Oil tankers refer to "vessels" carrying petroleum and petroleum products (such as diesel, gasoline and heavy oil).Its structural features are: ① cargo is loaded and unloaded by oil pump through pipeline, so there is no cargo lifting equipment and large cargo hatch on the deck, but there is an inlet hatch. ②As oil is easy to volatilize, burn and explode, the fire safety requirements are strict,International Maritime OrganizationThe 1978 Protocol stipulates that new oil tankers with a deadweight of more than 20000 tons must haveinert gasExplosion proof facilities, engine room must be set at the tail. ③Cargo oil tanks are separated by multiple longitudinal bulkheads and multiple transverse bulkheads to reduce the influence of free liquid surface on stability. ④The hull length depth ratio is large and the bending moment is large, so the longitudinal frame structure is often used to increase the longitudinal strength. ⑤The transportation is usually one-way. In order to maintain a certain draft during the return empty release, a large amount of ballast water must be loaded. Therefore, modern large oil tankers must be equipped with special ballast water tanks or oil tanks to load ballast water. Before ballasting, the oil tanks must be cleaned. Therefore, oil tankers must be equipped with crude oil tank washing equipment.With the rapid growth of oil production and transportation volume, oil tankers are becoming larger and larger. The largest oil tanker in the world is Japan's "Sea Giant", with a total length of 458.54m, a ship width of 68.8m, a molded depth of 29.8m, a draft of 24.6m, and a load capacity of 560000 tons.[1]
In the early days, oil was bottledDry cargo shipTransported.The "Lucky Luck" motorboat built in Britain in 1886 willCargo holdDivided into several rectangular compartments, it can hold 2307 tons of oil, loaded and unloaded by pump and pipeline system. It is the first bulk oil tanker with the characteristics of modern oil tankers.By 1914, the world's tanker tonnage had accounted for 3% of the world's total merchant tonnage.the First World WarLater, with the rapid growth of oil production and transportation volume, oil tankers have become specialized and large-scale, and gradually become an important special transport ship.In 1930, the world's oil tankers accounted for 1/1 of the world's total tonnage of merchant ships, which rose to nearly 1/3 in 1960 and then to 1/2 in 1980.At the beginning of 1980, the total carrying capacity of oil tankers in the world reached 330 million tons.However, since 1975, due to the oil crisis, the transportation capacity of excess oil tankers has exceeded 100 million tons, a large number of oil tankers have been idle, and the growth rate of oil tanker tonnage has stagnated or even declined.
along withPetrochemical industryWith the development of, the transportation of crude oil and product oil tends to be specialized, and there are special crude oil transportation ships and product oil ships.In terms of crude oil transportation, in order to overcome the weakness of poor economic benefits of one-way transportation, in the late 1950s, many kinds of crude oil and other bulk cargoes were transported simultaneouslyDual-use ship。With the portSingle point mooringWith the development of technology, crude oil transport ships must be as large as possible under the channel conditions to achieve higher economic benefits.1967~1975Suez CanalClosing period,Persian GulfCrude oil transportation to Europe and America must be bypassedCape of Good Hope, also promotedCrude oil tankerTo become larger.In 1980, the world oil tanker fleet comprised more than half of the tonnage of medium and super large oil tankers (with a load of more than 200000 tons) and super large oil tankers (with a load of more than 300000 tons).In the late 1970s, large oil tankers of more than 500000 tons appeared, such as the 550000 ton sister ships "Battilius" and "Bellamya" built by France from 1976 to 1977.In 1980, Japan transformed a 420000 ton oil tanker into the "Sea Giant", with a total length of 458.54 meters, a ship width of 68.8 meters, a molded depth of 29.8 meters, a draft of 24.6 meters, and a carrying capacity of 560000 tons. It is the largest ship in the world.With the reopening of the Suez Canal and the adoption of energy-saving measures by various countries, a large number of giant oil tankers are in surplus, and the process of large-scale crude oil tankers has ended.Due to the limitation of cargo volume and equipment conditions of ports and refineries, the carrying capacity of product oil tankers is generally 20000 to 40000 tons, and the maximum is 70000 tons.Due to the variety of product oil, it is not suitable for mixed loading. There are many independent loading and unloading on the product oil shipOil pumpandPiping。[2]
On February 2, 2024, the China Shipbuilding Industry Association released the Analysis of the Economic Operation of the Shipbuilding Industry in 2023, which showed that in 2023, China's export of ship products amounted to 31.87 billion US dollars, an increase of 21.4% year on year.Among them, the export amount of bulk carriers, oil tankers and container ships, the three main types of ships, totaled US $18.71 billion, accounting for 58.7% of the total export amount.China's ship products are exported to 191 countries and regions, and the amount of ships exported to Asia, Europe and Latin America is 17.73 billion, 2.9 billion and 2.84 billion dollars respectively.[3]
main features
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52500 ton crude oil tanker (Ruijintan)
Oil is fluid, easy to volatilize, burn and explode, so the tanker has the following characteristics in terms of structure, equipment and operation: ① strict requirements for fire safety.Intergovernmental Maritime Consultative Organization(later changed toInternational Maritime Organization）1978protocolIt is required that newly built oil tankers with a carrying capacity of more than 20000 tons must haveinert gasExplosion proof facilities;To avoid cargo oil or oil gas leakage, the cargo oil tank area is the same asForepeak、engine room、Pump roomThere must be a compartment between;The engine room must be set at the tail to prevent fire caused by sparks falling from the chimney to the cargo oil tank area. ②Cargo tankUse 1~3 channelsLongitudinal bulkheadAnd 4~10 tracksTransverse bulkheadSeparation, so as to reduce the influence of free liquid surface on ship stability, and also facilitate the separate loading of different types of oil. ③Special oil pump and oil pipe shall be used for loading and unloading, and all cargo oil can be loaded and unloaded within a few hours to one day and night;In order to discharge the residual oil at the bottom of the tank, the tank sweeping pipe system is set;In order to reduce the viscosity of heavy cargo oil for loading and unloading, heating pipe system is provided;Generally, cargo lifting equipment and large cargo hatches are not set on the deck. ④For oil tankers without special ballast tanks, the freeboard is very small when sailing with full load, and the deck is easy to surf. Therefore, footbridges are often erected on the deck to facilitate crew passage. ⑤Large length depth ratio of hull, bendingmomentLarge, so the structure is mostly of longitudinal skeleton type to increase the longitudinal strength. ⑥The transportation is usually one-way, and a large amount of ballast water must be loaded to maintain a certain draft during the return empty release.Before arriving at the loading port, if the hydraulic carrier water is discharged into the sea, it will cause serious pollution.For this reason, the oil tank shall be cleaned before ballasting, and the tank washing water shall be stored in the special dirty oil tank;Also setOil water separatorTo strictly control the oil content of discharged ballast water.Effective October 1983《International Convention for the Prevention of Pollution from Ships, 1973》It is required that newly built crude oil carriers with a load capacity of more than 20000 tons and product oil tankers with a load capacity of more than 30000 tons must be equipped with special ballast tanks, and new oil tankers must be equipped with crude oil tank washing equipment.[2]
Main categories
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Zhenyang 29 oil tanker
There are many types of oil tankers, which can be divided into different types from different angles.
It can be divided into self-propelled oil tankers, non self-propelled oil tankers and floating production, storage and unloading tankers according to whether they have self-propelled capacity or not;
According to the use of oil tankers, it can be divided into: special purpose oil tankers and multi-purpose oil tankers;
The oil products can be divided into:Crude oil tanker, product oil tanker, crude oil/product oil concurrent carrier, oil/chemical concurrent carrier, non oil oil carrier;
According to the size of deadweight tonnage, it can be divided into: small oil tankers (below 6000 deadweight tons, mainly carrying light oil), medium-sized oil tankers (0.6-3.5 million deadweight tons, mainly carrying refined oil), large oil tankers (3.5-16 million deadweight tons, mainly carrying crude oil, occasionally carrying heavy oil), giantSuper oil tanker (VLCC of 160000 deadweight tons and above, ULCC of 300000 deadweight tons and above, dedicated to carrying crude oil);
The world shipbuilding industry classifies oil tankers into the following categories according to their load ship types: general-purpose (oil tankers below 10000 tons), handy (generally referred to as 10000 to 50000 ton oil tankers, which are divided into big handy and small handy. The big handy oil tankers with a load capacity of 40000 to 50000 tons are characterized by strong flexibility, shallow draft, short length, large number of cabins, and large demand);Panamax (ship typepanama canalThe navigation conditions are the upper limit, for example, the canal affects the ship widthdraftAnd the deadweight ton is between 60000 and 80000 tons);Afra type (with the highest average freight index AFRA and the best economy, it is the best type of tanker suitable for navigation in the Bering Sea ice area, with a deadweight tonnage between 80000 and 120000 tons);Suez type (ship typeSuez CanalNavigation conditions are the upper limit, and the deadweight tonnage is between 120000 and 200000 tons);VLCC (giant crude oil tanker with a deadweight tonnage of 200000~300000 tons), ULCC (ultra giant crude oil tanker with a deadweight tonnage of 300000 tons and above);Knock Nevis.
Loading and unloading operation
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transport
1. Deliver the oil from the oil loading place to the oil unloading place on time and safely as required.
2. Its loading weight shall not exceed the loadingWaterline。
3. It is required to be free of pollution and leakage during loading and unloading.
4. Oil tanker operators must hold the oil tanker operation certificate issued by the port supervision department.
5. Explosion proof tools must be used correctly when assembling and disassembling oil pipes.
6. The oil delivery hose connecting the ship and shore shall be of sufficient length.
Oil loading
1. When connecting the oil pipe between ship and shore, the grounding wire must be installed first, and then the oil pipe.
2. When installing the grounding wire, one end of the shore is first installed on the oil pipe and connected to the ground, a switch is installed in the middle of the grounding wire, the switch is pulled open, and then the ship end of the grounding wire is connected to the hull, and finally the switch is connected.
3. Open the input pipeline valve to the oil tank and the valve of the aft oil storage tank, and close the output pipeline valve and other oil tank valves.
4. The oil delivery shall be slow at the beginning, and the oil pipes, joints, gate valves, etc. shall be checked to ensure that there is no error, and the oil has flowed into the designated oil tank normally without leakage. Only when there is no leakage, can the shore be notified to gradually increase the oil loading speed, and after reaching the normal speed, the inspection shall be carried out again.Slow down before oil loading to avoid oil spillage.
5. No one can leave the inspection hole during the whole process of oil loading, and the personnel on duty should often observe the oil loading speed.
6. Half an hour before the termination of oil loading, notify the shore side to get ready, and notify the shore side to slow down according to the progress, so that the oil pump can be stopped in time when the last tank is full.
7. The oil loading speed is very fast, and the draft of the ship changes greatly. The personnel on duty should pay attention to adjusting the tightness of the cable at any time.
8. After the whole ship is filled with oil, remove the hose first, and then the electrostatic ground wire.
9. Close the large and small valves of each cabin and various gate valves on the pipeline for lead sealing.
10. Assist relevant personnel to lead seal the hatch covers, holes and pipeline gate valves.
Oil unloading
1. After arriving at the unloading place, contact the consignee in time to report the variety and quantity.
2. Fasten the head cable, tail cable and phase bumper.
3. The ships are connected with copper wires, and then connected with the land electrostatic ground wire.
4. There shall be no less than 4 fastening bolts for the oil delivery hose joints, and oil resistant sealing rings shall be padded between the flanges, and an oil basin shall be placed below.
5. Assist relevant personnel to check the lead seal.
6. The oil unloading shall be started slowly. When the oil pipe, joint and gate valve are checked to ensure that there is no error, the unloading speed shall be gradually increased to the normal speed, and then the inspection shall be carried out again.
7. Pay attention to adjusting the tightness of the cable during oil unloading.
8. Before the completion of oil unloading, the valves on the ship shall be closed after the valves on the shore are closed.
9. Remove the hose first and then the electrostatic ground wire.
