paul
Well-known member
Would like to know if a double can take the same loads which ever way it is fitted ie:- bolt up or bolt facing down ?
doubles
- Thread starter paul
- Start date
philliosmaximus
Moderator
i always put punch-ups on upside down doubles i cant see any difference if the double is touching the same of tube it should have the same friction :wondering:
ive always used a double each way including a brace, i put the gate in the way the weight is as in upside down on a dropper and normal on a ledger. Also right way top of a brace and upside down on the bottom.
Ive heard the only problem is when you put a sideways load on a puncheon like edge protection, its not designed for it so some edge protection has a brace in now.
Ive heard the only problem is when you put a sideways load on a puncheon like edge protection, its not designed for it so some edge protection has a brace in now.
Would imagine the gate on a double would take more weight than the bolt in the case of droppers or puncheons. Remember when I was with SGB, was told that B/P in the normal position would take more weight than if you put it on sideways, though I've often heard different, not convinced, I stick with the SGB version.
philliosmaximus
Moderator
that would make sense brandy as the standard is in more contact with the fitting in the right position and on its side it is only the bolt of the plate that is making contact.
ISITJELL
Active member
Right Angled Load Bearing
Just had a look through some of the British Standards and design specifications that I’ve collected, and I can’t find anything to state if the double (Right Angled Load Bearing Coupler) should be put on the upright in any particular way. It’s recommended that it should have the bolt on the top in some of the old training manuals, but I haven’t got any in a digital format. However the cruciform strength of the fitting is exactly the same, that’s the point at which it would snap if too much force was applied.
Have a look at this handrail assembly; in figure 2, the puncheon is only 550mm from the centre of the beam, the puncheon is only about a 1.6m in length, with a double handrail.
According to the calculations on this drawing, it would only take 250kg to push this handrail over. I know some of you have your own businesses or are in charge of big sites, but I bet there’s not a lot know about this British Standard for Temporary Edge Protection BS EN 13374, the HSE do!
I'll put the document I'm refering to on a new thread entitled Handrails
Just had a look through some of the British Standards and design specifications that I’ve collected, and I can’t find anything to state if the double (Right Angled Load Bearing Coupler) should be put on the upright in any particular way. It’s recommended that it should have the bolt on the top in some of the old training manuals, but I haven’t got any in a digital format. However the cruciform strength of the fitting is exactly the same, that’s the point at which it would snap if too much force was applied.
Have a look at this handrail assembly; in figure 2, the puncheon is only 550mm from the centre of the beam, the puncheon is only about a 1.6m in length, with a double handrail.
According to the calculations on this drawing, it would only take 250kg to push this handrail over. I know some of you have your own businesses or are in charge of big sites, but I bet there’s not a lot know about this British Standard for Temporary Edge Protection BS EN 13374, the HSE do!
I'll put the document I'm refering to on a new thread entitled Handrails
Last edited:
philliosmaximus
Moderator
so what should it hold then isitjell ? as we cant see what your talking about mate ? punch up should be on 2 doubles on a beam so it will be as strong as the beam lets it be
ISITJELL
Active member
on the butt
No the tube on the beam is on beam clamps, the puncheon is fitted to the butt on one fitting as usual.
No the tube on the beam is on beam clamps, the puncheon is fitted to the butt on one fitting as usual.
250kg to push it over. Thats 3 men x 80 kg each falling against it. Could the butts on the beam not be extended out and run a ledger along them and rake up to the guardrail to strenghten it.
ISITJELL
Active member
check this link
Have a look at this link, I think they're saying you need a drawing for a handrail.
http://www.nsguk.net/docs/toolbox/Edge_Protection_Temporary.pdf
Have a look at this link, I think they're saying you need a drawing for a handrail.
http://www.nsguk.net/docs/toolbox/Edge_Protection_Temporary.pdf
Nothing new in that, that method been used for as long as I can remember.
philliosmaximus
Moderator
This is a tried and tested method as brandy says , i have seen shuttering landed on handrails like this and they haven't moved . remember that there is nearly always gonna be a column to tie around usually 6 meters apart
paddy carr
Moderator
A double is a double, it is a designed fittiing to carry a vertical load and as such the horizontal face will be also rigid. the problem arises, if this fitting is in a singular mode, 2 barneys on a tube, no problem thats what they are made for.
philliosmaximus
Moderator
The problem with the handrail on the drawing is not the double it is the fact that it is on 2 steel clamps on a RSJ and that is acting as a pivot point , any weight put against the handrail will force the butt down. But a handrail is not supposed to be load bearing as long as it stops someone falling over the side then surely it has served its purpose.
ISITJELL
Active member
3 classes of roof
A little further information about the Temporary Edge Protection PDF Doc. I don't think a lot of people realise the importance of these documents, the HSE have already acted on a number of occasions and prohibition orders have been issued. The ACOP - BS EN 13374:2004 imply that all edge protection handrails must have a drawing showing the calculations for side impact. If you look at the NSG Doc, they show that the puncheon is set at 550mm from the centre of the steel H girder, with the top guardrail at 1.6m from the node point. The node point is the fixing point at the bottom of the puncheon arrangement. This is also where the cruciform strength of the fixing is calculated. According to the calculations on this example, it only takes 240kg of force (side impact) using Class A fittings and 480kg using Class B fittings to start the process of the puncheon arrangement bending at the node point.
The NSG doc is the only drawing I have come across, with calculations provided. The further the puncheon is placed away from the H girder beam, on the supporting tube, (the tube fixed to the beam, with girder clamp fittings), the weaker the puncheon arrangement. It appears designers are reluctant to provide calculations, for puncheon arrangements, the further the puncheon tube is placed away from the supporting girder clamps on the support tube, as the cruciform strength of the bottom fitting (node point) and the elasticity of the supporting tube is considerably weakened on the puncheon arrangement.
You must also take into consideration that the distance from the top hand rail to the bottom fitting at the node point is 1.6m, in this example. The further the distance between these two points the weaker this arrangement of components could be. Design input must be required to erect these handrails or other arrangements should be made to protect persons and materials from falling from roofs.
There other considerations that may also be of interest, BS EN 13374 identifies 3 different classifications of roofs that are determined by the gradient of the roof, for example,
Class A is set at 0º to 10º, where the gaps between the rails are set at 470mm, about 18½ inches
Class B is set at 10º to 30º, where the gaps between the rails are set at 250mm, just over 9 inches
Class C is set at 30º to 60º, where the gap is set at 100mm, 4 inches.
A little further information about the Temporary Edge Protection PDF Doc. I don't think a lot of people realise the importance of these documents, the HSE have already acted on a number of occasions and prohibition orders have been issued. The ACOP - BS EN 13374:2004 imply that all edge protection handrails must have a drawing showing the calculations for side impact. If you look at the NSG Doc, they show that the puncheon is set at 550mm from the centre of the steel H girder, with the top guardrail at 1.6m from the node point. The node point is the fixing point at the bottom of the puncheon arrangement. This is also where the cruciform strength of the fixing is calculated. According to the calculations on this example, it only takes 240kg of force (side impact) using Class A fittings and 480kg using Class B fittings to start the process of the puncheon arrangement bending at the node point.
The NSG doc is the only drawing I have come across, with calculations provided. The further the puncheon is placed away from the H girder beam, on the supporting tube, (the tube fixed to the beam, with girder clamp fittings), the weaker the puncheon arrangement. It appears designers are reluctant to provide calculations, for puncheon arrangements, the further the puncheon tube is placed away from the supporting girder clamps on the support tube, as the cruciform strength of the bottom fitting (node point) and the elasticity of the supporting tube is considerably weakened on the puncheon arrangement.
You must also take into consideration that the distance from the top hand rail to the bottom fitting at the node point is 1.6m, in this example. The further the distance between these two points the weaker this arrangement of components could be. Design input must be required to erect these handrails or other arrangements should be made to protect persons and materials from falling from roofs.
There other considerations that may also be of interest, BS EN 13374 identifies 3 different classifications of roofs that are determined by the gradient of the roof, for example,
Class A is set at 0º to 10º, where the gaps between the rails are set at 470mm, about 18½ inches
Class B is set at 10º to 30º, where the gaps between the rails are set at 250mm, just over 9 inches
Class C is set at 30º to 60º, where the gap is set at 100mm, 4 inches.
paddy carr
Moderator
Drawing for a handrail
FFs Im a Celery,get me out of here
I can honestly say that now i am sick of all this drawing sh1t, basically pissed off with the whole game now.
FFs Im a Celery,get me out of hereI can honestly say that now i am sick of all this drawing sh1t, basically pissed off with the whole game now.
philliosmaximus
Moderator
So how much side impact must a handrail be capable of withstanding then to conform
isitjell ?
isitjell ?
its ok untill some knob comes along and dont no what hes doing at least it gives an alarm bell before its to late the amount of scaffolders ive seen that put the doubles back to front over the years mainly young lads when i was on sgb we had to put the dead legs inside the scaffold just incase the trainee
un done the fitting and it went over the side of the scaffold. saying that though i had a bloke on dungerness A station how through me a double and it went behind him over the side of the building lol!!!