ALBUQUERQUE - The 17-year effort to restore a Santa Fe Railway 4-8-4 to operation cleared a major hurdle Tuesday with the completion of a hydrostatic test and internal inspection.

The two-day test on No. 2926 began Monday as the boiler filled with heated water pressurized to 25 percent above its maximum operating pressure of 300 psi. While others watched for external leaks, Scott Altenbach of the New Mexico Steam Locomotive & Railroad Historical Society maneuvered inside the firebox with a hammer tapping rivets and the 3,740 staybolts that brace the boiler crown sheet.

"That's 3,700 places it could leak times two," says NMSL&RHS Chief Mechanical Officer Rick Kirby. A few staybolt caps leaked and were replaced, and a leaking washout plug also was fixed, he adds.

The crew drained the boiler after four successful hours under pressure.

Federal regulations require an internal inspection when a boiler is pressurized beyond its operating limit, and that happened Tuesday. With the manway hatch holding pressure-relief valves removed from atop the boiler, Altenbach was again at work with a headlamp and hammer checking connections, braces, and brackets.

No problems were found, Altenbach says.

No. 2926 was one of 30 Baldwin 4-8-4s in the 2900 class delivered in 1943-44. Due to wartime limits on lighter materials, they were the heaviest 4-8-4s ever built.

The Santa Fe put more than 1 million miles on the locomotive before donating it to the city of Albuquerque, which placed it in Coronado Park in 1956. The NMSL&RHS acquired it from the city in 1999, and, after an intermediate stop at a nearby siding, moved it in 2002 to the work site off what is now the BNSF Railway's Sawmill Spur.

Federal Railroad Administration Safety Inspector Dan Lucero was on hand this week to observe although the 2926 is still exempt from most regulations since it is not yet in service. Lucero, who as a kid played on the locomotive in the Albuquerque park, has made periodic visits to the site as the project leadership sought his advice on safety and regulatory issues.

He watched closely as the 2926 crew performed the tests.

"I'll report [that] I observed the inspections and noted no exceptions," Lucero told Trains News Wire.

The next big step in the restoration is installing bundles of superheater tubes inside the boiler shell. They've already been tested to 500 psi but will require an additional hydro test after installation.

Former NMSL&RHS President Frank Gerstle says he is nearing completion of the FRA Form 4 boiler certification and plans to submit it, repair documentation, and welding certifications later this year. Still to come is lining the firebox with brick, loading the tender with oil and water and firing up the 2926 for the first time since 1956.

The NMSL&RHS holds work sessions on Wednesdays and Saturdays, maintains a Facebook presence, and posts project updates and other information on its website nmslrhs.org. The annual project open house is schedule for 9 a.m.-5 p.m. on Saturday Sept. 23.

For more on the history and restoration of No. 2926 and other locomotives currently in operation, see the newly published Trains special ""Big Steam is Back."

https://kalmbachhobbystore.com/product/special-issue/vt-tr2170601

https://www.facebook.com/NMSX2926/

http://www.nmslrhs.org/