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Wilmington, North Carolina once had a thriving Black middle class and an elected interracial government. In 1898 white supremacists used violence to overthrow that government, kill Black residents and drive many others from the city.
MORE →Reflects the personal views, recollections, and perspective of the author, Mike Davis.
This is a personal recollection on the Move fire on May 13, 1985
Asdic was the British version of sonar developed at the end of World War I based on the work of French physicist Paul Langevin and Russian engineer M. Constantin Chilowsky. The system was developed as a means to detect and locate submarines by their reflection of sound waves. By the start of World War II in 1939, most British destroyers and smaller vessels were fitted with it in a variety of different sets.
| Name | Date of Introduction | Dome | Notes |
|---|---|---|---|
| Type 112 | 1920 | Fitted to some V and W-class destroyers and small escorts like P and PC-class sloops | |
| Type 119 | 1930 | B-class destroyers | |
| Type 121 | Tested 1931 in Woolston | First production retractable dome | Fitted in D, E, F, and G-class destroyers, some cruisers and the sloop Enchantress |
| Type 122 | Detachable | Designed for trawlers and other auxiliaries with a turbo alternator | |
| Type 123 | 1934 | Detachable | Replaced Type 122, designed for ships with a high-frequency motor alternator |
| Type 124 | 1934 | Retractable | C, H, I, J, K, and Tribal-class destroyers, some sloops and older destroyers. First system with a range recorder |
| Type 127 | 1937 | As per Type 122 | Designed for sloops, but widely fitted in frigates and older destroyers. Electronics as per Type 123 |
| Type 128 | Tested 1937 in Acheron | Retractable | A, L, and Hunt-class destroyers |
| Type 141 | ? | No dome, but some modified with British dome as Type 141A | American QCJ/QCL system in Lend-Lease Town-class destroyers, modified with British range and bearing recorders |
| Type 144 | Trials in Kingfisher in 1941 | Retractable | First set specifically intended for ahead-throwing weapons like Hedgehog |
| Type 145 | 1942? | Detachable | Like Type 144, but intended for slower escorts |
| Type 147 | Sea trials aboard Ambuscade, May 1943 | ? | The 147 set with its beamforming 'sword' transducer produced a horizontal 'fan' beam that could give a depth estimate.[1][2] This, as well as the Q attachment, improved targeting for directable weapons, like the new Squid, that were capable of making use of this information. |
| Q attachment | 1943 | NA | Depth-measuring set with 3° horizontal beam, modification to existing Type 144 systems |
Source: Wikipedia. Article content is retrieved live through the MediaWiki API.
Asdic was the British version of sonar developed at the end of World War I based on the work of French physicist Paul Langevin and Russian engineer M. Constantin Chilowsky. The system was developed as a means to detect and locate submarines by their reflection of sound waves. By the start of World War II in 1939, most British destroyers and smaller vessels were fitted with it in a variety of different sets.
Bold (also called Bolde, a term derived from kobold) was a German sonar decoy, used by U-boats during the Second World War from 1942 onwards. It consisted of a metal canister about 10 cm (3.9 in) in diameter filled with calcium hydride. It was launched by an ejector system colloquially referred to as Pillenwerfer (English: "pill thrower"). When mixed with seawater, the calcium hydride produced large quantities of hydrogen, which bubbled out of the container, creating a false sonar target. A valve opened and closed, holding the device at a depth of about 30 m (98 ft). The device lasted 20 to 25 minutes. It replicated the echo of an Asdic-sonar submarine contact. The Royal Navy called it SBT (Submarine Bubble Target).
The early phase of the Battle of the Atlantic during which Kriegsmarine U-boats enjoyed significant success against Allied warships and merchantmen was referred to by U-boat crews as the Happy Time (German: Die glückliche Zeit), and later the First Happy Time, after a second successful period was encountered. It started in July 1940, almost immediately after the Fall of France, which brought the German U-boat fleet closer to the British shipping lanes in the Atlantic. From July 1940 to the end of October, 282 Allied ships were sunk off the north-west approaches to Ireland for a loss of 1,489,795 GRT of merchant shipping. The reason for this successful Axis period was the British lack of radar and huff-duff-equipped ships which meant that the U-boats were very hard to detect when they made nighttime surface attacks – ASDIC (sonar) could only detect submerged U-boats. When it ended is a matter of interpretation, with some sources claiming October 1940 and others extending it to April 1941, after the Germans lost three prominent U-boat commanders: Günther Prien, Joachim Schepke, and Otto Kretschmer.
The Good Shepherd is a 1955 British novel about naval warfare during World War II, by C. S. Forester, exploring the difficulties of the Battle of the Atlantic, specifically as seen through the eyes of the United States commander of an escort fleet during a 52-hour period: the crews' struggle against the sea, the enemy, and the exhaustion brought on by constant vigilance. The novel also details the problems of the early radar and ASDIC equipment available, and the poor communications between the fleet and Admiralty using HF Radio and early manual cryptography. In 2020, the novel was adapted as a film, Greyhound, written, produced by and starring Tom Hanks. That year, an audiobook version of the novel was also published.
Before the 1921 destruction of Tulsa’s Greenwood District, Black residents had created a remarkable center of business and community life. The district included stores, professional offices, entertainment venues and homes owned by Black citizens. Understanding Greenwood means learning what was built—not only what was burned.
MORE →The Greenwood District.
