Engineer Courtney Gregg continues the show with Ex-Canadian National #7470 on the fifth, and final runby for the Massachusetts Bay Railroad Enthusiasts 'Steam in Snow!' special. Appropriately, light snow started to fall. This will be #7470's last runby before she heads out for her FRA mandated 1472 day inspection.
The Federal Railroad Administration allows a steam locomotive in the U.S. to operate for 1,472 days (4 years) during a maximum time of 15 years. A 'steam day' (one day of the 1472) is any day that the boiler is above atmospheric pressure. After you use 1,472 days or exceed 15 years, the locomotive is due for another 1472 Day Inspection. This inspection involves looking at the entire boiler, including all annual and 5th annual inspection requirements as well as any other items required by the FRA inspector. To properly conduct this inspection, all the 2" flues need to be removed and the interior of the boiler needs to be cleaned so that the interior boiler shell can be inspected. Outside, the boiler jacket has to be removed for access to the boiler plate. The boiler is then measured with a non-destuctive tester over its entire surface in order to determine thickness. Interior stays and braces are inspected for deterioration and suitability for their intended purpose. Any defects must be repaired and then the FRA Form 4 is calculated taking into account boiler working pressure and the minimum thickness of the boiler sheets. When it is all done, the FRA reviews the Form 4, an FRA inspector witnesses a hydrostatic test, and then if all is well you are good to go for another 1472 day/15 year cycle. The FRA granted the Conway Scenic RR a wavier to exceed the 15 year requirement in part because they still had over 900 unused 'steam days,' allowing her to operate for 2015's 'Steam in Snow!'
As you just read this, work is already underway to complete this process for #7470 in about 2 years.
