M40 or M-40 may refer to:

In transportation:

In science:

In firearms and military equipment:

See also

The M40 Field Protective Mask is one of various gas masks used by the military of the United States and its allies to protect from field concentrations of chemical and biological agents, along with radiological fallout particles. It is not effective in an oxygen deficient environment or against ammonia.

Characteristics

The M40 Field Protective mask features 3 voicemitters, one on either the right or left side, and one in front. A voicecom adapter may be placed over the front voicemitter to amplify the user's voice. The mask can be adjusted in the field to accept the filtering canister on either side, so that a weapon may be shouldered. Right-handed shooters will normally locate the canister on the left side of the mask and vice versa.

The C2 canister on the M40 mask can protect the user from up to 15 nerve, choking, and blister agent attacks, and two blood agent attacks.

The M40 comes with a drinking system that allows the user to drink water when donning the mask for long periods of time in a chemically contaminated environment. In order to use the drinking system the user must also have suitably equipped canteen lids or an adapter for other containers.

The M9 and is a local bus routes that operates along the Avenue C Line (also known as the Houston Street Line), in Manhattan, New York City, United States. The route runs mostly along Essex Street and Avenue C from Battery Park City to Kips Bay. Originally a streetcar line, it the Avenue C Line is now part of the M9 route, as well as the M21, which operates on the Houston Street Line. The M9 is operated by the New York City Transit Authority, and based out of the Michael J. Quill Depot.

History

The Avenue C Railroad (changed to the Houston, West Street and Pavonia Ferry Railroad in the early 1880s) was chartered June 3, 1874, and opened the Avenue C Line on October 18, 1869, connecting the Pavonia Ferry at the foot of Chambers Street with the Green Point Ferry at the foot of East 10th Street. Its route ran along West Street, a one-way pair of Charlton Street, Prince Street, and Stanton Street (eastbound) and Houston Street, 1st Avenue, and 3rd Street (westbound), Pitt Street/Avenue C, and 10th Street. By 1879, the line had been extended north on Avenue C from 10th Street, west on 17th Street (eastbound) and 18th Street (westbound), north over the Central Park, North and East River Railroad (First Avenue and East Belt Line) on Avenue A, 23rd Street, and 1st Avenue, west on 35th Street (westbound) and 36th Street (eastbound), north on Lexington Avenue, and west on 42nd Street to Grand Central Terminal. The Third Avenue Railroad also used the trackage on 42nd Street by 1884.