2020 was a tough year everywhere, the USS Pampanito Submarine Museum and Memorial was no exception. The Covid-19 pandemic closed the boat to visitors and led to staff furloughs. A massive fire destroyed Pier 45 Shed C next door and threatened to destroy our facility. In Jan 2021 her moorings dragged in a storm causing damage to the submarine and the brow (gangway on/off the boat). Finally we were overdue on spending a matching grant for superstructure (deck) repair and replacement of the missing 5" gun foundation aft that had been extended more than once.
Our staff and Board of Trustees looked for a way to find opportunity in all this disaster. Our insurance company recognized that the storm damage would be best be repaired in dry dock and payed for the storm repairs. While in dry dock we fulfilled the grant by replacing the 5" gun foundation, and repairing the wooden main deck and deck beams. We raised enough in both cash and in-kind donations to do very basic preparation and coating of the underwater hull. This reset the timer for our next preservation drydocking. Doing the dry docking while we were closed by Covid-19 saved all the lost visitor experience opportunities (our mission), and and all the lost revenue that would occur if we went two years later. Finally, Bay Ship & Yacht had a 5 week availability on short notice expected to start 12 April 2021.
So with only a few weeks time to prepare and a low budget (roughly $800,000 including both cash and in-kind donations) USS Pampanito went to drydock for a 6th museum era drydocking on 20 Apr 2021. The focus of all our previous museum drydockings has been on the underwater hull and projects that absolutely cannot be done at the pier. This drydocking was different. The goals were to repair storm damage to submarine and brow (gangway), minimal underwater coatings maintenance, and to execute the matching grant for replacement of the missing 5 inch gun foundation, building a new brow landing platform, and main wood deck with steel deck beam repairs.
Below are a series of blog posts created by one of the volunteers during the drydocking to document the process and work. We were shorthanded during this drydocking so we skipped blogging about many of the shipyard processes that were the same as our 2016 posts.
20 Apr 2021:
Someday I would like be part of a ship evolution that does not start at 04:30am. The powerful 200 foot crane barge arrived to remove the brow (gangway) visitors use to get on the boat, the chains that hold Pampanito off the pier, and the twin 20mm gun that needs restoration. They also picked up the replica foundation for the second 40mm gun and wood for the deck to be delivered to the shipyard.
20 Apr 2021:
Prescot Stone and Charlie Butcher before departure.
20 Apr 2021:
While Pampanito is being towed to the drydock, the crane barge pulled the aft morning chains up to connecting link for inspection. Everything looked good. The forward chain was checked after the forward anchors dragged in the storm during January so they did not need to be inspected again.
20 Apr 2021:
Photo by Rony Sagy of Pampanito under tow past Alcatraz on the way to drydock.
20 Apr 2021: Pampanito under tow.
20 Apr 2021:
Pampanito entering the lowered drydock, then as the water is pumped out of its wing wall tanks, the drydock and boat rise together.
20 Apr 2021:
Prescott Stone, deckhand, trustee, and all around nice guy took these photos yesterday.
21 Apr 2021:
The crane barge carried some big items that will be needed during drydock to Alemeda just down the road from the shipyard. Aaron's photo below is of the crane barge unloading the replica 40mm gun foundation that will be mounted forward. I can also see the douglas fir wood for the deck battens on a truck. The big item not in the photo, but also carried to Alemeda by the barge was the aluminum gangway we use to access the boat. It was damaged in a recent storm and will be repaired at the shipyard.
21 Apr 2021:
Here are some photos taken by Aaron Washington before cleaning. Not surprisingly, she looks better today after 5 years in the water than she did last drydocking when she had been 10 years in the water. You can see many of the sacrificial zincs still with material. This is probably both because of the shorter interval, but maybe also because of the work we did on Pampanito's electrical supply update in 2018-2019.
22 Apr 2021:
The shipyard started to water blast the bottom, assemble scaffolding, and survey the work. My first impression is that the bottom coatings are in pretty good condition.
An update, there is still going to be quite a bit (20% of underwater hull) that has to be prepped to bare metal. The partial coating of the bottom with donated anti-fouling coatings is going to complicate this drydocking's coating scheme.
24 Apr 2021:
A couple photos of the fiberglass covers on the propellor shafts, no repairs will be needed.
24 Apr 2021:
Shipyard started removing the mostly rotted out decking. It is not surprising that the frames, coamings, and plates below the wood deck are damaged. It is still hard to look at, particularly in the areas that are accessible from below. More steel repair under the wood deck will mean less money available for steel repair elsewhere.
Update: I was asked why we did not do this work at Pier 45. Our original plan was to do the deck work dockside, but it never came together. It pains me to see the amount of uncoated wasted material that is in areas that can be accessed dockside. However the areas under the wood on the frames and coamings really are a problem to replace at the pier because the beams cross the deck and the wood needs to come out for access which means nothing is left for visitors to walk on. Although expensive, much of this work will be more quickly and efficiently (but at higher cost) done in the drydock without dodging visitors, rolling boat, dust collection, expensive crane service, commuting skilled workforce, etc.
24 Apr 2021:
These are the sacrificial zinc anodes that protect the coatings and steel below the waterline. Last time after 10 years between drydockings there was pretty much nothing left. Here you can see that at 5 years they still have some metal weight left.
24 Apr 2021:
The non-historic lifting eyes and door strong back (locking bolts) are distracting, but I never get tired of looking at how sleek she is in the bow. The camera is not distorting the view much, it really looks like this.
24 Apr 2021:
One more still photo taken from a drone by John Johnson showing Pampanito being moved away from Pier 45 on Tuesday 20 Apr 2021.
26 Apr 2021:
Storm damage.
2 May 2021:
New deck beams going in. Note they are normal angle steel, not the bead angle used during the war that is unavailable as a normal commercial purchase.
4 May 2021:
This is the deck under the wood and diamond plate steel where our brow (gangway) has been landing since 1981. This is also where the 5" gun foundation was installed in summer of 1945. During 1960 or 1961 the foundation was removed when Pampanito was prepared to be a shore side training platform for Navy reservists. They needed the space under the deck for the simulator equipment and a strong deck for the simulator. After they removed the foundation they replaced the wooden deck in this area with this steel deck. There will be a future project to restore the wooden deck back to the original 1945 location aft of the gun sponson, but we do not have the funds to do it now.
5 May 2021:
Stern shot.
5 May 2021:
These are the screens that were around the ballast tank vents. They are going to be removed to our collection to make it easier to prep and paint below the deck. They were around the vent valves to keep loose junk from getting in the valves and preventing their full closure when diving.
5 May 2021:
Another area of storm damage has been cropped out and is being prepped for the replacement insert. The second photo shows the welder driving a wedge into a temporary dog that has been welded to the hull. This allows him to force the roughly shaped metal close to the hull. These are really important and frequently used tools of ship fitting.
5 May 2021:
The bottoms of the chain locker and adjacent void were cut out to provide easy access for maintenance. The pieces will be welded back near the end of the drydocking.
6 May 2021:
The metal fabrication shop has started breaking (bending) the curved parts of the gun foundation.
6 May 2021:
Wood template, cut plate, welded repair.
6 May 2021:
Just to be clear, not all the deck beams under the wood were bad. As we removed the wood we saw four types of wood, the original teak and three replacements (mahogany, treated yellow pin, douglas fir). We also saw a mixture of bronze and galvanized bolts. The areas where the wood was replaced more recently would have had the steel below painted. This explains why many of the frames forward are still good, but aft are mostly bad.
The machinist is loosening the bolts on the 5" gun in preparation for lifting it off the boat. Note that only some of the bolts were installed, this foundation forward was designed and had a 4" gun on it during WW II. The 5" gun has a different bolt hole pattern so only some bolts were fitted in newly drilled holes when the 5" gun was mounted during the museum era.
6 May 2021:
We just mechanically prepped in spots, and now those spots are getting primer. Normally we would sand blast and spray paint as well as open all the torpedo shutter doors to have more complete coverage. We are doing a lot less preparation and coating than we normally do in drydock because of the very thin budget outside the grant and insurance work.
7 May 2021:
Progress on the 5" foundation.
7 May 2021:
14,105 pounds of 5" 25 cal gun was removed from the 4" 50 cal gun foundation forward. When returned to Pampanito it will be mounted in the historically correct position aft of the conning tower.
9 May 2021:
Here is a bit of a typical museum project question. How was the twin 20mm gun mounted on the forward gun foundation?
In the summer of 1945 the four inch gun was removed and a twin twenty was installed in its place. The black and white photo shows a twin twenty mount with the guns removed mounted center of the 4" 50 cal foundation. You can also see the empty mounting holes left from the 4" 50 cal. This is our restoration goal, twin twenty on the forward gun foundation.
Shortly after becoming a museum in 1982, they found and mounted a hydraulic operated 5" gun that was never used on submarines. I am not sure how many bolts holes they added, but the bolt hole pattern was definitely not the same as a 4" 50 cal so they added holes.
Later they traded this for an appropriate 4" 50 cal. that was on the boat for many years. This matched the 6 war patrols, but not the summer of 1945 restoration target date. This should have fit without new holes.
Later we gave the USS Navy the 4" 50 cal, and they provide a 5" 25 cal gun to match our summer of 1945 restoration plan. Because the foundation aft was missing, the gun was temporarily put on the foundation forward and more non-historic holes where drilled to bolt it down.
So now look at the photo of the gun foundation. Knowing the history the swiss cheese of holes starts to make sense. However, what I do not see is a 26.375" dia. circle of 5 mounting equally spaced holes that are used to mount a twin twenty. So either the holes have been filled in, the wood replaced early in the museum period, or there was some kind of mounting adapter.
More research is needed.
9 May 2021:
These are all photos of Pampanito from July-August 1945 in the water, and Nov-Dec 1945 in the graving dock showing our target restoration period.
They show the 5" 25 cal gun aft, antennas leading forward with extra spreaders, two Bofors 40mm guns, and a twin 20mm gun forward.
9 May 2021:
So I searched harder and found two more photos that really nail down the 20mm mount bolt hole question. The photo with the red gun shows the 4" 50 cal when the museum installed it including the distinctive 4 holes out of the circle aft.
The second photo is the critical one. It shows the foundation top in the museum era, but before any gun was mounted. There was a stanchion in place to fill the hole and prevent people from falling through. The interesting part is that the photo clearly shows the 4" 50 cal bolt hole pattern, and the 5 hole pattern for the 20mm foundation. So I expect we will only have to clear out whatever they used to plug the 5 holes, prep, paint, bed, and we will able to install the 20mm without an adapter or any new holes. I will be in the shipyard next week to get photos from below to confirm the holes are still open in the steel.
Update: The 5 hole pattern is in the steel, they are filled in the wood so it will be easy open them up. We will have to fill in the swiss cheese of holes added during the museum period to hold the two different 5" guns that had been mounted on this foundation.
Update2: The wood currently installed (not in the photo above) is douglas fir, not the teak we think was used during the war.
10 May 2021:
Two of the large inserts repairing storm damage are completed. Lots of smaller, coamings and deck frames by way of the main deck wood areas are completed.
10 May 2021:
Replacing the coaming close to the conning tower that was rotted out.
10 May 2021:
Here is a view I have never seen before. This is the bottom of the 5" 25 cal stand. We can see the roller path of the traversing bearing.
12 May 2021:
More progress on the foundation parts. They will be able to start welding soon.
12 May 2021:
The steel deck above the 5" foundation on the gun sponson has been removed, it will later be replaced with a round hole for the foundation. The bottom gets coped (fitted to the curve) into the round of the hull. Today the engineer was measuring up the pipes and frames that will have interferences with the foundation. If needed the replica foundation will be modified to minimize changes to the historic fabric.
On the inside of the hull the cork insulation by way of the welding outside the hull was removed for fire safety in preparation for welding. This is natural cork glued in place with 1943 glue. Even through the 7/8" hull the welding heat could start a fire.
12 May 2021:
During the restoration of the 5" gun we spent a lot of time working with its drawings and found this detail. The stand of the 5" gun has an arrow cast into one of its gussets that indicates the direction of the barrel when stowed. So this gusset will point aft when the gun is bolted to the foundation. It was pointed in the wrong direction during the time it was mounted on the 4" foundation forward.
12 May 2021:
The original deck frames on the boat have the interesting profile shown in this photo. Notice the rounded bulb that stiffens the angle iron on the bottom. We could not make or find this profile steel in the hurry to drydocking so we are using normal angle iron.
12 May 2021:
Enclosed are photos of interesting features normally hidden below deck that are temporarily easy to photograph.
The section of the pressure hull with all the bolt heads is a soft patch that could be removed in drydock to facilitate replacement of batteries.
The second is the modern electrical panel we added a few years ago to supply power to a modern hydraulic pump, welding outlet and deck lighting. https://maritime.org/pres/electrical
12 May 2021:
A view of the forward escape trunk.
14 May 2021:
Punching holes in the new deck for the bolts that will fasten the deck battens.
The second photo shows the overhead in the crew's berthing where the cork insulation has been removed in preparation for welding outside the hull.
17 May 2021:
Gun foundation is tacked together. There are two pipes that are likely interferences, and the coping between the round hull and the conical foundation. Finally the fit to the deck. 3D geometry that is computer modelled and ultimately adjusted with traditional shipfitting on the boat.
19 May 2021:
The mounting holes being drilled with one of my favorite tools, a magnetic drill.
20 May 2021:
Repairs have started on the gangway. It was badly damaged in the storm.
20 May 2021:
Most of the holes for the deck fasteners have been punched or drilled. Underwater coatings repair continues. Repairs are being made to the original gun sponson.
23 May 2021:
When Pampanito went to drydock on short notice we chose to finish restoration and re-assemble as quickly as possible our second Bofors 40mm gun so it could be mounted during the crane availability in drydock. We completed re-assembly and coatings this morning. Note the rough black paint from above and grey from the sides. This is Measure 32 camouflage to hide from airplanes when dived, and minimize visibility on the horizon when surfaced. The black is applied with a sloppy, stippled painting to avoid sharp lines and invoke the look of war time shipboard painting. The restoration is documented on this page: https://maritime.org/pres/bofors
Gun is de-milled, rendered incapable of loading a shell or firing.
24 May 2021:
Steel repair under the wood deck is done, prep and coating is ongoing.
24 May 2021:
Aluminum brow repairs are ongoing.
24 May 2021:
Gun foundation is landed on Pampanito. Now the tricky part is getting it parallel with the ship's baseline, centered on the sponson, hole pattern properly oriented aft, and the correct height. The last photo shows the BS&Y crew spiling (marking the steel a uniform height from the hull) the bottom of the foundation in preparation for precise fitting.
24 May 2021:
Inside the gun mount looking up. Also, I think my first ever selfie.
26 May 2021:
The 3" thick, douglas fir is being prepared for the gun. The 2" deck batons are being painted. The wood hatches have had their steel frames repaired and are starting to be fitted.
26 May 2021:
Work has started on the non-historic brow landing platform. This is needed to free up the original gun sponson that had been used for the brow since arrival at pier 45 in 1981.
26 May 2021:
Foundation has been trimmed to height, leveled, and welded to the hull. The shipfitters are now working on the framing. We removed the cork insulation inside the hull where it was welded on the outside. The hull is 7/8" thick here, but even with stich MIG welding it was warm to the touch inside the hull. There was a continuous fire watch and ventilation in the hull for safety.
The more of the frames that are installed, the less room there is to maneuver. The shipfitters often work in lots of tight spaces, and yet generate really nice looking welds.
27 May 2021:
First of the wood batons are going in. Wood on top of the foundation is taking shape. Note the mounting hole pattern sitting on top.
28 May 2021:
5" gun mount has all the frames tacked in. The wood deck and wood deck hatches are going in forward. The restored 40mm Bofors gun was moved to the shipyard in preparation for installation next week.
28 May 2021:
Some of the steel deck removed around the aft gun sponson will be replaced with new steel. The many holes are to prevent air from being trapped when diving that would slow down the dive. The area extending from the existing wood deck forward of the sponson to just aft of the sponson should be wood deck instead of steel. The steel decking was installed when they removed the 5" mount in 1960. It would have been great to replace this with wood now, but we did not have the funding.
Also enclosed is a photo showing progress on repairing the storm damage to the aluminum brow.
1 June 2021:
Sacrificial zincs have been replaced. These are less noble, more easily eroded by electrical activity than the steel. They help preserve the coatings and steel.
2 June 2021:
Wood deck is progressing. Note the scarf (joining of the ends of the wood) is as specified in the drawings.
2 June 2021:
Progress on the non-historic brow landing platform.
6 June 2021:
Welding on the 5" gun foundation is completed. The new brow landing platform is close to completion.
6 June 2021:
The crew at Bay Ship and Yacht are really talented welders, shipfitters, joinery/wood workers, painters, safety, etc. It is our last Sunday before undocking and they are busy at work.
7 June 2021:
Wood is installed on the 5" gun foundation. It is ready to receive the gun.
7 June 2021:
Marine glue (pitch) has been used on wood decks for hundreds of years. The big hunks are broken off of the shipped block, melted, and poured in to protect the heads of the bolts and wood. It softens and reforms its seal on hot days. The downside is that on hot days shoes can carry it about. We have rubber mats over the visitor walkways so this will not be a problem.
Update: SF Maritime Small Craft Department added that they use an electric double boiler to avoid burning the pitch.
7 June 2021:
The machinists bolted down the replica 40mm foundation with the original bolt holes. The photo shows the bedding compound used between the foundation on the boat and the replica foundation. The bolts that held the 20mm stand in this position were too long. We used a bunch of washers to make up the difference until we can get the right length bolts once we are back home at Pier 45.
8 June 2021:
5" 25 cal wet mount gun has been loaded aft. The 1-3/4" 6 TPI bolts the shipyard provided were just a bit short. They are getting longer bolts tomorrow. Yes I know we need a better photo of the gun in place.
8 June 2021:
They used the big pitch pot heating the marine glue today, but a really small pouring pot to make it easy to fill the small countersunk bolt holes.
9 June 2021:
Bofors 40mm gun is now mounted forward. When we get back the deflection rail and muzzle lock needs to be replicated. The muzzle lock aft is the wrong type so it will get replaced at the same time. A loader cover has been repaired for the forward gun. It is getting plated this week and then will be painted. Until then a blue Ikea bag fits.
9 June 2021:
The five inch gun was mounted aft of the conning tower yesterday. The foundation looks great. The shipyard is still scrambling to finish the stanchions that hold the visitor rails and the non-historic brow landing platform. They will finish today, but it will be tight. They are also cutting it pretty close on the aluminum brow repairs. There will be some painting to do once we get back to pier 45.
There will be also a long list of small changes needed to complete the exterior restoration to summer 1945 back at the pier. Antenna outrigger and mast on port needs to be restored, outrigger on stb, the antennas properly rigged forward. The muzzle support for the 5" gun. If we get really ambitious, replicating the deflection cam and training scales on the gun.
9 June 2021:
The shipyard glory photos are always of the guy on deck, but the guy under the deck usually has the harder job.
9 June 2021:
Two Bofors 40mm aboard Pampanito. First time since 1945.
9 June 2021:
The brow repairs are progressing, but they will be working late.
9 June 2021:
The loader cover for the 2nd Bofors has been repaired and plated by local shops. Now two coats of epoxy primer and two coats of polyurethane top coat are needed before it can go on the boat.
10 June 2021:
Photos by "Drones by the Bay" John Johnson show Pampanito undocking and heading down the Alemeda estuary. The last photo showing her nearing the exit to the estuary shows how clear a day it was. If you look carefully you can see the Golden Gate Bridge past the Bay Bridge. Amazing photography.
10 June 2021:
Pampanito escorted by the San Francisco Fire Department boat rounding Pier 39.
10 June 2021:
Pampanito was lashed up with Power Engineering DB Pacific crane barge away from Pier 45, then moved as a unit into place. The crew re-installed the mooring lines to the pier while the crane barge kept Pampanito off the pier. Finally, the powerful crane lifts the offshore mooring chains into place so a crew in a small boat can re-attach them to the submarine.
10 June 2021:
Our CEO Darlene Plumtree was at the pier to welcome Pampanito home.
10 June 2021:
That is Aaron Washington our ships manager on Pampanito directing the re-installation of the mooring lines, and under the boat during drydock. It is really hard to express how much gratitude he deserves for this project. After 15 absolutely grueling months of short staffed operations during Covid-19 closure he had only a few weeks to plan and execute this drydocking. He had the help of Charlie Butcher shown standing on the right of this photo, myself, our CEO, and Board of Trustees, but the burden was almost entirely his. He was tireless, fearless, and effective. BZ (Navy speak for well done). Thank You.
10 June 2021:
The last step was re-installing the brow on the new, non-historic landing platform. The Bay Ship and Yacht crew shows up tomorrow at 0600 to complete/fix some of the stanchions, reinforce the brow landing platform, complete painting, and other details.
10 June 2021:
Three deck guns in the correct, Aug 1945 configuration.
14 June 2021:
A view of the 5" gun foundation below deck after coatings. Also a view inside after battery/crew's berthing after the cork insulation was replaced and painted after return to pier 45 by the shipyard crew.
16 June 2021: Pampanito re-opened after drydocking and Covid-19 closure.
