Is this man an idiot?

[Jeff H.]

I went to Italia Granite & Marble in Sparks NV to pick up 3 slabs on the other day. They brought the 1st slab and went back for another. As the forklift came down the aisle I saw they had 2 slabs on the clamp. I told the 2 young guys controlling the slabs that they are never to lift 2 at once if they want to load my trailer. The driver (Mike) stopped and came over to me. He said I was never to talk to his help like that and he's been moving slabs like this for years. I explained why he should never lift 2 at once and that I've had slabs fall off the clamp in my shop because of this practice at the slab yards. I also told him that if he read the instructions he would have seen the warning about lifting more than 1. I then explained to him that safety should be his biggest concern when moving slabs for himself & his employees. This is when it got ugly! I won't go into the details, but I won't be sending any clients to this supplier ever again.
As I was leaving he threw one more dig at me so I told him that I took a picture for proof in case of an accident and that he would have a law suit on his hands.

[tim farr]

I say a fool more than an idiot. If more people would refuse shipments from these irresponsible vendors the problem would fix itself. If a truck shows up with the smiley cracks I refuse the shipment and then refuse to buy from them again.

[Dan R.]

Fool, idiot, whatever...We are splitting hairs over an obviously unsafe practice.

The person to talk to is the fork truck driver's boss. People need to be responsible for their actions and not just because a lawyer sues them.

[Omni Cubed Larry]

Definitely not safe. Bummer it got heated and he responded the way he did (many of us let our own pride get in the way when others try to correct us or give us good advice). It could be more ignorance and lack of judgement based on what he said about practicing this method for years. It sounds like you did the same thing in the past... but you learned. We all do unsafe things now and then without even knowing it. And sometimes we do it when we know it isn't safe, but without knowing just how unsafe it is.

The idiocy comes if he continues to do the same thing and doesn't heed your warning of your past experience. I'm glad you said something about it. Who knows, even though it got heated, he may sleep it off and wake up in the morning with better judgement.

Sadly, easily avoidable accidents in our industry are not good for any of us.

[Jeff H.]

Dan, the forklift driver is the owner. That's what makes this so crazy!

[Dan R.]

You may need to speak to his boss, his wife.
Explain to her that since you do not spend x amount of dollars at the distributor, then their joint income will suffer by a considerable amount.

[innstone]

You may need to speak to his boss, his wife.

HA!

Jeff, I was just there 2 weeks ago, I told them the same thing. I never talked to the owner. The warehouse guys said they had never heard of this happening. I am shocked that I didn't have more of an impact and they didn't change their ways then (maybe "shocked" isn't the right word, maybe "not surprised" is what I mean).
I say this every time I have to go get slabs, nobody seems to take it seriously in Reno yet.
I have said it before, Reno NV. has the worst slab warehouses in our area. I buy 85% from Sacramento & San Fransisco, and they deliver!

[innstone]

Actually, I have had success with Randy @ Design Tile in Sparks.

[Darryl Miller]

We have a supplier here that does this all of the time. I have explained the issue to the owner/manager and all of his employees. Most of them just laugh it off. But I have sent material back to them on more than one occasion because of the cracks caused by it. Some people just don't care.

[Steve A]

Can someone explain the issue with lifting 2 slabs?

Is this only an issue with 3cm material? If so I completely agree, 1 slab at a time. I would in fact disagree if the same is reasoned for 2cm material. I think this issue is not as one sided as most may feel.

Hear me out please. First and foremost you need to consider the type of material you are moving. Example - Travertine should probably never be lifted with a clamp let alone 2 at a time, this would go for any material that has potential to shear apart under its own weight.

Every lift has potential danger, moving slabs is THE most dangerous aspect of our jobs. Best to approach every lift with this mindset, be ready for the worst. I have moved thousands of slabs, perhaps tens of thousands of slabs. I have never had a problem when lifting 2 slabs together in the clamp, in fact the opposite has been the case, its only single carried slabs that I have had fail. I have never had a slab "slip" from the clamp. The few times that we have lost a slab has been either due to an existing crack in the slab or the forklift was jostled and the slab tore itself apart or hit something.

I firmly believe that lifting two 2cm slabs together is safer with certain material than lifting only 1 at a time. The 2 slabs give each other support.

Again this only my argument for 2cm material. Regarding 3cm or thicker I'm still on the wagon!

[Darryl Miller]

This is how I view it, regardless of material thickness. If either or both slabs are bowed away from each other, the stress of forcing them together can cause one or both to crack along the stress points. I am sure that some material can safely be lifted like this if the slabs are flat. But as a good safety habit we never pick up two slabs at a time. Sure it saves time to do so, but the safety of employees and others in the area and the cost of losing one or two slabs of material is better than the time saved.

Just my opinion.

[Dan R.]

Lifting 2 slabs (of any dimension) can cause half moon fissures if the slabs are not perfectly flat. The weight of the hanging slabs exerts pressure to sandwich the slabs together even more. This can cause a half moon fissure. Chances are any slab that has fallen from a clamp with the clamp retaining this half moon has been lifted as a pair. These fissures may hold together forever or break up on the next lift. It is a fact, not an opinion. An opinion you can debate. This is not debatable.

If it never happened to you, consider yourself lucky. Change your methods and do things safer. It would be horrible if your first instance was a severe injury. What would you say? It never happened before? You did not know of this potential issue?
Learn from others here. IT DOES HAPPEN. IT WILL HAPPEN EVENTUALLY.

Distributors and fabricators do this to save time. Time is money, after all.

Many clamps are not designed to pick up 2 cm material.
An Abaco style slider 3 cm clamp is not safe to use on a 2 cm slab. Do not use it on 2cm, we all have done it. It is dumb. Even dumber, if you know in advance.

Learn Share Prosper

[Ken Lago]

That I did not know Dan, please explain why its not safe on 2cm.

[Dan R.]

The roller mechanism is based on the thickness of the stone. It is engineered for 3 cm stone. The weight of the stone puts pressure on the rollers and they grip even tighter. The opening (closing) distance while it can hold a 2 cm slab, it can not close tight enough to properly secure it.

If it could safely lift 2 cm, why wouldn't they call it a 2 cm clamp?

For lifting 2 cm material we use the 3 cm clamp (or larger) and use a scrap of stone as the filler. This allows the clamp to properly close and not put stress on the slab, if it is bowed.

[Ken Lago]

Would my sissor clamp be safer for 2cm?

[Darryl Miller]

Would my sissor clamp be safer for 2cm?

I would say yes to that.

[Omni Cubed Larry]

Too often slabs are very warped, so clamping "forcing" them together when they are warped is not good. Causing a fissure near where the clamp is could spell disaster for the next lift or the next person.

Here is my simplified Larry speak.
Even if the slabs are perfectly flat and even if they don't have any fissures, it still comes down to the functional geometry of the clamp and the amount of friction you have between the clamp and the stone. This is also why they are rated for certain slab thicknesses.
The force (or weight) the clamp can lift is the Coefficient of Static Friction multiplied by the Normal Force. f=uN
The Normal Force is the force perpendicular to the slab, so in this case it is the Clamp Force. But the Clamp Force is a function of the weight of the stone and the functional geometry of the clamp. The Coefficient of Static Friction is related to how "grippy" the rubber is and how "slippery" the smooth (and often dusty) stone is (it is a number that relates to the interface between the two materials and how easily they slip past each other). It also happens to affect the Clamp Force but that is more complicated. When you reduce the Friction you reduce the Clamp Force. Clamping two pieces of stone together effectively means you have half as much rubber per slab, and the slab-to-slab Friction is much lower than slab-to-rubber Friction. Fortunately there is a safety factor designed into these clamps, but you are asking for a higher potential for danger whenever you reduce the Friction by either picking up very dusty slabs or by picking up multiple slabs or by using a clamp with messed up rubber, etc.
There are also dynamic forces in play. When ever you drive over a bump, the vertical load the clamp and slab experiences can be multiplied greatly. So, if you pick up two slabs and everything "seems" fine, but in reality it is barely holding the slabs, they could drop when you hit a bump because of the multiplication of the load due to the up and down motion of the boom.

Just because it has worked for you and you haven't had an incident, doesn't mean that it is not risky. Sometimes no incidents make us complacent to the real danger. Kind of like the guy who grinds without safety glasses for two decades without incident. Don't be a fool, safety glasses are cool!

[Darryl Miller]

Here is my simplified Larry speak.
Even if the slabs are perfectly flat and even if they don't have any fissures, it still comes down to the functional geometry of the clamp and the amount of friction you have between the clamp and the stone. This is also why they are rated for certain slab thicknesses.
The force (or weight) the clamp can lift is the Coefficient of Static Friction multiplied by the Normal Force. f=uN
The Normal Force is the force perpendicular to the slab, so in this case it is the Clamp Force. But the Clamp Force is a function of the weight of the stone and the functional geometry of the clamp. The Coefficient of Static Friction is related to how "grippy" the rubber is and how "slippery" the smooth (and often dusty) stone is (it is a number that relates to the interface between the two materials and how easily they slip past each other). It also happens to affect the Clamp Force but that is more complicated. When you reduce the Friction you reduce the Clamp Force. Clamping two pieces of stone together effectively means you have half as much rubber per slab, and the slab-to-slab Friction is much lower than slab-to-rubber Friction. Fortunately there is a safety factor designed into these clamps, but you are asking for a higher potential for danger whenever you reduce the Friction by either picking up very dusty slabs or by picking up multiple slabs or by using a clamp with messed up rubber, etc.
There are also dynamic forces in play. When ever you drive over a bump, the vertical load the clamp and slab experiences can be multiplied greatly. So, if you pick up two slabs and everything "seems" fine, but in reality it is barely holding the slabs, they could drop when you hit a bump because of the multiplication of the load due to the up and down motion of the boom.

I thought you said simplified.....

[ageless]

Larry, might want to attach a drawing to simplify even more. Lol!

[Jonathan]

Don't be a fool, safety glasses are cool!

And knowing is half the battle!

[ChrisGraham]

This is a result of picking up two slabs at the same time. We call it a shark bit. Its from the same distributor Darryl is referring to I think. C clamp two bow parts together and see if they don't crack. I have mention my concerns to them about this, but at the end of the day they move hundreds of slabs per day to my 8-10. So just be damn carefull every every every single slab!! or it could be your last.

[Dan R.]

Larry =

I would think the scissor clamp would be better for 2 cm than a 3 cm Abaco clamp.

Shark bite..... I love it!

[Darryl Miller]

Yes Chris, I can tell from the truck that it is the same supplier. When did this happen? I stay on Eric about this all the time. I no longer send clients there because of this and some of the quality issues.

[innstone]

Too often slabs are very warped, so clamping "forcing" them together when they are warped is not good. Causing a fissure near where the clamp is could spell disaster for the next lift or the next person.

Here is my simplified Larry speak.
Even if the slabs are perfectly flat and even if they don't have any fissures, it still comes down to the functional geometry of the clamp and the amount of friction you have between the clamp and the stone. This is also why they are rated for certain slab thicknesses.
The force (or weight) the clamp can lift is the Coefficient of Static Friction multiplied by the Normal Force. f=uN
The Normal Force is the force perpendicular to the slab, so in this case it is the Clamp Force. But the Clamp Force is a function of the weight of the stone and the functional geometry of the clamp. The Coefficient of Static Friction is related to how "grippy" the rubber is and how "slippery" the smooth (and often dusty) stone is (it is a number that relates to the interface between the two materials and how easily they slip past each other). It also happens to affect the Clamp Force but that is more complicated. When you reduce the Friction you reduce the Clamp Force. Clamping two pieces of stone together effectively means you have half as much rubber per slab, and the slab-to-slab Friction is much lower than slab-to-rubber Friction. Fortunately there is a safety factor designed into these clamps, but you are asking for a higher potential for danger whenever you reduce the Friction by either picking up very dusty slabs or by picking up multiple slabs or by using a clamp with messed up rubber, etc.
There are also dynamic forces in play. When ever you drive over a bump, the vertical load the clamp and slab experiences can be multiplied greatly. So, if you pick up two slabs and everything "seems" fine, but in reality it is barely holding the slabs, they could drop when you hit a bump because of the multiplication of the load due to the up and down motion of the boom.

Just because it has worked for you and you haven't had an incident, doesn't mean that it is not risky. Sometimes no incidents make us complacent to the real danger. Kind of like the guy who grinds without safety glasses for two decades without incident. Don't be a fool, safety glasses are cool!

I was going to say almost the exact same thing;2 slabs = BOOM

[Omni Cubed Larry]

Darryl, I know, I know. I didn't think anyone would read my explanation... even if it IS simplified.
Rey, trust me on this one... the drawing would just complicate things.

Dave, thanks for the funny comics you emailed me.