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Tobius
Post subject: Re: Practical Nuclear Merchant VesselPosted: October 9th, 2017, 6:14 am
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The conclusion which I hope you can generate from the examples and the analysis is that contrary to what is usually taught in many cases, that is the the same factors that determine how a human being reacts to close maneuver against a fixed object (warping into a pier side berth) applies in a close approach problem in multiple moving body situations. The statement that if you see the object from the bridge wing, then something has gone so wrong that it is not possible to do anything about it. Well, I was immediately struck by the situations among, Victoria/Camperdown, Stockholm/Andrea Doria and the Brooklyn/Texas.

And I realized that here were three similar examples of turning ships, all about similar speeds, ranges, and approximate times to fix the mistake in progress; which is 100-150 seconds in available time and about a kilometer and a half separation and with combined closing speeds in excess of 16 m/s. Now George Tryon, the esteemed RN reformer admiral, in example one, deliberately set up the interleaving inward turn maneuver of the two lines he had, to force his subordinates to creatively solve that problem with applied engine backing and rudder control. He does this in clear weather with lookouts, with possibly the best trained fleet in the world. How does it turn out? Not well. The best trained crews in the world, with some of the best designed ships and with a tradition produced by the book chain of command robots who drove their ships into each other. Tryon did not explain intent to his captains. The flag signals the Victoria ran up were unclear and the robot men ran their ships into each other. Tryon did not survive his error. Guess who noticed this debacle and tried to figure out what happened? June 22 1893? Rear admiral Henry Erben, USN, commander for the US fleet in Europe at the time. He will do something about it, but not for the Royal Navy.

Now I have already covered the Stockholm/Andrea Doria fiasco. It is the same thing, an over-confident veteran Regia Marina veteran, Captain Piero Calamai, who thought he knew what he was doing, who more or less ran that ocean liner like an Italian navy warship made a mistake. His crew was too awed to question his decisions. He was the man who ordered the turn to port. The only mistake he actually made, was in contravention to the information his own radars and his posted lookouts told him. That is why many analysts blame him. No-one contravened or had the guts to second-guess him.

The Swedes do not get off, either. Captain Gunnar Nordenson apparently thought he knew what he was doing. He thought his bridge crew was trained and capable. He was not at his post when the situation developed, and he certainly left a man, Third Officer Johan-Ernst Carstens-Johannsen, who made numerous procedural errors, in charge in a fog bank. This man was the one who screwed up the radar plot. I note that no-one on the Stockholm's bridge second guessed or checked him. You see where this is going?

Now we come to the Brooklyn and the Texas. Schley was in the middle of a fierce gun action. He had the Spanish flagship charging him to ram Brooklyn on one side and the American fleet behind him barreling at him at top speed, shooting into the Spaniards for all they were worth. Nobody on Brooklyn had run up any flag signals to detail what the battle plan is. Basically, when Sampson left the scene to see that incompetent General Shafter, he left no instructions. At Schley's court martial; he said, as OTC, he ordered "Close enemy, ship on ship." which is akin to Fighting Instructions; "Form line ahead; engage enemy opposite." Captain Francis of the Brooklyn, and Captain Philip of the Texas claimed they never saw that signal. But what they did; was train their helmsmen and deck officers to think for themselves because in previous fleet maneuvers under that Admiral Erben I mentioned, he exercised the Atlantic squadron in how to avoid collision in line of battle because Erben believed that fleet battles in the age of steam would degenerate into a melee and fleet organization might collapse in all the smoke, noise, and confusion. Everything goes into local control and independent initiative rules for better or worse. So Schley orders the counterturn the wrong way to avoid the Maria Teresa's ram attempt, and the Texas immediately all backs full as the lookouts shout warnings; in the middle of almost blinding smoke, flame, noise, and battle confusion; with Philips cursing his helmsman and Francis straightening out the Brooklyn's turn with a similar string of obscenities and everyone needing a new pair of pants. Of course Schley orders general pursuit as Brooklyn clears Texas and it has a happy American ending; but the point is that the proper steps were taken and the proper training was in place and the properly designed control positions had the right people manning positions doing their jobs the right way.

Now docking is a matter of collision avoidance of the same kind of people who make mistakes because they are confused or do not understand or panic, or fail to follow procedure and double check. These control issues and outcomes can be affected by human factors design errors. Can you see the design errors in that ocean liner?


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Wikipedia & Universe
Post subject: Re: Practical Nuclear Merchant VesselPosted: October 10th, 2017, 5:43 am
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What are we even talking about again? I'm already leaning toward ditching the forward pilotage idea in favor of a more conventional bridge placement. We're getting WAAAY off track here.

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Tobius
Post subject: Re: Practical Nuclear Merchant VesselPosted: October 12th, 2017, 8:59 am
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That would be a good decision.


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Wikipedia & Universe
Post subject: Re: Practical Nuclear Merchant VesselPosted: October 12th, 2017, 10:32 pm
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Ok, I'm going to reboot this discussion with some questions:

  • How well do hull shapes scale on container ships? How much commonality can be achieved from the keel up between vessels in different DWT/TEU classes (e.g. from Old Panamax to E-Class to Triple E-class etc.)?
  • I'm envisioning maybe 3 different classes of ships ranging from, say, 5,000 TEU (around the upper limit of Old Panamax) to around 20,000 TEU (the largest ULCVs built to date), with an intermediate variant between the two (say 10,000 TEU or so). The idea is to have an option to fit through legacy infrastructure, an option to carry more freight through upgraded infrastructure (think Neopanamax), and a ULCV. Does this sound like a good range of categories? Any other suggestions?
  • How much hull commonality can be achieved between a container ship and a RORO?
  • How much commonality of any kind can be achieved between a container ship and a dissimilar hull such as a bulk carrier?
  • With the LFR option out (my proposed solution to freezeups not having been tested experimentally, so I'll avoid it to be safe), what are good options for civilian ship reactors? Is it just good old PWRs, or are there others?

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acelanceloet
Post subject: Re: Practical Nuclear Merchant VesselPosted: October 13th, 2017, 7:44 pm
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Wikipedia & Universe wrote: *
Ok, I'm going to reboot this discussion with some questions:


How well do hull shapes scale on container ships? How much commonality can be achieved from the keel up between vessels in different DWT/TEU classes (e.g. from Old Panamax to E-Class to Triple E-class etc.)?
  1. I'm envisioning maybe 3 different classes of ships ranging from, say, 5,000 TEU (around the upper limit of Old Panamax) to around 20,000 TEU (the largest ULCVs built to date), with an intermediate variant between the two (say 10,000 TEU or so). The idea is to have an option to fit through legacy infrastructure, an option to carry more freight through upgraded infrastructure (think Neopanamax), and a ULCV. Does this sound like a good range of categories? Any other suggestions?
  2. How much hull commonality can be achieved between a container ship and a RORO?
  3. How much commonality of any kind can be achieved between a container ship and a dissimilar hull such as a bulk carrier?
  4. With the LFR option out (my proposed solution to freezeups not having been tested experimentally, so I'll avoid it to be safe), what are good options for civilian ship reactors? Is it just good old PWRs, or are there others?
I can add some answers/thoughts to some of these issues:
  1. Hull scales very good with small changes, except for the bulb of the ship, but with size differences like mentioned you will have most likely a few separate hull designs. How about taking a look at the SIGMA and ENFORCER lines, which have a common hull design but can be sized up by adding sections to the upper deck or to the length of the ship, with a fixed draft and cross section? That woul help you with the major issue: the powerplant having to vary with the hulls size.
  2. roro and container ship commonality: depends. their construction is completely different, but hull shape can come close, as both are relatively fast ships most of the time. Container ships can be weight limited though, while RORO ships are as far as I know always volume limited
  3. container ship and bulk carrier commonality: none. they have completely different hulls, speed profiles, volumes, stability requirements and load profiles. That said: there are so called multi-purpose freighters, mostly coasters and relatively small, which can do both. Those might be master of none though........

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Thiel
Post subject: Re: Practical Nuclear Merchant VesselPosted: October 14th, 2017, 11:29 pm
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It should be noted that the difference between a 5000 teu and a 20000 teu ship is huge difference in terms of dimension, mass and power requirements.
Compare the 10.000 TEU Maersk Sovereign to the 20.000 TEU Madrid Maersk

Maersk Sovereign
Length: 331.98 m
Beam: 42.80 m
Draught: 14.5 m
Power: 56,000 kW

Madrid Maersk
Length: 399 m
Beam: 58.6 m
Draught: 16.02 m
Power: 2 × 80,080 kW

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Wikipedia & Universe
Post subject: Re: Practical Nuclear Merchant VesselPosted: October 17th, 2017, 11:58 pm
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acelanceloet wrote: *
Wikipedia & Universe wrote: *
Ok, I'm going to reboot this discussion with some questions:


How well do hull shapes scale on container ships? How much commonality can be achieved from the keel up between vessels in different DWT/TEU classes (e.g. from Old Panamax to E-Class to Triple E-class etc.)?
  1. I'm envisioning maybe 3 different classes of ships ranging from, say, 5,000 TEU (around the upper limit of Old Panamax) to around 20,000 TEU (the largest ULCVs built to date), with an intermediate variant between the two (say 10,000 TEU or so). The idea is to have an option to fit through legacy infrastructure, an option to carry more freight through upgraded infrastructure (think Neopanamax), and a ULCV. Does this sound like a good range of categories? Any other suggestions?
  2. How much hull commonality can be achieved between a container ship and a RORO?
  3. How much commonality of any kind can be achieved between a container ship and a dissimilar hull such as a bulk carrier?
  4. With the LFR option out (my proposed solution to freezeups not having been tested experimentally, so I'll avoid it to be safe), what are good options for civilian ship reactors? Is it just good old PWRs, or are there others?
I can add some answers/thoughts to some of these issues:
  1. Hull scales very good with small changes, except for the bulb of the ship, but with size differences like mentioned you will have most likely a few separate hull designs. How about taking a look at the SIGMA and ENFORCER lines, which have a common hull design but can be sized up by adding sections to the upper deck or to the length of the ship, with a fixed draft and cross section? That woul help you with the major issue: the powerplant having to vary with the hulls size.
  2. roro and container ship commonality: depends. their construction is completely different, but hull shape can come close, as both are relatively fast ships most of the time. Container ships can be weight limited though, while RORO ships are as far as I know always volume limited
  3. container ship and bulk carrier commonality: none. they have completely different hulls, speed profiles, volumes, stability requirements and load profiles. That said: there are so called multi-purpose freighters, mostly coasters and relatively small, which can do both. Those might be master of none though........
  1. Hmmm... Yeah, it looks like going with separate hull designs that resemble each other is the best route. Those Damen vessels don't look like they'd be good precedent for a huge freighter.
  2. Interesting. I'll come back to this idea at a later point, prioritizing the container idea for now.
  3. Roger. Looks like the bulker would have to be a completely different design.
Thiel wrote: *
It should be noted that the difference between a 5000 teu and a 20000 teu ship is huge difference in terms of dimension, mass and power requirements.
Compare the 10.000 TEU Maersk Sovereign to the 20.000 TEU Madrid Maersk

Maersk Sovereign
Length: 331.98 m
Beam: 42.80 m
Draught: 14.5 m
Power: 56,000 kW

Madrid Maersk
Length: 399 m
Beam: 58.6 m
Draught: 16.02 m
Power: 2 × 80,080 kW
The power requirement is what really sticks out to me. How would this translate to using reactors instead of diesel engines? Could one use the same reactor design with one in the smaller ship and two in the larger ship?

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odysseus1980
Post subject: Re: Practical Nuclear Merchant VesselPosted: October 18th, 2017, 2:09 am
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Perhaps yes, this could be done. But it would be a very large reactor, which woulld be heavy. Read carefully this link:

http://www.eng-tips.com/viewthread.cfm?qid=104814


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Thiel
Post subject: Re: Practical Nuclear Merchant VesselPosted: October 30th, 2017, 10:27 pm
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Wikipedia & Universe wrote: *
The power requirement is what really sticks out to me. How would this translate to using reactors instead of diesel engines? Could one use the same reactor design with one in the smaller ship and two in the larger ship?
I honestly don't know. I know how a nuclear reactor works in principle, but I have no idea how they scale.
At this point you're probably better off designing a single ship instead of a whole fleet.

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heuhen
Post subject: Re: Practical Nuclear Merchant VesselPosted: October 30th, 2017, 10:41 pm
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With two reactors, you need to double up on all the system around it. So instead of 1 power plant, you have 2 powerplant. But they can power a single engine if you want that.

But two nuclear power plant, would weight more, than 1 large nuclear power plant, delivering the same power... So long the ratio of nuclear fuel to the heat/power produced, scales accordingly. the main increase of the weight of two reactors, is the reactor vessel

A nuclear reactor work basically in the same way as an steam engine... The reactor is you're steam boiler. Except with a reactor, you need a lot of additional equipment to run it. So if you want to use two reactors you have to double up the equipment and systems around it... But they can both power 1 single turbine or multiple.

Same is it with a steam engine, these more boiler you have, these more equipment around it you need.


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