At sea and underway, the measurement is in Feet, and it is measured from the Keel of the boat. If it's past a "certain point" it's not a good thing.
While in port, the Topside Watch notes the ship's draft depth in feet by noting the depth marks on the rudder every hour. This is done to detect any flooding that might not be readily apparent.
There are depth gage repeaters in Sonar Control, Main Control on the Helmsman/Planesman panel, and one in Maneuvering where the Reactor, Engines and Turbine Generators are operated. This is a safety feature in case the primary in Control goes bad or gets stuck for whatever reason. Someone is always monitoring depth. It has happened in the past where a main depth gage has failed and a boat drifted too deep, but was saved before it hit crush depth when the guys in Maneuvering saw they were below safe depth limits. Any time a submarine goes to deep depth, it is rigged for Deep Submergence - all damage control teams are in place and watches are essentially at battlestations.
John P. Holland is credited with inventing the first modern submarine and is considered the father of modern submarines.
A pressure gauge is an instrument that measures the pressure in a vessel, a line, or whatever the pressure gauge is connected to. Pressure gauges come in at least two different types: differential pressure gauges, and absolute pressure gauges. Differential pressure gauges measure - surprise - DIFFERENCES in pressure. Pressure gauges that read "zero" when not attached to anything would actually be differential gauges that measure the difference between atmospheric pressure and the pressure of whatever they are attached to. Vacuum gauges are differential gauges that measure how far BELOW atmospheric pressure the pressure is in a vessel or pipe. Gauges that measure "gauge pressure" are just differential gauges that are calibrated to measure zero at atmospheric pressure. Absolute pressure gauges would only read "zero" if they were attached to an absolute vacuum. A common type of absolute pressure gauge is a barometer. Strictly speaking, a mercury barometer is really a differential gauge that measures the difference between the vapor pressure of the mercury and the surrounding atmosphere, but the vapor pressure of the mercury is so low that the error in treating it as an absolute pressure gauge is generally negligible. There are many different kinds of gauges used to measure pressure including: Instruments hydrostatic - These measure pressure according the height of a liquid in a column. The height of the liquid is proportional to the pressure. Common types of hydrostatic gauges include: manometers, McLeod gauges, and piston gauges. aneroid - The pressure sensing element may be a Bourdon, a diaphragm, a capsule, or a set of bellows, which will change shape with changes in the pressure of whatever the gauge is attached to. The deflection of the pressure sensing element is read by a linkage connected to a needle or by a secondary transducer. The most common secondary transducers in modern vacuum gauges measure a change in capacitance due to the mechanical deflection. Gauges that rely on a change in capacitance are often referred to as Baratron gauges. Electronic sensors thermal conductivity - including two wire and one wire gauges that measure pressure via changes in the thermal conductivity of the wires as they are placed under strain. Something like this is used in a lot of electronic bathroom scales. ionization gauges - These are primarily used for measurements of low-pressure gasses. They sense pressure indirectly by measuring the electrical ions produced when the gas is bombarded with electrons. Fewer ions will be produced by lower density gases. they have to be calibrated against another type of pressure gauge and depend on the gas being measured.
yes
Modern Submarines do not have a keel like other ships....
He is the Inventor of the Modern Submarine.
WWII boat shaped bows; nuclear subs have cigar shaped hulls.
Harry S. Truman
The modern submarine was invented by John Phillip Holland. He callled it the Holland 1. He tested it in the passaic river in Paterson , New Jersey. Before inventing that he was a teacher in St. John Catholic school.
2.5 billion dollars
The songs used in the Yellow Submarine film were remixed in stereo and issued on CD as the Yellow Submarine Songtrack. These are modern stereo mixes, in contrast to the ones made at the time, which now sound rather peculiar.
John P. Holland, an Irish engineer, is credited with developing the first practical modern submarine. He launched the Holland VI in 1897, which was the first submarine to be commissioned by the U.S. Navy in 1900. Holland's designs laid the foundation for future submarine technology.
Modern nuclear submarines can work (or patrol) for 3 months or more.