Sound

In physics, sound is a vibration that propagates as a typically audible mechanical wave of pressure and displacement, through a medium such as air or water. In physiology and psychology, sound is the reception of such waves and their perception by the brain.

Acoustics

Acoustics is the interdisciplinary science that deals with the study of mechanical waves in gases, liquids, and solids including vibration, sound, ultrasound, and infrasound. A scientist who works in the field of acoustics is an acoustician, while someone working in the field of acoustical engineering may be called an acoustical engineer. An audio engineer, on the other hand is concerned with the recording, manipulation, mixing, and reproduction of sound.

Applications of acoustics are found in almost all aspects of modern society, subdisciplines include aeroacoustics, audio signal processing, architectural acoustics, bioacoustics, electro-acoustics, environmental noise, musical acoustics, noise control, psychoacoustics, speech, ultrasound, underwater acoustics, and vibration.

Urethral sounding

Sounding or urethral sounding is the medical use of probes called sounds to increase the inner diameter of the urethra and to locate obstructions in it. Sounds are also used to stretch the urethra in order to receive genital piercing.

Urethral sounding and urethral play are also used to refer to this practice in a sexual context.

Urethral play can involve the introduction of either soft or rigid items into the meatus of the penis (as well as farther in). Objects such as sounds are usually only inserted about halfway into the glans and can usually be easily retrieved. Other toys and items, such as catheters, may be introduced deeper; in some cases even into the bladder. Some items may even be allowed to curl several times or expand within the bladder. This action in the male may be directly or indirectly associated with stimulation of the prostate gland and some types of bladder control.

Risks

If not conducted carefully, sounding carries a risk of irritation, tearing of the urethra, or of urinary tract infection. Infections may become serious if they progress to the bladder or kidneys, and should be referred to a doctor.

Sound (nautical)

In nautical terms, the word sound is used to describe the process of determining the depth of water in a tank or under a ship. Tanks are sounded to determine if they are full (for cargo tanks) or empty (to determine if a ship has been holed) and for other reasons. Soundings may also be taken of the water around a ship if it is in shallow water to aid in navigation.

Methods

Tanks may be sounded manually or with electronic or mechanical automated equipment. Manual sounding is undertaken with a sounding line- a rope with a weight on the end. Per the Code of Federal Regulations, most steel vessels with integral tanks are required to have sounding tubes and reinforcing plates under the tubes which the weight strikes when it reaches the bottom of the tank. Sounding tubes are steel pipes which lead upwards from the ships' tanks to a place on deck.

Electronic and mechanical automated sounding may be undertaken with a variety of equipment including float level sensors, capacitance sensors, sonar, etc.

LCM 1

The Landing Craft, Mechanised Mark 1 or LCM (1) was a landing craft used extensively in the Second World War. Its primary purpose was to ferry tanks from transport ships to attack enemy-held shores. Ferrying troops, other vehicles, and supplies were secondary tasks. The craft derived from a prototype designed by John I. Thornycroft Ltd. of Woolston, Hampshire, UK. During the war it was manufactured in the United Kingdom in boatyards and steel works. Constructed of steel and selectively clad with armour plate, this shallow-draft, barge-like boat with a crew of 6, could ferry a tank of 16 long tons to shore at 7 knots (13 km/h). Depending on the weight of the tank to be transported the craft might be lowered into the water by its davits already loaded or could have the tank placed in it after being lowered into the water.

Narvik and Dunkirk claimed almost all of the 1920s Motor Landing Craft and, therefore, the LCM(1) was the common British and Commonwealth vehicle and stores landing craft until US manufactured types became available. Early in the war LCM(1) were referred to commonly as Landing Barges by both the military and the press. Prior to July 1942, these craft were officially referred to as "Mechanised Landing Craft" (MLC), but "Landing Craft; Mechanised" (LCM) was used thereafter to conform with the joint US-UK nomenclature system. This being the earliest design in use at the time, it was more specifically called “Landing Craft, Mechanised Mark 1” or LCM(1).

LCM-8

The LCM-8 ("Mike Boat") is a river boat and mechanized landing craft used by the United States Navy and Army during the Vietnam War and subsequent operations. They are currently used by governments and private organizations throughout the world. The acronym stands for "Landing Craft Mechanized, Mark 8". (The "Mike Boat" term refers to the military phonetic alphabet, LCM being "Lima Charlie Mike".)

The vessel weighs 135,000 pounds (61,200 kg) and has a crew of four: a Boatswain's Mate petty officer, an Engineman petty officer, a non-rated fireman, and a seaman. US Army specifications call for a crew of six: two coxswains, two seamen and two enginemen. The LCM-8s are constructed from welded steel and powered by two 12V71 diesel engines, twin propellers, and rudders. The ship can carry 60 short tons of cargo. It was designed by Marinett Marine Corp Dimensions. It has a range of 190 miles at 9kts with a full load.

Modifications

A modified version, the Zippo boat, carries flamethrowers. Another modified version, the LCM-8 Mod 2, was used to fulfill command, personnel, salvage, and firefighting functions. There is also another version with an aluminum hull. This version is mostly carried by pre-positioned ships.

Landing Craft Mechanized

The Landing Craft Mechanized (LCM) or Landing Craft Mechanical is a landing craft designed for carrying vehicles. They came to prominence during the Second World War when they were used to land troops or tanks during Allied amphibious assaults.

Variants

There was no single design of LCM used, unlike the Landing Craft, Vehicle, Personnel (LCVP) or Landing Craft Assault (LCA) landing craft made by the US and UK respectively. There were several different designs built by the UK and US and by different manufacturers.

The British Motor Landing Craft was conceived and tested in the 1920s and was used from 1924 in exercises. It was the first purpose built tank landing craft. It was the progenitor of all subsequent LCM designs.

LCM (1)

The Landing Craft, Mechanised Mark I was an early British model. It was able to be slung under the davits of a liner or on a cargo ship boom with the result that it was limited to a 16-ton tank.

The Landing Craft, Mechanised Mark I was used during the Allied landings in Norway, and at Dieppe and some 600 were built.