Plant erection depends on three things lining up: equipment and steel arriving when they are needed, the right crews and cranes ready to install them, and the surrounding work, foundations, access and piping, in the right state at the right time. They rarely line up by themselves. Plant erection planning for equipment, workforce and site interfaces is the work of making them do so.
What is plant erection planning?
Plant erection planning defines the sequence in which steel, equipment, modules and piping will be installed, the cranes, crews and materials required for each step, and the handovers needed from civil works and to following disciplines, so that erection proceeds without waiting or rework.
Why erection needs its own plan
The overall construction schedule rarely shows crane positions, lift sequences or the exact order of equipment setting. An erection plan adds that detail, and that detail is where most erection delays are either prevented or created.
Inputs to the erection plan
- Equipment list with weights, dimensions and delivery dates
- Structural steel erection sequence from the fabrication plan
- Foundation completion dates and survey results
- Plot plan, access roads and laydown areas
- Crane availability and lift studies for heavy items
- Vendor representative requirements for setting and alignment
Planning the equipment side
Erect heavy and tall items first
Large vessels, columns and heavy equipment are usually set before surrounding steel and piping close off crane access. Leaving them too late can force much larger cranes or even partial dismantling of steel already erected.
Match delivery to setting
Equipment that arrives months early needs storage, preservation and double handling. Equipment that arrives late holds up steel and piping around it. The delivery schedule should be negotiated around the erection sequence, not the reverse. For steel, the same logic is explained in planning structural fabrication for industrial projects.
Prepare for receipt
Inspection on arrival, preservation, storage conditions and loose parts control prevent problems later in the sequence.
Planning the workforce
Erection workforce demand moves in phases: steel erectors and riggers first, then mechanical fitters and crane crews for equipment setting, then pipe fitters and welders. Supervisors and lead riggers should arrive before their crews. Vendor representatives need booking well ahead, because their availability rarely matches a slipping schedule. Build some flexibility into those bookings, or agree a standby arrangement, so a delayed delivery does not mean losing the vendor’s slot entirely.
Planning site interfaces
| Interface | What must be agreed |
|---|---|
| Civil handover | Foundations cured, surveyed and released, with anchor bolt positions confirmed |
| Structural steel | Which steel is erected before and after each major equipment item |
| Piping | Nozzle orientation confirmed and piping connected only after equipment is aligned |
| Electrical and instrumentation | Access routes for cable trays and instruments preserved |
| Access and laydown | Roads, crane pads and laydown areas available when needed |
| Operations, on brownfield sites | Lifting near live equipment, outages and permits |
The civil to mechanical handover is the most common source of erection delay and is detailed in civil and mechanical coordination on plant projects.
The erection sequence plan
Bring the above together in an erection sequence plan: a set of drawings or 3D snapshots showing the plant at each stage, with crane positions, laydown, access routes and which items are installed. It helps every discipline understand the plan and reveals clashes before they happen on site. Heavy lifts within the sequence need their own detailed planning, covered in heavy lifting and rigging coordination for plant erection.
Common planning pitfalls
- Planning erection from delivery dates instead of a logical sequence
- Ignoring crane access for late-arriving heavy items
- No contingency for late vendor deliveries
- Piping crews mobilized before equipment is set and aligned
- Laydown areas sized for average rather than peak deliveries
Fitting erection into the wider plan
The erection plan is a detailed part of the construction execution plan and should use the same schedule and histogram. The overall erection scope is described in industrial plant erection services.
Apex Core Engineering supports erection planning and supervision through its construction management services.
Frequently asked questions
Why are heavy items usually erected first?
Because surrounding steel and piping can block crane access later, forcing larger cranes or rework if heavy items are left too late.
What is an erection sequence plan?
A set of drawings or model snapshots showing the plant at each stage of erection, with crane positions, access routes and installed items.
When should vendor representatives be booked?
Well ahead of planned setting and alignment dates, with flexibility agreed in case the schedule moves.
Plan your erection phase with Apex Core Engineering.