L4 or L-4 may refer to :

Transportation

SP&S Class L-4 The Spokane, Portland and Seattle Railway (SP&S) class L-4 steam locomotives were originally used by the Astoria and Columbia River Railroad (AC&R). They became SP&S locomotives when the SP&S acquired the A&CR. Background The Astoria & Columbi ...

, an 1884 steam locomotives class * USS ''L-4'' (SS-43), a 1915 United States Navy L-class submarine * HMS ''L4'', a 1918 British L class submarine * Lawson L-4, a 1924 American unflown biplane airliner *

Piper Cub The Piper J-3 Cub is an American light aircraft that was built between 1938 and 1947 by Piper Aircraft. The aircraft has a simple, lightweight design which gives it good low-speed handling properties and short-field performance. The Cub is P ...

(U.S. military designation: L-4), an aircraft *

Inline-four engine A straight-four engine (also called an inline-four) is a four-cylinder piston engine where cylinders are arranged in a line along a common crankshaft. The vast majority of automotive four-cylinder engines use a straight-four layout (with the ...

(L4), a type of inline internal combustion four cylinder engine ** Liberty L-4, a World War I four-cylinder, water-cooled, inline, aero-engine *

Lynx Aviation Lynx Aviation, Inc. was a regional airline based in Denver, Colorado, United States. The airline began as a sister company to, and operated feeder service for, Frontier Airlines. The Lynx name plays off of the tail pictures of its planes, speci ...

(IATA code) * L4 (New York City bus), a temporary bus route in New York City * Chaika L-4, a Russian twin-engined amphibious aircraft *

Soviet submarine L-4 The World War II Soviet submarine ''L-4'' belonged to the L class or of minelayer submarines. She had been named ''Garibaldets'' in honour of the men of Garibaldi. During the war she was commanded by Evgeniy Petrovich Polyakov (russian: Евге ...

Science and technology

L4 microkernel family L4 is a family of second-generation microkernels, used to implement a variety of types of operating systems (OS), though mostly for Unix-like, ''Portable Operating System Interface'' (POSIX) compliant types. L4, like its predecessor microkernel ...

, a family of operating system kernels *L4, the transport layer in the

OSI model The Open Systems Interconnection model (OSI model) is a conceptual model that 'provides a common basis for the coordination of SOstandards development for the purpose of systems interconnection'. In the OSI reference model, the communications ...

of computer communications * L4, the fourth

Lagrangian point In celestial mechanics, the Lagrange points (; also Lagrangian points or libration points) are points of equilibrium for small-mass objects under the influence of two massive orbiting bodies. Mathematically, this involves the solution of th ...

in an astronomical orbital configuration * L⁴, an L^p space for p=4 (sometimes called Lebesgue spaces) * L-4, the fourth iteration of

L-carrier The L-carrier system was one of a series of carrier systems developed by AT&T for high-capacity transmission for long-distance communications. Over a period from the late 1930s to the 1970s, the system evolved in six significant phases of develo ...

, high capacity frequency division multiplex over coaxial cable used by the Bell System

Biology

Haplogroup L4 (mtDNA) Haplogroup L4 is a human mitochondrial DNA (mtDNA) haplogroup. It is a small maternal clade primarily restricted to Africa. L4 is important in East Africa. The highest frequencies are in Tanzania Tanzania (; ), officially the United ...

, a human mitochondrial DNA haplogroup * Ribosomal protein L4, a human gene * L4, a

lumbar vertebra The lumbar vertebrae are, in human anatomy, the five vertebrae between the rib cage and the pelvis. They are the largest segments of the vertebral column and are characterized by the absence of the foramen transversarium within the transverse p ...

of the vertebral column, in human anatomy * The fourth and last larval stage in the ''

Caenorhabditis elegans ''Caenorhabditis elegans'' () is a free-living transparent nematode about 1 mm in length that lives in temperate soil environments. It is the type species of its genus. The name is a blend of the Greek ''caeno-'' (recent), ''rhabditis'' (ro ...

'' worm development

Other uses

* L4, a modern version of the

Bren light machine gun The Bren gun was a series of light machine guns (LMG) made by Britain in the 1930s and used in various roles until 1992. While best known for its role as the British and Commonwealth forces' primary infantry LMG in World War II, it was also use ...

in the British Army * ISO/IEC 8859-4 (Latin-4), an 8-bit character encoding

Transportation

Science and technology

Biology

Other uses

See also