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Interestingly ships get cut in half and reassembled "all the time". Certainly way more than people think. See for example https://www.maritime-executive.com/ar
by WJW 6y ago
Interestingly ships get cut in half and reassembled "all the time". Certainly way more than people think.
See for example https://www.maritime-executive.com/article/photos-fincantieri-begins-first-ever-cruise-ship-lengthening https://www.maritime-executive.com/article/photos-fincantier..., where an entire cruise ship was cut in half and an extra section was inserted into the middle before welding everything together again. I will also never forget the training ship of the Dutch Navy, which was shortened by cutting it into half and removing a section from the middle. Sadly this messed up the hydrodynamics fiercely and it was extremely seasickness inducing in even moderate seas. The ship certainly was effective as a training vessel though.
- nightfly 6y ago> With demand soaring, many cruise shipbuilders are booked into the early 2020s... That didn't work out so well for them.
- wongarsu 6y agoCruise lines seem to have survived just fine and are starting operations back up (for vaccinated passengers). And if you believe that all publicity is good publicity they should have no problems filling those ships
- lifeisstillgood 6y agoThis is turning out to be an interesting business model - there are obviously the "pay us and we keep your money, but keep offering you future cruises till the pandemic is over" Additionally they are now offering "single country cruises" - start in one country, sail from port to port in same country - which radically simplified the vaccination
- thrower123 6y agoIt'd be nice if the US would ditch it's statutes from the late 19th century that make it illegal for foreign-flagged vessels from taking passengers from one US port to another. This is why, for example, almost all Alaskan cruises sail from Vancouver.
- sandworm101 6y agoWithout those rules, what is to stop foreign vessels from replacing domestic passenger ships? The Staten Island ferry might just adopt a foreign flag and staff the ships according to foreign (ie cheap) labor laws.
- netflixandkill 6y agoA better law that more precisely addresses the various situations instead of depending on the verbiage chosen by the long dead.
- sandworm101 6y ago>> verbiage chosen by the long dead. Look at the average age of the people writing laws. I'd say that 90% or more of current law was created by people now "long dead".
- excalibur 6y agoWhat could be more American than that?
- thrower123 6y agoWhat domestic passenger ships? There's a handful of cruise ships that are US flagged specifically for the Hawaii route. That's it. If you're concerned about car ferries, you can make specific laws about them. Or better yet, New York state could, since that's in their jurisdiction.
- rtkwe 6y agoIt's a bit of a few different thigns. There are tons of ferries across the US and getting rid of that rule would require either rewriting the law to maintain the change for them or for every state along the coasts to do their own regulating. Then there's a desire to maintain some domestic shipping and ship building industry from a national security standpoint and from the goal of protecting the environment immediately around the US.
- doikor 6y agoThe cruise line business is very cyclical so the companies hold really big piles of cash for when things get slow (like 2007-2008 financial crisis) All the big companies had a couple billions each sitting around just for shit like this. They just fired most of the crew (they still need to have 100+ crew per ship to keep them in good condition) and anchored them waiting for better days. With this reduction in costs they could easily wait out a year or two for business to come back. Wendover Productions did an excellent video on the topic https://youtu.be/N4dOCfWlgBw https://youtu.be/N4dOCfWlgBw (including how they solved getting their tens of thousands of employees back home when planes were not flying really)
- devoutsalsa 6y agoThe USS George Washington was originally going to be an attack submarine, but instead they decided to lengthen it by 130 feet & make it a ballistic missile sub. [1] [1] https://en.wikipedia.org/wiki/USS_George_Washington_(SSBN-598)#Construction_and_launching https://en.wikipedia.org/wiki/USS_George_Washington_(SSBN-59...
- brandmeyer 6y agoSSBN-626 and -635 were both ballistic missile submarines that were converted into training ships by going the other way and ripping out the missile compartment.
- devoutsalsa 6y agoThat's cool. I hadn't heard that before. Thanks for sharing.
- mandevil 6y agoThose changes were made without any actual cutting though: the decision was made early enough in the process that there was nothing to cut apart. They just put some different pieces together than originally planned. Source: personal conversation with Dr. Gary Weir, US Naval History and Heritage Command.
- underwater 6y agoThey spent 450,000 man hours to extend the ship from 195m to 210m long. That is a 7% increase in length. That seems like a lot of work for a tiny bit of gain.
- WJW 6y agoThey will spend a lot more man-hours than that, since the 450.000 hours only included welding the ship back together. The article also mentioned that the operation represents about a 12% increase in passenger capacity, since it's mostly cabins and amenities rather than non-money generating stuff like engines or anchors. According to wikipedia passenger capacity went from 540 to 608 passengers. So let's do the math: The article states that "Pricing for the 7-day cruise starts at $5,600 per person." Presumably some passengers will pay more, let's assume an average of 6k/passenger/week. Assuming 45 sailings weeks per year (the rest being relocations and maintenance periods), the 68 extra passengers will bring in slightly over 18 million USD per year in extra revenue. Wages in Italy are not that high, so even assuming all workers are welders making the maximum from http://www.salaryexplorer.com/salary-survey.php?loc=105&loctype=1&job=6194&jobtype=3 http://www.salaryexplorer.com/salary-survey.php?loc=105&loct..., it would only be about 20 EUR/hour. That makes the price of the 450k manhours "only" 9m EUR, so it seems likely they'll make back the total price of the expansion quite quickly.
- VBprogrammer 6y agoI've no particular knowledge in this case but presumably they would undertake such work at a time when the ship was due or nearly due a refit.
- depaya 6y agoYour analysis doesn't include the engineering to make this possible, the materials and labor to create the new section, the fees associated with using the dry dock, the lost revenue while the ship was out of service... I find it hard to believe they will make it back quickly.
- WJW 6y ago
- aardvark179 6y agoYeah, it’s surprisingly common. For years when getting the a CalMac ferry from Oban in Scotland you could spot that the MV Isle of Mull had been extended because they had to repaint the ship’s name. That was done to fix stability as all the steel was right at the thickest end of the specified tolerance resulting in the ship being heavier than intended.
- perl4ever 6y agoI think the "surprising" or unintuitive part for me is that I wouldn't have thought that a join could be sufficiently strong. However, in another thread recently, it was mentioned that large ships can't support their own weight without water anyway, so I guess that the strength needed is mainly just in tension?
- walrus01 6y agoThe front 1/3rd of the Maersk Honam was burnt beyond repair in a fire in 2018. That included the bridge and accommodation block. They cut it off, took the rest of it back to the shipyard on a heavy lift ship, and built a new front... https://en.wikipedia.org/wiki/Maersk_Honam https://en.wikipedia.org/wiki/Maersk_Honam on fire: https://www.google.com/search?q=maersk+honam+fire&client=ubuntu&hs=TO3&channel=fs&sxsrf=ALeKk0249lRXSdr1w40siBjmQtja47xguQ:1618484544887&source=lnms&tbm=isch&sa=X&ved=2ahUKEwjC_fzijIDwAhXKv54KHRhCDCsQ_AUoAXoECAEQAw&biw=1282&bih=903 https://www.google.com/search?q=maersk+honam+fire&client=ubu... here's some photos of it on the heavy lift ship: https://www.google.com/search?q=maersk+honam+heavy+lift&client=ubuntu&hs=0N3&channel=fs&sxsrf=ALeKk00mvdDWLEun0r4G7_DTRrEVOBZrSA:1618484515428&source=lnms&tbm=isch&sa=X&ved=2ahUKEwjZ7PbUjIDwAhVF6Z4KHdXnAGcQ_AUoAnoECAEQBA&biw=1282&bih=903 https://www.google.com/search?q=maersk+honam+heavy+lift&clie...
- WJW 6y agoyou could say the front fell off? https://www.youtube.com/watch?v=3m5qxZm_JqM https://www.youtube.com/watch?v=3m5qxZm_JqM
- typon 6y agoI can't help but feel God playing jokes when you see a fire in the middle of an ocean
- King-Aaron 6y agoI had an old Datsun 180B that caught on fire in the pouring rain once, and I felt this way
- jonplackett 6y agoIs there some kind of standard sizing that makes this kind of thing possible?
- ceejayoz 6y agoThey'll have the blueprints and the actual ship to measure and confirm against. I'd imagine most of these are heavily custom jobs.
- rtkwe 6y agoDepends on the project; for the cruise ship it's a newly built section built specifically for that ship and the submarines they were both the same design so as long as you cut in the same place on both ships they should fit together plus or minus 2x the tolerances it was originally built with.
- ansible 6y agoNote that ships in the same class are rarely actually identical. There was also quite a bit of time since they were both built, and the later vessel no doubt incorporated changes / improvements on the design. And then you get into the really fun stuff, where what's on the plans, and what actually got built are usually at least a little different... and maybe the as-built documentation was not finished correctly either.
- sandworm101 6y agoThey also sag. A half of a ship isn't as rigid as an entire ship. It changes shape in all sorts of unpredictable ways. There is lots of lifting and pulling before the two hulls line up well enough to start welding them together.
- rtkwe 6y agoIn a dry dock though they’ll be better supported so the differential sagging will be much smaller. It’s how they were originally built as well.
- 51Cards 6y agoThat cruise ship example is wild. To do all that work (450,000 man hours) to just add 50 feet to the length of the ship... a 12% increase in passenger capacity. Obviously it must be cost effective but on face value it looks crazy.
- dspillett 6y agoMy dad used to work for a ship servicing & repair shop ("Humber Ship Repairers"), now defunct. I remember them doing this to a Sally Line ferry. It was fascinating seeing the progress when we occasionally drove past the dry dock. Very little for a while as things were cut through internally, then suddenly one trip the thing was in two halves and the new middle was being put in place.
- zymhan 6y agoIt does seem crazy. This bit in the article claims that a retrofit would be faster than building entirely new ships. > The lengthening is a novel approach to adding vessel capacity as shipyard availability shrinks. With demand soaring, many cruise shipbuilders are booked into the early 2020s, and expedition/luxury lines are increasingly ordering newbuilds at yards that used to specialize in offshore vessels or yachts.
- henshao 6y agoback of envelope: 450k man hours = 225 people full time, 1 year @ ~ 70k a year = 15m They added 34 more suites * 2 people * $1000 per person per cruise week = 78000 more per trip ~200 trips to pay back the cost - not sure what the utilization of cruise ships is usually, but if they do 40 packed cruises a year, they're at a ~5 year ROI. I guess I forgot the cost of the new section itself, but I'm going to guess all in, < 10 years ROI?
- pengaru 6y agoFord lengthened 50s-era freight ships used for hauling raw materials in the Ford River Rouge Complex an additional 120-feet in the 70s for increased capacity. [0] Someone uploaded a TV special centered on the SS Byron D. Benson and its captain, in which he speaks to the lengthening and how it affected the ship. [1] [0] https://en.wikipedia.org/wiki/SS_William_Clay_Ford https://en.wikipedia.org/wiki/SS_William_Clay_Ford [1] https://www.youtube.com/watch?v=cFiF5LUsi1A https://www.youtube.com/watch?v=cFiF5LUsi1A
- eternalban 6y agoThat cruise ship is a great example of a well designed extensible modular monolith.
- Johnny555 6y agoI'd feel a lot more comfortable in a ship that's been cut apart and welded back together than I would in a submarine.