How To Properly Patch Your Iowa-Class Battleship

There’s a saying among recreational mariners that the word “boat” is actually an acronym for “bring out another thousand”, as it seems you can’t operate one for long without committing to expensive maintenance and repairs. But this axiom isn’t limited to just civilian pleasure craft, it also holds true for large and complex vessels — although the bill generally has a few more zeros at the end.

Consider the USS New Jersey (BB-62), an Iowa-class battleship that first served in the Second World War and is now operated as a museum ship. Its recent dry docking for routine repair work has been extensively documented on YouTube by curator [Ryan Szimanski], and in the latest video, he covers one of the most important tasks crews have to attend to while the ship is out of the water: inspecting and repairing the hundreds of patches that line the hull.

These patches aren’t to repair damage, but instead cover up the various water inlets and outlets required by onboard systems. When New Jersey was finally decommissioned in 1991, it was hauled out of the water and plates were welded over all of these access points to prevent any potential leaks. But as the Navy wanted to preserve the ship so it could potentially be reactivated if necessary, care was taken to make the process reversible.

Patches that project out from the surface are easier to remove.

Squatting underneath the 270 meter (887 feet) long battleship, [Ryan] points out one of these patches and explains how they were installed. Rather than welding a flat plate over the hole, the patch was boxed out from the surface so that it could be easily cut off without damaging the ship’s hull. A set of eyelets were also welded to the hull around the opening, as they would have been used to help hoist the heavy patch into position.

Once installed, a pressure gauge and an air hose would be attached to a opening built into the patch. Compressed air would be pumped in, and the pressure would be monitored to see if there were any leaks. Should the pressure drop, spraying soapy water on the weld seams would usually reveal where the air was dribbling out of.

According to [Ryan], only one of these patches is known to have developed a leak in the 32 years since the bottom of the ship was last inspected and serviced. But given the fact that the ship won’t be removed from the water again for the next several decades, the plan is to go around pressure testing the patches and repairing any welds that might not be up to standard.

The Battleship New Jersey YouTube channel is a phenomenal resource for anyone interested in the nuts-and-bolts of warships, with videos covering everything from the ship’s original WWII equipment to the modern electronic retrofits made to the ship in the 1980s and 90s.

28 thoughts on “How To Properly Patch Your Iowa-Class Battleship

  1. Quick research:
    Original cost: about $100,000,000 1938 dollars
    2024 equivalent: about 2 billion dollars.

    Rule of thumb for boats: 10% of original cost/year in upkeep (freshwater).
    200 megabucks/year.
    They claim to have been spending $10k/day…3.6megabucks/year.
    It’s rotting away. Rust painted over for decades. Deferred maintenance a mile deep. No matter how little of the original ship they are even attempting to maintain.

    Amazing it hasn’t sunk.

    1. Idk maybe that rule of thumb changes when it’s got economy of scale and military backing and training and personnel and probably some subsidies. What’s that rule for, a freshwater fishing boat?… wakeboarding boat?

      1. that rule’s likely for vessels in active use, i bet it’s cheaper to maintain one that’s just sitting at dockside being a museum. still not likely to be _that_ much cheaper, i’ll admit.

      2. Anything in fresh water. Power, sail or commercial. It is a ‘rule of thumb’, broad strokes and ballpark.

        I’d bet that most Navy ships exceed the rule of thumb for salt water (20% of new cost/year). Hard to separate maintenance from operations.

    2. Willing to bet that “rule of thumb” changes quite a lot when it stops being an active serving battleship and becomes a floating museum, given how much of that original cost would be weapons systems and other things that you aren’t keeping operational.

      What would a similar-size cargo ship or barge have cost back then? 1/2, 1/4? 1/10th?

  2. I owned a 14′ fishing boat a while back. Aluminium build, but it leaked slightly. On stripping back bits of the decking, the previous owner had allowed fishing hooks to drop into the bilge, which then proceeded to corrode and create pin holes. Far too thin for welding so bought a couple of pots of thick lorry under-seal and liberally coated both sides. Worked a treat. No more leaks. However, owning a boat is a nuisance, best time was when I bought it and then when I sold it again. Downsized to sit on top kayak – loads more manageable and more fun.

  3. Expenses for boats are measured in Boat Units. The fix of a particular system has a very similar cost in Boat Units from one vessel to the next — e.g. 1 BU to change the oil — but the dollar equivalency varies. Small boats might get away with $1,000 BUs, but this Iowa class must be in the $100,000 BU class (or higher).

    Contrary to popular belief, boats don’t float on water, but instead utilize the anti-gravity effect afforded by the application of money. Stop showering C-notes on a regular basis and the boat will surely sink.

  4. Wow the complainers are out and about.
    The dry docking of the USS Texas was even more interesting and yes the Battleship New Jersey group covered it and used it as a template.
    As to the cost it is a museum people. They are not profit centers usually but some like this one are very popular tourist attractions so the state and the city involved feel it is worth the expense.
    The Texas is over 100 years old and was in a lot worse shape than the New Jersey. She had a lot of problems and was close to sinking when finally it was dry docked. For sitting in the water for 30 some years the New Jersey really is in great shape. There was only one small leak and that was in a test valve on a blocking plate.
    I would make a guess that all the lessons learned from small pleasure boats may not apply to massive steel ships that are desinged from the start to be hard to sink even when people are shooting really big guns into them.

  5. So they kept a list of all the patches they’d applied? This is a different type of patch log to what we usually read about on HaD…
    And if they’re going around testing them is that a regression test?

    1. Tracking patches would be as simple as adding them to the plans. My Uncle Jimmy was one of the draftsman that would add upgrades and repairs to the original plans by hand on a drafting board. He was still doing this in the early 2000’s part time after he retired. BIg giant rolls of Vellum laminated to fabric. All systems had to be recorded so if you were removing bulkheads to upgrade something you didn’t kill everyone by cutting a live steam pipe or high voltage cabling in drydock.

    1. I think it depends on the ship, its size and such. Dry docks are limited in number and I imagine building one is very expensive. There is an experimental sub called the Albacore in Portsmouth NH which has its own drydock so it doesn’t require the hull to be watertight, but I imagine it still needs to be waterproof to maintain the innards, and there is the normal wear and tear of visitors, and things need to be painted. Perhaps it works out to be cheaper to use a dry dock once every 30 years than to try and build one and do the normal maintenance anyways.

    2. In theory yes about being better. Cheaper not so much. First of all you wouldn’t really want to tie up a dry dock that large. You would also have to service the drydock. In theory you could possibly use what is called a floating drydock. That could lift the ship up to ground level. Then you would need to have some kind of lifting and moving system for the entire ship. Removing the Turrets could reduce the weight a lot and could then be replaced once the ship was moved to the new location.
      But you have to understand that a battleship or carrier involes a mind numbing amount of mass. For the New Jersey you are talking about over 45,771,099 Kg. There are other ways you could do it like diging a waterway and then building a foundation for the ship to rest on then back fill part of it and then pump it out.

    3. They cover permanent drydocking on their youtube channel. Ships this large are not designed for long term support out of water and will start to sag under their own weight.

      1. Just put it in sand that forms around the hull like water and voilà.
        You can even just build a barrier around it and pump out water while pumping in sand – so it does not have to be moved.
        They create islands like that constantly; so it’s exisiting tech.

  6. The NJ is in great shape. No signs of rust on the hull and 1 small leak that was known for years. The NJ will only be in dry dock for2 months. The Battleship Texas is a much older ship. I watched some of the Texas dry dock videos and amazed it was in such poor shape. Imagine using blown in insulation to keep it from sinking!

  7. Naval warfare is changing dramatically, ergo the Russian experience in the Black Sea. If this sort of heavyweight battleship were reactivated today, along with appropriate modern modifications, how would it fare against the latest anti-ship technology? Might seem to have an advantage above the waterline with thick, steel walls. But against a modern torpedo that expodes under (not into) the ship to break it’s beam? Are large and expensive warships still feasible? Spread out the expensive smart weapons on smaller, dispensable delivery hosts? Swarm tactics? Just asking, cause the tide is turning.

    1. All you had to do so far was making sure people you attacked only had simple primitive weapons and no subs or any real navy.
      The problem in that regard is that now even the most primitive groups have missiles and drones and such, meaning you have to adaptt to the new reality.

    1. Brilliant hack: if you want to preserve it, but can’t get it into a museum for whatever reason, just convince everyone to keep it as unmodified backup. When it gets too old for a backup, chances are it is now historically important, which implies a better chance to finally get it into a museum.

  8. I serve as a volunteer on the USS New Jersey as part of the Radio and Communications Restoration Gang. There are a number of other groups consisting of volunteers who have been restoring systems throughout the ship, not to operational status but by simulating the look and feel of systems as they would have been when the ship was actively serving as a Navy asset. It’s a pleasure for me to be a part of the effort to keep this ship alive!

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