I would have used Velcro.

[martin-w 3,288]

 

[birdguy 3,965]

That seems like an awful lot of trouble to go through just to weld a couple of rails together.  Why?

Noel

[mwilk 1,109]

18 minutes ago, birdguy said:

That seems like an awful lot of trouble to go through just to weld a couple of rails together.  Why?

Noel

This process basically melts the two sections of rail together. A weld would break due to constant flexing. They used to use gussets and bolts to join 2 sections of rail.

[birdguy 3,965]

After watching this I looked up railroad rail welding.  Apparently there are several types of welding used.

Shielded Metal Arc Welding

Gas Metal Arc Welding

Flux Cored Arc Welding

Oxyfuel Gas Welding

And Thermite as described above.

Do each have advantages and disadvantages?  Where would one type of welding be used over another type of welding?

Noel

[188AHC 2,141]

Thermite is without a doubt the most efficient, safest, method to use today.to achieve the greatest penetration and reliability of all methods used in the past. The process heats the base metal far faster which results in an almost perfect weld.

I specified thermite welds on ground rods that were driven more than two rods deep because of this.

Major rail lines have been using thermite welds for decades as apposed to butt and bolt.

 

[birdguy 3,965]

How long do they weld rail segments?  There has to be a break someplace to compensate for thermal expansion and contraction.  How do they do that?

For instance at my house it was 30 degrees this morning and it's 80 degrees right now.  The rail line that goes through Roswell has to be able to compensate for that.

Noel

[martin-w 3,288]

14 hours ago, birdguy said:

How long do they weld rail segments?  There has to be a break someplace to compensate for thermal expansion and contraction.  How do they do that?

For instance at my house it was 30 degrees this morning and it's 80 degrees right now.  The rail line that goes through Roswell has to be able to compensate for that.

Noel

 

Good point. Everything expands and contracts. Although I guess steel is flexible so wouldn't crack. Could bend I guess. 

 

Quote

 

When I first started working on the railroad, I worked in the Track maintenance department, and one of my assignments was working with a rail welding crew that was following the rail gang. The rail gang laid down welded rail in 1/4 mile long sections. It was a 25 mile project, and we Thermite welded every joint for the whole 25 miles, some joints required stretching the rail together with a hydraulic tool and other joints required cutting the 1 inch gap between the rail heads more than once if it closed up when the joint bars were removed in preparation for welding.

We had very specific charts and instructions on how to handle the expansion and contraction of the rail including installing rail anchors on every cross tie for the first 700 feet from the joint to hold the track in place. That segment of track was in Minnesota where temperatures ranged from minus 40 degrees F. in winter to 100 degrees F. in summer, and there were no problems with expansion or contraction of the rails in that area, so it’s all about having all the proper anchors and fasteners in place with a well maintained roadbed to hold the tracks in alignment.

 

 

https://www.quora.com/How-do-welded-railway-tracks-survive-during-summer-Don’t-they-need-space-for-expansion-when-they-get-hot#:~:text=There may be no expansion,at the formerly-many joints.

[Fielder 3,829]

The default planes fly like they are on rails!