "extreme" danger area for fire risk. Is that affecting steam operations? 

If the track was welded rail, every other tie would be boxed with rail anchors, and a foot of ballast would extend each side of the ties.  Steel is compressed when it expands, and is stretched when it gets cold. Steel is more elastic than it expansion or shrinking factors.  The rail anchors hold it to the ties and ballast which hold it in place.  Wood tie track is bound to the dents in the base of the wood and the course stone in the road bed.  If a surface tamping machine had recently lifted the track, it would not be secure to those rough stones, and need more trains to compress the ties to the new stone base.  Not a good time for track surface work in the hottest time of the year.

Jointed rail track should be observed at various temperatures to see the gaps at the joints are open on cool mornings and watch them close as the heat rises.  The track cars track inspector can feel the open gaps and also feel and hear the joints when they close up real tight.  This will be a learning lesson for the crews and may never happen again, as they can shorten some of the rails and give it a little more stretch in the cooler times such as the winter. Pull-aparts in winter are much rarer and easily found and not as dangerous as heat kink
.
This track has the finest track inspection of any railroad in the whole country, because it uses track motor cars 5 times a day. 

 



Edited 1 time(s). Last edit at 06/22/16 05:06 by PlyWoody.

The procedure for laying jointed rail at the correct end gap, to manage the expansion as explained above, was to use wood or fiber shims between each rail.
These vary by the temperature at the time the rail is installed, joined, and anchored, from an AREMA table for 39-foot rails
Below 6    5/16"
6-25          1/4"
26-45         3/16"
46-65         1/8"
66-85         1/16"
Over 85      none
As degrees Farenheit.
Coming up in the industry when the focus was on CWR, I had to go back to the books to learn this after being questioned by old heads as to what shims we were using on a branch line job.

 

Back when jointed maintenance was a more strident thing and the gangs didn't have 50 miles to look at
you'd see them oiling the fish plate bolts. All those nice shims don't do much if the "slop" in the bolt holes
is rusted in place, the clearance allows the rails to expand and contract as required.

Out

Was not that bad of a kink....go slowly, you will make it through:)

(Just kidding)

In the live steam world (7.5" & 4.75" gauge) we have the same problems. To tight of a rail joint, bam! Sun kink

Posted from iPhone

It might be interesting to look at a little history of the D&S NG past practice.  Not too long ago they bragged about using bank-run gravel as it was very cheap.  This is like putting marbles on your track and under your ties.  What holds the ties in place is the compaction of the ties onto the stones below.  You want those stones to be very secure and locked together with a very rough surface that dents and locks into the bottom of the wood ties.  When the stones are round and polished like river wash they will not pack in a secure manner.  The D&S admitted that past mistake and have been using crushed stone and trying to work up and over those bank run gravel.  Only someone who can inspect that area would be able to say this is the case for the heat kink here.

Years ago the maintenance practice every few years was to use a nut runner machine and remove all the bolts, knock the joint bars completely off, oil the rail and joint bars and re-bolt the track back together. Graphic paste would be used today instead of oil for EPA pleasure.  And the center of each rail would be boxed with rail anchors against several ties so it would not creep.

 



Edited 1 time(s). Last edit at 06/19/17 04:36 by PlyWoody.

SP did this years ago on the Santa Paula branch on a section of track. It constantly slid to one side, the downhill side of a small one sided fill. Every few months the F&W would go out there and jack the track back up and dump crushed rock.