A hemp rope can hold up a large ship weighing tens of thousands of tons? Why not use steel cables and hemp ropes when the giant ship is docked?

Why not use steel cables and hemp ropes when the ship docks?

When a ship docks, in addition to anchoring and storing on shore, most of the methods used are mooring, which means the ship is docked on the shore and secured with ropes tied to shore stakes.

Before the invention of ship ropes, people used more metal ropes such as iron and steel cables;

However, due to the humid marine environment, metal ropes and cables are prone to rusting, corrosion resistance, heavy weight, high cost, and difficult to operate. They will not be damaged for long;

In addition, when the ship docks on the water surface, tides and wind waves can cause it to sway left and right, and there are certain requirements for the elasticity of the ropes. Steel cables with high strength but low elasticity are obviously not suitable.

So when chemical raw materials such as cotton and polyester were developed, they quickly replaced steel cables and were used for ship mooring.

Nowadays, the most commonly used material for ship ropes in China is polypropylene filament, and the highest grade rope material is high molecular weight polyethylene.

Compared with steel cables, these cables are not only sturdy and wear-resistant, but also have good stretchability. They are lightweight, rust resistant, and have very high tensile strength.

Taking the 300000 ton oil tanker COSPEARL LAKE from China COSCO Shipping as an example, the Dyneema ultra-high molecular weight polyethylene high-performance cable is used;

Under the same diameter, the weight of fiber rope is only 1/7 of that of steel wire rope, but the load strength can reach the same standard;

The mooring operation that usually takes 4 hours to complete can now be operated in just 70 minutes using fiber ropes, and the service life of the ropes can reach ten years or even longer.