We can handle a lot of heavy lifting with our staff, but sometimes we need to call on outside experts for help. Such was the case with No. 3746, a Japanese mini-submarine designed by Nishimura Ishimatsu. We needed to lift the sub onto a custom cradle and relocate it. Often this is a simple task with objects in the Museum’s Collection; however, due to the sub’s size (35 feet long and 20 tons), there was no way we could do this in-house.
This “simple” task was actually the culmination of several years’ worth of planning and only possible due to many people’s support. The Museum’s Bronze Door Society approved the funding of a custom cradle for the submarine during their 2019 annual dinner. The cradle would fully support the hull and make it easier to move the sub. We could also conserve and display the submarine in its new support. Hannah, our archaeologist, shared with the Society why the sub is so special and the need for a new support. You can learn more about the history of the sub and the start of the project in our past “In the Land of Submarines” series posts; history; assessing; and documenting.
Moving day started early to make sure there was plenty of time. Crofton Industries set the crane up the day before to be sure everything was ready. The sub looked big until the 60-ton crane was next to it!
The riggers attached shackles to the original eyebolts. Even after 80 years, they were strong enough to use for lifting the sub. Once airborne, the sub hovered two feet off the ground for a minute. This was to verify that the eyebolts would hold and see what the keel wanted to do. The keel had deteriorated from being in contact with the ground for decades. We were ready if portions of it detached. Thankfully, the keel remained intact and the lift was smooth sailing!
Once the sub was steady, it was slowly moved into place on the cradle. You can see the chalk outline of where each support needed to align. These corresponded to the sub’s inner frames, making sure the sub was supported at the right locations. Each support had wooden cribbing that fit the hull’s curve, making for a snug fit.
The next step was moving the whole thing onto a flatbed truck and securing it. The truck and crane were then moved behind the conservation labs to the sub’s new home. The sub will be located next to the “tank farm”, an area that houses tanks with USS Monitor objects. During the move, Laurie and Elsa took advantage of the nice weather to screen Monitor concretion!
Finally, it was time to move the sub into position. The crane lifted it up and over our storage shed, rotating it as it came down. The cradle was set onto concrete blocks to elevate it off of the ground.
Now it is easy to access the sub. The cradle fully supports the hull and keel. And there is great airflow, which reduces corrosion.
Thank you all!!
Thank you to all of the people that made this project possible; Fairlead Boat Works for building the cradle, Blair Brothers and Crofton Industries for prepping the new space, and Crofton Industries for relocating the sub! In addition to our outside partners, thank you to the Bronze Door Society for their support and the efforts of our team and volunteer Gerry Hanley! The submarine will be very happy in its new home thanks to everyone’s hard work.
The future of the sub
So what is next?! The sub needs a cover to protect it from the elements. Once in place, it will be fairly stable until conservation can start. We do intend to conserve it, but nothing is scheduled yet. This will be a major undertaking that will involve multiple people several years. I do know that when it is complete, it will go on indoor display!