M13 link

The M13 link, formally Link, M13, is the U.S. military designation for a disintegrating metallic link specifically designed for belt-fed firearms and rounds; it was introduced in the mid-20th century. It is the primary link type for the U.S., and among NATO for the 7.62×51mm cartridge. It has been in use for over 50 years as of 2007 and is used on the Dillon M134D Minigun, M60 Machine Gun, FN MAG, AA-52, HK21, and the MG3, among others.

The left side of a single link had a semi-circular loop which would hold the main body of the cartridge case below the shoulder, and an extension on the right that formed two similar loops which was designed to fit in between the two right-side loops of the next link, and which had a small metal tab that extended down to the cartridge base and fit into the extraction groove of the case. Unlike the older M1 link which bound cartridges to each other at the neck, the M13 bound the rounds from half way down the length of the case to the case head. This was designed so that the bolt of the machine gun using the link would come forward upon squeezing the trigger and strip a round from its link from below the cartridge, and the round would be chambered, fired then extracted and ejected. The feeding pawl in the gun would pull the belt to the right as the gun was fired or cocked, sending the loose link out to the right side of the receiver, where the expended case was also ejected, normally separately from a different ejector port to the link.

M13

M13, M-13 or M₁₃ may refer to:

Second Avenue Line (surface)

The Second Avenue Line is a bus line in Manhattan, New York City, United States, running mostly along Second Avenue (and northbound on First Avenue since 1951) from Lower Manhattan to East Harlem. Originally a streetcar line, it is now the southbound direction of the M15 bus route, the busiest bus route in the U.S. with an annual ridership just shy of 17.5 million. (However, the M15 is the only route on First and Second Avenues, while the one-way pair of Madison and Fifth Avenues has a higher frequency of local buses past Central Park, split among four routes (M1/M2/M3/M4).MTA Regional Bus Operations, under the New York City Bus and Select Bus Service brands, operates the local out of the Tuskegee Airmen Bus Depot and the SBS is operated from the Mother Clara Hale Bus Depot. Service is operated exclusively with articulated buses.

History

The Second Avenue Railroad opened the line in 1853 and 1854, from Peck Slip on the East River north along Pearl Street, Bowery (shared with the Third Avenue Line), Grand Street, Chrystie Street, and Second Avenue to East Harlem. A short branch was later built along Stuyvesant Street and Astor Place to end at Broadway in NoHo. The Metropolitan Street Railway leased the line in January 1898, and on April 3 the line from Astor Place to Manhattan was electrified. The original line was later electrified to the Bowery, where streetcars used the Third Avenue Line to City Hall, and the line to Peck Slip was abandoned. Buses were substituted for streetcars by the East Side Omnibus Corporation on June 25, 1933. The New York City Board of Transportation took over operations in 1948, with the New York City Transit Authority replacing it in 1953. In 1974, the M15 was chosen to be one of the first routes to operate Limited stop service. The new service would act as an express version of the M15, only stopping at major attractions and transfer points north of Houston Street.

M13 road (Durban)

The M13 is a metropolitan road in Durban, South Africa.

Route

The route starts in the Durban Central Business District. For the first few kilometres of its length, it runs parallel to the N3 on both sides as King Ndinuzulu Road North and King Ndinuzulu Road South (former Berea Road). At the Tollgate Bridge, it then turns to the south and passes through Mayville, before crossing under the N3 and passing through Sherwood.

At 45th Cutting, the route becomes a dual-carriageway freeway for the rest of its length. The route passes over the N2 (providing no access to it), and passes through Westville and Cowies Hill. The route then briefly touches the N3 at the Paradise Valley interchange, before passing through Pinetown.

After Pinetown, the route goes up Field's Hill, a 3km 1:15 gradient (this section is notorious for heavy vehicle accidents that can close an entire carriageway of the road). The route then passes through Kloof and Gillitts, before the R103 diverges, providing access to Hillcrest. The route then passes south of Hillcrest and through Assagay before merging with the N3, where it ends.