Structural Steel Erection Contractor

Setting out and survey of the foundations, receipt inspection of the members, lifting each member to a lift plan, plumbing and aligning, making the bolted or welded connections, installing bracing, purlins and secondary members, and handing over with survey and torque records. It stops at the primed and painted steel frame — cladding, sheeting and equipment are separate scopes unless they are part of the same order.

AKEN prepares it and issues it for the client to review before the lift, because the plan depends on the member, the crane and the ground on that particular site. It states the load weight and centre of gravity, the crane position and working radius, the rigging arrangement and sling angles, the ground bearing under each outrigger, and the exclusion zone below. Nobody stands under a suspended load at any point of the lift, and the plan is what makes that enforceable rather than a habit.

In two directions, at right angles to each other, using a total station, theodolite or plumb lines depending on the height and the access. Reading one face only tells you the column leans in one axis and says nothing about the other. The column is adjusted on packers and shims at the base plate, and it stays guyed or braced until the permanent bracing in that bay is fitted and the connections are tightened.

Ground that has been checked, not ground that looks solid. Outrigger loads are calculated from the crane and the load, then compared with what the ground can carry — and on made-up ground, over backfilled trenches or over buried services, that means spreader mats or a designed crane pad. This is the single most common cause of a crane settling mid-lift, and it is decided before the crane is mobilised.

Yes, and it is a normal arrangement when the client has bought the steel separately. In that case we ask for the erection drawings and the member list up front, and we inspect the members on receipt, because erection tolerances are only achievable if the delivered steel is within its own fabrication tolerance. A frame that was not trial-assembled in the shop will be trial-assembled here, at height.

The lift is held and the fit-up is measured before anything is forced. Sometimes the cause is a foundation that is out, sometimes a shop error, sometimes a drawing revision that reached one party and not the other. Connection holes can be reamed within the allowance the design permits; beyond that the member is re-made or re-detailed. Pulling a connection home with a spanner preloads the frame in a way nothing in the design accounted for.

The tolerance is written into the project specification and the design code the frame was detailed to, and we agree it at order rather than applying a default of our own. It covers plumb per storey and over the full height, elevation of beam and purlin lines, and the straightness of the frame down its length. Whichever figure is agreed, it is measured and recorded, so the client can hold us to it at handover.

Often it has to be. Where a new frame lands near live equipment, over a cable trench or beside a running line, the client may only permit work in an agreed window. We plan the picks so that the frame is stable at the end of every window, and so that nothing is left half-connected across a restart — a partially braced frame near an operating line is a hazard long before it is a programme problem.

It depends on tonnage, bay count, height, crane reach and how much of the bracing and secondary steel is in the same lift as the primary frame. A single-span shed with simple bolted connections goes up far faster than a multi-bay process building with crane gantries and heavy trusses. The reliable planning unit is frames per week at the crane and ground conditions that exist on your site, and that is what we quote against after a site visit.

Mobile elevating work platforms where the ground allows, scaffold where it does not, and netting or a fall-arrest system where neither is practical. The choice is made from the bay, the height, the plant underneath and the safety requirements the site imposes, and it is priced as part of the erection rather than left as an extra. Working at height without a chosen system is not something we quote.