CABRILLO Historic Structures Report

Figure 26. This concrete gun emplacement is partially buried.

BATTERY BLUFF, NORTH AND SOUTH GUN EMPLACEMENTS (Stabilization)

Location

These gun emplacements, located at the edge of a bluff overlooking San Diego Bay, are reached from the Bayside Trail. Public access is prohibited.

History

Constructed in 1942, this World War II battery consists of two mounts located on the east side of Point Loma, at the edge of a high bluff overlooking the Bay. Serving as an anti-motor torpedo boat battery, it protected the entry channel to San Diego Harbor. Each mount held a 37mm M3E1 gun. An azimuth instrument was mounted on the associated four-foot steel pipe filled with concrete to the north, when the battery was active.

Description

Each semi-circular concrete emplacement is three feet wide and originally two feet high on the inside (figures 26 and 27). Although partially buried, approximately 13-inches of the two-foot high emplacement remains visible. Eight bolts attaching the weapon's base plate are embedded into concrete at the center of the northern emplacement, but if they remain at the southern emplacement, they are no longer visible. Traces of paint are visible on the inside concrete surface of the south emplacement. Remains from associated wood structures are nearby, in addition to the azimuth instrument pole.

Condition

Due to erosion, these two emplacements are now perched precariously at the cliff edge. Both are partially filled in with sand and vegetation. A fissure present in the soil 12-inches in front of the south gun emplacement jeopardizes the structure. Cracks in the concrete mount are visible signs of ground instability. Plant growth is present in one of the surface cracks, accelerating deterioration. The north gun emplacement remains about three feet from the cliff edge. Site instability limits the life span for these structures.

Structural Analysis

The major concern associated with these emplacements is the stability of the cliff-top where they are located. The edge of the cliff is only two or three feet from the front of the north emplacement, and it is only a matter of time before the cliff erodes back to the face of the emplacement. The south emplacement is further back from the cliff-top, however it appears to have settled at the front side and is now slightly tilted. The concrete ring structures themselves are in reasonable condition, although the south emplacement has large circumferential cracks (up to one-half-inch wide) in the concrete.

Figure 27. Bolts to attach the weapon's base plate are visible at the north emplacement.