Cable length
{{short description|Unit of length}}
{{Infobox unit
| name = cable length
| image = Broad chain closeup.jpg
| caption = A chain cable. A cable length is based on the historic length of a ship's cable.
| standard = Imperial/US units
| quantity = Length
| units1 = Imperial/US units
| inunits1 = {{val|0.1|ul=NM}}
| inunits2 = {{val|185.2|ul=m}}
| units_imp1 = Imperial/US units
| inunits_imp1 = {{ubl|{{val|100|ul=fathom}}|{{val|600|ul=ft}}}}
| units_imp2 = Metric (SI) units
| inunits_imp2 = {{val|182.9|ul=m}}
| units_us1 = Imperial/US units
| inunits_us1 = {{ubl|{{val|120|ul=fathom}}|{{val|720|ul=ft}}}}
| units_us2 = Metric (SI) units
| inunits_us2 = {{val|219.5|ul=m}}
}}
A cable length or length of cable is a nautical unit of measure equal to one tenth of a nautical mile or approximately 100 fathoms. Owing to anachronisms and varying techniques of measurement, a cable length can be anywhere from {{convert|169|to|220|m|yd|0}}, depending on the standard used.
Etymology and origin
The modern word cable is directly descended from the Middle English cable, cabel or kabel and also occurs in Middle Dutch and Middle German. Ultimately the word comes from Romanic, probably from a cattle halter.{{sfn|OED-cable}} A cable in this usage cable is a thick rope or by transference a chain cable.{{sfn|OED-cable}} The OED gives quotations from {{circa|1400}} onwards. A cable's length (often "cable length" or just "cable") is simply the standard length in which cables came, which by 1555 had settled to around {{convert|100|fathom}} or {{convert|1/10|nmi}}.{{sfn|OED-cable}}
Traditionally rope is made on long ropewalks, the length of which determines the maximum length of rope it is possible to make. As rope is "closed" (the final stage in manufacture) the length reduces, thus the ropewalk at Chatham Dockyard is {{convert|1/4|mi}} long in order to produce standard {{convert|220|m|fathom}} coils.{{sfn|Master Ropemakers Ltd|2023}}
Definition
The definition varies:
- International: 185.2 m, equivalent to {{frac|10}} nautical mile
- UK traditional: {{convert|100|fathom}}, though (The Admiralty) used {{frac|1|10}} of a sea mile, 1 minute of latitude locally.
- US customary (US Navy): {{convert|120|fathom}}{{sfn|Fenna|2002}}
In 2008 the Royal Navy in a handbook defined it as {{quote|text=A cable equals one-tenth of a sea mile - 608 ft. The length of a ship's hempen anchor cable was formerly 101 fathoms. 100 fathoms = 1 cable 10 cables = 1 nautical mile (very nearly){{sfn|Royal Navy|2007}}}}
References
{{reflist}}
Citations
- {{citation | last = Fenna |first = Donald | year = 2002 | contribution = cable, cable length, cable's length | title = A Dictionary of Weights, Measures, and Units |url=https://books.google.com/books?id=RZfGWl-RCQcC |contribution-url=https://books.google.com/books?id=RZfGWl-RCQcC&pg=PA35 | location = Oxford | publisher = Oxford University Press |pages=35 | isbn = 0-19-860522-6 |oclc=62608533 |access-date=12 January 2017}}. Also [https://books.google.com/books?id=RZfGWl-RCQcC&pg=PA88 "fathom"], from the same work (pp. 88–89, retrieved 12 January 2017).
- {{citation | author= Master Ropemakers Ltd |title = Showing you the ropes| website = Historic Dockyard Chatham |date= 2023| url=https://thedockyard.co.uk/master-ropemakers/|access-date=20 December 2023}} Various subpages within the ropery section.
- {{Cite OED|cable|2955013352|ref={{harvid|OED-cable}}}}
- {{citation | author=Royal Navy | url = http://www.royal-navy.mod.uk/server/show/nav.3807#content | archiveurl = https://web.archive.org/web/20080707042523/http://www.royal-navy.mod.uk/server/show/nav.3807#content | archivedate = 2008-07-07 | title = Navy Slang: Cable – Curry | publisher = Royal Navy |date=2007 | access-date=1 February 2011}}.
{{imperial units}}
{{sailing-stub}}
Category:Customary units of measurement in the United States