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Re: Backing & Hauling in Slocum
From: George Huxtable
Date: 2003 Dec 17, 17:15 +0000
From: George Huxtable
Date: 2003 Dec 17, 17:15 +0000
Bill Noyce wrote- >> I was interested in the use of "drew" and "hauled" to describe the >> change in wind direction in this passage (in the southern hemisphere). >> >> > The phenomena of ocean meteorology were interesting studies even here >> > in the trade-winds. I observed that about every seven days the wind >> > freshened and drew several points farther than usual from the direction >> > of the pole; that is, it went round from east-southeast to >> > south-southeast, while at the same time a heavy swell rolled up from >> > the southwest. All this indicated that gales were going on in the >> > anti-trades. The wind then hauled day after day as it moderated, till >> > it stood again at the normal point, east-southeast. This is more or >> > less the constant state of the winter trades in latitude 12? S., where >> > I "ran down the latitude" for weeks. >> >> Seems like we were debating the terms used in this situation a while ago, >> though I don't remember whether we reached a conclusion. Slocum seems to >> feel "drew" needs explanation, while "hauled" is treated as self-evident, >> though perhaps it's just obvious that it's the reverse of the prior motion. And Herbert Prinz replied- >No, Bill. The wind "draws" simply means that it fills the sails. The change of >direction that is opposite to "haul" is expressed by "farther [...] from the >direction of the pole". From George- I think it's less simple than Herbert makes out. I will quote below two mailings from earlier this year on a related thread, "Veering and backing" From me on 4 March- =========================== >Veering and backing, again. > >A thread arose, then fizzled out, some weeks ago about the meaning of the >terms veering and backing of the wind, particularly as to how these terms >apply in the Southern hemisphere. I was away at the time, but have done a >bit of book-study since. I no longer have records of that correspondence, >so can't recall the precise title of that thread, nor much about the >postings. So if I repeat here what others have said, I'm sorry. > >Anyway, here's my ha'porth. > >American readers will no doubt regard what Bowditch says as gospel. On >page 906 of vol 1 (1977), in the section on tropical cyclones, is the >statement- > >"Within the cyclonic circulation, a VEERING wind (one changing direction >to the right in the Northern Hemisphere and to the left in the Southern >Hemisphere) indicates the vessel is probably in the dangerous semicircle, >and a BACKING wind (one changing direction opposite to a veering wind) >indicates the vessel is probably in the navigable semicircle." > >Here, we are not considering Bowditch's impeccable advice about storm >tactics, just his definition of veering and backing. > >Bowditch is supported, to some extent, by the usually-dependable Peter >Kemp (ed) in the Oxford Companion to ships and the sea. > >Kemp states- "The wind is said to back when it changes contrary from its >normal pattern. In the northern hemisphere, north of the trade wind belt, >the wind usually changes clockwise- from north through east, south, and >west. When the change is anticlockwise, the wind is backing. In the >southern hemisphere, the reverse is the general pattern of the winds. When >the wind backs in either hemisphere it is generally taken as a sign that >it will freshen." > >About backing, Bowditch and Kemp agree. But a question arises about what >Kemp thinks of as the "normal" pattern of the winds. When a depression >passes westward across the norther hemisphere, mariners to the north of >its track will see the wind direction changing in an anticlockwise >direction, those south of its track will see the reverse. At least, that's >what my own thumbnail sketches suggest. There could be just as many >mariners in each category. So why should Kemp say that in the northern >hemisphere "the wind usually changes clockwise". It seems against >commonsense, and contrary to my own experience at sea. Can others comment? > >However, Kemp defines "veer" as- "The operation of the wind when it >changes direction in a clockwise direction. A wind which veers is >frequently a sign of settled weather in the northern hemisphere, of >unsettled weather in the southern.". It's clear from that last sentence >that he really does expect veer to mean a clockwise change, worldwide. In >that respect it is NOT the converse of his definition for "back" (which >seems odd), and is quite contrary to Bowditch. > >It's all rather unsatisfactory. How would the "Bowditch definition" work >out in practice? Remember that in a broad band around the equator, >Coriolis forces are negligible anyway, so this business about the law of >storms just doesn't apply. Is the Bowditch definition of "veer" intended >to suddenly reverse as the equator is crossed? Put yourself in the >position of a watch-officer in low latitudes having to report a 2-point >change in the wind direction to the old-man. Would you have to think-out >which side of the equator you happened to be before you reported it as a >veering or a backing? And would the old-man need to agree about which >hemisphere, and which definition, before he understood? It seems a crazy >arrangement that would not stand up at sea: not in a windship, anyway. >Perhaps the Bowditch definition is by, and for, meteorologists. > >I will cite another authority who disagrees with Bowditch completely (in >respect of Southern waters). In "A Glossary of Sea Terms" (Cassell, 1954), >Gershom Bradford is quite specific. He states- "The wind backs when it >changes against the hands of a watch, but veers if it changes with them.", >and "When the wind changes direction to the right with the hands of a >watch- for instance, from west to north, it is said to veer; otherwise, it >backs. This holds in both hemispheres, North and South." > >However, he goes on to complicate matters by adding- "If the wind is abeam >and changes forward, it is said to haul, and if it changes aft it veers. >It is, however, often spoken of as hauling aft." Here is a completly >different application of the word "veer", now with respect to the >direction of the ship's bow. According to modern usage these words haul >and veer would correspond to today's heading and lifting of the wind. >Harland , in "Seamanship in the Age of Sail", refers (only) to this >understanding of "veer". > >In an attempt to get a definitive answer (in terms of 18th century >practice) I have examined the Beaglehole edition of Cook's journal of his >first circumnavigation (1768 - 1770) in Endeavour, skimming through for >references to backing and veering. Most of that voyage was in Southern >latitudes. > >I have not found a single mention by Cook of "backing" of the wind. >However, he used "veering" 13 times, all when he was well into the >Southern hemisphere. In 2 of those references, it wasn't possible to be >sure, from the context, whether this corresponded to a clockwise or >anticlockwise change in the wind direction. On 7 occasions this was >clearly an anticlockwise change, and on 4 it was clearly clockwise. It >appears that Cook took the word "veer" to imply no more than a change in >wind direction, and didn't care which way the change occurred. > >Anothr word Cook occasionally used for changes in the wind direction was >"shifting", but I haven't been able to conclude whether this corresponded >to a particular direction of change. > >After all that, my conclusion, about the use of "backing" and "veering" in >the Southern hemisphere, is that there is no conclusion to be drawn. The >words can take either meaning. At least, in Northern waters, there's no >disagreement about their usage. > >George Huxtable. ============================ and from Dan Allen on 12th March. > From John Harland's "Seamanship in the age of Sail" (Naval Institute >Press: 1985) -- an excellent summary of how ships were sailed from >1600-1860 -- he has written on page 12: > >Veering, hauling and backing of the wind. > >When the wind shifts around, so as to come from further aft, the modern >convention is to say it has 'veered'. An older alternative was to say >the wind 'larges'. If the wind draws forward, 'scants' as the >old-timers put it, it is said to 'haul'. Thus the wind 'hauls >forward', but 'veers aft'. I do not know how ancient this rule is, but >I have seenit as far back as 1878 (Uggla). To find the principle >violated, the wind 'hauling aft' is not unusual in the old accounts, >some preferring 'draw aft', and 'haul forward'. Along the same lines, >convention has it that the wind 'veers' when it shifts to the right or >clockwise, as one looks at the horizon, or with the sun. >Counter-clockwise movement is called 'backing'. This is another area >where some confusion exists, some authorities considering 'haul' as >synonymous with 'veer' in this particular context. Furthermore the >idea underlying 'backing' is that the wind is moving contrary to the >usual pattern of wind shifts, which in the Northern Hemisphere is >clockwise. The exact opposite, however, is true in southern latitudes. >(Kemp; de Kerchove). A wind which kept changing direction was said to >'chop about', and Uggla says that a wind which had shifted about was >said to have 'checked around'. In Danish, there were different words >for a sudden marked change, vinden springer, 'the wind jumps', and a >gradual change, vinden skager sig, 'the wind checks [itself]'. The >Elizabethan expression 'spring a-loof', meaning to turn abruptly to >windward is using 'spring' in this sense. Skage literally means >'shake', but is closely connected with 'check' in its sea-sense. > >Dan ================================================================ contact George Huxtable by email at george@huxtable.u-net.com, by phone at 01865 820222 (from outside UK, +44 1865 820222), or by mail at 1 Sandy Lane, Southmoor, Abingdon, Oxon OX13 5HX, UK. ================================================================