Posted on 09/22/2016 6:11:49 AM PDT by artichokegrower
The U.S. Navy’s new high tech destroyer has been sidelined for repairs after suffering a seawater leak in its propulsion system less than a month before its expected commissioning.
(Excerpt) Read more at gcaptain.com ...
This is an interesting description of a problem that you don't normally see with surface ships. On most traditional naval ship designs, shafts are connected to the power plant. In most cases on Navy ships, these are either gas turbines or nuclear (carriers). The shafts pass through the hull, and connect with the propeller blades or screws.
These shafts transmit power from the engines through to the screws (propellers) by spinning. The faster they spin, the faster the ship goes through the water. Some ships also have variable-pitched propeller blades that can maintain a certain shaft rotation, but can increase or decrease the speed based on the angle of the prop blade.
The propeller shafts passing through the hull is not a trivial design. The seals have two primary functions: 1) is to allow the shaft to spin freely; and 2) is to maintain enough watertight integrity to prevent seawater from entering in too large amounts. As some alluded to in their posts, it is inevitable that some seawater will enter. Any water that enters will be directed to the bilge areas and will be pumped overboard. Kind of a sump pump for your home, except it's on a ship.
The Navy (and its contractors) have been building ships with shaft seals for a long time. I can only imagine that this hull design called for something more radical and unproven. Hopefully, it's nothing that will sidetrack the ship for too long.
If propulsion is electric generated, I’m surprised they didn’t do an APOD design.
Well I can see it’s problem right there in your pic —the thing can’t sail in a straight line! /snort
I don't believe this ship has electric propulsion. It most certainly has gas turbines for generators of internal electrical components, but not for main propulsion. Otherwise, an APOD may make sense.
Interesting. The thing is the size of a pre-dreadnought battleship.
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Like "collateral damage"?
Engineering casualties relate to propulsion, electrical generation, fire pumps, and other related equipment.
You should not read anything sinister or misleading into the term. So far as I know it was in use before WWII.
"Ceterum censeo Hillary esse delendam."
Garde la Foi, mes amis! Nous nous sommes les sauveurs de la République! Maintenant et Toujours!
(Keep the Faith, my friends! We are the saviors of the Republic! Now and Forever!)
LonePalm, le Républicain du verre cassé (The Broken Glass Republican)
I’m not sure the Coast Guard has the budget to maintain an LCS. They’ve got an icebreaker that’s been laid up an inordinate amount of time with a engine that supposedly cannot be repaired. To their credit they’ve had gas turbines in their ships before the Navy.
She does have electric propulsion and makes enough power to run a city.
http://www.naval-technology.com/projects/dd21/
Lack endurance, lousy bad weather performance
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