Wednesday, September 26, 2012

Twisted Straps

Have you ever held a piece of paper up to your lips, pulled it tight and blew on it?  If you did it right, you just turned a piece of paper into a musical instrument.  If you are dealing with a $30.00 strap this same principal can ruin your investment and actually decrease the chance of the freight staying put on your deck.  Here is an illustration of how air at speed can affect the object that it is flowing around.  In this case a load strap.  On the bottom near the letter "c" the air flow is minimal causing barely any movement in the object being affected by the air.  As you climb up to "b" and "a", the vibrations increase.  These vibrations can wreak havoc on load straps


In this picture, the straps are exposed to the air:
Here is a set of crates that were to be transported without a tarp.  There is a picture of an umbrella on these crates and that means that this load should be tarped, but the customer did not want it tarped so it wasn't. The straps are clearly seen with a twist in them.  The distance the straps are from the load and from the trailer to the top of the load is a factor.  On a short load or where the load is as wide as the trailer is, a twist is not necessary.

If there were no twists in these straps, the air would cause vibrations in the straps. The straps would rub violently on the load at all of these points:

The twist keeps this vibration from happening.  All there needs to be is one twist in the strap in between the top of the load and the trailer on this load.  In addition to this the load requires strap protectors which are the small plastic pieces that cover the edge of the crates where the strap touches the load. 

If you didn't twist these straps, they would vibrate and stretch and loosen up as you drive down the road.  They also will rub on the trailer, the load, and wear the strap out.  This load required 8 straps.  They are about $30.00 each so that is about $240.00 worth of straps.  Properly maintained straps can last for ten years on hundreds of loads in all weather conditions.  Improperly maintained straps will last you one load.  Maybe even two. 

7 comments:

june in florida said...

Very interesting,astounding how much you know.

Ed said...

Thanks June, I am constantly learning. Of course most of my lessons are money savings related. You know what they say, "You learn something new everyday."

ELH said...

Hey ED, me too...now I would've thought straps should be tight and solid, no twists..I thought twists would be more likely to cause drag and turbulance ...

ELH said...

You're right Ed, makes sense to me,that's why I enjoy your posts..always learn something new and plenty to think about..you guys have a great wknd..

Scott said...

Speaking of CSA... do you have any posts that explain how that affects the driver record?

Ed said...

Scott,You can go here:
https://csa.fmcsa.dot.gov/default.aspx

I don't have any posts yet that go into detail about CSA. It is a new system and it is still undergoing changes as it is not a good system. But I can do a post on it. Thanks for the request.

My take on CSA is simple. Satisfy all of the requirements on their list and all of them are found in the FMCSA regulation book.
The highlights are:
-Up to date and accurate logs
-Equipment and load securement devices in good condition
-load securely tied down, blocked, and braced as per regulations
-All truck related paperwork in order (registration, insurance, inspections etc.)

Ed said...

ELH, if you are talking fuel mileage, then a tarp should be broken out here, but the load was light and not going far, so it wasn't necessary. Every driver has their own way of doing things. Normally flatbeds don't hold a candle to a van trailer and all their aerodynamics, so for me safety overrides aerodynamics. Also with the new CSA laws, damaged straps carry heavy penalties. But does a vibrating strap have less aerodynamics than a twisted one? That is a good question. Unfortunately since I have to consider that I can't buy straps after every load I strap down, I need them to last as long as they can. Unless I were to save $300 in fuel per load and then be able to buy new straps at the recieving end and also be able to pass any load inspections that I have along route, putting a twist in them is the only way to go. No damaged straps, no failed inspections, load delivered on time, no hassles. You have to weigh it all out. I also like to extend the life of my equipment, so owning a ten year old strap that has seen hundreds of loads with no damage means a lot to me.