Maximum length of a Transom

[cassie]

As long as you pick the weight up correctly, go as long as you like.. pick up as required by the duty rating...

 

[Mr.B]

Is it not for anything more than 2 inside, and 4 boards, that TG 20:08 requires a drawing on that sort of straight forward Independent?
Then that Appendix A and all the other types of T&F scaffolds that are classed outside of the basic scaffold structure need to be designed by calculation.
Alistair, my friend, i think i can remember the post you mention, regarding the Beam Transom, just prior to TG 20 being implemented.

PS. your still posting some good job questions and knowledgeable info, keep up the good work.

Isn't there a bit in there for 5&2 for masonary scaffolds?

 

[paddy carr]

MR B i think your correct there mate, originally when TG 20:05 came out, i think there was a lot of major concerns regarding the std configuration of a 'Independent scaffold only being allowed 1 inside board, or else 'Drawing by calculation'. this i believe, was one of the reasons for TG 20:05 being removed and re-invented as TG 20:08 which in fact never came into circulation until 2010, which then as you say........allows for a 5.2.4 or 5 and 2 inside boards without having a design.

 

[Jason-Gibbs]

The maximum span of a transom is determined by the load imposed apon it and not a pre determined dimension.
The limiting factor is not always the transom but may be the ledger that supports it. For instance a short transom with a heavy load may fall mid span on a long span ledger and the ledger may prove to be the weak link.
regards
Alan

Good post as always Alan mate.

Max length: Id say, as long as you want... provided there is sufficient Tubes/Ledgers underneath to support it.
You wont want your Standard spacings much further then 2m or so, so your Ledgers under your Transoms would also be roughly 2m apart (if its a Birdcage) then i suppose if you had a big enough area to build as long as you kept to roughly 2m centers you could have 21ft Tubes as Trannies Sleeved onto another 21ft, Sleeved onto another 21 and so on for as long as you wanted.

 

[Alan Reade]

Alan Reade

"The maximum span of a transom is determined by the load imposed apon it and not a pre determined dimension."
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I am soooooooo imprested will your knowledge and ability to write your answer's in concise plain English.

Keep up the good work,

Thanks........I think??:bigsmile:

 

[Havespannerwilltravel]

Good post as always Alan mate.

Max length: Id say, as long as you want... provided there is sufficient Tubes/Ledgers underneath to support it.
You wont want your Standard spacings much further then 2m or so, so your Ledgers under your Transoms would also be roughly 2m apart (if its a Birdcage) then i suppose if you had a big enough area to build as long as you kept to roughly 2m centers you could have 21ft Tubes as Trannies Sleeved onto another 21ft, Sleeved onto another 21 and so on for as long as you wanted.

Theoretically yes as long as the sleeves werent too far away from the ledgers.

 

[Alan Reade]

Good post as always Alan mate.

Max length: Id say, as long as you want... provided there is sufficient Tubes/Ledgers underneath to support it.
You wont want your Standard spacings much further then 2m or so, so your Ledgers under your Transoms would also be roughly 2m apart (if its a Birdcage) then i suppose if you had a big enough area to build as long as you kept to roughly 2m centers you could have 21ft Tubes as Trannies Sleeved onto another 21ft, Sleeved onto another 21 and so on for as long as you wanted.

Whilst I am aware that the original post referred to the length of the transom, unless I have misinterpreted the original post I would believe the question was related to the span of the transom.
TG20, for non-designed scaffolds, Table 1 indicates 5+2 boards. thus 1.2c/c pre design.
As previously mentioned, the transom may not be your limiting factor as with a light load such as 0.75kN/mSq your transom could easily cope BUT the ledger below may be an issue. As AsXD has stated you would need to reduce your standard spacing’s to avoid bending in the ledger. This problem is multiplied if you use inside boards due to the cantilever effect on the transom.
Regards
Alan

 

[oldscaff]

0.75kN/m2 very light duty.

Not bad spanners for a part1:laugh:

 

[Havespannerwilltravel]

Not bad spanners for a part1:laugh:

I am reading TG 20 as I am unable to go to work at present.
Its a national holiday here tomorrow so pretty much a normal day for me.

 

[Alan Reade]

Whilst I am aware that the original post referred to the length of the transom, unless I have misinterpreted the original post I would believe the question was related to the span of the transom.
TG20, for non-designed scaffolds, Table 1 indicates 5+2 boards. thus 1.2c/c pre design.
As previously mentioned, the transom may not be your limiting factor as with a light load such as 0.75kN/mSq your transom could easily cope BUT the ledger below may be an issue. As AsXD has stated you would need to reduce your standard spacing’s to avoid bending in the ledger. This problem is multiplied if you use inside boards due to the cantilever effect on the transom.
Regards
Alan

Not sure if I have explained myself in a clear fashion?
Please see sketch