Readylock Transoms

Readylock Transoms are commonly used all over now for independents without ledger bracing, anybody got any manufacturer calcs to prove ledger bracing not required??

I have bold statements in ancient SGB literature of "ok to use up to 30m without ledger brace...tied in 4m x 4m grid" but no calculated proof.

Notice thier absence in TG20.

With so many suppliers you would hope one of the manufacturers had produced something to support their application.

Any help appreciated.

Morning HJA
having worked for a good few years at SGB in the past, I can advise that this topic is still under discussion today. Their Chief Engineer retired yesterday after many years on the job and readylok is still undecided.

As a seeker of this information I can tell you that to my knowledge the SGB Readylok was never tested. It was a reasonable assumption that the depth of the fitting connecting the transom to the standard woud give adequate stiffness to obviate the need to ledger brace.

The restrictions on Readylok are as follows:
1)you need not ledger brace up to 30m
2) NO SHEETING may be applied without ledger bracing.
3) If you need to build a higher scaffold, say 50m, you brace the first 20m and then not brace the top 30m.

When questioned this year SGB (Harsco) stated they have intention to test the product, but they have been saying that for all of my time in this industry.
When questioned with regards ledger bracing the SGB (Harsco) stance was " no bracing required up to 30m, HOWEVER, due consideration must be given to bracing, should sheeting need to be added"

The alternative to bracing may be tying every node point!
regards
Alan

Alan,

The docs I have "state" UDL 7kN or PL 3.5kN, safe slip 5.25kN and the interesting one "Rotational Strength Approximate To A Welded Tube". As an insider your saying SGB published this without doing any testing??

It's the "Rotational Strength Approximate To A Welded Tube" that I'm interested in. Do you have or are you aware of an actual or assumed moment resistance value for the transom/ledger connection? given this we can at least start to calculate the lateral restraint of a frame.

It is concerning that even the might of probably the biggest and most respected design departments didnt see this through.

HJA

---------- Post added at 08:40 AM ---------- Previous post was at 08:25 AM ----------

Alan,

The docs I have "state" UDL 7kN or PL 3.5kN, safe slip 5.25kN and the interesting one "Rotational Strength Approximate To A Welded Tube". As an insider your saying SGB published this without doing any testing??

It's the "Rotational Strength Approximate To A Welded Tube" that I'm interested in. Do you have or are you aware of an actual or assumed moment resistance value for the transom/ledger connection? given this we can at least start to calculate the lateral restraint of a frame.

It is concerning that even the might of probably the biggest and most respected design departments didnt see this through.

HJA

Gentlemen,

Ah the world of ready lok transoms... we have just designed a big job using them and there are a few things you must do that is not that well known.

Firstly, all points Alan makes are correct.. however, SGB never tested them so how they can actually state ANY guidelines at all is beyond me.

I spoke with ASP (now Combisafe) the other day regarding their Readyloks and the guy there admitted to me that ASP just copied the SGB design and literature and reprinted it without testing. When asked about bracing requirements for sheeted scaffold I was told there was no information available.

Readyloks are actually covered in TG20.. by 'covered' I mean mentioned. Page 64. However, their only use in relation to TG20 is that they provide the 'transom fixed at every ledger braced node with load bearing couplers', otherwise they are to be treated no different to a regular transom on B&P's.

It should also be noted that when using Readyloks the tie method must effectively restrain the standard to prevent buckling parallel to the facade. If the tie can not support this load then you must either face brace the inside row of standards or plan brace... or prove (by frame analysis I guess) that the entire structure is sound. But then brings back the problem of the joint stiffness mentioned above.. so you're back at square one.

There is also the issue of effective length of the standards if the scaffold is unbraced. With the TG20 method of calculating effective length you must take care to ensure that you have satisfied all the necessary criteria... otherwise you can't say that the scaffold is erected or designed in accordance with TG20.

B.

Sorry HJA for the delay in response, I did respond earlier however it would appear to have not been posted.

I have the original SGB sales sheets for this and an extract from the SGB booklet dated 1971. The information is limited but I could copy and send if required.

I am not sure if you are misreading the rotational value?
The rotational value relates to the transom to standard connection not the transom to ledger connection.

The statement in the SGB Data is "Rotational strength approximates to 'H' frame scaffolding"

Regards
Alan

I always ledger brace arms... you ledger brace transoms, and basically thats what these are.. so get em braced.. lazy twa.ts lol

cala said:

I always ledger brace arms... you ledger brace transoms, and basically thats what these are.. so get em braced.. lazy twa.ts lol

Click to expand...

Most scaffolders i know only brace the base lift

Hi Chaps,

Oh..the readylok debate! They are a royal pain at the moment. I agree completey with what BMB is saying. The manufacturers should be the ones getting them tested as it is a joke they can sell/hire them without this basic information. I have seen one set of tests carried out whereby a frame was constructed and the displacement measured for a 2kN horizontal load at the node. This was then carried out with a ledger braced frame and compared. Both had very similar maximum deflections. The only trouble is they have now, for some reason, withdrawn the test and are not providing this as evidence that they work.

In my opinion a lot more needs to be done than the above in order to provide designers and scaffolders with what they need to enable the ledger bracing to be omitted. It has taken 30 years to get this far and may take another 30!

Something must be done as I am fed up with the debargo.

R.

one things for certain, ledger bracing stiffens the scaffold up ... like I said I always brace arms, and whether others do is their business..

Scaffold_Engineer said:

Hi Chaps,

Oh..the readylok debate! They are a royal pain at the moment. I agree completey with what BMB is saying. The manufacturers should be the ones getting them tested as it is a joke they can sell/hire them without this basic information. I have seen one set of tests carried out whereby a frame was constructed and the displacement measured for a 2kN horizontal load at the node. This was then carried out with a ledger braced frame and compared. Both had very similar maximum deflections. The only trouble is they have now, for some reason, withdrawn the test and are not providing this as evidence that they work.

In my opinion a lot more needs to be done than the above in order to provide designers and scaffolders with what they need to enable the ledger bracing to be omitted. It has taken 30 years to get this far and may take another 30!

Something must be done as I am fed up with the debargo.

R.

Click to expand...

Morning R
well said fella. I have been working with readylok for nearer 40 than 30 years and this problem has been around for all of my time.
I know the tests to which you refer and I have commenetd on this subject before.
I do not believe the tests as shown are the correct tests and I do not believe them to be adequate. The test relates to a locally applied load which at best tests the local transom unit which may or may not be adequate as a transom. It does not however test the scaffold. The scaffold tested is not under a vertical load representative of a 30m high scaffold with imposed loads. I could go on but that will not change the problem.

This is a manufacturerd and hirers problem they are putting untested un quantified product into the market place without adequate information on it safe use and erection proceedures.

I feel I will have long retired before this is resolved
regards
Alan

Dont hirers/suppliers have to give the relevant info under section 6 of haswa? or would this not be relevant because of a CE mark???

ready trannys need to be braced these days as you wont get a design company to give you a drawing without them as the regs seemed to have changed i recently dont done two blocks of flats with them ten lifts high with a total of 262 appollo ties and the design company wouldnt change drawings as he had the new regs in front of him