Oil tankers are humungous ships that have the sole purpose of transporting of liquid gold. Since their inception in the 1860s as crude oil became the talk of the town, ships and especially oil carriers have been in demand. From barges in the early days to steam engines to the supertankers of today with large storage capacities, the oil tanker business has grown exponentially.
In today’s world, transporting oil through tankers is the cheapest mode of transportation apart from pipelines. The annual carrying capacity of these oil tankers exceeds 2 billion barrels. The two most notable divisions of oil tankers these days are crude tankers and product tankers. Crude tankers transport crude oil while the product tankers move finished products.
Oil Transporting Capacity of an Oil Tanker
Oil tankers have different classifications that differentiate their transported product or capacity. As mentioned above, there are two main types of oil tankers. Medium range tankers have the capacity of transporting around 500,000 barrels. These oil tankers typically weigh around 25,000 to 45,000 in DWT or deadweight tons.
The next categories are the VLCC and ULCC which translate to a very large crude carrier and ultra-large crude carrier. These supertankers can convey around 2,000,000 barrels of oil or 318,000 metric tons. This huge capacity makes these ships quite expansive with some ULCC’s spanning over 400 meters in length. These ships are normally used on longer routes and have to shed some load when docking at ports.
Contracting Oil Tankers
Contracting oil tankers can be a complex process as it requires some planning to rent an oil tanker. Getting an oil tanker to perform a specific job is called chartering and there are four popular types of charters. Firstly, there is the voyage charter in which the client rents the oil tanker from the port of origin to discharge. The time charter specifies a period where the oil tanker will be used for the client’s services.
Next is the bareboat charter where a company assumes control of the oil tanker and is responsible for provisions and maintenance. Lastly, the contract of affreightment refers to a detailed charter specifying volumes, time duration, and sizes. Freight rates apply to the product and occur in different types. These include lump-sum rates, time-bound, rates per deadweight tonnage, or the Worldscale rate.
Operations aboard an Oil Tanker
Operations of oil tankers are highly regulated and standardized to avoid any spills or other hazardous events. There are various ways to move the product of the ship such as mooring the ship alongside a pier, mooring to offshore buoys, or ship to ship transfers. Before any transfer operations begin, pre-transfer planning occurs with onshore and offshore crew leaders.
Loading and unloading of oil tankers follow a similar trajectory with few differences. As the oil enters the ship vapors form that must be expelled. Both loading and unloading start at low pressures to check the viability of connections and the processes until it is increased to reach peak capacity.
Typically, oil tankers employ around two dozen crew members depending on the size and operational requirements. If the oil tanker requires ship to ship transfers, more manpower may be required thus increasing crew members to around 35. For more opportunities browse through nauticjobs.com.