Ship Stability

Learning Lots at the Bridge! 

The  Bridge

Ship Stability in a Nutshell! 

I took some notes, because I thought it would be easier to explain with some visuals. Ship stability is a complex process. This is what I wanted to learn about because prior to learning about this I wasn't quite sure how we were remaining a float. In Figure 1.1 you see M, the meta center, G, the center gravity and K, the keel. The Keel is the bottom of the ship that remains constant and the center of gravity, G is the most important. In figure 1.1 you also notice that there is KM, GM, and KG. This is important to know where to put weight to remain stable, and balanced. I think I will get to help (really just watch) the next time the chief mate gets to do these calculations.  The KM, GM, and KG gives us our extremely important equation for ship stability KM-KG= GM 

You never want your GM to be negative, negative is bad!! 

You also have to account for free surface! Free surface is the surface of a liquid that is subject to constant perpendicular normal stress and zero parallel sheer stress.Take a look at figure 1.2. Now imagine you have a container or tank containing liquid. If it is empty obviously there isn't and issue and if full you do not have free surface because there isn't any free space for the liquid. Free surface is a bad thing, but it does exist. You want either full or empty containers. But imagine a fuel tank, we are constantly burning fuel so will be having free surface moments for sure. This has to be accounted for, and corrected in the calculations for ship stability. 

This is the computer program that the Chief Mate uses to balance the ship! 

In Figure 1.3, you notice the righting arm, so if a cup is floating and rocking back and forth, it has a tendency to come back. If you lose your righting arm.....well..... you don't come back up. 

Kelsey, Miss engineer, we can practice some cool problems when I get home! Miss you and Rachel! I feel like I wanna be hanging out with you guys, send me some pics or long fb messages. Im starting to get a tad bit homesick !

Cool Terms I Learned

Heal: If the ship is leaning starboard or port side 

Trimmed: If the ship is tilting FWD or Aft 

Equations and Units 

moment= tonsX KG 

m^3 x density (salt water = 1.025 t/m^3) = t (tons) 

This is my teacher :) ! He is teaching me so much. He has let me borrow books on navigation  and keeping busy with learning is really the only thing that takes my mind off of being in stuck out here! I have mastered the phonetic alphabet and morse code bc of him. So Awesome! I want to send codes to everyone, I actually want to stop talking and just code (i picture  mom and dad laughing like we wish you didn't talk so much either). So the reason my blogs aren't crying and screaming that I want to come home has a lot to do with all the stuff I'm learning out here from him! The only problem is.....he is well, an eagles fan! Yes and a very obnoxious eagles fan at that. (which goes without saying)  I think he hates the Cowboys more than Grammy hates the Redskins! Grammy don't kill me for being friends with him lol I know they boo'd Michael Irving and most of all threw snowballs at santa. But anyways I have learned so much and enjoyed my time out here because of it so..... 

 Thanks Mr. Chief Mate ! 

 Also 10 bucks to whoever can decode my Morse Code youtube video I emailed all of you guys! I have become pretty badass at it! I practice the alphabet frontwards and backwards before I go to sleep and when I wake up! But I need a better flash light, mine sucks. 

Morning Sunrise. Wow, Breathtaking. Views like this just calm my soul, and I take a big breath and realize its gonna be ok