Saggar kiln debris. Modern saggars are made of alumina ceramic, cordierite ceramic, mullite ceramic silicon carbide and in special cases from zirconia. By far the largest number of UK pottery manufacturers were based in and around Stoke-on-Trent in a region known as The Potteries. Their businesses, locally known as potbanks, fired their wares in distinctive bottle ovens. At the turn of the twentieth century over 4,000 of these were in use, although by 2014 only 47 survive, all of which are no longer in production but are listed buildings. The saggars were used for the biscuit and the glost firing. They
Torpedo trials craft "This list is incomplete" Torpedo trials craft Torpedo trials craft are primarily naval auxiliaries used by navies for the development of new naval torpedoes and during practise firings. These craft are designed to track and monitor the torpedo and to be able to locate and retrieve the spent torpedo for analysis, and refurbishment for reuse. Torpedo trials craft had their greatest use during the years around World War II when the torpedo was the primary anti-ship weapon of submarines, destroyers and naval aircraft. Modern navies will usually not have ships dedicated to this one role, but have multirole underwater support