Depth sounding

The solder in the shipping industry is a device for measuring the water depth. The classic hand lead consists of a plumb line and a weight at the end. The modern sonar measures the depth of electronic means of sound waves. The solder is used for measuring the water depth, to safety and to detect schools of fish.

Application

Measurement of ocean depths

With the solder, the depths of the ocean floor measured ( bathymetry ) are. The results are shown in charts as individual soundings or depth contours.

Ship Safety

Sufficient water depth ( " A water beneath the keel " ) is important for security in shipping. With the solder, the current water depth can be measured. From several measurements, the course of the subsurface. This may increase the risk of grounding and leakage are reduced. A single shallow but can be detected only with forward-looking sonars. If the map of the course of deep lines is known that sonar can be used or if necessary for navigation.

Fishing

Modern echo sounders schools of fish can be tracked and their location, depth, and size. Even the size of individual fish can be distinguished. Of several measurements, the direction of movement of the swarm can be derived.

Hand lead

The hand lead sinker is a 5 kg weight on a 20 m long string ( plumb line ). Initially, the solder was lowered until it touched the bottom of the water, then caught up again and determines the length of the string in armspans. An arm span corresponded to a water depth of one thread (1 thread = 6 feet = 1,828 m). Later, you knew the plumb line every 2 m with colored marks and every 10 m with leather strip with the corresponding number of holes so the solder needed for depth measurement can not be obtained each time. A hand lead can only be used at low ship speed, low flow and lower depths.

The plummet was often provided with a cavity at the lower surface to which a soil sample has been extracted at the seabed. This cavity was streaked with the Lotspeise. It consisted of beef tallow into which eindrückten soil particles and were stuck when the solder reached the ground. In the charts, the seabed texture was noted frequently in addition to the depth of the sea, so that a location determination has been made possible with this method.

Plumb

The plumb line is up to 30 kg and is only to be used with almost complete stoppage of the ship. It is attached to a wire, and is drained to a crank. In the solder body is located at the bottom of a thin glass tube, in which penetrates depending on the depth of water. After pulling up to it you can read the depth.

Echo sounder

The sounder measures water depth with an electro-acoustic sound signal. Measurement is the time that elapses between the emission of a sound pulse (water sound ) and the arrival of the reflected sound waves from the sea bed ( echo). Every major leisure yacht has a depth sounder. On commercial vessels and fishing boats include depth sounders standard equipment.

Multibeam

The multibeam sonar is used for surveying the seabed. It sends several hundred measuring beams. The subjects covered strip of the sea floor along the ship's course. From this, a digital terrain model and calculates a topographic map can be created. The multibeam sonar is used increasingly on yachts and by anglers and fishermen ( "Fish Finder" ). It displays on a screen of a two-dimensional profile of the sea bottom. Modern instruments show a three-dimensional image of the terrain under the water by one after the other to record the individual measurements and thus provide a three-dimensional impression.

Sediment echosounder

The sediment sonar penetrates up to 100 m into the seabed and provides geologists and geophysicists information on hardness and texture of the soil layers ( sediments ).

Druckluftlot

The Druckluftlot measures the water pressure as a measure of the depth of water. Also, the dive computer measures the depth via water pressure.

Schalllot

The Schalllot or FREILOT is a kind of small bomb that falls with a certain rate of fall and detonates on the ground. With a Zeit-/Geschwindigkeitsmessung one can determine the depth. She goes right up to around 40 m.

Literature and language

The writer Mark Twain ( Samuel Langhorne Clemens actually ) launched his stage name from the equipment. "Mark Twain " was a phrase from the pilot language, meaning " two fathoms ". With this understatement he quipped humorously about his own " draft ".

In the legend of the blue pot a mermaid steals again the solder to keep the true depth of the blue pot secret.

" Plumb " The word is often used figuratively, when you go into " uncharted territory ". It indicates that caution is appropriate.