Walking Tour: Stop #6

The Locomotive Repair House (Building 97)

Looking south at the Locomotive Repair House (Building 97) and the reactor containment shell at the grand opening of Horace Hardy Lester Nuclear reactor in 1960

The Locomotive Repair House (Building 97) was constructed in 1920 to house and repair the Arsenal’s fleet of locomotives, switch cars and cranes, which moved freight and equipment around the grounds over seven-and-a-half miles of railroad tracks. In 1959, Building 97 was transformed into a materials testing laboratory and equipment facility supporting the Horace Hardy Lester Nuclear Reactor

Switching locomotive moving freight cars
Whitcomb switching locomotive in front of Building 311, c. 1921
Looking south at the Locomotive Repair House (Building 97) in 1991

Building 97 was connected to the reactor through a corridor with double air locks on each side. It had labs, decontamination showers, storage, and equipment supporting ongoing experiments involving the reactor. The building remained an active laboratory after the reactor was decommissioned in 1971.

Interior view of main entrance to Building 97 in 1991
Interior view of main air-lock entrance to Lester reactor from Building 97, 1991

The Horace Hardy Lester Reactor

View looking south at Horace Hardy Lester Nuclear reactor containment shell in 1991

The Horace Hardy Lester reactor was built in 1959-60 at a cost of $1.3 million. The reactor’s air-tight, pressurized containment shell was 80 feet wide and 69 feet high. It had 2-foot thick concrete walls with a welded ½ inch thick steel plate exterior shell. Inside, the octagonal shaped, water-cooled “tank” reactor was 31 feet deep and held 44,000 gallons of water. The reactor core was submerged in 22 ft. of water and surrounded by the tank’s 5ft. thick concrete walls.

(Left) 1960 interior view of Horace Hardy Lester reactor with surrounding containment shell 1960. (Right) 1991 view of main experiment floor in Horace Hardy Lester reactor with main entrance at lower right

When it opened in 1960, Building 100 was the only experimental nuclear facility of its kind operated by the U.S. Army. During its 10 years of operation, the Lester reactor provided new opportunities for scientists to conduct tests and analysis of metals and other materials at the atomic level. The reactor was named for Arsenal Scientist Dr. Horace Hardy Lester, who had pioneered the use of radiography (x-rays) to assess the strength and quality of metals in the Arsenal’s laboratories.

South Face of The New Erecting Shop (Building 311)

Looking north from Stop #6 – New Erecting Shop (Building 311) in 1982 showing the original end of the 1917 building on the right and 1942 addition on the left.

In 1942 the Army added a western addition to the New Erecting Shop that doubled the size of the building. Along with new space for ordnance production, large this western addition contained space for a new experimental x-ray facility for non-destructive testing of metals. After World War II Building 311’s production areas remained active through the 1950s and early 1960s. After the closure of the Arsenal in 1967, the building continued to house the x-ray facilities and several small machine shops, and served as a shipping/receiving area for the Army Materials and Mechanics Research Center.

New Erecting Shop Interior Looking West, 1991

The Projectile Machine Shop (Building 36 – Now Demolished – Current Site of the Parking Garage)

Looking east at the Projectile Machine Shop – Building 36 (now demolished) from the former West Gate at School Street and Wooley Ave. in 1939

Before World War II, the western boundary of the Arsenal property was at School Street. In the 1930’s the Army added the ‘West Gate’ entrance at the intersection of present day School Street and Wooley Avenue. This entrance provided direct access to a large paved parking area built in a large open area south of the New Erecting Shop (bldg. 311) and west of the Projectile Press Shop (bldg 36 – demolished during the redevelopment of the Arsenal) and Projectile Machine Shop (bldg 45 – demolished in 1967).

View of the Projectile Press Shop (demolished) in 1982
The view looking southeast at railroad tracks in between the Projectile Press Shop (now demolished) and the Locomotive Repair house in 1917

Return to the beginning of the tour: Stop #1