Replacing the flues and getting the boiler water tight.

Back in the early 20th Century, when labor was inexpensive the boiler flues were assessed and if found to be sound, they were cut out, cleaned of scale and then reused. This was because material was expensive. Today, it’s the other way around, materials are relatively inexpensive compared to the cost of labor it would take to clean and repair 148 flues.

Now that all the old tubes are out of Engine 28’s boiler and the crown sheet has been repaired, and stay bolts replaced, we are completing the tube job and getting closer to the hydrostatic testing.

Photo of tubes with letter key Fig 1

This image is a close up of the tube sheet, also called the flue sheet. You can see that the tube sheet has been cleaned and ground off (C), this was done to clean up any chipping or unsavory remnants left behind from the removal of the old flues. Removing the old flues requires the use of force in hand with some sensitivity to the surface of the flue sheet. However, at times even the most seasoned boiler worker can chip the flue sheet.

The copper ferrules ( F) are gently tapped into the flue holes with a hammer. The ferrules are expanded into place to ensure that they do not move when the tube is applied.  They act as a seal between the tube sheet and the new tube. Next, the tubes are inserted into the flue holes (D) leaving  a small protrusion.   The standard measure of protrusion of the new tube is ¼”. Then they too, are expanded and rolled. The result is a tight fitting tube with a visible indentation on the interior (A ) and a slight flare at the end of the tube. The extra ¼” of tube allows for a good bead (B) that seals the flue to the flue sheet and makes the boiler water tight. After the beading of the tubes, another light roll is given to each new tube because the beading is an aggressive action.

Beading is an art. It involves using a pneumatic hammer or riveter and a specialized tip. In the image above (E) shows a bead that is rough, and (B) shows a bead that is more controlled and refined. It takes a bit of practice to get all the beads looking smooth, but regardless of the appearance, the work will hold.

Fig.2

This image shows the business end of the tube roller/expander. The old rusty shaft next to it is one of the older pieces of a previous roller/expander from the earlier days of boiler work in the roundhouse.

For this project we used this modern electric motor to roll and expand the tubes ( left), but back in the day a pneumatic model would be used ( right)..

Fig 5 drawing from REB

This diagram is from The Railway Educational Bureau Instructional Papers of 1927. It shows a beaded flue end from the side and the front views.

Phil beading, Fig 6

Here you can see Phil Hard beading one of the flues. The pneumatic hammer weighs over 20 pounds, so you can imagine the amount of strength required to do beading all day.

 

After all the beading is done, each flue then gets another straight roll to ensure the tube is tight in the flue sheet. Beading is intrusive work and it can cause the flues to loosen. The final roll remedies this.

expander rollers Fig 7

These are the tips that are used with the electric motor for the final, straight roll.

 

After all the beading and rolling, it is time to fill up the boiler and check for any leaks. With the boiler full of cold water at local pressure we begin to assess and address leaks. Once these are addressed it will be time for a true Hydrostatic Test, adding pressure and heat to the 93 year old boiler of Sierra Engine No. 28.

 

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Installation Of Staybolts

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Now that the firebox sheets have been replaced, the primary focus is now on the installation of the staybolts. Approximately 300 staybolts were cut out in the areas where the new firebox sheets were applied.

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Assortment of old staybolts that were removed.

The firebox sheets are supported by many stay bolts. The boiler shell (wrapper sheet) around the firebox has a water space between the inner and outer sheets.  The staybolts function is to hold the boiler shell and the firebox firmly together.

flex stay-bolt

Diagram of a Flexible Stay-bolt showing the wrapper sheet (left) and the firebox sheet.

fig45

Staybolt layout

 

boilerfigs1

The original stay-bolts were 3/4” diameter according to the original build sheet. The new stay-bolts are 1” in diameter. They are increased in size due to repeated renewal of the threads during the tapping process. Re-threading the staybolt holes ensures a snug fit with the new staybolts.  The holes are stepped up in 1/16″ increments.

028

New staybolts  awaiting installation.

A staybolt tap is used to clean up the threads prior to installation of the stay bolts. An air motor is used to turn the stay bolt tap to cut threads in the wrapper and firebox sheets. The staybolt is then threaded into the sheets and the ends peened over with an air hammer.

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Tools of the trade.  Three reamers and a staybolt tap.

 

007

Running a reamer through a mud ring rivet hole.

 

462

Bucking Bar

While the staybolt is being driven with a pneumatic hammer it is simultaneously being braced. To prevent damaging the staybolt’s threads, the opposite end must be supported. A bucking bar is placed on the end of the staybolt to back it up.

461

Peened staybolt.

 

 

Hydrostatic Testing on the Superheater Tubes

Advancement on the No. 28 project-

IMG_0730

Pressurizing superheater tubes.

A hydrostatic test was conducted on all 21 superheater elements. 300 lbs. of pressurized water was applied to determine if there were any leaks. Steam engine Superheaters were engineered to increase efficiency by transforming saturated steam into dry steam.  Saturated steam moves from the throttle valve through the dry pipe into the superheater header attached to the tube sheet in the smoke box. This steam then passes through elements which are housed in the superheater flues. Combustible gasses from the firebox move through the tubes and heat the water and the steam inside of the superheater element.  At the end of it’s cycle through the elements, it proceeds into a separate compartment of the superheater header into the distribution pipes, then on to the piston valves and then on to the main steam cylinders. Dry “superheated” steam is more efficient than wet saturated  steam.

Superheaters are more expensive and require extra maintenance however the benefits are reduced water and fuel consumption.

Interior view of a superheater unit

Interior view of a superheater unit

Performance of a steam locomotive superheater.

caption here

Warren Smith polishing seats prior to hydrostatic test.

Photo of a hydro test conducted on the super heaters.

Park Volunteers Warren Smith and David Ethier performing the hydrostatic test.

 

caption here

Superheater tubes awaiting inspection.

Leaks that were found were marked for repair. Only 3 had leaks and were welded to repair.

 

Tube marked to be repaired

Tube marked to be repaired

After the cleaning, testing, and repairs were completed, the superheater tubes were stored awaiting installation.

Previous Sierra No. 28 Update: Removal of Firebox Pieces for Replacement

Next Step: Fabrication and Installation of Boiler Patches

 

Removal of Firebox Pieces for Replacement

The goal of this project is to replace corroded staybolts, and thinned sections of the firebox.  While we have the locomotive disassembled, we are also completing the 1472 day inspection.  It is helpful to understand the anatomy of the boiler in order to follow along.

The firebox is a compartment, within the boiler, where combustion occurs.  It is surrounded by sheets of steel on five sides.  It is through these sheets of steel, that heat is transferred to the water on the other side.  For heat to transfer efficiently, the sheets need to be relatively thin (about 3/8″).  The firebox is subject to up to 13 tons of pressure per square foot.  To prevent collapse from dramatic changes in pressure, the firebox is tied to the outer portion of the boiler (wrapper sheet) by hundreds of bolts which span the distance between the wrapper and the side sheets.  In oil burning locomotives, like the No. 28, the bottom and sides of the firebox are lined with firebricks.

Side view diagram of locomotive boiler showing the location of the firebox, and rear view of firebox.  J.F.Gairns, illustrator

Side view diagram of locomotive boiler showing the location of the firebox in relation to the boiler, and rear view of firebox. J.F.Gairns, illustrator.  (This diagram does not specifically represent the No. 28, so there are some minor differences)

thisi siisss

x

In his book, A.F. Huston makes the argument in favor of a new kind of boiler, due to the inherent flaws of the radial stay boiler.  The new design never took off, but these photos demonstrate how common these issues are in steam boilers, and underline the challenge of continuous operation of historic boilers today.

x Over time, changes in pressure, as well as exposure to water, condensation, and scale, corrosive forces will prevail.  When the annual inspection was conducted on the boiler in 2010,

Top (water side) of the No. 28 boiler. Over time, the effects of stress corrosion can be seen. When the annual inspection was conducted  in 2009, pitting like this  on the water side of the crown sheet was observed.

 

Butt welded patches are a common repair practice.  This is an example of a previous repair on the No. 28.

Butt welded patches are a common repair practice. This is an example of a previous repair on the No. 28

Staybolts, removed by acetylene torch.  Some removed due to corrosion, others because they were attached to firebox portions that were removed.  In all, approximately 500 staybolts were removed, and will be replaced with new material.

Staybolts, removed by acetylene torch. Some removed due to corrosion, others because they were attached to firebox portions that were removed. In all, approximately 500 staybolts were removed, and will be replaced with new material.

crown sheet being removed

Removing pieces of the crown sheet that have but cut with a torch.

The piece was lowered through the firebox and removed from underneath.

The piece was lowered through the firebox and removed from underneath. lifting eyes welded to crow sheet, handy electric chain hoist– 200 lbs.

The tube sheet bottom being removed

Grinding where tube sheet bottom was removed, in preparation for application of the patch .

To repair the No. 28, it is necessary to remove patches of steel under the tube sheet, under the firebox door, and the crown sheet, including the knuckle where the sides and crown meet, over the door.  On this boiler the rear corners have been repaired twice before, the front once, as the material has been consumed by use.

Next Step:  Hydrostatic Testing on the Superheater tubes

Previous Sierra No. 28 Update: Removal of corroded staybolts; firebox & tube sheet inspection.

Just an Average Thursday

The SIerra No. 3 being prepared for 4th of July weekend

The Sierra No. 3 being prepared for 4th of July weekend

The Sierra Railroad passing through on the main line, hauling empty lumber cars to the mill in Standard.

The Sierra Railroad passing through on the main line, hauling empty lumber cars to the mill in Standard.

 

Park volunteers making lunch for other volunteers.

Park volunteers making lunch for other volunteers.

Railroad Restoration Lead Worker George and Senior Maintenance Aide Phil getting some office work done

Railroad Restoration Lead Worker George and Senior Maintenance Aide Phil getting some office work done

Maintenance Aide Ray murdering weeds in the pond

Maintenance Aide Ray murdering weeds in the pond

Volunteer Laverne collecting sign in sheets to record volunteer hours

Volunteer Laverne collecting sign in sheets to record volunteer hours

Volunteer David working on valve repairs for the No. 3

Volunteer David working on valve repairs for the No. 3

Volunteer Tim leading a tour of the historic machine shop for park visitors.

Volunteer Tim leading a tour of the historic machine shop for park visitors.

Volunteer Coordinator Dave!  Working on the volunteer schedule.

Volunteer Coordinator Dave! Doing what he does best.

 

Park Maintenance Aide Scott working on boiler repairs on the No. 28.

Park Maintenance Aide Scott working on boiler repairs on the No. 28.

 

Volunteer Leroy working on repairs to the first-class car ceiling.

Volunteer Leroy working on repairs to the first-class car ceiling.

 

 

Volunteers Bill & Bob decorating for the 4th.

Volunteers Bill & Bob decorating for the 4th.

Volunteer Al cleaning out the cars for the weekend

Volunteer Al cleaning out the cars for the weekend

Volunteer Jeannie- car cleaning!  One of the most important (and under-recognized) jobs at the park.

Volunteer Jeannie- car cleaning! One of the most important (and under-recognized) jobs at the park.

Volunteer Hal and Park Maintenance Worker Rob- working on a broken water pipe.

Volunteer Hal and Park Maintenance Worker Rob- working on a broken water pipe.

Just another Thursday at Railtown.

Railtown 1897 Offers Behind-the-Scenes Peek at Work Underway During Special “Roundhouse Day”

JAMESTOWN, Calif. – Before the historic locomotives start rolling along for a new season of train rides this spring, Railtown 1897 State Historic Park (SHP) is offering a special “behind-the-scenes” view of important maintenance, cleaning and preparatory work underway inside and outside the Roundhouse and Shops on Saturday, February 15, from 10 a.m. to 2 p.m.

View of the Roundhouse and turntable. Photo by Michael Sharps

View of the Roundhouse and turntable. Photo by Michael Sharps

As part of this special event that showcases the inner workings of what keeps the historic locomotives and cars in operation at the Park, visitors will have the opportunity to watch the annual maintenance and cleaning of the Hetch Hetchy motor car and the Angels Camp “shorty” car No. 6.  Railtown 1897 SHP guests can also see the historic belt-driven machine shop up in full operation and filled with activity plus participate in hourly tours.  And, as a special highlight, Railroad Restoration Lead Worker George Sapp will present a compelling slide show highlighting the current Sierra No. 28 project, provide an in-depth walking tour of work being done on the project and be available to answer questions from Park guests.

Volunteer John Stier pilots the No. 19 "Hetch Hetchy Car."

Volunteer John Stier in the No. 19 “Hetch Hetchy Car,” just one well-preserved rare piece of history visitors can get an up-close and personal look at during Roundhouse Day

Widely known as “The Movie Railroad” due to the hundreds of films and movies that have been shot on-location at the historic site, Railtown 1897 SHP is home to the Historic Jamestown Shops and Roundhouse of the Sierra Railway. This one-of-a-kind attraction combines industrial heritage and railroad history with the lore of Hollywood’s film industry. The Railtown 1897 Interpretive Center, the authentic roundhouse and shops, and the Depot Store (a railroad specialty gift shop) are among the Park’s unique year-round offerings.

Railtown 1897 SHP admission costs are as follows:  $5 for adults, $3 for youths ages 6-17 and free for children five and under.  For more information about Railtown 1897 SHP, call 209-984-3953 or visit www.railtown1897.org.

Sierra No. 28 Repair Project: Removal of Corroded Staybolts plus, Firebox and Tube Sheet Inspection

 

The No. 28 Repair Project continues to move forward. Largely, staff and volunteers have been working to remove corroded staybolts in order to replace them. Dye penetrent testing of the tube sheets is also being done, which helps to visually assess damage to the tube sheets.

Project staff member Norman Comer uses a torch to burn out a corroded staybolt where it meets the boiler.

Project staff member Norman Comer uses a torch to burn out a corroded staybolt where it meets the boiler.

Interior of the firebox. The holes on the top right are a result of removed staybolts.

Interior of the firebox. The holes on the top right are from where stay bolts were removed.

Staybolts that have been removed due to excess corrosion.

Stay bolts that have been removed for replacement, due to thinning.

Project Volunteer David Ethier recently conducted a dye penetrant test on the front tube sheet. Here, he applies red dye to a tube sheet.

Project Volunteer David Ethier recently conducted a dye penetrant test on the front tube sheet. Here, he first applies a specially formulated red dye.

Ethier allowed the dye to sit on the tube sheet for 30 minutes before using a specialized cleaning product to thoroughly remove it from the surface.

Ethier allowed the dye to sit on the tube sheet for 30 minutes before thoroughly removing it from the surface. The dye will be left behind in cracks, pits, and other porous spots only.

Next Ethier sprays on a developer, which appears white when applied, but develops the red dye left behind in cracks and pits, making them easy to spot visually.

Next Ethier sprays on a developer, which appears white when applied, but develops the red dye left behind in cracks and pits, making them easy to spot visually.

Here you can easily see a small crack in the tube sheet, highlighted by the red dye.

Here you can easily see a small crack in the tube sheet, highlighted by the red dye. Cracked areas will be repaired by grooving out the damaged material and welding in new.

Previous Sierra No. 28 Update: History of the Sierra No. 28

Next Sierra No. 28 Update: Removal of Firebox Pieces for Replacement