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Moreton Bay Pile Light was a pile lighthouse positioned at the mouth of Brisbane River, in Moreton Bay, Queensland, Australia, marking the entrance to the port of Brisbane. The light's early history was closely related to the dredging of the Brisbane River. It was established in 1884 as a result of a new channel that was cut, and relocated in 1913 due to another change in the channels. The structure was badly damaged by a barge in 1945 and finally destroyed when hit by a tanker in 1949. An automated light operated on the ruins until 1966–1967 when it was removed. ==The first light== Dredging of the first channel through the Brisbane River and into the Brisbane Port began in 1862. Though the path was originally planned by Lieutenant G. P. Heath, RN, who was then appointed Marine Surveyor and was later to be appointed the Portmaster for Queensland, the path was later changed as the Superintendent of the dredge, Thomas Francis, located what he believed to be a better path. After much debate and a Select Committee of the Queensland Legislative Assembly, it was decided to continue with the path suggested by Francis. The dredging of the channel has completed in 1866 and it was known as the Francis Channel. However, Heath did not give up on his original path, and by 1882 work had begun dredging a path according to Heath's original path and by 1883 the new channel was operational.〔 As the new channel was cut, a light was required to replace the 40-year-old lightship ''Rose'', which was not suitable to be used at the exposed end of the new channel.〔McLeod, G Roderick (1990). "Some aspects of the History of the Brisbane River". In Peter Davie, Errol Stock, Darryl Low Choy (Ed.), ''The Brisbane River: a source-book for the future'', Australian Littoral Society in association with the Queensland Museum〕 The light was erected at together with signal and telegraph station by government staff. The structure was designed by Heath. It was hexagonal in form, containing six rooms of equal dimensions housing three persons, and had a total height of . The seven piles supporting the structure, one at each point and one at the middle, were made of wrought iron, diameter, with screws. They were screwed in the mud, in water which was at low tide and at high tide. The operation of the lighthouse was delayed by bad weather. It was first used on 31 May 1884. The installation of the telegraph line to Brisbane was delayed even longer and it was only installed on 8 August. The apparatus was a 4th order dioptric lens and it was displayed at above high-water mark, at the top of the structure. The light characteristic shown was occulting for two seconds every 12 seconds during flood tide and fixed during the ebb. It was also sectored, showing white light when the ships are in the direction for the deep water channel and red otherwise, and had an intensified sector using reflected light from the unused direction. In addition to the task of pointing ships into the channel, the lighthouse also signaled ships about the state of the tide. During the day this was performed using two day signals installed on two corners of the structure, while during the night two 6th order dioptric lights showing different colors coded the state of the tide.〔 The different colours were changed manually, by lowering glass cylinders over the lanterns, which could be done from inside the structure.〔 Records of the tide were also kept automatically by floats in tubes which graphed the tide level. The graphs were replaced every month and were sent to Greenwich where they were kept. 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「Moreton Bay Pile Light」の詳細全文を読む スポンサード リンク
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