Nautical thread

Physical unit
Unit name	Nautical thread
Unit symbol	${\displaystyle {\mathsf {fm}}}$
Physical quantity (s)	length
Formula symbol	${\displaystyle l}$
dimension	${\displaystyle {\mathsf {L}}}$
system	Anglo-American system of measurement
In SI units	${\displaystyle \mathrm {1\,fm=1{,}828\,8\;m} }$
Derived from	yard
See also: cable length

The board thread (from the English "fathom", to German: "thread", and " fathom called") is a non- SI -compliant unit of length which especially in the English-language navigation - in the nautical - for depth indications in use is. Originally, the measure was the span of the arms of a full-grown man, historically equated to six feet, the fathom.

1 sc = 2 yd = 6 ft = 72 in = 182.88 cm = 1.8288 m

1 statute mile = 880 fm

Occasionally a newer, non-standardized definition is used:

1 fm = 1/100 cable length = 1/1000 nautical mile = 1.852 m

In the EC Directive 80/181 / EEC, the first definition is based on, but rounded the numerical value to 1,829 meters.

Different definition of thread in seafaring

The Paris line is calculated here with 2.2558 mm.

designation	int.		Paris lines	meter
Prussian thread	1 thread	= 6 feet (Prussian) = 1/2 rod	736.2	1.88312 meters
Danish thread	1 favo	= 6 feet	834.7	1.88291626
French thread	1 bream	= 5 feet	720	1.624176
Hamburger thread	1 HF	= 6 feet	762	1.7189196
Dutch thread	1 Vaam	= 6 feet	834.8	1.88314184
Neapolitan thread	1 NF	= 5 feet	720	1.624176
Portuguese thread	1 Braca	= 8 palmos	775.2	1.74869616
Swedish thread	1 SF	= 6 feet	789.6	1.781968

(Sources below)

See also

• Order of magnitude (length)
• Node (unit)

literature

• Erna Padelt, Hansgeorg Laporte: Units and magnitudes of the natural sciences. Fachbuchverlag Leipzig 1967, p. 153
• Wolfgang Trapp : Small manual of the dimensions, numbers, weights and the time calculation. With tables and figures . Philipp Reclam jun., Stuttgart 1992, p. 131 f. (= Universal Library No. 8737) ISBN 3-15-008737-6 .

Individual evidence

1. ^ Christian Noback , Friedrich Eduard Noback : Complete paperback of the coin, measure and weight relationships. Volume 1, FA Brockhaus, Leipzig 1851, p. 114.
2. ↑ Gustav Adolph Jahn: Dictionary of applied mathematics: a manual for use. Volume 1, Reichenbach'sche Buchhandlung, Leipzig 1855, p. 417.