Ships collide on MS River near Convent (MM 160)

quote:

---

Explain how ships are tied up please, expert/NOLAtard.

---

quote:

---

Mooring lines are usually made out of synthetic materials such as nylon. Nylon is easy to work with and lasts for years, but has a property of very great elasticity. This elasticity has its advantages and disadvantages. The main advantage is that during an event, such as a high wind or the close passing of another ship, excess stress can be spread among several lines On the other hand, if a highly stressed nylon line does break, or part, it causes a very dangerous phenomenon called "snapback" which can cause fatal injuries. Snapback is analogous to stretching a rubber band to its breaking point between the hands, and then suffering a stinging blow from the retracting loose ends of the band - in the case of a heavy mooring line this blow carries much more force and can inflict severe injuries or sever limbs. Mooring lines made from materials such as Dyneema and Kevlar have much less elasticity and therefore much safer to use, but the lines do not float on the water, and tend to sink, are costly, so they are used less frequently. Manila rope is preferred.

Some ships use wire rope for one or more of their mooring lines. Wire rope is hard to handle and maintain. There is also a risk of using wire rope on a ship's stern in the vicinity of its propeller.

Combination mooring lines made of both wire rope and synthetic line can also be used. This results in a hawser. This is more elastic and easier to handle than a wire rope, but not as elastic as a pure synthetic line. Special safety precautions must be followed when constructing a combination mooring line.

---