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I'm amazed that these welds can hold ship sections like that. I wonder if this is regulated in any way? E.g. class and quality of welds required etc. On anothe

I'm amazed that these welds can hold ship sections like that. I wonder if this is regulated in any way? E.g. class and quality of welds required etc. On another note, a 2 billion investment to build a ship seems absolutely crazy. How long does it take to make that kind of money back, and how long does a ship need to sail to pay itself back?

NullPrefix 2y ago
A weld doesn't have to be weaker than the parent metal. I assume these people might inspect their welds before painting them over. Same process as when they make new ships
newsclues 2y ago
It’s the same way the ship is built to start with
- mensetmanusman 2y ago
  How to build a ship: Step 1: cut a ship in half…
deleted 2y ago
[deleted]
doe_eyes 2y ago
For the most part, it doesn't matter how long it takes to pay this back. They borrow the money, pay installments, and still end up with a 10-15% profit per passenger from day one (and that's after deducting deprecation). But because they live on credit, they were pretty badly hosed during COVID-19.
frognumber 2y ago
* Regulation is non-existent in the cruise industry. You shop for the venue with the most lax regulations of the ≈200 countries in the world. * The equivalent is insurance. Insuring a $2B ship carries pretty good due diligence. A ship simply failing is rare. Of course, ship insurance doesn't care about employee rights, safe food, medical care, or other things one might expect to keep people safe. It's about protecting the capital expense. If everyone on the ship dies, but the ship survives, that's okay! * Welds are quite strong -- it just extends the metal. This is especially true when the baseline quality of the metal is not high. On something heat-treated SAE AISI 4130 steel (what e.g. fancy steel bicycles are made of), you see significant weakening. There is a heat-affected zone where the normal tempering is taken off, and the joining material isn't the fancy CrMo of the baseline material. I'm not a nautical engineer, but I doubt cruise ships are made of overly fancy steel. When you're making a 180,000 ton ship, your best bet is to use cheap steel, and if you need more strength, to simply use more of it. A good weld should be every bit as strong as the cheap steel around it, and the heat-affected zone is a lot less important if the steel isn't heat-treated or tempered in any way in the first place. It will harden the steel a bit, of course, but it shouldn't be the same level of impact. It's also worth noting you already have welds, and things need to be engineered for welds. It's not hard to reinforce the welds. Indeed, on a bike frame, the welds are where the stresses are highest, and you get around that by making the tubes a bit thicker (or, for fancier bikes, thicker just near the welds -- that's what a butted bike tube does). I think cruises are horrible, horrible things for a whole slew of reasons, but none having to do with the ship sinking Titanic-style.
- personjerry 2y ago
  This comment was very useful and informative! Thank you.
- zikduruqe 2y ago
  > SAE AISI 4130 steel (what e.g. fancy steel bicycles are made of) Wouldn't a fancy bicycle use Reynolds 853 steel? /s
- cm2187 2y ago
  And the original hull wasn't made of a single piece of steel in the first place, it is already a patchwork of steel plates welded together, isn't it? And I think it is assembled as vertical sections like the one being added.
  - icegreentea2 2y ago
    Yeah, exactly how a ship is built will differ, but generally you build up fairly large structural blocks, and then assemble (uh, a lot of welding) them together. Example time lapse of another cruise ship being built about a decade ago: https://www.youtube.com/watch?v=Pk_JIHel7To https://www.youtube.com/watch?v=Pk_JIHel7To Depending on the ship, shipyard, and I imagine a host of other factors, you might assemble a ship directly out of the order of ~50-100 blocks, or you might pre-assemble into order of ~10 "mega-blocks" which then get assembled together.
  - Ekaros 2y ago
    Not exactly full sections, but very large sections. For example the crane in shipyard building the largest cruise ships can lift 1200 tonnes to 90 metres height...
- ajb 2y ago
  Very informative, thanks. "none having to do with the ship sinking Titanic-style." It's rare, but not nonexistent. The Costa Concordia springs to mind. Schettino ended up with all the blame, but it did seem to be that there was some degree of institutional incompetence as well. But not with the construction AFAIK
pintxo 2y ago
Icon of the seas, back of the envelop calculation: Revenue: 52 weeks of sailing x 5.6k passengers [1] x 1.8k $/week [2] ~= 525m $/year Costs: Interest [3] 160m $/year + Crew [4] 118m $/year + Hospitality [6] 200m $/year = 478m $/year Profit ~= 47m $/year or ~9% [1] https://en.wikipedia.org/wiki/List_of_largest_cruise_ships https://en.wikipedia.org/wiki/List_of_largest_cruise_ships [2] https://www.cruzely.com/heres-how-much-money-cruise-ships-make-off-every-passenger-infographic/ https://www.cruzely.com/heres-how-much-money-cruise-ships-ma... [3] 8% on 2b$ [4] Crew: 50k $/year * 2350 crew [5], just guessing the costs here, including all accomodation + living costs, probably still to high? [5] https://en.wikipedia.org/wiki/Icon_of_the_Seas https://en.wikipedia.org/wiki/Icon_of_the_Seas [6] Hospitality: 100 $/guest/day? = 52 * 7 * 100 * 5.6k = 200m $/year
- ta1243 2y ago
  You've got to factor in deprecation. If the vessel cost $2b and lasts 20 years you need to repay $200m a year to repay the amount over 20 years. However I suspect 8% would be far higher that the rate they'd get. You'd also have to include maintenence costs, and also the reduction in revenue as it gets older (people will presumably not pay as much to travel on an older ship than a newer one), or the refurb costs you'll need to offset. On the other hand inflation has to be factored in. At 2% that debt will reduce 30% over the period.
  - lotsofpulp 2y ago
    I feel like it’s just easier to use the existing cruise companies’ public financials. It looks like 10% to 15% are the real world profit margins, but with quite a bit of volatility. https://www.macrotrends.net/stocks/charts/RCL/royal-caribbean-cruises/profit-margins https://www.macrotrends.net/stocks/charts/RCL/royal-caribbea... https://www.macrotrends.net/stocks/charts/CCL/carnival/profit-margins https://www.macrotrends.net/stocks/charts/CCL/carnival/profi... https://www.macrotrends.net/stocks/charts/NCLH/norwegian-cruise-line-holdings/profit-margins https://www.macrotrends.net/stocks/charts/NCLH/norwegian-cru...
    - onlyrealcuzzo 2y ago
WJW 2y ago
Don't forget it's not just the welds on the outside, but also the welds on all decks and walls on the inside. The resilience of modern vessels mainly comes from the internal structure rather than the hull. The hull is just the skin and needs to be strong enough to withstand the impact of water and tugboats etc but it's not responsible for holding the ship together.
timrichard 2y ago
Tonight's on-board movie will be The Finest Hours....
- Hnrobert42 2y ago
  Ha! I just read that book because of a different HN thread. It was excellent. As I read about this process, I thought of the same thing. For those not familiar, "The Finest Hours" by Michael J. Tougias and Casey Sherman recounts the 1952 rescue mission off Cape Cod. In a tragic coincidence, a storm split two different oil tankers in half. Both tankers split as a result of a construction process, at least superficially, similar to the one in TFA.
brudgers 2y ago
how long does a ship need to sail to pay itself back? Some uninformed guessing: A operational net of $100/passenger/day is 10,000,000 passenger days per billion dollars. That’s 27,000 passenger years. With an average load of 5000 passengers that’s about five years per billion dollars. My guess is that average operational net is well above $100/passenger/day because cruising caters to luxury market segments; the scale is vast; people expect to be up sold; and gambling. All with little regulatory oversight.
yuliyp 2y ago
I'd guess the average revenue per passenger to be on the order of $200 / day so for that 10k passenger ship that's about $700M of revenue per year. If they can put $200M of that toward the cost of the ship that'd pay for itself in a decade.
whymauri 2y ago
They are regulated by regional professional boards with reciprocity. For example, the American Bureau of Shipping in North America. This concept is called a Classification Society https://en.m.wikipedia.org/wiki/Ship_classification_society https://en.m.wikipedia.org/wiki/Ship_classification_society They are unlikely to skimp on this due to the insurance implications.

NullPrefix 2y ago

A weld doesn't have to be weaker than the parent metal. I assume these people might inspect their welds before painting them over. Same process as when they make new ships

newsclues 2y ago

It’s the same way the ship is built to start with

mensetmanusman 2y ago
How to build a ship: Step 1: cut a ship in half…

deleted 2y ago

[deleted]

doe_eyes 2y ago

For the most part, it doesn't matter how long it takes to pay this back. They borrow the money, pay installments, and still end up with a 10-15% profit per passenger from day one (and that's after deducting deprecation). But because they live on credit, they were pretty badly hosed during COVID-19.

frognumber 2y ago

* Regulation is non-existent in the cruise industry. You shop for the venue with the most lax regulations of the ≈200 countries in the world. * The equivalent is insurance. Insuring a $2B ship carries pretty good due diligence. A ship simply failing is rare. Of course, ship insurance doesn't care about employee rights, safe food, medical care, or other things one might expect to keep people safe. It's about protecting the capital expense. If everyone on the ship dies, but the ship survives, that's okay! * Welds are quite strong -- it just extends the metal. This is especially true when the baseline quality of the metal is not high. On something heat-treated SAE AISI 4130 steel (what e.g. fancy steel bicycles are made of), you see significant weakening. There is a heat-affected zone where the normal tempering is taken off, and the joining material isn't the fancy CrMo of the baseline material. I'm not a nautical engineer, but I doubt cruise ships are made of overly fancy steel. When you're making a 180,000 ton ship, your best bet is to use cheap steel, and if you need more strength, to simply use more of it. A good weld should be every bit as strong as the cheap steel around it, and the heat-affected zone is a lot less important if the steel isn't heat-treated or tempered in any way in the first place. It will harden the steel a bit, of course, but it shouldn't be the same level of impact. It's also worth noting you already have welds, and things need to be engineered for welds. It's not hard to reinforce the welds. Indeed, on a bike frame, the welds are where the stresses are highest, and you get around that by making the tubes a bit thicker (or, for fancier bikes, thicker just near the welds -- that's what a butted bike tube does). I think cruises are horrible, horrible things for a whole slew of reasons, but none having to do with the ship sinking Titanic-style.

personjerry 2y ago
This comment was very useful and informative! Thank you.
zikduruqe 2y ago
> SAE AISI 4130 steel (what e.g. fancy steel bicycles are made of) Wouldn't a fancy bicycle use Reynolds 853 steel? /s
cm2187 2y ago
And the original hull wasn't made of a single piece of steel in the first place, it is already a patchwork of steel plates welded together, isn't it? And I think it is assembled as vertical sections like the one being added.
- icegreentea2 2y ago
  Yeah, exactly how a ship is built will differ, but generally you build up fairly large structural blocks, and then assemble (uh, a lot of welding) them together. Example time lapse of another cruise ship being built about a decade ago: https://www.youtube.com/watch?v=Pk_JIHel7To https://www.youtube.com/watch?v=Pk_JIHel7To Depending on the ship, shipyard, and I imagine a host of other factors, you might assemble a ship directly out of the order of ~50-100 blocks, or you might pre-assemble into order of ~10 "mega-blocks" which then get assembled together.
- Ekaros 2y ago
  Not exactly full sections, but very large sections. For example the crane in shipyard building the largest cruise ships can lift 1200 tonnes to 90 metres height...
ajb 2y ago
Very informative, thanks. "none having to do with the ship sinking Titanic-style." It's rare, but not nonexistent. The Costa Concordia springs to mind. Schettino ended up with all the blame, but it did seem to be that there was some degree of institutional incompetence as well. But not with the construction AFAIK

pintxo 2y ago

Icon of the seas, back of the envelop calculation: Revenue: 52 weeks of sailing x 5.6k passengers [1] x 1.8k $/week [2] ~= 525m $/year Costs: Interest [3] 160m $/year + Crew [4] 118m $/year + Hospitality [6] 200m $/year = 478m $/year Profit ~= 47m $/year or ~9% [1] https://en.wikipedia.org/wiki/List_of_largest_cruise_ships https://en.wikipedia.org/wiki/List_of_largest_cruise_ships [2] https://www.cruzely.com/heres-how-much-money-cruise-ships-make-off-every-passenger-infographic/ https://www.cruzely.com/heres-how-much-money-cruise-ships-ma... [3] 8% on 2b$ [4] Crew: 50k $/year * 2350 crew [5], just guessing the costs here, including all accomodation + living costs, probably still to high? [5] https://en.wikipedia.org/wiki/Icon_of_the_Seas https://en.wikipedia.org/wiki/Icon_of_the_Seas [6] Hospitality: 100 $/guest/day? = 52 * 7 * 100 * 5.6k = 200m $/year

ta1243 2y ago
You've got to factor in deprecation. If the vessel cost $2b and lasts 20 years you need to repay $200m a year to repay the amount over 20 years. However I suspect 8% would be far higher that the rate they'd get. You'd also have to include maintenence costs, and also the reduction in revenue as it gets older (people will presumably not pay as much to travel on an older ship than a newer one), or the refurb costs you'll need to offset. On the other hand inflation has to be factored in. At 2% that debt will reduce 30% over the period.
- lotsofpulp 2y ago
  I feel like it’s just easier to use the existing cruise companies’ public financials. It looks like 10% to 15% are the real world profit margins, but with quite a bit of volatility. https://www.macrotrends.net/stocks/charts/RCL/royal-caribbean-cruises/profit-margins https://www.macrotrends.net/stocks/charts/RCL/royal-caribbea... https://www.macrotrends.net/stocks/charts/CCL/carnival/profit-margins https://www.macrotrends.net/stocks/charts/CCL/carnival/profi... https://www.macrotrends.net/stocks/charts/NCLH/norwegian-cruise-line-holdings/profit-margins https://www.macrotrends.net/stocks/charts/NCLH/norwegian-cru...
  - onlyrealcuzzo 2y ago

WJW 2y ago

Don't forget it's not just the welds on the outside, but also the welds on all decks and walls on the inside. The resilience of modern vessels mainly comes from the internal structure rather than the hull. The hull is just the skin and needs to be strong enough to withstand the impact of water and tugboats etc but it's not responsible for holding the ship together.

timrichard 2y ago

Tonight's on-board movie will be The Finest Hours....

Hnrobert42 2y ago
Ha! I just read that book because of a different HN thread. It was excellent. As I read about this process, I thought of the same thing. For those not familiar, "The Finest Hours" by Michael J. Tougias and Casey Sherman recounts the 1952 rescue mission off Cape Cod. In a tragic coincidence, a storm split two different oil tankers in half. Both tankers split as a result of a construction process, at least superficially, similar to the one in TFA.

brudgers 2y ago

how long does a ship need to sail to pay itself back? Some uninformed guessing: A operational net of $100/passenger/day is 10,000,000 passenger days per billion dollars. That’s 27,000 passenger years. With an average load of 5000 passengers that’s about five years per billion dollars. My guess is that average operational net is well above $100/passenger/day because cruising caters to luxury market segments; the scale is vast; people expect to be up sold; and gambling. All with little regulatory oversight.

yuliyp 2y ago

I'd guess the average revenue per passenger to be on the order of $200 / day so for that 10k passenger ship that's about $700M of revenue per year. If they can put $200M of that toward the cost of the ship that'd pay for itself in a decade.

whymauri 2y ago

They are regulated by regional professional boards with reciprocity. For example, the American Bureau of Shipping in North America. This concept is called a Classification Society https://en.m.wikipedia.org/wiki/Ship_classification_society https://en.m.wikipedia.org/wiki/Ship_classification_society They are unlikely to skimp on this due to the insurance implications.