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An Encyclopedia of the History of Technology part 58

An Encyclopedia of the History of Technology part 58. This one of a kind encyclopedia presents the entire field of technology from rudimentary agricultural tools to communication satellites in this first of its kind reference source. Following an introduction that discusses basic tools, devices, and mechanisms, the chapters are grouped into five parts that provide detailed information on materials, power and engineering, transportation, communication and calculation, and technology and society, revealing how different technologies have together evolved to produce enormous changes in the course of history | PART THREE TRANSPORT blocks placed in the centre of the bottom of the dock. She would then be supported on either side by shores against the dock side before the dock would be drained by sluices as the tide ebbed. From the eighteenth century onwards docks began to be lined with brick or stone and the sides were often stepped to facilitate fixing the shores. Later still pumping machinery was provided to empty the dock while instead of gates the entrance was often fitted with a caisson a floating structure which fitted the entrance closely but which could be floated to one side or into a special recess to allow entrance or exit of ships. If no dock was available ships under repair had to be careened or hove down to a steep angle using special blocks and tackles to the mastheads. In tidal waters however gridirons or hards could be used the ship standing upright and work being done between tides. The building and maintenance of royal fleets was everywhere entrusted very largely to state dockyards which incorporating as they did all the various necessary trades in the one establishment became the earliest large-scale industrial undertakings employing more than 1000 men even in the late seventeenth century. The largest warships were so much bigger than any merchant ship as to be beyond the capacity of private shipbuilders and this was a powerful influence in the rise of dockyards in addition the existing ships had to be cared for an peace as in war while large stocks of all kinds of stores had to be kept up against the eventuality of hostilities. In many cases the dockyards embodied the most advanced techniques of their day such as the early use of stone for docks large-scale manufacture of rope and early in the nineteenth century mass-production methods in Marc Isambard Brunel s block-making machinery see p. 405 in matters of detail there is ample evidence of careful thought in layout. At Sheerness in the 1820s Rennie had the opportunity of creating a new yard to .