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13 votes
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What is it about the cabin electrical supply on cruise ships that makes surge protectors dangerous?

From USCG Surge Protective Devices Onboard Vessels A marine casualty investigation of two separate stateroom fires onboard a U.S. Flag Container ship revealed that the sources of the fires were ...
StainlessSteelRat's user avatar
6 votes
Accepted

Why did the Soviet Alfa-class submarines have a titanium hull?

the former soviet union had plentiful stores of titanium on hand, so its expense was not an issue. Being nonmagnetic, a titanium hull would be more difficult to detect with magnetometers. Note ...
niels nielsen's user avatar
5 votes
Accepted

Will this water jet propulsion system design produce any forward thrust?

No, it would just create a torque couple and rotate the boat anticlockwise. Let's say the small propeller has an output volume, q grams/s, and the distance between inlet pipe and outlet is 5cm. The ...
kamran's user avatar
  • 22.4k
5 votes

Finding phase velocity for froude number scaling

I'm not sure where did you brought the 'deep water relationship' in here. If you're dealing with usual water wave (gravity, surface, linear, and close to sinusoidal wave form), then the relationship ...
HLee's user avatar
  • 51
5 votes
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How much longer could Titanic have remained afloat if it had gotten rid of its anchor and chain right after hitting the iceberg?

A Negligible difference If the anchor and chain weighed 116 tons... Compare to the weight of the unflooded Titanic: 52,310 tons So the anchor & chain was 116/52310 = .22% of the total weight of ...
Tiger Guy's user avatar
  • 6,901
4 votes

What is the best practice for ensuring the best possible connection between a battery cable and a battery terminal

We really need more info on the batteries and type of connection. Will the connection be permanent? In that case soldering or welding are the best choices. If you're connecting to wire, you'll need ...
Drew's user avatar
  • 1,971
4 votes
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Disposition of the generators on the shipwrecked Costa Concordia

Carnival Splendor is an example of Concordia class ships. From Costa Concordia deck plans: Costa Concordia (built 2006, scrapped in 2015) was the first of all five Concordia-class liners operated by ...
StainlessSteelRat's user avatar
3 votes

Disposition of the generators on the shipwrecked Costa Concordia

Engineering is a knowledge of physics and a game of economic tradeoffs. I have not designed any watercraft, and have less knowledge this specific wreck than the OP, but I can explain some of the ...
ericnutsch's user avatar
  • 8,151
3 votes
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How do cracks form on a ship's hull?

The news item said it grounded, pretty typical,along with "hit rocks". There is so much mass in a ship that good steel with a 4:1 design safety factor can't resist fracture in a "crash&...
blacksmith37's user avatar
  • 6,134
3 votes

X-form and cross-form rudders in underwater control

People, people people (by which I mean the unreferenced other answers at this time) ! look it up! Here is info from a Chinese research paper: . Compared with the cross rudder, X-form rudder has ...
Carl Witthoft's user avatar
2 votes

How Big can Hydrofoils get?

There is no hard limit on the size of an airfoil/hydrofoil. A ships hull is a hydrofoil. This is how a sailboat sails into the wind for example. A keel is a large hydrofoil used in addition to the ...
ericnutsch's user avatar
  • 8,151
2 votes

How to design a reinforced concrete ship keel?

You intend to submerge a rectangular concrete section in a fairly corrosive environment (ocean water). The section is 11.5" wide and 18" deep. During the 20 year life span of the boat, you anticipate ...
SlydeRule's user avatar
  • 1,226
2 votes

Purpose of spheres and fins on submarine propeller

Submarine propulsor designers are least concerned about hub vortex cavitation as they are primarily concerned about cavitation inception, or the onset of cavitation, which first occurs in the tip ...
Wes's user avatar
  • 503
2 votes

Preheating Diesel before injection?

Consider how much energy is needed to heat the fuel that is injected each time compared to the energy that can be recovered from the turbo-charger for example. One thing to note is that many of the ...
Solar Mike's user avatar
  • 15.8k
2 votes

X-form and cross-form rudders in underwater control

×-form surfaces result in a shallower draft. ×-form surfaces are more convenient for landing on the floor. With +-form the bottom fin which stick down below the bottom of the vehicle. From what I'...
Nick Alexeev's user avatar
  • 1,035
2 votes
Accepted

What are the 'poles' off the side off this aircraft carrier's flight deck?

They are HF radio masts that are hinged down for flying operations. My initial thoughts they were radio direction finders or airframe recovery booms, but my research does not support it. In port ...
StainlessSteelRat's user avatar
2 votes

Why did the Soviet Alfa-class submarines have a titanium hull?

It was more a political decision than engineering. The problems with fabricating thick titanium plate are enormous = expensive, and the Russian engineers did a remarkable job. There is much ...
blacksmith37's user avatar
  • 6,134
2 votes

Why aren't there many ships with transom bows?

Ships dont have transom bows because marine designers generally know what they are doing. Ships cut through waves. High waves can break even over the bow. Waves hitting againt a flat surface would ...
Tiger Guy's user avatar
  • 6,901
2 votes

Why aren't there many ships with transom bows?

The cargo ships are desinged for high-seas with possibilty of storms with waves of 80-100 feet high. As they are their simple geometry means more strength and resilience. Any additional corners or ...
kamran's user avatar
  • 22.4k
2 votes

Benefits of twin-in/single-out propulsion

Four into two arrangement can help with mid speed fuel economy, but that often isn't enough by itself to justify the complexity. Sometimes, the the general arrangement of things is better. The two ...
Phil Sweet's user avatar
  • 4,755
2 votes

How do you generate a wave scatter plot showing the probability of occurrence of sea states?

Judging by the question, I assume this task is with regards to a homework assignment or a similar project. I will therefore not provide an explicit solution, but rather some guiding assistance. As you'...
ToxicOwl's user avatar
  • 369
2 votes
Accepted

What is the name of this power connector used in the USS Yorktown?

The surface Navy had (has?) a whole set of casualty electrical power systems for use in restoring power. This is part of those systems. I say surface Navy because I sure don't remember this on my ...
Tiger Guy's user avatar
  • 6,901
1 vote
Accepted

Why aren't there many ships with transom bows?

The problem is known as slamming. From Ship Design And Construction - Lamb (2003): The problem of slamming, that is when the forward bottom of ships strikes the sea when sailing with low forward ...
StainlessSteelRat's user avatar
1 vote

Why aren't there many ships with transom bows?

Try pushing a knife through water edge first, then flat face first or even a plate. What do you notice? Boats, planes even cars have pointy ends because pushing fluid out of the way means work. Then ...
Solar Mike's user avatar
  • 15.8k
1 vote
Accepted

Computation of the moment of restoring forces for a floating vessel

The gravitational force and the buoyancy force create what is known as a moment couple (or sometimes just couple). Essentially they are two equal (because buoyancy and gravity should be equal in a ...
NMech's user avatar
  • 24.3k
1 vote

How do cracks form on a ship's hull?

MV Wakashio ran aground on a coral reef off Mauritius on July 25. MV Wakashio is a 300m Bulk Ore Carrier. It was empty at the time (no cargo). From BBC: Mauritius declares emergency as stranded ship ...
StainlessSteelRat's user avatar
1 vote

Auxiliary engines on cargo vessels, what types are used for what purpose?

There is no one way to do things. Ship design is continually evolving. In general, cargo ships are low and slow, as in powered by large 2-stroke diesel engines with big propellors and slow speeds. ...
StainlessSteelRat's user avatar
1 vote

How the design of ship help to survive in the water

This is the end part of the ship during the construction and is not finished yet. This part when finished will be called Stern. The stern houses the rudder and the propellers and follows the keel. ...
kamran's user avatar
  • 22.4k
1 vote

Will this water jet propulsion system design produce any forward thrust?

The water starts out stationary. It ends up being jetted out the stern. Yep, that makes thrust. There will be some pressure interaction over the entire hull of the ship. That is geometry dependent. It ...
Phil Sweet's user avatar
  • 4,755
1 vote

Sea waves: Having trouble visualizing the difference between group celerity and celerity

Lets ignore wave groups for starters. You are looking at a model of a steady gravitational free surface wave train of parallel waves. We have equations for that. See pages 16 to 39. The feature of ...
Phil Sweet's user avatar
  • 4,755

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