About Education Events USS Pampanito Support Visit

The next step was to gather all of the information we could about what had been done for the submarine over the years. All records of surveys and maintenance while she was owned by the Navy were obtained from Mare Island Naval Shipyard. Builder's plans and detailed blueprints, however, could not be obtained because they were still classified at that time and could not be released to us.

Built in 1943, Pampanito served on six patrols in the Pacific during World War II. She was taken out of service in December, 1945 and was placed in reserve at Mare Island Naval Shipyard where she underwent regular maintenance and inspections until the mid 1950s. Great care was taken by the Navy to preserve the submarine and the equipment aboard. They had every intention of returning her to active service at some point in the future. Interior spaces were dehumidified, piping was drained and dried, preservative was used in machinery, flood ports and through hull fittings were blanked off, regular detailed surveys were performed, and she underwent an extensive haul out in 1955.

During the 1960s she served as a Naval Reserve training platform at Mare Island and was no longer the recipient of regular maintenance, except for "housekeeping" activities. Some minor modifications were made to the submarine at this time. In 1970 she was opened for industrial stripping by the Navy and several key pieces of equipment were removed. During this process little care was taken in the removal of equipment, often wires were cut with a hacksaw and pushed back out of the way. In 1971 she was stricken from Navy records, but was left in storage at Mare Island without regular maintenance. The Maritime Park Association (formerly the National Maritime Museum Association) assumed possession in 1976, but due to unexpected local political problems, a public berth could not be obtained at that time. Pampanito was placed in storage at a private shipyard where she remained for almost six years.

From the time of the 1955 dry docking until she was opened to the public in 1982, preservation activities had gradually slowed until they completely stopped in the early 1970s.

All vessels that are afloat need periodic dry dockings, the frequency of which is dictated by the conditions that the vessel is subjected to. It became clear to us that Pampanito had not been dry docked since 1955, twenty-seven years prior, and that she had been in salt water the entire time. Based on our desire to preserve the vessel and prevent problems rather than repair them, it was decided that Pampanito would be placed in dry dock as soon as possible. In order to determine how much money would be needed, an accurate assessment of her physical condition was required so that the scope of the work to be done could be determined.

Our preservation plan, as it was developing, had two basic components; work done by a shipyard or outside contractors, and work accomplished by staff and volunteers. This meant not only developing a regular dry dock schedule, but also working to preserve and restore the submarine on a daily basis. Another aspect of the planning process was to work toward restoring the vessel to her condition and appearance at a specific point in time. Because Pampanito underwent some major alterations during the summer of 1945, that point in time was chosen as our goal.

To develop a schedule and decide upon the initial work that needed to be done in the shipyard, Association staff began a methodical survey of the submarine to accumulate as much information as could be obtained while the vessel was afloat. Every part of the submarine that was accessible was evaluated. This included all tanks, free flooding areas, void spaces, the shell plating and the pressure hull as well as all piping and machinery aboard. Special attention was focused on the areas around the waterline. Problems that could be addressed immediately, such as corrosion in the superstructure, were repaired. Missing vintage equipment was located and installed on the boat.

Two teams of divers were then sent down to assess the underwater hull. Unfortunately, the waters of San Francisco Bay are murky and visibility is limited to a few inches. Also, the marine growth on the hull was over three inches thick as the vessel had been without anti-fouling coatings for several years. The divers were able to determine, however, that the outer shell was in fairly good shape, except for pitting along the waterline. We knew that the submerged areas of the bow and stern superstructures had problems, and the divers confirmed that they extended below the waterline.

The next step was to have a professional marine surveyor evaluate Pampanito's condition. Based on ultrasonic gaugings it was determined that the outer shell was deteriorated up to 14% and the portions of the pressure hull that were in contact with salt water were deteriorated up to 9%. Portions of the pressure hull inside the ballast and fuel tanks were well coated and in excellent shape.

We began to get an idea of what had to be done in the shipyard and specifications were drafted. Because there were still areas of the submarine that were not accessible, and some problems would not reveal themselves until Pampanito was out of the water, the specifications, and more importantly our funding, had to have room to incorporate additional work. We did not know, for example, the condition of the weld seams on the underwater body.

To further complicate the drafting of shipyard specifications, there was some confusion as to what standards should be used to determine the scope and intent of the work to be performed by the shipyard. In the absence of national standards to look to for guidance, there was much discussion about the methodology to be used. Many members of the Association Board of Trustees were maritime industry professionals who felt that applying standard ship repair practices was the logical approach. Active merchant ships, and even Navy ships, are seen as having a finite lifetime. The most important thing is to repair the vessel in the most cost effective manner and get her back in service. At some point in the future the vessel would no longer be of value, or be outdated, and would be scrapped. Also in this line of thinking there is no interest in preserving the historic fabric of the vessel or in using original construction techniques and materials for repairs.

On the other hand, many of the Trustees and staff felt that our goal was to preserve the vessel as she was built, and that she did not have a finite life expectancy. They felt that our goal was to preserve the submarine indefinitely, and that the same standards that apply to historic artifacts or historic buildings, for example, should be applied to preserve the vessel. Further, it was felt that all work be done as accurately and carefully as possible.

Fortunately, at this time there was a growing movement to define the standards for historic vessels. The Association for the Preservation of Technology (APT) held a conference in San Francisco to formally discuss this issue. The result of this conference on our internal decision making process was that we developed shipyard specifications that reflected the need to preserve the historic fabric and integrity of the submarine. This led to the establishment of the National Maritime Initiative of the NPS and the publishing of the Standards for Historic Vessel Preservation Projects.

The next step was to decide upon an underwater coating system. When Pampanito was last dry docked in 1955 she had been coated with a "hot plastic" coating which would have to be completely removed so that a new system could be applied. Removal meant sand blasting the entire underwater body to Steel Structures Painting Council SP-10 (near white metal) to assure a good bond for the new coatings. This is something that we did not want to do each time the vessel was dry docked, not only because of the cost involved, but also because of the repeated loss of original material inherent in sand blasting to white metal.

We arrived at a system using a bonding primer on the bare metal, two anti-corrosive coats and two anti-fouling coats. Also a tough anti-chaffing coating was to be applied to the entire waterline. All surfaces in contact with salt water, including all interior free flooding spaces, were to be coated in this manner. We set up a regular dry dock schedule to put Pampanito in dock every five years, which was based on the life expectancy of the anti-fouling coatings. This schedule allowed us to repair the coating system in subsequent dry dockings rather than replace it each time. This regular schedule would reduce both the long-term costs and wear and tear on the historic fabric. A high pressure water blast, instead of sand blasting to bare metal, could be used the next time in dock to prepare surfaces for recoating.

It was decided that Pampanito would be refloated after the coatings were applied, shifted on the blocks, and dry docked a second time so that the portions of the underwater body that were obscured by blocks could be reached. In following dry dockings we would use an alternate blocking position each time and dock the submarine only once each cycle. The original Navy docking plan was obtained from Mare Island Naval Shipyard, where Pampanito had last been dry docked. It called for a three position blocking plan to reach the entire underwater hull, so the development of a two position plan was included in the specifications for the initial docking and we would use the original three position blocking plan there after.

The specifications then needed to be approved internally so that they could be sent out to the shipyards for bids. This involved review by staff, Board members and marine engineers. The specifications reflected the goal of preserving the historic integrity of the submarine. The debate over the standards to be used to guide the work continued until the Trustees, after much discussion, approved the specifications and the regular dry dock schedule. The specifications were ready to send out for bids.

Pampanito would remain in the shipyard for about six weeks. Because the submarine is open to the public year round, lost income during this time was another factor that had to be added in to our preservation budget. January, February and early March are our slowest visitation periods, so we chose that time to carry out the work. A deadline for finishing the work, with a daily penalty for delay beyond a specific date, was added to the specifications. The specifications were sent out to bid and a shipyard was chosen.