This shutdown surveys FAQ answers the questions Australian maintenance managers, turnaround planners and reliability engineers ask most often before booking survey support for a planned outage. We cover scope, cost, cooldown, access, datums, turnaround and round-the-clock crewing — answered from ISS field experience across Pilbara iron ore, Bowen Basin coal, Hunter Valley power and Gladstone alumina. Where it matters we name the equipment, standards and tolerances rather than speaking in generalities.
Key takeaways
- A shutdown survey is dimensional control work executed inside an immovable outage window — mill, kiln, crane-rail, conveyor and structural geometry captured while the plant is cold and isolated, then turned around fast enough to feed live maintenance decisions.
- Expect 2-6 mm real-world accuracy from a terrestrial scanner such as the Leica RTC360 or FARO Focus in a dusty plant, and sub-millimetre to 1-2 mm from a Leica total station on alignment datums and crane rails.
- Cold geometry matters: a kiln or SAG mill shell stopped for six hours may still sit above 100 degC and be thermally expanded — confirm cooldown requirements before the team mobilises or accept reduced accuracy.
- Indicative pricing runs roughly AUD 5,000 for a single one-day alignment check to AUD 25,000+ for a multi-day 3D scanning programme across several assets, with out-of-hours work attracting a 25-50% premium.
- ISS crews work 24/7 to suit shift patterns, deliver coordinates to GDA2020 / MGA2020 and AHD or your local mine grid, and provide preliminary results on site before demobilisation.
What is a shutdown survey?
A shutdown survey — also called a turnaround or outage survey — is precision measurement work carried out while a plant or a major asset is stopped, isolated and accessible. During normal operation, rotating equipment is moving, hot and guarded; the only time you can reach a SAG mill girth gear, a rotary kiln shell, a crane runway or a conveyor drive to measure it accurately is during the shutdown.
Typical scope includes mill and kiln alignment, crane-rail straightness and gauge, conveyor structure and pulley alignment, structural as-built capture for retrofits and tie-ins, vessel and tank verticality, and deformation comparison against previous epochs. The defining constraint is time. Every hour the plant is down costs money in lost production and idle labour, so the survey has to be planned to the schedule, executed without delay, and turned around fast enough to be useful while the asset is still open.
How is a shutdown survey different from a normal survey?
The measurement techniques are largely the same — total station, laser scanning, precise levelling — but the operating environment is the opposite. An operational survey can be rescheduled, extended and worked around production. A shutdown survey cannot. It runs against a fixed window where any overrun cascades onto every other contractor queued behind you.
That changes how the work is resourced. Shutdown crews are sized to finish inside the window, often run across day and night shifts, mobilise at short notice, and carry redundant equipment so an instrument fault never stops the job. Data has to be processed in near real time, because a clearance check or an alignment result is only valuable if the fitters can still act on it before reassembly. It is the difference between measuring a building you will return to next month and measuring a machine that closes back up in eighteen hours.
When in the shutdown should the survey happen?
Sequence it deliberately. For most precision tasks the asset must be stopped, isolated under lockout/tagout, and cooled before measurement. A rotary kiln or large mill shell holds enormous thermal mass; surveying a shell that is still hot captures thermal expansion, not the cold geometry your alignment is referenced to. As a rule of thumb, cold alignment work needs surface temperatures below about 40 degC, which can mean 12-24 hours of cooldown depending on the asset.
The survey also needs to land after any cleaning, stripping or component removal that exposes the measurement points, but before reassembly begins. That window is often narrow, so we map the survey into the shutdown schedule at planning stage and confirm the access and isolation milestones that gate it. Where hot alignment is genuinely necessary, it can be done with heat shielding at higher temperatures, with a documented reduction in accuracy — we will flag that trade-off during scoping rather than discover it on the day.
How accurate are shutdown survey results?
Accuracy is task-dependent, and we match the instrument to the tolerance. For alignment datums, crane-rail geometry and machined surfaces a Leica total station delivers angular and distance precision supporting 1-2 mm positional results, and precise levelling resolves height to better than a millimetre over a runway. For capturing complete as-built geometry — structural steel, congested pipe racks, vessel internals — a terrestrial scanner gives 2-6 mm point accuracy in real plant conditions of dust, mixed reflectance and vibration, well short of the headline 1 mm lab figure but more than adequate for clash detection and dimensional control.
Registration quality is the largest single variable on scan work, which is why we tie scans to surveyed control rather than relying on cloud-to-cloud matching alone. Where a single asset needs both — say a mill where the trunnion datums demand total-station precision but the surrounding structure only needs as-built capture — we combine techniques so each measurement carries the accuracy its purpose requires.
How much does a shutdown survey cost in Australia?
Cost is driven by scope, duration, access, mobilisation distance and shift pattern. The headline ranges below are indicative; a fixed-price quote against a defined scope is always more useful than a rate card.
| Scope | Indicative cost (AUD) |
|---|---|
| Single asset, one-day alignment or check survey | 5,000 - 10,000 |
| Multi-asset alignment plus as-built capture | 10,000 - 20,000 |
| Multi-day 3D scanning programme across several assets | 20,000 - 50,000+ |
Each additional day on site adds roughly AUD 3,000-8,000 in survey fees before the far larger cost of extended downtime. Remote mobilisation to the Pilbara, Bowen Basin or NT adds travel and FIFO costs, and night-shift or weekend work attracts a 25-50% premium. The real economics, though, sit in what accurate data prevents — a single avoided clash on a retrofit tie-in, or one eliminated return mobilisation, typically covers the survey several times over.
How quickly can we get the results?
Fast enough to act on. The whole point of a shutdown survey is that the data informs decisions while the asset is still open, so we provide preliminary measurements and alignment results on site before demobilising — fitters do not wait days to know whether a mill is within tolerance. Formal reports, registered point clouds and modelled deliverables follow on an agreed turnaround, typically within five business days, with rush processing available for time-critical outages when flagged at scoping.
This is where laser scanning earns its place in a turnaround: because it records the complete scene rather than only the points someone thought to measure, questions that surface weeks later can often be answered from the cloud without a return visit to a plant that is back in production.
Frequently asked questions
Do you work night shift and around the clock during a shutdown?
Yes. ISS crews run 24/7 to suit your shutdown shift pattern, including back-to-back day and night rosters so survey work never becomes the bottleneck holding up reassembly. Out-of-hours work attracts a premium of around 25-50% depending on the roster, and we ask that non-standard hours are booked at least two weeks ahead so we can resource the crew and instruments. Peak outage seasons — broadly the autumn and spring shutdown periods — book out four to six weeks in advance.
Who provides access, scaffolding and isolation?
The site does. Survey crews bring measurement equipment, not access equipment. Scaffolding, manlifts, confined-space entry support and lockout/tagout isolation are the site's responsibility and the most common cause of survey delay when they are not ready. Confirm the division of responsibility in writing before the contract is signed, and verify the access route physically about a week out — a survey team standing idle waiting for a platform still charges for the time.
What datum and coordinate system do you deliver in?
For any Australian site we deliver to the current national framework — GDA2020 with MGA2020 grid coordinates horizontally and AHD for elevation — so results tie cleanly into your as-builts and design models. On mine sites we routinely transform into your local mine grid as well, so the deliverable speaks the coordinate language your surveyors and engineers already use. Supply existing control marks or a grid definition and we register to them; if none exist we establish control with GNSS and total station first.
Do shutdown surveys need a licensed surveyor?
Where the data must be legally defensible, certified, or tied to a registered control network, a licensed surveyor should supervise the work — and mine surveying is a statutory function under each state's mining safety legislation. ISS operates under qualified surveyors, so where your outage needs control-connected, certifiable accuracy that requirement is covered. For routine internal dimensional checks the certification overhead is usually unnecessary; we scope it to what the deliverable actually has to support.
Can you use drones inside a shutdown?
Sometimes, and it can be the safest option for inspecting elevated or confined structures without sending a person to height. Any UAV operation must comply with CASA Part 101 and be flown under our operator's certification, and indoor or near-structure flight inside a plant carries its own risk controls. For most internal shutdown geometry, terrestrial scanning and total-station work remain the primary tools; drones come into their own for stack interiors, roof structures, stockpiles and external as-built capture around the outage.
Ready to scope survey support for your next outage? Whether it is a single mill alignment, a crane-rail check or a full multi-asset scanning programme, ISS delivers control-connected, fast-turnaround shutdown surveys across Australia with crews that work to your shutdown clock. Call 0407 057 015 to discuss your scope, schedule and datum, and request a fixed-price quote tailored to your turnaround.