AS people have posted YOU are the one who suffers, use their own weapon against
them, it is called Health & Safety write a written letter putting your thoughts down
and make sure, that they sign it or send the firm a e-mail which is also addressed
to yourself , which you can use as evidence , It is wrong that the driver who wishes to
work in a law abiding way is hampered by those who wish to acts as skinflints to save
money at others expense,Those wish to profit from their greedy ways of saving money which
is a danger to others, sorry in this day and age it just does not work out right any more
we are so called professional drivers ■■?
bubsy06:
44 Tonne Ton:
No you’re supposed to be aware that it’s YOUR responsibility to see that the load is secure! The comeback will be on you…Not had any come loose yet.
Heard this from a company who ran hookloader skips with knackered locks on the vehicles/trailers. This had an impact on an accident! Literally!
This is what eventually happens if you use damaged straps 
A CAR owner had a lucky escape after this EIGHT tonne boulder fell off a lorry and flattened their motor.
The huge rock was being transported from a nearby quarry in Hayfield, Derby, when the accident happen yesterday.
Fortunately no one was in the car at the time, but residents said they were shocked by what happened.
Adam Chatterton, who took the photo, said: "We were outside and heard a massive bang. Everyone rushed into the road and saw the lorry.
“It was then that we saw the rock had fallen on to the car, completely crushing it.”
A spokesman from Derbyshire Police confirmed the incident had happened, but refused to comment further.
Wheel Nut:
This is what eventually happens if you use damaged straps
Result!! 
When I was on decks, we would sometimes carry containers on flats without twistlocks… Chain front and rear and a bunch of straps over the top. We always put a twist in them because it makes a hell of a noise when they drum against the side, but also because they could wear right through on a Montreal run home if they were left to vibrate.
Remember we use 4" straps with 5400lb break strain. Any load which is high enough that the straps will vibrate usually means they have a twist in them because it saves the load and the straps.
I was always more concerned with twists in chains than in straps. When those bear trap tensioners go off, they really do hurt. I don’t mean they should be coiled into tubes, but a single twist is all. If in doubt, use more straps. Then again, the DOT are more realistic here. If they see a ■■■■■■■■ a load which has a cut in it then they will simply ask you to change it, and as long as there is more strap tolerance used than load weight they leave you alone.
HomoFaber:
Not sure about “weaker” but they are certainly more loaded, as the deformation adds stress. It also causes the load to distribute differently, particularly into shear, as pointed out before. The straps were designed to resist tension, they are not great in shear (and rubbish in bending, torsion and compression; that’s why you can wind, twist and crumple them, they deform easily).
As of the weakness, it’s difficult to say, the cross section are stays the same but moment of inertia and section modulus change, so twisted straps respond to load differently (also vibrate differently, as observed). Extreme case would be to twist the strap so that it would form a tube, but not perfect as it would have a helical split all along… You can ask your traineee to do the mathI’m too lazy tonight
Ah! Now that’s where I disagree somewhat - In my head I have it that the cross section stays the same, therefore the moment of inertia stays the same. Section modulus I assume to be how the Young’s modulus varies according to cross section, again, as the cross section stays the same…
Having said that, if we were to take an extreme case with the strap twisted so much it forms a tube, then I could accept that the properties of the strap would change. The amount the strap under tension deflected for a given side-load, for example, should be fractionally less. It might be possible to extrapolate this to a microscopic decrease in strength, I don’t know…
I think the people that are talking about the twists introducing a shearing effect are right, but again I think the actual shear component is tiny, like, so tiny that any loss of strength in the strap would be hidden in the natural variations in strap strength from the manufacturing process.
Well, cross-section area, section modulus, moment of inertia and Young’s modulus are four different terms.
Young’s modulus is property of material. The other three refer to geometry, they are related but not the same.
Cross section area is clear, no explanation needed there I think.
Moment of inertia or second moment of area is not about the area only, but also about the shape and its orientation.
Section modulus is the moment of inertia divided by distance of extreme to neutral axis (so =radius for circular cross section, e.g.).
Simple example: think of a slat, long flat piece of wood or steel. It’s easy to bend and break about flat sides but much more difficult to bend and break about the short side. How come, cross section (area) is still the same, isn’t it?
Well, section modulus is different: W=1/6ab^2, where b is the dimension in the direction of loading. Let’s have the slat 5mm thick and 50mm wide. Bending it about flat side: W=1/6505^2=208.33mm3. Bending it about edge: W=1/6550^2=2083.3mm3; 10x larger section modulus.
Enough of the boring theory; I did a simple and quick structural analysis. Two flat bars made of steel, one straight, one twisted, both 10x100mm cross section, 1m long (actually the twisted one is a bit longer, as I made the ends flushed, that should not affect the stress field massively), both have one end fixed (those light blue arrows at the top/left end) and the other one free, loaded with 9810N of axial force (about 1 metric ton pulling them) - that’s the blue arrows at the bottom/right end. No other load in any other direction.
I’ve done this really quickly so wouldn’t bet much money on the exact numbers; but for this purpose the MPa values do not matter, we only want to see the difference the twisting does.
So, the pics below shows stress distribution in the bars (von Misses stress, in case you wonder, kind of a “total stress”), colours reflect the magnitude of the stress - red means high stress, blue means low stress. And it’s all plotted on the deformed shape of the bar/-s. The green triangles/pyramids form computational mesh - don’t worry about them.
view from the other side:
The straight bar is pretty much all blue - i.e. under tensile load it develops a uniform stress field of certain value (9.81MPa - well, that makes good sense (9810/(10*100)).
The twisted bar is nicely colourful, i.e. under pure tensile load it develops much more interesting stress field. While the stresses in the part towards the loaded end of the bar are about 2x higher (cyan patch) than in the corresponding part of the straight bar, the stresses towards the clamped end are about 5x higher (it’s that bright green region). Moreover, the stresses nearer the edges of the twisted bar are about 10x higher than those at the edges of the straight bar (those red patches).
Conclusion: twisted bar can develop significantly higher stresses than a straight one, even though the cross section area and the external load is the same.
As of the individual components of the stress and their contributions - you could do a prof degree on it. Skipping that here.
Another interesting plot: displacement (=deformation). While the straight bar stretches longitudinaly under the load (by about 0.05mm, the model says), the twisted bar not only stretches but also bends down- and sideways (the green “ghost” mesh represents undeformed shape); total displacement of nearly 15mm… Ooooouch…
This indirectly ansewers the question whether a twisted strap is weaker than a straight one or not - it is. It deforms differently and more.
Yes, straps in question are not made of steel but nylon fibres, different properties, different behaviours… different numbers, but general view is (should be) about the same.
OK, thanks very much for going to this much trouble. I could see that in the case of a flat steel bar, altering its cross section to, for example, a U shape without altering the cross sectional area would of course alter the properties of the bar. Now thanks to your diagrams I can understand that a twist is going to make a difference too.
Now, it looks like I have a qualitative answer, but there are still a couple of points - as you mentioned, the straps do have quite different properties form a steel bar. Could it still be that the quantitative answer - in the case of straps - is that it doesn’t make any significant difference (accepting that the stress is a lot higher in the twisted case of the steel bar example you show)? Also, I get the idea from your displacement plot that twisting the strap is going to make it more elastic. This could maybe give rise to the possibility that a twisted strap could perform better, ie absorb the effect of the trailer chassis twisting, in a situation where a straight strap, having less give, would snap?
Again, thanks very much, this question has turned out a lot more interesting than I thought!
This is a good point to admit that I did a Young’s modulus related experiment today, and found the elastic limit of a pair of hydraulic hoses - that I forgot to uncouple when uncoupling the tipping trailer of the w&d I was on. 
No probs, engineering can be sooo exciting sometimes but not to ladies, that I can tell
I do admit that using steel bar wasn’t the brightest idea as it’s likely to mislead, so I modified the material to nylon and reduced the load to 981N as I wasn’t sure how fair it would be to expect nylon to hold 1t.
(That was about 10min job, including runtime and I did that on my lunch break)
So the bars are now made of solid nylon, as the load was reduced 10x I’d expect the stresses to come 10x lower and possibly litle bit different as we changed the material from metal to plastic with different Young’s modulus and Poisson ratio, The stress distribution should be the same. Do you believe me?
So under 981N of tension a 10x100x1000mm straight nylon bar sees 981kPa of mechanical stress. A twisted one sees nearly 10MPa.
Increase the load 5x (to 500kg) and the straight slat sees ~5MPa while the twisted one ~50MPa.
Given that yield point of nylon is ~40-50MPa and ultimate strength ~70-80MPa… while straight one is fine, twisted one is giving up, stretching like chewing gum. If you increased the load further, the twisted slat would break in two while the straight one would still be fine.
Approximating vowen fibrous strap by a solid bar is not great but not a terrible mistake (imho). Yes, the strap has significantly different structure than a solid bar. But it does not perform its function loose - it has to be tightened, stretched - the fibres are pressed together to form something resembling a rectangular bar.
Just a few comments:
- Changing cross section geometry does make difference regardless of material, even when keeping cross section area unchanged. Take a piece of paper and have a play
that it doesn’t make any significant difference (accepting that the stress is a lot higher in the twisted case of the steel bar example you show)?
That higher stress is the significant difference! See above. The stress in any component cannot exceed strength of the material the component is made of. It actuall never does, as the part breaks apart when you reach the limit. In case of straps, twisted strap is much closer to its limits. Run into a pothole, your load jumps (and so does the strap load) and twisted strap snaps while a straight one stands (assuming equal conditions for both).
Also, I get the idea from your displacement plot that twisting the strap is going to make it more elastic.
Just a detail, elasticity is a property of material, stiffness is property of geometry. So twisting the strap will make it less stiff - to deform more than a straight strap under the same load. Twisted strap will “react better” (deform more) to trailer deformation than a straight one, but it will not hold the load so good - because is gives more. It is like a loose strap, allows the load to move (more than a straight one does). When straight strap snaps twisted one is long gone.
As you are becoming an expert in the field of twisted straps and snapped hoses, you can perform a simple test in the yard: one crate, tied to trailer by two straps, both in the same state, one straight, one twisted, both stretched by the same force, crane lifting the crate and observe (from sfe distance) which strap gives up first
I love engineering problems too and working out a solution. Using flat bar as an example is a good one too, they use it to hold lorry fuel tanks securely onto the chassis without any twists
I can understand the tear argument which prompted me to follow the career of Thomas Smith and why there is a twist in a Christmas Cracker 
Wheel Nut:
This is what eventually happens if you use damaged straps
A CAR owner had a lucky escape after this EIGHT tonne boulder fell off a lorry and flattened their motor.
The huge rock was being transported from a nearby quarry in Hayfield, Derby, when the accident happen yesterday.
Fortunately no one was in the car at the time, but residents said they were shocked by what happened.
Adam Chatterton, who took the photo, said: "We were outside and heard a massive bang. Everyone rushed into the road and saw the lorry.
“It was then that we saw the rock had fallen on to the car, completely crushing it.”
A spokesman from Derbyshire Police confirmed the incident had happened, but refused to comment further.
It was on the BBC Local TV News the other night,it showed a HIAB lifting the boulder of the car and guess what ? One of the lifting straps broke and dropped it again.
Wheel Nut:
I love engineering problems too and working out a solution.
Is there a way of attatching a ratchet strap to a drivers bollox so if it falls off the lorry it takes the driver with it.
3 times in one shift this week i had to go into the “live” carriageway to retrieve straps and buckles, Incompetent twunts need the strap wrapping round their bollox and 3 points on their licence to make them think a bit more 
ladungssicherung.de/content/ … 3_1315.pdf
page 2, bottom left picture, the text reads “twisting like this can lead to strap edge overload”
OK, thanks to that, now I’ve got an easy way of visualising it - a line up the centre of a twisted strap is shorter than the edge - has to be, because it takes a shorter path. Bingo! Of course there’s more stress in a twisted strap. Thanks! 
Steve-o:
Also, if you lose part of your load on a bend and the police notice that the rest of your straps are twisted then they could decide to try and shaft you with some C&U Reg? All depends if you interupted PC Angus Nairn in the middle of his roll’ sausage n’ tattie scone that morning
Or forgetting C&U, if the load went through some passing innocents windscreen/car, would you feel as shafted as the other party 
, because you couln’t be arsed replacing the FAULTY straps like Buby 06
Unless I’ve missed it (or am too late after a few days off) I also suggest that a twisted strap will present a reduced surface area of restraint upon the stuff being secured. Thus, I imagine that a reduced surface area would result in a higher pressure (where it touches) - which to my vague imagination isn’t too advisable if it can/should be avoided.