Marine loading arm

One of three marine loading arms connects this oil tanker to the pier.

A marine loading arm, also known as a mechanical loading arm, loading arm, or MLA is a device consisting of articulated steel pipes that connect a tankship such as an oil tanker or chemical tanker to a cargo terminal. Genericized trademarks such as Chiksan (often misspelled Chicksan) are often used to refer to marine loading arms regardless of their manufacturer.

Operation and design

A marine loading arm is an alternative to direct hose hookups that is particularly useful for larger vessels and transfers at higher loading rates and pressures. Controlled manually or hydraulically, a loading arm employs swivel joints and can, to some extent, follow the movement of a moored vessel. Many loading arm systems feature quick-connect fittings. Gasket or o-ring arrangements are required to make a secure seal to the ship's manifold flange. A loading arm must be drained or closed off before the connection is broken off.

Loading arms can handle both liquids and gases, in a wide range of viscosities and temperatures. Cargoes from liquid sulphur to liquefied natural gas are moved through marine loading arms. Loading arms service vessels in a wide range of sizes, from small river barges to the largest supertankers.

Various designs exist, and specific installations can be tailored for a given port based on considerations such as vessel size, cargo flow rate and cargo temperature. Environmental constraints, such as the range of tide, wind conditions, and earthquake tolerance can also effect choice of loading arm. A loading arm installation may include add-ons such as hydraulic or manual quick connect couplers, position monitoring systems, emergency release systems, and piggyback vapor return lines.

Compared to cargo hoses, the loading arm's main drawback is its comparative lack of flexibility.

A chemical/oil tanker connected to the pier with a marine loading arm.

Chiksan brand marine loading arm manufacturer FMC Technologies claims to have built the world's first marine loading arm in 1956 and to have over 8,000 units installed worldwide.

See also

• Oil tanker
• Chemical tanker

References

• FMC Technologies (2005). "Chiksan Marine Loading Arms". FMC Technologies web site. FMC Technologies. Retrieved 2008-10-04.
• FMC Technologies (2005). "About Us". FMC Technologies web site. FMC Technologies. Retrieved 2008-10-04.
• Hayler, William B. (2003). American Merchant Seaman's Manual. Cornell Maritime Pr. ISBN 0-87033-549-9. {{cite book}}: Unknown parameter |coauthors= ignored (|author= suggested) (help)
• Huber, Mark (2001). Tanker operations: a handbook for the person-in-charge (PIC). Cambridge, MD: Cornell Maritime Press. ISBN 0-87033-528-6.
• International Chamber of Shipping (1996). International Safety Guide for Oil Tankers and Terminals (ISGOTT). New York: Hyperion Books. ISBN 1-85609-081-7.
• Turpin, Edward A. (1980). Merchant Marine Officers' Handbook (4th ed.). Centreville, MD: Cornell Maritime Press. ISBN 0-87038-056-X. {{cite book}}: Check |isbn= value: checksum (help); Cite has empty unknown parameters: |accessyear=, |origmonth=, |accessmonth=, |month=, |chapterurl=, and |origdate= (help); Unknown parameter |coauthors= ignored (|author= suggested) (help)