Long lever ratchet
The long lever ratchet , also known as a pull ratchet , is used as a tensioning element when securing loads with lashing straps . Since April 2004, a long lever ratchet has to provide preload forces of 375 to 500 daN according to EN 12195. The pretensioning force is expressed as STF (Standard Tension Force) in the unit daN (deca Newton). However, ratchets are also available that achieve pre-tensioning forces of up to 1,000 daN.
In contrast to the short lever ratchet , the long lever ratchet is a pulling ratchet, ie it is pulled down when operated. As a result, a significantly higher power transmission is achieved compared to a pressure ratchet and operation is made much easier. In addition, the pulling movement is ergonomically more advantageous for the user and protects the spine. For this reason, the long lever ratchet is also called the Ergo ratchet . It is more expensive to buy than the short lever ratchet, but the preload force achieved is up to 100% greater. The following applies to both types of ratchets: the belt may be max. 3 layers must be wound on the winding shaft, otherwise an unintentional loosening of the locking slide can render the load securing useless.
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High-quality ratchet designs show the actually achieved pretensioning force when lashing down with an integrated tension force indicator, the preload measurement display . This makes it easier for the user to calculate the pre-tensioning force and serves as proof of the pre-tensioning force achieved in the event of a vehicle inspection.
Another well-known user problem is that due to the high physical forces, the tension is suddenly released when the lashing is opened and the load may get out of control. For this reason, some manufacturers have developed ratchets that release the ratchet steplessly using an anti-belt slip method . This enables the pre-tensioning force to be released in small steps, particularly in the case of a load that is at risk of tipping and leans into the belt.
In the EU, ratchet lashing straps are subject to mandatory identification with a special label. Both the fixed end (end with integrated ratchet element) and the loose end of a lashing strap must contain all technical information. The STF (Standard Tension Force) must be stated on the fixed end label .
Bent, heavily corroded or non-functional ratchets lead to the immediate discard of the lashing strap and, according to EN 12195-2, may no longer be used. The VDI guideline VDI 2700 Part 3.1 even requires an expert to check all lashing equipment once a year. This guideline is not legally binding, it is merely a recommendation.
See also
literature
- Lamps, Alfred: Load securing: guidelines for practice; Avoid damage and accidents: up-to-date information for drivers, shippers, contractors and for everyone who is responsible for securing loads . Hendrisch, 2013, ISBN 978-3-938255-05-6 .
- Rompf, Oliver .: Lower costs for securing loads: with detailed practical tips on tools and vehicle selection . Vogel, 2006, ISBN 978-3-574-26228-9 .