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Dear Phil, The deepest development shaft on the Tavistock Canal Tunnel was 350ft, using a horse whim to haul waste rock to surface, between 1805 and 1811. They used a whim for pumping one of the shafts too, though this was given up after a short time as the water won! Robert Waterhouse -----Original Message----- From: mining-history [mailto:[log in to unmask]] On Behalf Of NEWMAN, Phil Sent: 04 October 2008 21:22 To: [log in to unmask] Subject: Limitations of the Horse whim Dear List, Can anyone offer suggestions for some reading on the subject of the maximum operational depth of the horse whim, preferably from 18th-19th century accounts? Clearly there are many variables involved, such as the weight and nature of the load, strength of rope (I beleive hemp was preferred) and number and size of horses etc. At later mines, where alternatives were available, there was also the decreased efficiency of using it to hoist from greater depth; Davies (1894, Machinery for Metalliferous Mines) considers the machine only capable of lifting 2-2.5cwt at a rate of 75ft per minute. To those working the apparatus there must have been an approximate consensus at to a maximum depth, beyond which the horse whim would not operate safely or efficiently. Any thoughts or suggestions gratefully received. Phil ____________________________________________________________________________ _____ Concerned about how climate change may affect older properties? What about saving energy? Visit our new website www.climatechangeandyourhome.org.uk today. This e-mail (and any attachments) is confidential and may contain personal views which are not the views of English Heritage unless specifically stated. If you have received it in error, please delete it from your system and notify the sender immediately. Do not use, copy or disclose the information in any way nor act in reliance on it. Any information sent to English Heritage may become publicly available. No virus found in this incoming message. Checked by AVG - http://www.avg.com Version: 8.0.173 / Virus Database: 270.7.6/1711 - Release Date: 06/10/2008 17:37