On 6/28/21, jim bell <jdb10987@yahoo.com> wrote:

WIRED: How Underground Fiber Optics Spy on Humans Moving Above. https://www.wired.com/story/how-underground-fiber-optics-spy-on-humans-movin...

https://www.youtube.com/watch?v=4iDnJ7F7NWE Heavyweight Acoustic Dispersal System HADS https://www.youtube.com/watch?v=AEqiLFSSlLE Low Vibes https://i.redd.it/bltym8yfjb831.png https://i.imgur.com/ub2rrXvh.jpg Tyler replied that the caterpillar would be mistaken for whales humping, or "some other seismic anomaly". This is almost certainly what led Ryan to put "two and two together" on the aircraft carrier, and deduce that the "magma displacement" that the USS Dallas was waiting for at the end of Red Route One could actually be the Red October. This is page 6 of a 20 January 1959 memo from Chief, Bureau of Ships to the Chief of Naval Operations entitled, "Nuclear Powered Submarines, Quieting of (U)." The memo gives the quieting measures applied to the Skipjack and Thresher class SSNs, as well as quieting methods that are in the research and development stage. These were, a) Development of flexible steam and exhaust connections and flexible couplings to permit sound isolation mounting of main and auxiliary machinery. b) Development of advanced design propulsion machinery to eliminate reduction gears and reduce turbine noise. c) Development of improved structural damping techniques and materials. d) Development of fluid acoustic filters to reduce piping flow noise. e) Development of ejector assisted scoop circulating systems to eliminate main circulating pumps. f) Development of improved high impedance tubular subbases and improved noise isolation mounting techniques, such as compound mounting. g) Development of quieter conventional machinery through redesign and more stringent manufacturing specifications. h) Development of inherently quiet machinery having few or no moving parts, such as thermo-electric generators, electrostatic blowers, magneto-hydrodynamic pumps and propulsion systems, absorption and thermo-electric type air conditioning and refrigeration. i) Research into structural mechanics to reduce the amount of acoustic energy being transmitted into the water. j) Research into the mechanisms of hydrodynamic noise to reduce sonar interference and piping noise k) Research into the mechanisms of generation, radiation, and propagation of blade-rate and other associated propeller excited noise. l) Research into mechanisms controlling void resonances, such as ballast tanks to the extent that they are a source of radiated noise. a) was essential for the sound isolation rafts used on the Thresher, Ethan Allen, and all future U.S. nuclear submarines. b) appears to refer to direct-drive turbines (used on the Jack and Narwhal), high power turboelectric drive (as installed on the Glenard P. Lipscomb; the Tullibee's low power turboelectric drive was already being built at the time of the memo), and possibly more exotic solutions such as hydraulic torque converters. e) is the origin of the Narwhal's main seawater intake scoop. The British used this on the Swiftsure, Trafalgar, and Astute SSNs (possibly as a result of U.S. research), and the Soviets developed it independently in the late 1960s. k) would result several years later in the adoption of seven-bladed skewback screws. --------------------------------------------------------------------------------------------------------------- What about item (h)? To me, it seems that the farthest a magnetohydrodynamic drive ever got was probably model tests (and in reality it probably never left the engineer's notebooks). Put simply, an MHD drive is a linear electric motor which moves seawater instead of magnets. Electrodes pump current into the water, and magnets accelerate that charged water with magnets via the Lorentz force. While it is true that magnetohydrodynamic drives have no moving parts, they have many disadvantages. The most serious is low efficiency. As you increase the current of electricity flowing into the seawater to get more power, more energy will go into heating and electrolizing the water (i.e. breaking into hydrogen and oxygen). Thus there is a maximum practical limit to the amount of current put into an MHD drive. And while you can also boost magnetic field strength to increase power, each additional amp of current to the electromagnets costs more in money, volume, and weight. In summary, it is not suitable for large-scale applications like submarine main propulsion. It is apparently not particularly quiet when used on large scales, which negates it purpose entirely. However, it may be useful for smaller-scale applications, such the myriad of pumps used in nuclear submarines. Item (h) seems to imply that with the partial exception of MHD, all of the exotic technologies listed are for relatively small-scale components such as air conditioning plants and pumps. This makes a lot more sense than using MHD for a full-size propulsion system. --------------------------------------------------------------------------------------------------------------- How did Red October get the idea? According to a friend who knew Tom Clancy, Clancy's inspiration for the Caterpillar Drive was the pod on the rudder of the Soviet Victor III. There was speculation that it could be some form of auxiliary propulsion system, perhaps an MHD drive, although we now know that it was a container for a thin-line towed sonar array. Clancy's conception of the Caterpillar Drive was not as an MHD drive, rather a long tunnel with multiple stages of rotors, essentially a super-long pumpjet. The movie changed the Caterpillar Drive to use MHD propulsion, possibly as a result of this article about the Soviet towed array pod. --------------------------------------------------------------------------------------------------------------- Underwater Sonar Test Ranges Mostly unrelated to above, but I found it interesting. Later, the memo discusses creating an underwater sound range for researching submarine noise, Current investigations indicate that an area in the Bahama Island Group called Tongue of the Ocean possesses the requisite acoustic and other properties to fulfill this need. A few years later, in collaboration with the British, the U.S. Navy built the Atlantic Undersea Test and Evaluation Center (AUTEC) near the Tongue of the Ocean. The much shallower Carr Inlet in Puget Sound was put forward as a possible range in the Pacific for additional research, although its depth would not allow for studies into low-frequency noise. Presumably this also led to the acoustic research conducted at Lake Pend Orielle in Idaho. The memo also recommends that the Albacore and Nautilus be used for noise-reduction research. Neither of these submarines was similar in structure to the submarines then in production, but BuShips suggested that the Albacore might suffice if modified. I would guess that the need for a submarine similar in structure resulted in the large scale models tested in Lake Pend Oreille. The first of these was the Kamloops, a 1/4 scale Sturgeon-class submarine, completed in 1967. Later, the Kokanee (LVS-1) and Cutthroat (LSV-2) would be used to research quieting for the Seawolf and Virginia.