CABRILLO Historic Structures Report

Figure 24. Rough-textured concrete provides camouflage for this structure.

BATTERY COMMANDER AND BASE-END STATION, BATTERY ASHBURN (Restoration)

Location

This battery commander station and base-end station, one of six for Battery Ashburn, is located west of the Army Radio Station.

History

Constructed c. 1936-1941 for use during WWII, the upper level served as a battery commander's station and the lower level was the base-end station and sleeping area. The five structures associated with the Battery supplied tracking data to Ashburn's two 16-inch coastal guns. The station closed in 1948. Later used as a whale watching station and a darkroom, the structure currently is vacant and closed to the public.

Description

Exterior

Battery commander's station is a multilevel, partially underground battery and base-end station comprising two semi-circular concrete mounds. Constructed with reinforced concrete using formwork for the foundation walls and rough camouflage techniques for the finish, the half buried structure cascades down the hillside (figure 24). The roof is a continuation of the concrete camouflage walls, formed of large aggregate, rough concrete. Concave voids at the edges appear to have been formed using approximately nine-inch diameter rock-like forms wrapped in burlap, pressed into the wet concrete. Rough drainage grooves penetrate the roof concrete. A stairway with pipe handrails descends to an exterior metal door. Observation slots facing the Pacific Ocean at both levels have six solid metal, rectangular shutters arrayed geometrically. Ferrous metal hook-and-eye hardware allows the shutters to be fixed in either the open or closed position.

Interior

This two-story structure contains three rooms, one on the upper and two on the lower level. All three rooms are rectangular in plan with concrete floors, walls and ceilings. The lower-level rooms are accessed from the battery commander's station through a manhole in the floor with a removable wood trapdoor. Steel rungs embedded into the concrete wall serve as a ladder. This space contains fluorescent light fixtures, plywood shelving, miscellaneous conduit, a circuit breaker and a junction box (figure 25). The space directly below was used for sleeping. This area contains a single-bulb light, miscellaneous conduit, a terminal block and telephone box. The forward lower-level room was the base-end station used for observation, separated from the sleeping area by a single, wood paneled door and five concrete steps. This space contains plywood shelving and drain board, wood two-by-four railings at the steps, water pipes, faucet and a steel sink.

Condition

Exterior

Concrete wall deterioration includes cracked and spalled sills and severely spalled stairway headers. All ferrous metal, including the shutters, shutter hardware and pipe railing, was badly corroded in 1998. Although abated and primed in 1999, it still requires a finish coat. Conduit extends through the base concrete wall at various locations. The staircase is missing its pipe railing.

Interior

The interior of the building features minor concrete spalls and flaking paint throughout. Steel shutters are primed, fixed in place and boarded over. Built in furnishings, including a window and chart shelf at the forward lower level room, are missing. Original conduit feeding holes in the concrete walls have been plugged in most cases.

Structural Analysis

No significant structural concerns were noted during the review this structure.

Figure 25. Embedded metal ladder rungs provide access to both floors of Ashburn's base-end station.