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When we read news articles or other materials about vessels, we often become confused because of the unfamiliar terms used. So today, we will try to learn about a few facts about ships and recent issues. Once you get to know each of them, you will realize that ships are not that difficult to understand.
1. How fast do ships travel?
The speed of ships is expressed in knots (kn), and one knot is the speed at which we would be able to travel one nautical mile in one hour. One nautical mile is 1,852 m, a little less than 2 km. Freight ships travel at 18~26 knots, and passenger ships at 21 knots. 10 knots is 18.52 km per hour, which means at 21 knots one can travel 39 km in one hour. Due to the resistance from the water, ships cannot travel as fast as cars do.
The speeds of container ships are sometimes intentionally lowered in order to save on fuel, which is referred to slow steaming. When a ship engages in slow steaming when the fare is low, it results in decrease in the supply of ships, which then raises the fare, and the slow speed helps to save on fuel costs, thereby enhancing the shipping company’s profits. However, if the days of navigation increase due to the low speed, it can also increase the cost of navigation, so one would need to consider pros and cons in terms of profit before slow steaming.
2. Which is the bow and which is the stern?
Writings about ships often refer to bow and stern. There are quite many people who confuse one for the other. Usually, the top structure where the pilothouse is located is the front part. The lower part of the top deck is divided length-wise into the bow part, mid-part and stern part, and the top of the top deck is referred to as the top structure.
3. How are ships anchored?
Do you know what that structure on either side of the bow part jutting out like eyes is? They are anchors. Anchors are used to anchor to ships. Anchors consist of the pendulum in the form of an arrowhead and the anchor chain.
Usually, when anchoring, either one of the anchors are used. If just one is used, it is called single-anchoring, and when two anchors are used, it is called double-anchoring. However, there is a risk of tangling when two anchors are used, so double anchoring is used only in special situations.
When the anchor becomes lodged onto the seafloor, the ship is pushed in a certain direction. And when certain angle is created between the seafloor and the chain, it creates holding power. This holding power varies depending on the conditions on the seafloor and the chain length, and they say that the inside of a large expanse of land creates the most holding power. The weight of the anchor and the length of the chain vary depending on the size and type of the ship and the area of the ship above the surface of the water.
4. Through what routes do ships travel?
Just like cars travel on roads and airplanes fly on air routes, ships also travel only on the designated routes on the vast ocean. The reason is that it ensures safety in navigation and economy. Then when second class mate reports a navigation route based on various weather conditions, the captain makes the final decision. And when this is entered into the auto-navigation device, the ship navigates automatically. They say that traveling in a semicircle generates the shortest navigation distance. For example, when a ship goes from Japan to the US, it does not travel in a straight line from the east but in a semicircle via Alaska. The reason for this is simple. It’s because the earth is round!
Recently, there has been an active review of the North Pole navigation route that passes through the North Pole in order to secure the shorter and faster seas route. When the North Pole navigation route is secured for the Asia-Europe route, it is expected to be considerably shorter than the current route that goes through the Suez Canal. However, ice-breaking devices are necessary in order to navigate through the ice in the North Pole, which reduces the speed. Therefore, changing the sea route to the North Pole route is not being actively pursued yet.
We have learned several things about sea navigation today. The shipping companies are trying to maximize their profits by adjusting themselves to various conditions including navigation routes, navigation speeds, number of ships, etc. In order to ensure quick and accurate profit analysis and customer support under these complex and diverse conditions, we need to look back and see whether we are using appropriate systems.