Shaft soothing oil

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Wave calming oil , and wave oil called, is in the Marine used the seas to cut down on the high seas. Traditionally it was olive oil , later animal oils or mineral oils were used. Today the application of this method is limited internationally to the absolute emergency due to the associated water pollution due to the MARPOL agreement . In the Austrian Maritime Shipping Ordinance (SeeSchFVO) of April 15, 1981, "lifeboats and rafts of ships in coastal travel" according to § 33 (equipping lifeboats and rafts) include a container containing 5 kg of wave oil, equip.

functionality

Since the oil molecules repel water, the oil settles in a layer on the surface and spreads horizontally on it. Even small amounts of oil are sufficient for large areas, since the oil molecules tend to settle in a monomolecular layer on the water - one molecule next to the other, not two on top of each other (see also oil stain experiment ).

This tough, elastic oil film ensures that wind occurring on the surface loses more energy when it moves the oil film and the water below. This prevents the formation of smaller waves and a chain reaction weakens larger waves. The American politician and scientist Benjamin Franklin carried out the first recorded attempts . He found that adding a teaspoon of olive oil to a pond made it mirror-smooth.

application

Joos de Momper: The Storm at Sea ( Kunsthistorisches Museum Vienna)

This effect has been observed earlier in shipping, for example when oil-transporting sailing ships lost parts of their cargo. The Romans are said to have used this wave-weakening method. An old maritime law later decreed that the oil should go overboard first if the cargo had to be abandoned in a storm. In the painting The Sea Storm by Joos de Momper , created around 1610/1615, one of the ships tips oil overboard to calm the sea.

A patented wave oil according to Dr. Judge . It consisted essentially of oleic acid with 10% amyl alcohol added.

The US amateur sailors Warwick Tompkins, who in 1937 with his family on the Wanderbird the Cape Horn sailed around, pointed out in his short film about the journey to the importance of wave calming oil. The agent still played a role in the 1960s: German ships were subject to the regulation of the See-Berufsgenossenschaft to always carry wave calming oil with them. Above all, it was intended to prevent the lifeboats from filling up with water. Since these were later mostly closed and there was also no agreement on the effectiveness of the measure, the provision was repealed. There are still lifeboats with a small oil can on board.

From a purely scientific point of view, the phenomenon was investigated in an experiment led by Heinrich Hühnerfuss from the University of Hamburg in the 1970s: In the area of ​​a two and a half square kilometer oil film that was spread on the North Sea, the height of larger waves was reduced by ten percent .

recommendations

The handbook for bridge and house of cards published by the Federal Maritime and Hydrographic Agency contains extensive recommendations on the “use of oil to smooth the sea”.

The oil unfolds its best effect in deep water, it has less or no effect on bars (shallows or sandbanks), it is ineffective above all on surf lakes . A warning is given against using oil when castaways are in the water.

Types of oil

Viscous oil is more suitable than thin and vegetable oil is preferable to mineral oil because of its biodegradability. The faster the oil spreads, the more effective it is. When it is cold, thick oil must be mixed with thin oil, for example petroleum.

Application

There are several ways of applying the oil: pumping it directly overboard, using containers that allow the oil to seep out, or using oil spray packs . Canvas bags or canvas tubes, which are loosely stuffed with tow and filled with oil, are recommended as containers . These are then provided with holes with the sailing needle and hung overboard at a suitable point.

Recommended use cases

There were precise instructions on how to use the oil in the following cases:

  • Tilted ships (up to 4 knots speed)
  • Towing ships
  • Mooring on a wreck
  • Takeover of a pilot
  • Man overboard
  • Sailing boats
  • Riding a storm in boats
  • Passing a shoal with boats
  • Strandings

Case studies

In the book Captains Report , published in 1936, captain Fritz Kruse describes a rescue of shipwrecked people from the wreck of the Norwegian steamer Sisto on the night of December 18th to 19th, 1934 in the North Atlantic. These were accordingly taken over to the New York ship he led with a lifeboat , while two other ships ( Aurania and Gerolstein ) stayed on the windward side of the wreck, among other things to calm the waves by draining oil.

Warwick M. Tompkins' film documentary about his passage from Boston to San Francisco on the pilot schooner No. 5 Elbe . To dampen the heavy waves off Cape Horn , carried wave calming oil was used for this purpose.

literature

Individual evidence

  1. ↑ a b Manual for Bridge and House of Cards . Federal Maritime and Hydrographic Agency, Section N2, Section 6.5 Use of Oil to Smooth the Sea , p. 129 f.
  2. ↑ § 33: Equipment of the lifeboats and lifeboats. Maritime Shipping Ordinance of April 15, 1981; Federal Chancellery of Austria
  3. ↑ Reto U. Schneider: Olive oil against the "Wuth of the waves". In: NZZ Folio . March 2006
  4. ↑ Interpretation of the motif: Rose-Marie and Rainer Hagen –- Pieter Bruegel D.Ä .: around 1525–1569; Peasants, fools and demons . Benedikt Taschen Verlag, Cologne 1999, ISBN 3-8228-6590-7 , p. 87 f.
  5. ↑ Attribution to Joos de Momper the Younger: KHM object database: Seesturm . Retrieved March 23, 2018.
  6. ↑ Soothing the waves with oil . In: Hansa: shipping, shipbuilding, ports. Volume 31, 1894, pp. 215-216.
  7. ^ C. Arnold: Hagers Handbook of Pharmaceutical Practice. Springer-Verlag, 2013, ISBN 978-3-642-47350-0 , p. 81 ( limited preview in Google book search).
  8. ↑ Modification of air-sea interaction processes by artificial sea slicks . In: H. Hühnerfuss, W. Walter, PA Lange, J. Teichert, H.-J. Vollmers: Proc. of the 16th IAHR-Congr. , São Paulo 1975, Vol. III, pp. 509-515.
  9. ↑ Fred Schmidt (ed.): Captains report ...: A book v. Men u. Ships . Verlag von Dietrich Reimer, Berlin 1936, pp. 29–41.