A lock of very large size and usually of irregular shape, the gates of which are kept open for several hours after high tide so that vessels may enter as long as there is sufficient depth over the sill. Vessels remain in the half-tide basin until the ensuing flood tide before they may pass through the gate to the inner harbor. If entry to the inner harbor is required before this time, water must be admitted to the half-tide basin from some external source.
Related Terms |
DIELECTRIC STRENGTH
A measure of the ability of an insulating material to withstand electric stress (voltage) without failure. Fluids with high dielectric strength (usually expressed in volts or kilovolts) are good electrical insulators. (ASTM Designation D 877.)
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CAM
Eccentric shaft used in most internal combustion engines to open and close valves.
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CORROSION INHIBITOR
Additive for protecting lubricated metal surfaces against chemical attack by water or other contaminants. There are several types of corrosion inhibitors. Polar compounds wet the metal surface preferentially, protecting it with a film of oil. Other compounds may absorb water by incorporating it in a water-in-oil emulsion so that only the oil touches the metal surface. Another type of corrosion inhibitor combines chemically with the metal to present a non- reactive surface.
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BLACK OIL
A lubricant containing asphaltic materials, which impart extra adhesiveness, that are used for open gears and steel cables.
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CARBON RESIDUE
Coked material remaining after an oil has been exposed to high temperatures under controlled conditions.
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REFRIGERATOR
A device to transfer heat from a low temperature to a high temperature medium.
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ADSORPTION
Adhesion of the molecules of gases, liquids, or dissolved substances to a solid surface, resulting in relatively high concentration of the molecules at the place of contact; e.g. the plating out of an anti-wear additive on metal surfaces.
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DEMULSIBILITY
The ability of a fluid that is insoluble in water to separate from water with which it may be mixed in the form of an emulsion.
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HIGH WATER INEQUALITY
The difference between the heights of the two high waters during a tidal day
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HIGH WATER
The maximum height reached by a rising tide. The height may be due solely to the periodic tidal forces or it may have super- imposed upon it the effects of prevailing meteorological condi- tions. Use of the synonymous term HIGH TIDE is discouraged.
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