LDH meaning in General ?

A fire hose (or firehose) is a high-pressure hose that carries water or other fire retardant (such as foam) to a fire to extinguish it. Outdoors, it attaches either to a fire engine, fire hydrant, or a portable fire pump. Indoors, it can permanently attach to a building's standpipe or plumbing system.

The usual working pressure of a firehose can vary between 8 and 20 bar (800 and 2,000 kPa; 116 and 290 psi) while per the NFPA 1961 Fire Hose Standard, its bursting pressure is in excess of 110 bar. (11,000kPa; 1600psi)Hose is one of the basic, essential pieces of fire-fighting equipment. It is necessary to convey water either from an open water supply, or pressurized water supply. Hoses are divided into two categories, based on their use: suction hose, and delivery hose.

After use, a fire hose is usually hung to dry, because standing water that remains in a hose for a long time can deteriorate the material and render it unreliable or unusable. Therefore, the typical fire station often has a high structure to accommodate the length of a hose for such preventive maintenance, known as a hose tower.

On occasion, fire hoses are used for crowd control (see also water cannon), including most notably by Bull Connor in the Birmingham campaign against protesters during the Civil Rights Movement in 1963.