Block (sailing)

Block (from Middle High German plock or Ploch: large or continuous piece ) is a seafaring term for a case in which there are one or more rotatable discs. Blocks are used to change the direction of tension of ropes, or to deflect lines in order to simplify the operation. Several blocks can be combined into a block and tackle ( pulley ) to exercise greater tensile forces. The housing modern blocks made ​​of plastic, aluminum or steel, the discs of polyamide, polyurethane, or hard tissue. Traditional material is wood. The discs are mounted on ball bearings ( for the reduction in the running resistance ) or have a plain bearing (allows higher loads and less maintenance ). The threading of a line in a block is called a Reeve ( " The line is reeved "). When inadvertent fast slipping out of the iterative part, the end of the train, from the block is spoken by flap apart ( " The line rushes off").

Size and shape of blocks are adapted to the use of:

  • A multi-disk block contains multiple slices in a housing which rotate about a common or different axes.
  • A fiddle block is a special form of the multi -plate block. There are two different sized discs on different axes in a housing. The name derives from the shape of such housing blocks, which reminds usually removed at the sound of a violin body. Fiddle blocks are often used for Baumniederholertaljen on dinghies.
  • Ratchet blocks (also: Knarrblöcke or ELVSTROM ( - knarr ) blocks after the inventor Paul Elvstrøm ) are Einscheibenblöcke whose disk is rotatable only in one direction (the direction of pull ). The hauling and holding the voltage is thus facilitated. To be able to handle emotional mainsheet with little wind, these blocks often have a freewheel setting in which the blocking is opposite to the direction of pull off with a lever. Most such blocks, the disk is notched or serrated in order to reduce the slipping of the sheet opposite to the running direction. Ratchet blocks are typically found as the first block of Großschottaljen on sailboats, provided that the mainsail can be operated even without winch. The function of the ratchet block resembles that of the Knarrpollers.
  • A race is a block Einscheibenblock disk with a particularly large diameter and a reduced housing, thus resulting in a low resistance and low weight. The term race refers to a block design and not blocks of suitability for regatta sailing.
  • The case of a folding block ( also: Snatch - block ) can be opened by loosening a locking flaps or by turning up. The whole block can subsequently placed on a taut leash without these must be threaded. For this reason, find folding blocks common in Barber haulers use.

Curry or V terminals are often attached to the housing of blocks, so that the current through the block line can be assigned directly. To attach ( striking ) feature blocks via fixed eyelets or strap to the housing:

  • A rotatable attachment for a shackle is called vertebrae.
  • An additional eyelet for knotting ( plugging ) of a line is called becket.
  • Various modern types of blocks

Fiddle Block with V- Clamp

Single ratchet block with swivel and lever for switchable freewheel

Regatta block

Mary Rose Sheave Dinghy sailing
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