Another tube in double bay sways?

Flinty

Flinty

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So....

The site I'm on is house bashing for the next 2 years (the stuff DREAMS are made of) and they insist on double bay sways, albeit, done incorrectly across 2 bays, 1 lift high. Now in addition another tube needs to be put horizontally through the swayed bays. Sort of another ledger or handrail.

Nobody on site actually knows why.

Anyone here know why?
 
Is this the base lift or all lifts? If I am understanding correctly, TG20 indicates the tube you describe on the base lift...apparently that is to stop peeps walking into the brace!
 
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I have seen it Flinty but only on the base lift of a pavement lift so the public doesn't walk into a brace and even then it was as I tell all my clients "Only an illustration.";)
 
AxSD said:
Is this note base lift or all lifts? If I am understanding correctly, TG20 indicates the tube you describe on the base lift...apparently that is to stop peeps walking into the brace!
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This is only put in on the base lifts, but as we go up we're leaving a single guardrail in, so wouldn't be able to put one in anyway!

So this is a case of allowing for OTS*??






*Other Trade Stupidity
 
I have noticed a few jobs on the streets!!!...that have introduced a third "ledger/high handrail"... though the lifts where 8-10 ft, so i suppose if some one was working off a small step ladder to do his work on windows etc, it could prevent him goin over if the clown fell off his step..
 
Flinty said:
So....

The site I'm on is house bashing for the next 2 years (the stuff DREAMS are made of) and they insist on double bay sways, albeit, done incorrectly across 2 bays, 1 lift high. Now in addition another tube needs to be put horizontally through the swayed bays. Sort of another ledger or handrail.

Nobody on site actually knows why.

Anyone here know why?
Click to expand...

Just thinking... since you are supposed to go through 2 bays an 2 lifts (if you are doing it by the new bible)... and if not, you are supposed to add plan bracing every x amount of bays and lifts, between three standards.. wonder if this a cheeky alternative?
 
Flinty said:
So....

The site I'm on is house bashing for the next 2 years (the stuff DREAMS are made of) and they insist on double bay sways, albeit, done incorrectly across 2 bays, 1 lift high. Now in addition another tube needs to be put horizontally through the swayed bays. Sort of another ledger or handrail.

Nobody on site actually knows why.

Anyone here know why?
Click to expand...

1) Additinal bracing is not called for in TG20 and is a chargable extra
2) Braces across two bays by one lift is in contravention to TG20
3) I see no structural advantage to the mid height tube and there is no mention that I can see in TG20 other than their inclusion in the Bracing Diagrams.
I do however see the logic as a guard rail to prevent people walking through and cracking their nut.
 
longun said:
Just thinking... since you are supposed to go through 2 bays an 2 lifts (if you are doing it by the new bible)... and if not, you are supposed to add plan bracing every x amount of bays and lifts, between three standards.. wonder if this a cheeky alternative?
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According to TG20..

If face (sway) braces are fitted across a single bay then plan braces are required.

Plan braces are required at a frequency of 4 lifts vertically x 12 bays horizontally....BUT are only required if the scaffold is "greater than 8m in height".

Also, agree with Alan Reade here the additional tube is a safety feature for dummies and offers NO additional structural integrity.
 
Alan Reade said:
1) Additinal bracing is not called for in TG20 and is a chargable extra
2) Braces across two bays by one lift is in contravention to TG20


I have seen this on a few designed jobs now Alan and whilst it looks pants I just assumed it was in scope as it's designed. It surprises me that as a few of the big boy's use it on some high profile jobs, there were a few pics on the forum.
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Hi AOM
If you are refering to the brace acroos 2 bays in one lift, it is not covered by TG20 that I can see, this would make it a design job which is where you say you have seen it.
Still not good to see, remembering that braces should be between 35 & 55 degs.
 
Build it to the guidelines otherwise charge more , then show them this on a smart phone ........[ame=http://www.youtube.com/watch?v=6G0s46l7Mas&feature=youtube_gdata_player]TG20:08 part 2 safe scaffold design for T&F - YouTube[/ame]
 
Alan Reade said:
Hi AOM
If you are refering to the brace acroos 2 bays in one lift, it is not covered by TG20 that I can see, this would make it a design job which is where you say you have seen it.
Still not good to see, remembering that braces should be between 35 & 55 degs.
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I agree that's why I was surprised. I assumed it must be correct on some level but obviously not.
 
Having given this some thought I can't understand the lower 35 deg limit in TG20. Considering the direction of the load these braces resist my opinion is the flatter the better...or do other designers disagree?

Additionally if a brace is fixed across 2 bays and 2 lifts with a single tube, where / what does the brace fix to in its centre as it clashes with the lift. OK these braces can be separate if necessary but cannot understand the lower 35 deg limit, the upper limit yes but not the lower.

We do, in some of our designs use a face brace across 2 bays and 1 lift.
 
Why the flatter the better, I would have said the closer to 45 the better. Thanks for clearing up that designers do infact specify 2 bay 1 lift.
 
I always try to put the Sway Bracing in at a 45 degree angle as a maximum.
Not steeper though - more flatter the better... as i think that after 45 degree's it starts to negate the point in having it.

I also prefer to put the Sway Bracing in between 1 Bay using 10fts and dog-legging it back up the Scaffold off Swivels, but im sure this is against the TG20 rules now.
 
It's not Jason, perfectly acceptable it's how we do it and always will. I still don't get the flatter thing and your stair case was one that looked a bit flat to me on the base but I know it was a design but no where near 45.

Maybe I'm getting mixed up, it could have been another job I'm not as young as I once was you know.:embarrest:
 
Ok I am going try and explain the flatter the better thinking.....

First imagine a knee brace to a beam or inside boards or anything cantilevering. Well I'm sure you will agree the steeper the better with a flatter brace being ineffective. Well thats because the load being supported is vertically downwards.

Now take that 'triangle' made with the knee brace and turn it on its side....well that is the same as a sway brace - resisting horizontal loads. Now the flatter the better because the load is now horizontal instead of vertical.

As Jason said above steeper than 45 degs and it's not worth having, that's because its too steep (like a very flat knee brace using my example).
 
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