Scaffold Myth Busters

[Justin T. Wittwer]

Here is where you can post your questions to be reviewed each month by our panel of super geniuses to see if what "that one guy" told you back in '86 is actually the truth, based on truth or just plain BS.  I'll get the ball rolling with two of my favorites listed below. Dig deep and fire away!

Cheers,

JW

[Justin T. Wittwer]

Is there a wrong way to put a clamp on? Hinge up or down?

[Justin T. Wittwer]

On a single bay tower is there a correct way to put the diagonals on? Should each leg get the top of a diagonal or can the tops of the diagonals meet on a common corner? 

[Doug Easter]

Justin, it has been a "while", but we always "jigged" our T&C (preset the clamps on the tubes) and we put the clamps on the jig with the hinge down so we could swing up the second half onto the tube and "burp" the nuts to the proper torque.  If setting freehand, the same thing but no pneumatic.

Justin T. Wittwer said:

Is there a wrong way to put a clamp on? Hinge up or down?

[Justin T. Wittwer]

I came up with another one. How deformed can a rosette system pin be before it should be replaced? And how many times can it be reshaped before it should be replaced?

[michael wilson]

Yes, there is a wrong way to put a clamp on, mainly when it is a load supporting clamp.  Clamps can fail, and if it does you want it to still support the load instead of opening and leaving your tube with no support...And it is best practice to always put your clamps on as a safety, why not, we should always take pride in our work!!!

Justin T. Wittwer said:

Is there a wrong way to put a clamp on? Hinge up or down?

[michael wilson]

If your diags are not chasing, then you are leaving volnarable corners to be able to twist, a scaffold never falls straight down, it has to twist to fall, unless it is a hanger, but differnt story... anyways, unless you are unable to x your diags from an obstruction, they should always chase each other..

Justin T. Wittwer said:

On a single bay tower is there a correct way to put the diagonals on? Should each leg get the top of a diagonal or can the tops of the diagonals meet on a common corner? 

[Justin T. Wittwer]

While I have heard the same thing and have subscribed to this theory for many years, I also think that if the clamp fails the hinge is not going to save the scaffold. I have stepped on clamps and had them open all the way. I have asked the question because I will be submitting these to an engineer and I was wondering if, from an engineering capacity if there is a right way or a wrong way and if it is figured in when they perform the calculations. I completely agree that the force being transmitted into the clamp should go against the hinge, not the bolt. 

michael wilson said:

Yes, there is a wrong way to put a clamp on, mainly when it is a load supporting clamp.  Clamps can fail, and if it does you want it to still support the load instead of opening and leaving your tube with no support...And it is best practice to always put your clamps on as a safety, why not, we should always take pride in our work!!!

Justin T. Wittwer said:

Is there a wrong way to put a clamp on? Hinge up or down?

[michael wilson]

   It is just best practice really, a clamp has a load rating, so it does't matter how you put it on. I just try to always teach new guys the best practice, but an engineer will tell you that it has the same rating no matter how it is put on..