TL;DR
An outage survey is precision measurement delivered inside the fixed window when a power station, processing plant or major asset is taken offline for maintenance. Because every hour of an outage costs $50,000-200,000 in lost generation or production, the shutdown survey work has to be planned to the hour, executed to sub-millimetre tolerances, and never sit on the critical path. This guide covers what an outage survey involves, the methods and equipment, the accuracy standards, when you need it, the deliverables, and how ISS delivers it without extending your window.
Key takeaways
- An outage survey is a shutdown survey scoped to a specific, time-bound maintenance window — typically a generating-unit outage, a boiler or turbine overhaul, or a calciner/cooler change-out — where the asset earns nothing until it restarts
- ISS achieves ±0.3-1.0 mm alignment accuracy and 2-6 mm at 50 m laser-scan accuracy using Leica MS60 MultiStation, TS16 total stations, RTC360 scanners and FARO trackers, all calibrated to ISO 17025
- The work splits into pre-outage baseline capture, in-outage alignment, fit-check and clearance measurement, and post-outage as-built verification before recommissioning
- Power generation, alumina refining, cement, steel and mineral processing are the primary users; outage frequency runs from annual minor outages to 4-6 year major overhauls
- Cost drivers are attendance pattern (standby versus scheduled), shift loading for 24-hour outages, scanning scope, and the safety regime — confined space, hot work and working-at-heights all add mobilisation overhead
What is outage survey services
An outage survey is the dimensional control, alignment and as-built measurement work carried out while an industrial asset is shut down for a defined maintenance outage. The term "outage" is most common in power generation — a unit outage on a coal-fired set such as Bayswater, Eraring or Loy Yang, or a boiler/turbine inspection — but it applies equally to a refinery turnaround or a mineral-processing shutdown where the line is deliberately taken out of service.
The problem an outage survey solves is simple to state and expensive to get wrong: when an asset is offline, the maintenance team needs to remove worn components, install or rebuild equipment, and put everything back within tolerance — and they need independent measurement to prove each step is correct before the next one starts. Without survey support, alignment is checked by feeler gauge and tape, fit-up problems are discovered when the crane is already holding a 40-tonne rotor, and as-built records are reconstructed from memory after restart.
A shutdown survey works by establishing a stable measurement reference (a survey control network) that survives the whole outage, then measuring equipment positions against that reference at each stage — before disassembly, during rebuild, and after completion. The same control lets ISS compare as-found against as-left and feed verified geometry straight into the recommissioning sign-off.
Key point: An outage survey is not the same as a routine alignment job that happens to fall during a shutdown. The defining constraint is the window. Methodology, crew size, instrument selection and reporting cadence are all chosen to fit the schedule, not the other way round. A method that is "more accurate" but two hours slower can cost more than it saves.
Why outage surveys matter
The financial logic is unforgiving. A mid-sized processing plant or generating unit loses $50,000-200,000 for every hour it stays offline. A 14-day alumina shutdown that slips by three days because the survey scope was discovered on the run can cost the operator close to half a million dollars in extended downtime — before any rework. The outage survey is one of the few activities that can either protect that window or quietly blow it, depending entirely on how it is planned.
Done well, an outage survey removes uncertainty from the critical path. Components are confirmed to fit before they are lifted. Alignment is verified before couplings are made up. Foundations and baseplates are checked while they are still accessible and clean. The result is fewer surprises, fewer re-lifts, and a recommissioning that proceeds on verified data rather than hope.
The other reason outage surveys matter is that the window is often the only time the asset is accessible. A turbine casing, a kiln tyre seat, or the internals of a precipitator can only be measured when the unit is cold and open. Comprehensive laser scanning during the outage — even of equipment not being worked on — creates an as-built record that supports every future modification, clash check and overhaul. The scan you capture in this outage is the design basis for the next one.
Watch out: The most common cause of survey-driven outage overrun is not measurement error — it is scope discovered too late. Treating the surveyor as a day-of call-out rather than a planned, scheduled resource almost guarantees lost hours waiting for control, access or line of sight.
The outage survey process
ISS runs outage surveys to a five-phase protocol refined across power, refining and mineral-processing turnarounds. The phases compress or expand with the outage length, but the sequence holds.
Step 1: Scope definition and methodology (4-6 weeks pre-outage)
ISS reviews the outage work list, isolates every survey-dependent activity, and develops a measurement methodology mapped against the outage schedule. A pre-outage site visit confirms access, hazards, control requirements and line of sight. This is where critical-path survey tasks are identified so they can be resourced rather than discovered.
Step 2: Control network establishment (1-2 weeks pre-outage)
A stable 3D control network is set out around the work area using a Leica TS16 or MS60, with monumented or semi-permanent reference points positioned to survive scaffolding, crane movements and demolition. Establishing control before the area is congested is the single biggest time-saver during the outage itself.
Step 3: Pre-outage baseline capture (outage minus 1-2 weeks, or hour zero)
As-found geometry is captured while the plant is still running or immediately after stop: rotating-equipment centrelines, tyre and roller positions, bearing elevations, clearances for removal, and structural references for reassembly. This baseline is the reference against which all post-work measurement is judged.
Step 4: In-outage execution (during the window)
The core of the shutdown survey. ISS measures in sequence with mechanical activity — dimensional verification after removal, alignment setting during rebuild, fit-check and clearance survey before installation, and level/flatness on cleaned foundations. Reflectorless and tracker measurement keep technicians clear of live lifting. Results are reported on the spot so the next activity is not held up.
Step 5: Post-outage verification and reporting (final 1-2 days, then within 1-2 weeks)
A final pass confirms every adjusted component is in tolerance and captures the as-built condition. ISS delivers alignment reports with deviation tables, fit-check confirmations, as-built plans and registered laser-scan data. A short-form compliance summary is issued before recommissioning; the full report follows within 5-10 business days.
Methods and equipment
Outage survey equipment has to be accurate, portable, fast to deploy and tolerant of heat, dust and vibration. ISS selects the instrument to the task and the schedule, not by default.
Robotic total station and MultiStation
The Leica TS16 robotic total station (±1 mm + 1.5 ppm distance, 1" angle) and the Leica MS60 MultiStation are the workhorses for control, alignment and setout. The MS60 combines angle, distance and scanning in one instrument, which matters when setup time is the constraint. Automatic Target Recognition allows remote operation, keeping the surveyor out of exclusion zones around active lifts.
3D laser scanning
The Leica RTC360 captures dense point clouds at 2-6 mm accuracy at 50 m, with a full setup in under two minutes. Scanning is the fastest route to comprehensive as-built capture — internals, pipework, structural steel and clearance envelopes recorded in hours rather than the days that discrete measurement would take. It is the method of choice for fit-check of replacement modules and for clash detection on tie-in work.
Laser tracker
For the tightest alignment work — turbine couplings, large bearing bores, machined seating faces — a FARO laser tracker delivers ±0.015-0.025 mm at typical working ranges. This is the instrument for coaxiality, concentricity and flatness checks where a total station's accuracy is insufficient.
Reflectorless and portable control
Reflectorless measurement reaches inaccessible or hot points without target placement. Portable, quickly recovered control targets minimise setup and teardown — critical when the same control has to serve repeated measurement cycles across a multi-day outage.
Key point: Scanning and total-station work are complementary on an outage. The scanner captures the whole condition for as-built and fit-check; the total station and tracker deliver the sub-millimetre alignment numbers the mechanical team signs against. Using one where the other belongs either wastes window time or undershoots the tolerance.
Accuracy and standards
Outage survey accuracy is matched to the engineering tolerance of the task, then verified against the relevant standard. The table below summarises typical ISS specifications.
| Parameter | ISS specification | Typical method | Notes |
|---|---|---|---|
| Rotating-equipment alignment | ±0.3-1.0 mm | Total station / tracker | Centreline and elevation, coupling faces |
| Coupling coaxiality / concentricity | ±0.02-0.05 mm | Laser tracker | Turbine, large drive trains |
| Foundation / baseplate flatness | ±0.2-0.5 mm | MultiStation / level | Per AS 1170 loading context |
| Clearance / fit-check | ±1-2 mm | Laser scanner | Module and component fit-up |
| As-built point cloud | 2-6 mm at 50 m | RTC360 scanner | Registered to site control |
| Crane runway / structural geometry | ±1-2 mm | Total station | Per AS 1418.18 where applicable |
All instruments are calibrated to ISO 17025 and measurements are traceable to national standards. ISS provides measurement uncertainty statements with alignment deliverables. Where the work touches structural or crane geometry, results are assessed against the relevant Australian Standard — AS 1418.18 for crane runways, AS 4100 for steel structures, and project or OEM tolerances where they are tighter than the code.
When you need an outage survey
You need an outage survey whenever measurement is on the critical path of a time-bound shutdown, or whenever recommissioning depends on verified geometry. Common triggers:
Power generation unit outages
Turbine and generator overhauls, boiler inspections, precipitator and mill internals, and condenser work all require alignment verification and as-built capture inside a fixed unit outage. Coal-fired sets across the Hunter Valley, Latrobe Valley and central Queensland run scheduled minor outages annually and major outages on a multi-year cycle.
Refinery and processing turnarounds
Alumina calciners, kilns, coolers and large rotating equipment are removed, rebuilt or replaced during turnarounds at sites such as the Gladstone and Bunbury alumina operations. Tyre and roller position, shell alignment and tie-in fit-up are all survey-dependent.
Mineral processing shutdowns
SAG and ball mill relines, girth-gear and pinion alignment, crusher and conveyor work during planned shutdowns at Pilbara, Goldfields and Bowen Basin operations. The mill alignment window inside a shutdown is short and unforgiving.
Component replacement and modification
Any change-out where the new part must fit the existing structure — a kiln shell section, a mill trunnion, a turbine rotor — benefits from a pre-outage fit-check scan and a post-install alignment survey.
If alignment is currently checked by tape and feeler gauge, if fit-up problems routinely surface mid-lift, or if as-built records are reconstructed after restart, those are clear signals that an outage survey will protect your window.
Deliverables
ISS scopes deliverables during planning so there are no surprises at handover. A typical outage survey package includes:
- Pre-outage baseline report — as-found geometry, clearances and reference positions
- In-outage alignment reports — deviation tables, as-set values, tolerance compliance per component, issued as each activity completes
- Fit-check and clearance confirmations — go/no-go advice ahead of lifts and installations
- As-built survey plans — final positions of installed and modified equipment
- Registered laser-scan data — point cloud georeferenced to site control, in agreed formats (E57, RCP, or native)
- Recommissioning compliance summary — short-form sign-off issued before restart
- Full report — consolidated documentation, uncertainty statements and photographic record, delivered within 5-10 business days
Critical results — anything a lift or a coupling decision depends on — are reported verbally and in writing on the spot. The formal report never holds up the outage.
Cost factors
Outage survey pricing is project-specific and quoted as a fixed fee or schedule of rates after a scoping call. Per-day rates run higher than routine surveys because the work demands standby reliability, safety certification and often round-the-clock cover. The main drivers:
| Factor | Impact on cost | Indicative range |
|---|---|---|
| Planning and pre-outage site visit | Fixed scoping fee | $2,000-3,500 |
| Control establishment | Per day, pre-outage | $2,500-3,500 |
| In-outage attendance (scheduled) | Per day, 10-hour shift | $3,000-4,500 |
| In-outage attendance (standby) | Per day retainer plus call-out | $2,500-3,500 |
| After-hours / night shift | Shift loading | +25-50% |
| Laser scanning scope | Per day, additional | $3,000-4,500 |
| Reporting | Fixed fee | $1,500-2,500 |
A limited-scope outage survey might run $15,000; a comprehensive program on a major turnaround with continuous attendance and full scanning can exceed $60,000.
ROI context: set against a single hour of lost generation or production at $50,000-200,000, the entire survey program is recovered the moment it prevents one re-lift or one schedule slip. The genuine cost is not the survey — it is the extended outage that an unplanned survey causes.
How ISS delivers it
ISS treats the outage window as the project constraint and engineers the survey around it. We lock scope 4-6 weeks out, establish control before the area is congested, and schedule attendance against the work list so measurement is ready the moment an area is — never before, never after. Our surveyors hold current confined space, working-at-heights and site-specific certifications for power, refining and mining environments, and we carry redundant instrumentation so a single equipment failure never stops the line.
Because we are independent of any OEM, we align and verify equipment from any manufacturer using consistent methodology, and we mobilise to remote sites across WA, Queensland, NSW and beyond. The combination of MultiStation, scanner and tracker means we bring the right accuracy to each task without leaving the critical path waiting.
Frequently asked questions
How is an outage survey different from a shutdown survey?
They describe the same discipline. "Shutdown survey" and "turnaround survey" are the broad terms; "outage survey" is the term used most in power generation and for any time-bound window where the asset is offline. ISS delivers all three under one methodology — the difference is the schedule, the safety regime and the deliverable cadence, not the measurement itself.
Can outage survey work be done without extending the window?
Yes, and that is the whole point. Well-planned shutdown survey work runs parallel to mechanical activity and stays off the critical path. The surveyor measures when an area is ready and reports before the next activity needs the result. Overruns come from late scope and missing control, both of which planning eliminates.
What accuracy do you achieve during an outage?
Alignment work is typically ±0.3-1.0 mm with total station and MultiStation, and ±0.02-0.05 mm for coaxiality and concentricity using a laser tracker. As-built scanning is 2-6 mm at 50 m. All instruments are ISO 17025 calibrated and uncertainty statements accompany alignment deliverables.
When should we book an outage survey?
Four to six weeks before the outage date. That allows scope definition, a pre-outage site visit, safety documentation and crew scheduling. Late bookings risk unavailable crews, rushed methodology and lost window hours.
What do we receive before recommissioning?
A recommissioning compliance summary confirming each adjusted component is in tolerance, plus verbal and written sign-off on every critical result as it is measured. The consolidated full report, as-built plans and registered scan data follow within 5-10 business days.
Outage windows do not wait, and the difference between a survey program that protects your shutdown and one that derails it is planning, credentials and the right instrument for each task. If you have a unit outage, turnaround or processing shutdown coming up, talk to ISS early — call 0407 057 015 or visit industrialspatial.com to scope your outage survey and request a fixed-price quote.