Day's run

A Etmal ( from Middle Low German: Etmal = recurring period) is that of a ship from noon to noon distance traveled. Lunch is the local high sun (ship lunch ).

The ship's lunch must be established for the location determination according to the astronomical navigation. This one has only to the determination of the sun is, ie without clock, a daily fixed lunch time on board. So it made ​​sense to hold the distance between two successive noons as a measure of the travel progress of the day.

In this sense, the Etmal has survived to this day. To expect and receive the most lines of commercial shipping daily noon position and the Etmal the previous day by radio or telephone. These two values ​​, the Etmal and the noon position are still the most important daily data of a ship for the cruise line.

Subtleties

On a trip to the west you can with a clock, especially one suitable for navigation chronometers, realize that the sun reaches its peak every day a little later. Between two so-called ship noons then go by a little more than 24 hours, when traveling to the East according to a little less. When traveling to the West has so a few extra minutes to drive the Etmal. The time difference depends on the direction of travel, speed and latitude. Every 15 minutes length changed the day time by a minute of time. At the equator, you have to drive 15 miles to the west or east for a time so minute. At 60 ° north or south latitude, eg in northern Denmark or at Cape Horn, all you need is 8 nautical miles. In fast travel near the polar regions, even with traditional sailing ships, can be won or lost for half an hour and the Etmal change by five to ten nautical miles regularly. During the crossing from Hamburg to New York on a modern container ship with more than 20 nodes, the usable time per Etmal even extended by about 50 minutes. And on a trip from Bergen to southern Greenland at 30 knots you would win 100 minutes, which increases the Etmal by 50 nautical miles. Either you lose on the same quick-return mode.

A further, but smaller, deviation occurs regardless of the direction of travel by the fact that the true length of a solar day only four times a year is exactly 24 hours ( see also equation of time ). This effect depends only on the eccentricity of Earth's orbit around the sun and the inclination of the ecliptic and is also independent of geographic location. Thus, the true solar day is around 1 January around for about 30 seconds and end June 12 seconds longer, whereas in early April and mid-September each about 20 seconds shorter. The in such a short time (not ) distance traveled is not reliably measurable usually by means of astronomical navigation.

In practice, to determine the Etmals this variable measuring times but explicitly, according to the definition, not incorporated, so that the Etmal only to approximate ( one-day) is average speed. In the traditional sailing ships of the error was usually less than 1% and therefore the order of the measurement uncertainty of the astronomical position determination, in modern seafaring but he's easily 5%.

Deviation from the intended use of language

Racing yachts

On modern racing yachts, the noon position is no longer detected, the location determination is carried out exclusively by GPS. Thus, the use of Etmal for the journey within 24 hours any route has established itself in the parlance of racing yachts. In English, they are more accurate than 24 hour distance called. In any 24 hours you put in general longer distances than just from noon to noon.

Cruising Yachts

On cruising yachts with overnight stays in port or at anchor a differing language use has been established. In navigation under the Country noon position does not matter, but here the nights are the fixed points of the journey and the distance of a day is officially declared as Etmal.

Outstanding Etmale for sailing ships

The Etmal, the daily distance is calculated from the distance between the positions lunch or measured in the chart and noted in the logbook. Outstanding Etmale are published and are suitable for the cruise line, ship or skipper to help to a certain reputation.

The fastest sailing ships of the 19th century were the clippers. So went in December 1854, the 259 foot long "Champion of the Seas " in the southern Indian Ocean under the command of Captain Alexander Newlands Etmal a breathtaking 465 nautical miles ( 862 km, average speed 19.4 knots). This will be held for the following 130 years for the largest daily route that has ever been handled by a sailing ship.

Only the ocean racing yachts of the late 20th century were able to exceed the Etmale the clippers. Although they are much smaller than the clippers, they may sail more than twice as fast due to new materials and new knowledge of fluid mechanics and navigation ( eg, weather routing), even over long distances. Furthermore, it is much riskier sailed due to the much better recovery and survival with virtually " unsinkable " boats.

In August 1984, the 80 - foot catamaran " Formule TAG" drove a Etmal of 512.5 nautical miles ( 24 hour distance record) under the Canadian skipper Mike Birch. The first monohull, which was the record for the "Champion of the Seas " broke, on 7 May 2002, the German yacht Illbruck Challenge ( skipper John Kostecki ), who drove 484 miles during the 2001-2002 Volvo Ocean Race in 24 hours and at the same time the " 20 - knot barrier " broke through.

Since 1 August 2009, the record is succeeded at 908.2 nautical miles (average speed 37.8 knots), as the French 40 -meter trimaran " Banque Populaire V " a record Atlantic crossing from New York to Lizard Point. The average speed of the entire 3 days 15 hours and 25 minute ride was 33 knots (61 km / h), which was faster than all Atlantic crossings to water before 1952 including the respective winners of the Blue Riband. The longest Etmal for solo sailors holding since 2012 Francis Joyon with 666.2 nautical miles ( average 27.8 knots) on his 30 -meter trimaran " IDEC ".

The Rekordetmal for monohulls is 596.6 nautical miles, held by the Volvo Open70 Ericsson 4, reaches for the Volvo Ocean Race 2008/ 09 on 29 October 2008. The average rate amounted to 25.11 knots ( = 46.5 km per hour). For solo sailing monohulls with the Rekordetmal on December 10, 2012, sailed ( 22.3 knots average ) by the Frenchman Francois Gabart during the Vendée Globe 2012/13 with 534.5 nautical miles.

Etmal outside the seafaring

The use of the word " Etmal " is not limited solely to the navigation. In the meaning " night and day " used in the saga " by King Charles, and the Frisians " of the Brothers Grimm: