Pre-ticked for falls, atmosphere, plant and temperature, with three rows written. A steel frame is stable when it is finished, and every hour before that it is standing on its temporary bracing.
A part-erected frame is a temporary structure
The temporary support limb covers work needing support to prevent collapse, and it gets read as being about existing buildings and propping. A frame part way through erection is exactly what it describes: it stands on its temporary bracing and guys until the last connection is made, and the bracing is a designed part of the job rather than something added when it feels lively.
Which is why the sequence and the bracing are designed together, and why the crane is not released until the bracing for that stage is in. Two bolts minimum in each connection before the hook comes off is the working rule, and it exists because a member held by one bolt is a hinge.
Fume is decided by what is on the steel, not by the process
The coating matters more than the arc. Galvanised steel produces zinc oxide, primed and painted steel produces whatever the coating decomposes into, and stainless produces hexavalent chromium, which is a carcinogen. The same welder doing the same weld on bare steel is in a completely different exposure.
So the first control is removing the coating back from the weld area before striking an arc, which is elimination rather than management. Local exhaust ventilation at the arc comes next, and it has to move with the work: extraction left at the bench while the welder is six metres away is doing nothing at all.
The fire is usually an hour after the arc
Hot slag and spatter fall, lodge in something combustible and smoulder. The fire starts after the crew has moved on, which is why a fire watch that ends when the welding ends is the one that misses it. Sixty minutes after the last arc is the usual minimum and longer where the material below could not be cleared.
The other half is looking down before starting. Sparks travel a long way vertically, and the combustible material is often somebody else material: packaging, membrane, a stack of insulation delivered that morning to the floor below.
Getting to the connection without climbing the steel
Access by MEWP is the first option, and free climbing the frame is the practice this trade has been moving away from for good reason. Where an unprotected edge cannot be avoided, fall arrest goes to a designed anchor rather than to whatever looks solid, and the rescue plan is written before anybody clips on.
Perimeter netting and void covers go in as the frame goes up rather than as a later package, because the gap between the steel being up and the edge protection arriving is exactly when people are working on it.
Arc eye reaches people who are not welding
Photokeratitis is a burn to the surface of the eye from ultraviolet light, and it does not need you to look at the arc. A reflection off a light-coloured wall or a bright steel surface is enough, and the pain arrives six to twelve hours later, usually in the middle of the night.
Which is why screens go round the arc rather than in front of the welder. The person who ends up in an emergency department is often a labourer who walked past twice, and they will not connect it to the welding because nothing hurt at the time.
Common questions
Is structural steel erection always high risk construction work?
In practice yes, and usually through several categories at once: falls over 2 metres, powered mobile plant moving in the area, and temporary support to prevent collapse while the frame is incomplete. Site welding can add the contaminated atmosphere limb depending on the location and the coating.
Does site welding need its own statement?
It is a different activity from erection, with different hazards and often a different crew, so it usually earns its own. Where the welding is a small part of the erection sequence it can sit inside the erection statement, provided the fume, fire watch and access controls are written properly rather than mentioned.
What extraction is needed for welding fume?
Local exhaust ventilation positioned at the arc and moved with the work, with the coating removed back from the weld area first. General ventilation dilutes fume across the space rather than capturing it, so it protects everybody slightly and the welder least of all, which is the wrong way round.
How long should the fire watch continue?
At least sixty minutes after the last arc as a normal minimum, and longer where combustible material below could not be removed. The reason is that slag smoulders: the fire that results from hot works usually starts well after the noise has stopped and everybody has gone.
Can I use a UK method statement for Australian steel work?
Not as it stands. The content is a reasonable starting point, and a SWMS has to name which high risk construction work is involved and say how the control measures will be implemented, monitored and reviewed. A method statement has no column for that last part, so it will come back.