Tag Archives: boiler

Installing and Rolling 1385’s Tubes

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In this C&NW #1385 update, we get a glimpse of the process of installing tubes in the boiler.

The tubes are installed by sliding them into the holes on the tubesheet. Their outside diameter is just slightly smaller than the holes in the tube sheet. However, in order to have a water-tight and steam-tight seal, there can’t be any gap. This is achieved through a process called rolling.

In the rolling process the tube is actually expanded from the inside using a roller. The roller presses the end of the tube against the hole in the tubesheet tightly enough to form a steam-tight seal.  The end of the tube actually sticks out of the hole a specified amount.  The portion that sticks out is then curled outward and back until it touches the tubesheet in a process called beading.  If the end of the tube were left hanging out by itself it would soon overheat and burn off or crack.  Since the beaded end of the tube is touching the tubesheet it will transfer some of the heat back into the tubesheet and not get hot enough to burn off or crack.

A Continental Fabricators employee trims excess tube material from the front of the boiler. Additional employees are on the firebox-end rolling and beading the tubes. Photos courtesy Continental Fabricators.

Additionally, the arch tubes have now been installed. Arch tubes provide increased firebox heating surface area and allow better circulation of water in the areas surrounding the firebox. The arch tubes also serve to support the brick arch, a series of firebricks that help direct heat from the fire more evenly throughout the firebox.

Arch tubes inside the 1385’s firebox as viewed from firebox door. S. Roudebush photo.

With the tubes now installed, a countdown clock has begun to tick. A boiler must be disassembled for extensive Federal Railroad Administration mandated inspections every 15 calendar years or 1,472 days of operating – whichever occurs first. Once the first tube was installed, the FRA gives a 1-year grace period in which to complete work before the 15-year time limit begins. If the locomotive is completed in less time, the 15-year clock starts once the FRA accepts the locomotive for service. If the locomotive is not accepted for service within the 1-year grace period, then the 15-year clocks starts anyway.

The next step for C&NW 1385’s boiler is the hydro test. Stay tuned!

Mid-September 2019 Boiler Update

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With structural welding and the post-weld heat treatment complete, the next step on Chicago & North Western #1385’s boiler progression was sandblasting and painting. This step was recently completed as seen in these photos supplied by Continental Fabricators. Paint has only been applied to the inside of the boiler at this stage. The exterior will be painted a bit later in the process.

C&NW #1385 boiler after being sandblasted. Photo courtesy Continental Fabricators.

The paint is APEXIOR No. 1, a product that has been used in locomotive boilers going back many decades and is proven effective and typically lasts for decades. The paint is designed to withstand continuous immersion in boiling water and steam up to 698°F (370°C). It serves to aid in preventing corrosion and scale buildup in the boiler by preventing the boiler water from touching the metal of the boiler shell.

Next on the to-do list: rolling boiler tubes.

Early September 2019 Boiler Update

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The busy bees at Continental Fabricators have been making excellent progress on C&NW #1385’s new boiler. By late August work on staybolt installation was wrapping up. The next few photos show that work taking place.

The first shot is looking from inside the firebox at the firedoor ring and we can see the finished welding.

In this second picture we’re looking toward the front of the firebox at the crownsheet and rear tubesheet. The small group of staybolts not yet welded in are the flexible stays and the larger holes in the firebox sheets will accept the arch tubes. The arch tubes have a dual purpose in that they will form a structure to hold the arch brick in the firebox. They will also promote much better water circulation around the firebox while the locomotive is in operation.

This third shot shows the outside of the staybolts yet to be finished and with the boiler rotated on its side. We’re looking at the top of the vessel in the center of the picture.

This fourth picture is looking down through the steam dome inside the boiler at the braces welded in place to support the rear tubesheet. Those braces were discussed in an earlier update and this is a look at the finished product.

With the structural welding completed, as people across the nation were getting ready to fire up their grills for Labor Day weekend cookouts, the folks at Continental Fabricators were preparing a roast of their own. C&NW 1385’s boiler was moved inside Continental’s enormous heat treating oven for its Post Weld Heat Treatment (or PWHT). This process helps to relieve stresses built up during the welding process. The following two photos were taken while the boiler was cooling off after completing the heat treatment.

Next up, the boiler will get sandblasted and painted. The interior will receive Apexior paint which will help protect the steel from corrosion as it boils the water for steam.

Late July 2019 Boiler Progress

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Welding and patience continues at Continental Fabricating as more stays are completed on the R-1 boiler.  No, the pictures are not upside down, that is merely the positioner at work to allow the greatest productivity and weld quality possible.  The steel forging which makes the base of the steam dome has been tack welded in place and you can see the welder’s feet as he makes the root and fill-in welding passes while he’s standing on the floor.

The other parts of the steam dome are being fitted together and the welding has been partially completed and soon will be done.  For the new boiler we have adopted a more European approach by having a removable steam dome.  This will make maintenance and inspection tasks much easier in the years to come.

Photos are courtesy of Continental Fabricators.

Early July 2019 Boiler Progress

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Progress continues with the welding of staybolts at Continental Fabricating. The boiler is now mounted to the positioner and like a huge rotisserie it can be rotated to allow the welders to work from the best possible position and comfortable welders make for better welds.

In these pictures, the boiler’s fireman (left) side is down to allow for work on the top of the wrapper sheet without having to set up scaffolding or work from a ladder. This minimizes or eliminates fall hazards. From the firebox side this will allow work to continue without welding overhead so the workers aren’t standing under a shower of sparks as they weld.

The below photo inside the boiler is a unique perspective that won’t be available much longer. The steam dome has not yet been welded in place so this allowed Continental Fabricator’s Tom G. to position the camera right in the top of the boiler shell where we can see the water side of the crownsheet and the rows of staybolts that tie the crownsheet and wrapper sheet together. We can also see the rows of staybolts yet to come, many of which will be flexible stays.

C&NW #1385 boiler as of July 8, 2019. Photo courtesy Continental Fabricators.