Frederick Benjamin "Ben" Carlin (27 July 1912 – 7 March 1981) was an Australian adventurer who was the first person to circumnavigate the world in an amphibious vehicle. Born in Northam, Western Australia, Carlin attended Guildford Grammar School in Perth, and later studied mining engineering at the Kalgoorlie School of Mines. After qualifying as an engineer, he worked on the Goldfields before in 1939 emigrating to China to work in a British coal mine. In the Second World War, Carlin was posted to the Indian Army Corps of Engineers, serving in India, Italy, and throughout the Middle East. After his discharge from service in 1946, he emigrated to the United States with his American wife, Elinore (née Arone).
Sparked by an idea he had had whilst in the military, Carlin proposed that the couple honeymoon by crossing the Atlantic Ocean in a modified Ford GPA (an amphibious version of the Ford GPW Jeep), which they named the Half-Safe. Beginning their trip in Montreal, Quebec, Canada, the Carlins finally completed the transatlantic crossing in 1951, after unsuccessful attempts. From there, they travelled to Europe, temporarily settling in Birmingham to raise more money. They resumed their journey in 1954, travelling overland through the Middle East before arriving in Calcutta. After a short fundraising trip to Australia, Carlin's wife left to return to the United States. He resumed the journey with new partners, travelling through South-East Asia and the Far East to the northern tip of Japan, and then to Alaska. After an extended tour through the United States and Canada, he and Half-Safe finally returned to Montreal, having travelled over 17,000 kilometres (11,000 mi) by sea and 62,000 kilometres (39,000 mi) by land during a ten-year journey. Following Carlin's death in 1981, Half-Safe was acquired by Guildford Grammar, his old school, where it remains on display.
- "Ben Carlin" | 2020-01-04 | 125 Upvotes 7 Comments
Fifty-eight selected navigational stars are given a special status in the field of celestial navigation. Of the approximately 6,000 stars visible to the naked eye under optimal conditions, the selected stars are among the brightest and span 38 constellations of the celestial sphere from the declination of −70° to +89°. Many of the selected stars were named in antiquity by the Babylonians, Greeks, Romans, and Arabs.
The star Polaris, often called the "North Star", is treated specially due to its proximity to the north celestial pole. When navigating in the Northern Hemisphere, special techniques can be used with Polaris to determine latitude or gyrocompass error. The other 57 selected stars have daily positions given in nautical almanacs, aiding the navigator in efficiently performing observations on them. A second group of 115 "tabulated stars" can also be used for celestial navigation, but are often less familiar to the navigator and require extra calculations.
For purposes of identification, the positions of navigational stars — expressed as declination and sidereal hour angle — are often rounded to the nearest degree. In addition to tables, star charts provide an aid to the navigator in identifying the navigational stars, showing constellations, relative positions, and brightness.
- "List of selected stars for navigation" | 2019-09-24 | 76 Upvotes 13 Comments
Pykrete is a frozen ice alloy , originally made of approximately 14 percent sawdust or some other form of wood pulp (such as paper) and 86 percent ice by weight (6 to 1 by weight). During World War II, Geoffrey Pyke proposed it as a candidate material for a supersized aircraft carrier for the British Royal Navy. Pykrete features unusual properties, including a relatively slow melting rate due to its low thermal conductivity, as well as a vastly improved strength and toughness compared to ordinary ice. These physical properties can make the material comparable to concrete, as long as the material is kept frozen.
Pykrete is slightly more difficult to form than concrete, as it expands during the freezing process. However, it can be repaired and maintained using seawater as a raw material. The mixture can be moulded into any shape and frozen, and it will be tough and durable, as long as it is kept at or below freezing temperature. Resistance to gradual creep or sagging is improved by lowering the temperature further, to −15 °C (5 °F).
- "Pykrete" | 2015-07-07 | 114 Upvotes 41 Comments
SkySails GmbH & Co. KG is a Hamburg-based company that sells kite rigs to propel cargo ships, large yachts and fishing vessels by wind energy. Ships are pulled by an automatically-controlled foil kite of some hundreds of square meters. For multiple reasons, they give many times the thrust per unit area of conventional mast-mounted sails.
The systems save fuel, and reduce carbon emissions and shipping costs, but have not been widely adopted.
- "SkySails" | 2019-07-04 | 126 Upvotes 42 Comments