The Ship(s) That Ate My Dining Room

[pnolan48]

The front ship is actually a bit shorter than the back ship--it's impossible to tell that in the photo angle. The front ship is a LNG tanker, which will have a huge structure atop the deck. It basically has five pressurized tanks that are nearly spherical. Hence there is room for a bow. The ULCC (ultra large crude carrier) is just simplified, so huge and heavy it plows through seas.

The LNG tanker, the Mozah, is also a showpiece for Qatar, so it's a bit sleeker than normal. It has twin propellers and rudders, unlike most ultra large ships.

Under both bows is a bulbous extension, much the shape of the nose of a nuclear submarine. It is this appendage that cuts drag.

In most cases the stern is barely in the water--it curves sharply from the deck to the waterline, resulting in a sharp taper at the waterline. So the ship does have a tapered tail, with the bulk ending at the propeller. The rudder is often partially out of the water, especially in unloading conditions. In a ballast configuration, the propellers may also be out of the water a bit.

[Spades]

On some MV it is the home of the bow thrusters

So the more pointy bow though a bit longer reduces the interior cubic yards ?

Is that less space for goods ?

[pnolan48]

On these ships, the thrusters require more space, and are behind the bulb.

[Spades]

Pete

I know this isn't the maritime forum.  These ships have anchors where do they put all that chain?

On these ships, the thrusters require more space, and are behind the bulb.

[pnolan48]

Pete

I know this isn't the maritime forum.  These ships have anchors where do they put all that chain?

But it's still a good question, as usually N scale chain for any purpose is hard to find. The chains for these ships are battleship large. The anchor windlasses are pretty far front, and right behind them (a straight drop) is a passage to a chain locker, usually deep down toward the keel. I think these commercial vessels don't carry as much chain as a warship. My neighbor was a young jr. lieutenant on a WWII destroyer, and described the chain locker that he had to inspect regularly (as jr. deck officer) as a pretty foul place.

[nkalanaga]

Wouldn't most of their anchoring be in harbors or other coastal waters, not more than a few hundred feet deep?  Military ships never know just where they might anchor, so would seem to need longer chains.

Or am I missing something about large ships and their anchors?

[pnolan48]

No, that's what I was saying about them carrying less chain than warships.

[nkalanaga]

Thank you.   I thought that was what you meant, but wasn't sure if it was because they anchored in shallower water, or maybe they used their thrusters for station keeping rather than the anchor when not tied to something. 

I grew up in a desert.  The only anchors we had were to keep the roofs from blowing away in sandstorms.  Old tires on the roof of a mobile home were a common sight, and some folks actually tied their roofs down with steel cables over the top, anchored to concrete on both sides, on both trailers and houses.  We had a river, but I'm not sure the towboats had anchors.  The ones I saw were either moving or tied to a dock...

I do enjoy your ship posts.  Model Railroading isn't only trains, and the other stuff can be very educational.

[Ike the BN Freak]

Served on the Ike 1979 - 1981... an awesome part of my life, working the flight deck launching Tom Cats off the bow at night in after-burner.  No better memory to have even though it is so many years in the past.  Thanks for sharing that aircraft carrier shot... actually helped launch many of the planes shown.

Night ops was always a favorite of mine, however I was Air Force. Loved doing End of Runway inspections during Red Flag, and watching 70-100 jets launching, most in burner.

[Spades]

The anchor doesn't  hold the ship to the bottom it is the weight of the chain.

Wouldn't most of their anchoring be in harbors or other coastal waters, not more than a few hundred feet deep?  Military ships never know just where they might anchor, so would seem to need longer chains.

Or am I missing something about large ships and their anchors?

[nkalanaga]

Spades:  Thank you!  That's what I was missing.  I always thought that the anchor dug into the bottom, like a fishhook, and held the ship in place.  So a ship needs a chain longer than the depth of the water, and the anchor is mostly for weight?

[wcfn100]

The anchor doesn't  hold the ship to the bottom it is the weight of the chain.

What situation are you referring to here?

The whole point and design of an anchor is to drop to the sea bottom and dig in to hold a ship in place.


Jason

[peteski]

The anchor doesn't  hold the ship to the bottom it is the weight of the chain.

Then why do anchors have the . . . anchor shape?  Their shape sure looks like it is meant to dig into, or snag onto something on the bottom

[Scottl]

I deploy moorings in lakes and the coastal ocean.  In deep water (say a few hundred meters) the rope weight can exceed that of the anchor.  Regardless, the anchor (whatever it's shape) definitely holds everything in place.  If the mass in the water column was the anchor, then the ship would move with currents.  There is usually nothing to snag on the bottom, the shape keeps it from sinking into soft sediment and the tines dig in if currents drag it.

As a tangent to trains, many oceanographic instrument moorings are anchored with railway wheels!

[Spades]

Too anchor the ship to the bottom.  Yes the anchor is important, you don't want the anchor to sink in.  How do you extract the anchor? If you drop anchor on on a 97 to 100K USN Aircraft Carrier that is a big pendulum, no anchor alone is going to hold anchorage.
A little Google and here it is explained by a US Navy O-6/Captain.  Just read the first part

, because it isn't the anchor that holds a ship fast to the bottom in the first place, but the weight of the chain. For this reason, we lay a scope of chain that is five to seven times the depth of the water, in fathoms, in which you are dropping the hook. What they are saying makes absolutely no sense to me, UNLESS the intent is to lay a greater scope of chain than was prescribed in the NSTM for ground tackle that has been more or less unchanged regarding anchors, etc. for the last 70 years. If a typical link is now 136 pounds, when for instance, a link weighed 380 pounds in Constellation, then perhaps they will lay a scope of chain that is 10 to 14 times the depth of water in fathoms. That's a shitload of chain, regardless of weight and I'm not even sure what that ship's chain locker will hold. I don't know; it's just all sort of weird.
 

What situation are you referring to here?

The whole point and design of an anchor is to drop to the sea bottom and dig in to hold a ship in place.


Jason