Sierra No. 28 Repair Project- Removing the Boiler Tubes

A major component of this repair project is the 1,472 day inspection, as mandated by the Federal Railroad Administration. The inspection requirement is that every fifteen years or 1472 “service days,” the boiler shell must be fully inspected, and an ultrasonic thickness (UT) survey of the boiler and firebox must be performed and documented.  From these test results, support the Form 4 engineering calculations for working pressure of the boiler.  The No. 28 would have been close to this milestone when the scheduled repair project was finished, so it was built into the project to avoid disassembling the locomotive twice in a row.

The boiler tubes must be removed to access the boiler for inspection. These tubes carry hot gasses from the locomotive’s firebox to more efficiently heat the surrounding water in the boiler, and make steam. They were last replaced during the last 1,472 inspection in 2003. When they are installed, a tool is used to expand the tubes into the tube sheet so they will not move or come loose.  To remove them, the tubes are cut away from the tubesheets at both ends (in the firebox, and the smokebox).  Then they are pounded loose and pulled out through the smokebox.

Senior Maintenance Aid Phil Hard uses a crafted lever to remove tubes through the front end.

Senior Maintenance Aide Phil Hard uses a shop-built lever to remove tubes through the front end of the locomotive.

A view of the front boilerplate. Tubes are being pulled forward through this plate. The smaller holes each contain a boiler tube, the larger holes are for superheater flues, which are not being removed.

A view of the front tube sheet. Tubes are being pulled forward through this sheet. The smaller holes each contain a boiler tube. The larger holes are for superheater flues,  which are not being removed.

____________ works inside the firebox to detach the boiler tubes from the rear boilerplate and help "push" them forward to be pulled out the through the front.

Machinist Tony Stroud works inside the firebox to cut the boiler tubes from the firebox tube sheet and help “push” them forward while another staff member pulls each tube through the front.

In this video, project volunteer Warren Smith shows the process in a bit more detail. Due to their position behind the branch pipe, some of the tubes could not be pulled out straight.   This problem was solved by pushing the tubes into the boiler, where they rolled to the bottom, were retrieved with a tool, and pulled out of a more accessible hole.  An alternative removal method is to pull out and cut off in segments, but the method used here was more efficient. The voice you hear at the other end of the boiler is that of Norm Comer.

The No. 28 has 148 of the 2″ tubes.  Removal took approximately 13 days with paid and volunteer labor.  The tubes are in generally good condition, and some cases could be re-installed.  However, for this project, we decided that it would be more time-effective to replace them with new material.  With the removal of the tubes, the final demolition is complete, and we are moving into the next phase of the project!

Previous No. 28 Update: Removing the Jacket

Next No. 28 Update: Ultrasonic Testing and Boiler Inspection

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