Within a certain speed, the higher the speed of the ship's propeller, the greater the thrust produced, and the faster the speed. But when the propeller exceeds the optimal speed, because the surrounding water is too late to flow when it rotates, the phenomenon of "cavitation" will occur, so its thrust is reduced, and the boat runs slowly. Generally, the best speed of a civilian ship is less than 300 revolutions per minute, and the maximum speed of a warship is less than 600 revolutions per minute.
Why are the various pipes on the ship painted with different colors of paint
This is of course not for aesthetics, but to identify the nature of the gas or liquid flowing in the pipe, such as red-brown for steam pipes, brown for fuel pipes, blue for gas pipes, light blue for air pipes, and yellow for lubricating oil pipes. Green means water consumption pipes, black means sewage pipes and exhaust steam pipes, and so on.
Why is it best to have proper tail inclination when a ship is sailing
Because of a certain tail inclination (that is, the draught at the stern is greater than the draught at the bow), the waves on the front deck can be reduced, and the working efficiency of the stern propeller and rudder can be improved. Generally, the stern value of an ocean-going vessel is preferably between 0.9 and 1.9 meters when unloaded, and between 0.3 and 0.5 meters when fully loaded. Some high-speed ships (such as the "Jinsha" of Tianjin Ocean Branch) have a slight arch when stationary, but they can maintain the tail tilt after sailing to meet the above-mentioned tail tilt requirements.
Why are the bows of new ships tilted forward
New-style ships all use inclined bows, which are not only generous in appearance, but also because the deck extends forward, so it can increase the deck area and reduce the degree of waves hitting the deck when the ship is sailing. If the bow of the ship collides with other ships or structures on the water, the damage is only in the water core, and the ship will not enter the ship, and it is easier to repair the damage.
The hottest seawater is in the Red Sea, where the seawater temperature can be as high as 36°C. The coldest seawater is in the Weddell Sea in Antarctica and the Danish Strait near Greenland, where the seawater temperature can be as low as minus 2.2°C.
The highest wave in the Atlantic Ocean appeared on the ocean at 52 degrees north latitude and 19 degrees west longitude on September 12, 1961. The height of the wave reached 20.4 meters. The highest wave in the Pacific Ocean appeared on February 7, 1933. It was measured by an American tanker, the Ramana, which was sailing from Manila to San Diego. The wave reached a height of 34 meters. The highest ocean current is in Finch Bay on the west coast of the Atlantic Ocean, with a current height of 18.2 meters.
The largest sea iceberg was discovered in 1927 near Glalems Island in the Antarctic region. It covers an area of 26,000 square kilometers and a height of 40.5 meters. It is closer to the equator than other icebergs, and its closest location to the equator is 26 degrees south latitude and 26 degrees west longitude.
The strongest ocean wind appeared in the coastal areas of East Pakistan on the night of October 31, 1960. The wind intensity reached an incredible level, and the wind gauge of the Chittagong weather station was blown off. According to the measurement afterwards, the wind speed was 60 meters per second. The highest wind speed of 416 km/h appeared in New Hampshire, USA on April 12, 1934.
The most frequent storms are the seas in the Antarctic region, where the expedition team fights the storm or the wind for up to 262 days in a year. The quietest sea is the Java Sea. There are only about ten storms a year.
The lowest typhoon sea pressure appeared on the ocean northwest of Guam, Japan on September 24, 1958. At that time, the sea pressure was 648 mm/mercury column. (The pressure at the edge of a typhoon is generally not higher than 755-760 mm/mercury, and the central pressure is not higher than 700 mm/mercury).
