As a case (neuter, plural: the traps) refers to sailing ships a piece of rope , the pull-up (set) and lowering (Bergen) or reefing of sail is used. Traps are part of the running goods of a sailing ship.
Types and names
To hoist (pull up) a triangular sail ( high sail ) only a single halyard is used, which is attached (attached) to the uppermost point of the sail, the sail head . When Gaffelsegel two traps are used for pulling up the gaff: the throat halliard close to the mast and the Piek case which engages approximately in the middle of the gaff. Otherwise, the traps are named after the sails that are hoisted with them - for example main halyard (for the mainsail ) or spinnaker case.
In general, the material for traps should meet some requirements:
- It should be as resistant as possible to salt water, UV radiation and abrasion
- It should stretch as little as possible, i.e. not lengthen under load, if possible, in order to avoid the sail "sagging" over time.
- The line should be as easy to grip as possible and easy to handle (“leaning”).
Originally only natural fibers such as hemp or sisal were available, but they stretched a lot and were sometimes very prone to rot. Therefore, even on traditional ships, they are mostly replaced by more modern materials today.
The next development step were traps made of steel ropes , which stretched significantly less and - especially when using stainless steels - were significantly more durable. However, these ropes can no longer be pulled by hand, so special wire rope winches must be used. In addition, individual cardels (the "strands") of the ropes can break and protrude from the rope, which means there is a risk of injury from so-called "meat hooks". However, wire traps are still in use on some traditional ships and yachts. Today traps are usually made of low-stretch synthetic fibers. If the requirements are low, lines made of polyester are used; because of its relatively poor stretching properties, regatta sailors and demanding cruising sailors use lines made of Dyneema instead .
Nowadays only braided cordage is used for traps , since the construction of the cordage has too much stretch.
Fall as running goods
On modern sailing yachts, traps can be laid inside the mast. They run over a roller, often with ball bearings, are stretched over a winch at the bottom and fixed with a latch stopper or are attached to a cleat (see assignment on the cleat ). The sail is attached to the other end with a shackle . The shackle is either spliced in , alternatively tied with a bowline or gordingstek .
The main halyard is doubled as a pulley block for heavy sails. An electrically or hydraulically operated winch is often used as support.
The halyard is used to control the luff when trimming the sail . This is then properly trimmed when the sail is wrinkle-free. Creases across the luff indicate that the luff tension is too low, while longitudinal creases indicate that the tension is too high. This tension is always dependent on the wind pressure that is effective in the sail at a certain time. Accordingly, the luff tension must be continuously adapted to the wind strength and the position of the sail, i.e. also with every change of direction. So that the sail does not always have to be pulled up against gravity with the fall, it is pulled down with a pulley system ( Cunningham straightener ) on well-equipped ships .