CABRILLO Historic Structures Report

In the following report, we evaluate nineteen structures at Cabrillo National Monument. The purpose of the report is to provide the monument's management and staff with the architectural information it needs to implement a long-range program to restore, rehabilitate and/or stabilize these increasingly significant military structures in order to achieve the park's mission and long-term goals.

The following are included in this report:

• A general history of the site, including period of significance.
• Descriptions of each of the structures, including material, configuration and condition.
• Material and structure specific recommendations for repair, taking into consideration the treatment goals established by the NPS.
• Maps, drawings, photographs and other graphic materials to assist in understanding the structures.
• Structural evaluation and recommendations.
• A cost estimate for the repair recommendations.

The structures examined are primarily constructed of reinforced concrete, and date from the mid 1910s through the mid 1940s. With the exception of the Radio Station, none are open to the public. Most are partially buried. The structures include fire control stations, searchlight shelters, gun mounts, hemi-cylindrical sleeping and storage bunkers, a generator station, a radio station, and an electrical connection box.

While most of the structures were found to be stable, the following deteriorated conditions were noted:

• Cracked and spalling concrete, sometimes in conjunction with corroding reinforcing rods.
• Corroding ferrous metal components, including hatches, shutters and associated hardware.
• Missing camouflage stones.
• Deteriorating wooden elements.
• Excessive vegetation.
• Pest infestations.
• Graffiti.

The second half of the report presents our recommendations. General repairs are as follows:

• Patching of cracked and spalled concrete.
• Painting of concrete and wooden elements where originally painted.
• Cleaning, patching and painting of corroded ferrous metal elements.
• Consolidating, preservative-treating and painting of wooden elements.
• Recommendations for further testing, survey and study, including concrete testing.