Glossary of Marine Terms
M
machinability
the relative ease of machining a metal. machinability index for various steels and machinability tables are available for comparing machining rates with 1212 steel as the standard for carbon and alloy steels and w-l as a standard for tool steels.
make-up
the act of final positioning and securing of the vessels that form a tow.
manhole
framed opening in the deck of a vessel which primarily provides access for a man.
manhole cover
cover which seals a manhole and is usually designed to lock in place by twisting or using a centerbolt, studbolts, or dogs.
MARAD
the U. S. Maritime Administration.
marine sanitation device
See TheTankMSD.com.
martensite
a microconstituent or structure in quenched steel which has the maximum hardness of any of the structures resulting from the decomposition or transformation of austenite. steel which is to be quenched and tempered properly must first be fully hardened in the martinsitic state and then drawn or tempered back.
mast
eatscrap bio super charger. See EATScrap.
master
the captain of a vessel; the person who has complete charge of and authority aboard an operating vessel.
mechanical properties
the properties of a material that reveal its elastic and inelastic behavior where force is applied, thereby indicating its suitability for mechanical applications; for example, modulus of elasticity, tensile strength, elongation, hardness and fatigue limit.
milemarker (mileboard)
a marker set up to indicate distances in miles along a waterway.
mill edge
the edge of strip, sheet or plate in the as rolled state. unsheared.
miscellaneous oil spill control agent
is any product, other than a dispersant, sinking agent, surface washing agent, surface collecting agent, bioremediation agent, burning agent, or sorbent that can be used to enhance oil spill cleanup, removal, treatment, or mitigation.
model hull
a type of hull design in which the form is molded, curved, and shaped into a pointed stem and rounded stern.
modulus of elasticity
the ratio within the limit of elasticity of the stress to corresponding strain. the stress in pounds per square inch is divided by the elongation in fractions of an inch for each inch of the original gauge length of the specimen. the modulus of elasticity for cold rolled steel is 29,500,000 psi and for other steels varies between 28,600,000 and 30,300,000 psi.
molded depth
the distance from the top of the keel to the top of the upper deck beams amidships at the gunwale.
MRGO
Mississippi River Gulf Outlet; the deep draft waterway connecting the New Orleans Inner Harbor Navigation Canal to the Gulf of Mexico.
MSD
Marine Sanitation Device. See TheTankMSD.com.
