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Post  Admin on Mon Jul 02, 2018 4:45 pm

Clean product tankers require good cleaning before each loading and for this reason, their tanks are coated with special points which can also assist to reduce corrosion. Furthermore, clean product tankers are characterized of higher and more advanced segregation systems and they can load separate grades of cargo without risk of contamination.

Dirty product tankers, on the other hand, are not equipped with special coating and they do not accommodate complex segregation systems, however they are usually equipped with heating coils so as to be able to pump the high-density grades of fuel oil. Product tankers vary in size from general purpose tankers up to about 160,000 tons deadweight.

Crude Carriers: Crude Oil cargoes are usually homogenous and even when different grades of crude oil are carried on board the same ship there is no risk of contamination since the oil will be refined before its sale to the end-users. Therefore, crude carriers are used for the carriage of the crude oil from oil producing countries to the refineries and their size ranges from about 50,000 MT deadweight to more than 500,000 MT deadweight which is the size of modern ULCC. These vessels can load one or up to two grades and their pumping and pipeline systems are relatively simple as opposed to the product tankers. In terms of size, product tankers and crude carriers are divided into the following main categories:

General Purpose tankers: They are used to load refined products and their size is between 10,000 MT and 25,000 MT deadweight.

Handysize tankers: Used to load refined products and their deadweight is between 25,000 MT and 40,000 MT

MR (Medium Range) tankers: Used to load refined products and their size is between 40,000 MT and 55,000 MT deadweight

LR1 (Long Range 1) tankers: They are used to load both refined products and crude oil. The ones suitable for dirty products or crude oil are used to be called panamax tankers. LR1 and panamax tankers have a deadweight of between 55,000 MT and 80,000 MT.

LR2 (Long Range 2) tankers: They are suitable for carrying both refined products and crude oil while their size is between 80,000 MT deadweight and 160,000 MT deadweight. It is worth to note that the LR2 vessels suitable to load crude oil are usually called Aframax tankers (from 80,000 MT to 120,000 MT deadweight) and Suezmax tankers (from 120,000 MT to 160,000 MT) instead.

Very Large Crude Carriers (VLCC) and Ultra Large Crude Carriers (ULCC) are used to carry crude oil only and their size can reach up to about 320,000 MT for the VLCC and up to about 550,000 MT for the ULCC.

Chemical tankers: They are also called parcel tankers and they are usually of small size from about 5,000 tons dwt to about 25,000 dwt while there are also a few chemical tankers up to about 50,000 tons deadweight. Chemical tankers are mainly used in two trades: For the carriage of oils which are extremely hazardous (IMO I) and the carriage of edible/vegetable oils as well as very clean oil products (IMO II / IMO III). In order to carry hazardous cargoes with safety these vessels need to be equipped with very high standards a few of which are the following: — The tanks are coated with high-grade materials such as stainless steel, epoxy resin and zinc silicate being the most popular. These coatings are cleaned easier and also prevent the chemical cargoes to react with the vessel’s hull and damaging the ship or the cargo. — Each tank has its own deepwell pump and pipeline system, therefore, the cargo of each tank is loaded and discharged separately. This way various different grades can be loaded separately while there is absolutely no risk of contamination since there is full segregation.

Gas Carriers: They are highly specialized form of tanker. The two types of gas carriers are known as LNG (Liquefied Natural Gas) and LPG (Liquefied Petroleum Gas). The LNG is the methane product and it is carried in insulated tanks in minus 162 degrees Celsius at atmospheric pressure so as to maintain in liquid condition. The LPG Carriers are used to load mainly propane and butane while they are also used for the carriage of chemical gas and ammonia and there are two different types of LPG Carriers. The fully pressurized vessels which load and maintain the cargo in a high pressure of 10-12 bars and the refrigerated which cool the cargo at temperatures of up to minus 50 degrees Celsius. The size of the Gas Carriers is usually declared basis their cubic capacity in CBM and there are LPG Carriers from small LPGs of about 500 cbm to VLGC of about 85,000 cbm while the LNG Carriers are as large as about 265,000 cbm. Specifically, the Q-Flex design which is about 210,000 - 217,000 cbm and the Q-Max with a capacity of about 261,700-266,000 cbm that make up the Qatari Q-Class offer the largest available capacities and they were accounted for about 18% of the total LNG carrying capacity at the end of 2016.

Asphalt Carriers: Small tankers suitable to carry asphalt/ bitumen most of which not exceed the 7,500 dwt while there are also a few larger bitumen tankers and recently some yards in China are marketing newbuilding designs of up to about 20,000 dwt. The main characteristics of these tankers are that they can achieve and maintain high temperatures of up to about 200 degrees Celsius. These vessels usually are not equipped with Inert Gas system and COW and they cannot load other oil cargoes except, probably, of a few dirty products which do not have risk for contamination and do not require cleaning.

Mini Bulkers with deadweight of up to about 15,000 tons. They are mainly used in short sea trades however most vessels of this size are either general cargo ships or short sea specialized vessels rather than common bulk carriers.

Handysize bulkers have a deadweight from about 15,000 tons to about 39,000 tons and they are usually equipped with 5 cargo holds, while the smaller handies may contain 4 cargo holds as well. Except the conventional handysize, there are also those handysize bulkers of heavier construction which can load logs (along with other conventional cargoes). These vessels, known as “Loggers” and they are additionally equipped with lashing materials, stanchion sockets and stanchions alongside the bulwarks on ship’s deck so as the logs to be loaded and securely stowed. These stanchions may be permanent or collapsible. Also, handysize bulkers of between 20,000 and 30,000 MT deadweight designed to transit the St. Lawrence Seaway are commonly known as “Lakers”. The design of laker handies is: LOA of 70 meters, beam of about 21.5 meters, draft of 7.92 meters freshwater and airdraft (height above water level) not to exceed 35.6 meters.

Handymax bulkers have a deadweight from about 40,000 tons to about 50,000 tons and they are equipped with 5 cargo holds. However, they are mainly older designs and only a few vessels are nowadays built within this deadweight range.

Supramax bulkers, which have recently replaced handymaxes, have a deadweight from about 50,000 tons to about 60,000 tons. Like handymaxes, supramax bulkers also contain 5 cargo holds.

Ultramax is a new design which has been appeared recently in the market. These vessels, which are usually equipped with “eco main engine”, have a deadweight of about 62,000 – 65,000 dwt. Ultramax bulkers are considered as an upgrade of supramax bulkers and they are designed with five cargo holds.

Panamax bulkers are those who have a deadweight of between 70,000 and 80,000 tons, however there are still older panamaxes in the market (mainly built before 2000) with deadweight of between 60,000 and 70,000 tons. Panamaxes usually have 7 cargo holds and their name and dimension characteristics were established according to the maximum allowable dimensions (length and beam) for transiting the Panama Canal. Though, after the recent expansion of the Suez Canal, larger designs appeared so as to take advantage of the max deadweight at current Canal limitations. These vessels are known as post-panamax bulkers and their size varies from about 90,000 tons to about 110,000 tons deadweight.

Kamsarmax bulkers are slightly larger than panamaxes however other than that they are almost the same and they currently share the same sub-market with panamaxes. They have deadweight of between 80,000 and 85,000 tons (with their most common design being about 82,000 tons) and their LOA at 229 meters, which is slightly higher than the 224-225 meters LOA of Panamax, is the maximum permissible LOA to enter the port Kamsar in West Africa, which is one of the largest ports of bauxite in the world.

Capesize have a deadweight of between 160,000 tons and 210,000 tons. In the past, there were also smaller Capesizes known as mini-capes or babe-capes ranging between about 110,000 to about 160,000 tons and despite that there are still a few in the market, this is not a common design anymore. Capesizes usually have 9 cargo holds. Large Capesizes with a maximum beam of 47 meters are called Newcastlemax and they are the largest vessels which can enter the Newcastle port of Australia.

Ultra Large Ore Carriers: These are bulkers which are larger than capesizes and they are mainly used to load iron ore. The largest vessels in this category are the Valemax (or Chinamax) vessels which have a deadweight of as high as 400,000 tons.


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