Views:1 Author:Site Editor Publish Time: 2019-11-02 Origin:Site
(1) Dry cargo ship. Cargo ships that mainly carry dry cargo, but can also carry liquid cargo in barrels. Including general cargo ships, bulk cargo ships, and multi-purpose ships. The general cargo ship is a dry cargo ship that mainly carries general cargo such as bales, bundles, and barrels, and can also carry some bulk cargo. Bulk cargo ships are dry cargo ships dedicated to transporting bulk cargo, such as grains, ore, coal and other bulk cargoes. A multi-purpose ship is a dry cargo ship that can carry various cargo such as containers, timber, ore, grains or other groceries.
(2) Tanker. A general term for cargo ships used to carry bulk liquid cargo. It can transport petroleum, water, vegetable oil, wine, ammonia and other chemical liquids and liquefied gases. Mainly include crude oil tankers, product tankers, liquid chemical tankers, liquefied petroleum gas tankers, LNG tankers, etc. Some of the loaded goods are flammable and explosive, some will cause serious environmental pollution after the ship is damaged, and some chemicals are extremely toxic. Therefore, the first consideration for such ships is the safety and reliability of transportation. According to the degree of flammability, liquid cargoes are classified into three grades, among which the vapor flash point of the first grade flammable liquid cargo is below 28℃; the second grade flammable liquid cargo has a vapor flash point of 28℃～60℃; the third grade flammable liquid cargo The vapor flash point is above 60°C. According to the different flammability of the liquid cargo being transported, as well as the toxicity of the liquid cargo and the threat to the environment, the shipping circles of various countries have formulated corresponding conventions and regulations, and accordingly carry out different structural designs for ships.
(3) Reefer ship. A cargo ship that transports fresh vegetables and perishable goods. It is mostly operated by regular liners, with a speed of 20-22 kilometers per hour. In order to prevent the transported goods from being crushed, multi-layer decks are often set up, and they have good heat resistance and moisture retention functions. According to different types of refrigeration, refrigerated ships are divided into refrigerated cabin ships and refrigerated container ships. The cargo hold of the former is made into a refrigerated cabin, the bulkhead has a good thermal insulation function, and the cargo is placed in the cabin in the form of pallets or baskets. The latter’s goods are packed in containers. There are two types of containers. One is a built-in reefer with its own refrigerator; the other is a clutch reefer without a refrigerator. The low-temperature cold air is cooled by the on-board refrigerator. Pour into the container.
(4) Container ship. It is a cargo ship specially developed to transport containers to improve transportation efficiency. The ship is thin, single-layer continuous deck, stern model, high power, fast speed, and high stability requirements; the cargo hold has large openings (which can account for 70% to 80% of the ship's width), standardized dimensions, and large average tonnage.
(5) Ro-Ro ships. A cargo ship that carries cargo or is loaded and unloaded in a horizontal direction in a rolling manner. It changes the traditional vertical loading and unloading process to a horizontal loading and unloading process, and increases the loading and unloading speed by "rolling up" or "rolling down", and reduces the ship's stay time in the port. Its main structural feature is high depth, the upper deck is straight through the entire ship, flat, without ridge arcs and beam arches, no cargo hatches, built-in multi-layer decks and inter-deck ramps or lifting devices, and external loading and unloading springboards. The superstructure and engine room are located at the stern, and the chimneys are located on both sides. Below the main deck is a double-layer hull, with special considerations for stability, sinking resistance, fire ventilation, seakeeping and maneuverability. Ro-ro ships are more commonly used in the coastal islands, between land islands and on both sides of the Yangtze River, but most of them are car ferries that take into account passenger transportation.
(6) Carrying barge. Commonly known as a mother-child ship, it is a ship dedicated to cargo barges. The retraction and unloading methods of the barge are divided into two types: lifting and floating. It has the advantages of short ship stop time, fast loading and unloading speed, and is not affected by the limitation of port water depth and terminal congestion, and is conducive to river-sea combined transportation. However, these advantages can only be shown through strict organization and management in terms of cargo source organization, transportation plan, barge collection and distribution, parent-child ship matching and air barge recovery, otherwise there will be concerns about suspension of navigation.
(7) Barge. A flat-bottomed boat that has no power or is equipped with a simple propulsion device, and is driven by a tug or push boat or transported by a barge.