Of "Pit Rats," "Grunts," and Ultrasounds on Engine 2926

Yesterday we wrote about history of Engine 2926 and its tender at the New Mexico Steam Locomotive & Rail Road Historical Society in Albuquerque. Today, we highlight the people involved in the restoration of these iron beauties.

"The eclectic crew (of volunteers) represents all walks of life, including doctors, engineers, machinists, welders, pipefitters, mechanics, and many other skills and occupations." Earlier this month it was reported that volunteers had put in 100,040 hours cleaning, painting and repairing the big 4-8-4 locomotive.

The Society's newsletter has recognized the work of some of the volunteers. For example, the "Pit Rats" are members assigned "to work in the pit under the locomotive where everything is dirty and greasy. The space is cramped, and removing heavy parts from overhead is normal work." That work is performed on the 2926, which weighs over 500,000 pounds and has thousands of parts, all heavy and many rusted in place, and all the work performed outside in whatever weather occurs. (Note: the combined weight of the locomotive and tender is over one million pounds.)

I don't have any photos of this work, but there is other work that is done in cramped spaces.

An example of how the most unusual skills of a volunteer can play a vital role in the restoration is provided by "Dr. Mike Hartshorne, a radiologist with extensive ultrasound experience- - - on people.... (In the 1970s), the Federal Rail Administration (FRA) developed standards that led to regular ultrasound tests (UT) of steam locomotive boilers...."

But, the simple sounding task of laying out a grid, getting UT readings where the lines intersect, and recording the readings both inside the boiler and outside the locomotive, "wasn’t so easy."

(Even before the ultrasound tests could be conducted, layers of asbestos had to safely be removed from the boiler and many other parts.) As the steel was exposed, every inch was carefully examined, and the exposed steel was mapped.

"The UT team thought measuring this flat part of the outer wrapper sheet was difficult—until they got into the tighter places, e.g., the firebox, combustion chamber, smoke box, and many more.

The data entered are used to calculate minimum boiler wall thickness to operate 2926 at 300 psi boiler pressure. The result of the calculation drives needed boiler repairs. It will show which areas can be trusted as is, which need build-up welding, and which need new steel.

The bolts seen in the photos above and below present another challenge. This time it is "the grunts" who are featured. They have the task of repairing hundreds of stay-bolt sleeves and caps.

"The universal method of staying flat surfaces of the fire-box at the sides and front is by the use of stay-bolts. These stay-bolts are screwed through the two sheets of the fire-box and are riveted over on both ends.

One sheet (A), being next to the fire, is kept at a much higher temperature while the boiler is at work than the outer sheet (B), which is subjected to the comparatively cool temperature of the atmosphere. This causes the plates A and B to have a movement relative to each other due to unequal expansion. And it is this unequal expansion that causes stay-bolts to bend and break.

"Stay-bolt breakage is also very large in bad water districts and gives a great deal of trouble on most railroads. The stay-bolt problem, therefore, is a very important one."

Work on the other end of the stay-bolt, i.e., in the boiler, included the same attention to the stay-bolts as well as pressure washing the inside of the boiler to remove scale and accumulated sand.

All of the 2300+ stay-bolts required removal for cleaning and decisions regarding repair or replacement.

Attention to detail is essential.

And what about new tires? These 80-inch wheels make 7 revolutions when the train is traveling at 90 mph.

"Replacing a whole wheel because of a worn contact surface is expensive, so older types of railway wheels were fitted with replaceable steel tires. The tire is a hoop of steel that is fitted around the steel wheel centre."

More complete (and, quite likely, more accurate) descriptions and explanations of the information in this blog can be found at the web pages listed at the end of this entry.

When fully restored, the group’s mission is to operate Passenger Excursion Service. It will be both a rolling history class and an addition to New Mexico’s tourism industry. It was hard for our tour leader John to be restrained on predicting a date for the full operation of the 2926, but whenever it is, it will be because of the attention to detail and the standard of excellence displayed by the leaders and volunteers who have assured that everything is perfect.

A final note: John noted the value of the feral cat population that we caught glimpses of during our tour. He pointed that they are well fed by the volunteers who greatly appreciate the cats' work in keeping the rodent population very, very low.

Resources:
The Society's official website is www.nmslrhs.org
http://www.wheelsmuseum.org/110212.html
http://www.sdrm.org/faqs/boilers/page45.html
http://en.wikipedia.org/wiki/Train_wheel