History of coal miners inventiveness in clothing their families. Mining has always been dangerous, because of methane gas explosions, roof cave-ins, and the difficulty of mines rescue. The worst single disaster in British coal mining history was at Senghenydd in the South Wales coalfield. On the morning of 14 October 1913 an explosion and subsequent fire killed 436 men and boys. It followed a series of many extensive Mining accidents such as The Oaks explosion of 1866 and the Hartley Colliery Disaster of 1862. Most of the explosions were caused by firedamp ignitions followed by coal dust explosions. Deaths were mainly caused by carbon
DAMP Project in New Jersey so that it could be evaluated and a summary report be forwarded on to the project sponsor, ARPA. During this period of operation, communications via satellite did not yet exist. As a result, communications between the DAMP ship and New Jersey was through the use of single-sideband (SSB) radio, generally through the use of a 10 kW transmitter. The DAMP ship generally transmitted upper sideband (USB) voice and/or lower sideband (LSB) frequency-shift keying radioteletype in the area of 16 and 22 MHz when atmospheric conditions were favorable. When communications became difficult because of atmospheric conditions, the DAMP