Important Ratchet Straps Information for Truck Drivers
Thursday, March 31st, 2011The ratchet tie downs are the assembly of webbing and ratcheting buckle , it’s a well recognized fact, but if we use cam buckle in place of ratchet buckle in the assembly we have cam buckle tie down, it’s as simple as that. Most likely these cam buckle straps are used on pick up trucks or passenger cars for luggage tie down, and small cam buckle(1”) are more popular than big ones(2”). Unlike cam buckle, ratchet buckle are much stronger, and 2”,3” and 4” ratchet buckles are used in industrial grade applications, such as heavy duty transportation, they have working load limit of 3,333lbs, 5,400lbs and 5,400lbs respectively, these assemblies have design factor of 3:1, thus the minimum breaking strength is 10,000lbs, 16,200lbs and 16,200lbs respectively.
So far we talked about tie down devices for flatbeds or similar commercial vehicles, in reality semi trailers are much more than flatbeds in numbers, since they are box trucks the tie down needs are different, you will see most box trucks have E Track installed and use logistic straps. It is estimated that 80% trucks are box trucks, and the e track tie down system is just for box trucks , so logistic straps are most popular tie down straps. With 1,000lbs working load limit and 3,000lbs minimum breaking strength, e track straps are not as strong as flatbed tie down straps, It’s easy to understand that why e track straps are not as strong as regular ratchet tie down straps, inside the box truck the loads already have strong support, at least there is no risk of falling off, all the e track straps will do is to fixate the loads more than tie them down.
As we discussed in the first paragraph, the design factor of ratchet straps is 3:1, that means the working load limit is 1/3 of the minimum breaking strength, for comparison purpose we know that the binder chain has a design factor of 4:1, which basically says that for the chains the working load limit will be 1/4 of their breaking strength, which indicates that tie down chains are designed for tougher environment than tie down straps are in. The most common materials in making tie down webbing are nylon and polyester, which serve different tie down applications. The typical application for nylon webbing is motorcycle tie down, while polyester webbing is ideal for tying down concrete pipes. Following watch list is essential for making tie down webbing, abrasion, elongation, breaking strength and use environment. When making tie down strap , manufacturer has to follow the recommendation of breaking strength and elongation requirements, when it comes to abrasion and environment, there are much more variations to be considered.