TL;DR: This mechanical surveys FAQ answers the questions Australian maintenance managers, reliability engineers and project teams ask most often — what a mechanical survey actually measures, the tolerances achievable, what it costs in AUD, and how to schedule one around a shutdown. Mechanical surveys verify and align industrial machinery and structures to sub-millimetre tolerances, and on critical rotating equipment the survey typically costs 1-3% of what misalignment costs in downtime.
Key takeaways
- A mechanical survey measures the geometry of industrial assets — mill and kiln centrelines, crane rail span and level, conveyor straightness, structural as-built position — to tolerances between 0.1 mm and 5 mm depending on the task.
- ISS works exclusively with Leica Geosystems instruments: the MS60 MultiStation (0.5" angle, 1 mm + 1 ppm distance) for alignment and monitoring, and the RTC360 laser scanner (2 mm at 10 m, up to 2 million points/second) for 3D as-built capture.
- Indicative day rates run $2,500-$4,500 + GST depending on service, with mobilisation to remote sites such as the Pilbara or the Bowen Basin adding travel and FIFO costs.
- Cold alignment (ambient) and hot alignment (operating temperature) can differ by several millimetres on a long kiln; an experienced surveyor accounts for thermal growth in the analysis.
- There is no single "mechanical survey standard" — instrument, method and tolerance are matched to the asset, with reference to AS 1418 (cranes), GDA2020/MGA2020 and AHD where site coordinates apply, and manufacturer alignment specifications.
What a mechanical survey covers
A mechanical survey is precision dimensional measurement of plant and equipment, not land. Where a cadastral or topographic survey deals in boundaries and ground level to centimetre accuracy, a mechanical survey works at millimetre and sub-millimetre tolerances on the assets that keep a plant producing.
The discipline groups into a handful of recurring jobs across Australian heavy industry:
| Service | What is measured | Typical tolerance |
|---|---|---|
| Dimensional control | A local reference network tying all measurements together | ±1 mm over 500 m+ |
| Mill and kiln alignment | Rotation-axis centreline, slope, tyre/roller contact, girth-gear runout | ±0.5 mm |
| Crane rail alignment | Span, gauge, top-of-rail level, straightness | ±2-3 mm |
| Conveyor alignment | Pulley and idler line, structure plumb, belt centreline | ±3 mm |
| Laser scanning | Full 3D point cloud for as-built, clash and clearance work | ±2 mm at 10 m |
| Monitoring / deformation | Movement of foundations, shells and structures over time | Sub-millimetre |
| Structural as-built | Steel and concrete position against design | ±5 mm |
These overlap in practice. A SAG mill realignment in the Goldfields, for example, usually starts with a fresh dimensional control network, then layers static centreline measurement and a laser scan of the surrounding structure on top of it.
How accurate is a mechanical survey?
Accuracy is chosen to suit the task rather than fixed in advance. For precision deformation monitoring, ISS achieves 0.1-0.5 mm using a Leica MS60 with multiple rounds of observation. Equipment alignment sits around 0.5-1.0 mm, general dimensional control 1-3 mm, and laser-scan detail 2-5 mm at 10 m range.
That range matters because chasing tenths of a millimetre on a conveyor gantry wastes money, while accepting 5 mm on a girth-gear alignment would be negligent. The skill is matching method to consequence — a 2.3 mm centreline deviation on a Pilbara SAG mill was enough to cut bearing life from twelve months to six weeks until it was measured and corrected.
What equipment and standards apply?
ISS uses Leica instruments end to end. The MS60 MultiStation and TS16 total station handle alignment and control work; the RTC360 captures point clouds; Cyclone and Infinity process the data, with least-squares network adjustment giving every coordinate a known uncertainty rather than a single uncorroborated number.
Standards depend on the asset. Crane runways reference AS 1418.1 and AS 1418.18 for tolerances and inspection intervals. Where a survey is tied to site or mine-grid coordinates, ISS works in GDA2020 with MGA2020 grid eastings and northings and AHD for height. Rotating-equipment tolerances come from the OEM's alignment specification — Metso, FLSmidth, thyssenkrupp and similar — read alongside the plant's maintenance history. Any UAV work supporting a mechanical survey (for example, scanning a high structure for as-built context) is flown under CASA Part 101 by a remote pilot operating to the firm's RePL and ReOC obligations.
Frequently asked questions
How much does a mechanical survey cost in Australia?
Indicative day rates are $2,500-$3,500 + GST for dimensional control, crane rail and conveyor work; $2,800-$4,000 for mill or kiln alignment; and $3,000-$4,500 for laser scanning. Most jobs run one to five days. The variables that move the price are remoteness (FIFO mobilisation to the Pilbara, Bowen Basin or Mount Isa), confined-space or working-at-heights access, after-hours or shutdown timing, and how tight the turnaround is. A clear scope produces a clearer fixed price — call 0407 057 015 to discuss yours.
How often should rotating equipment be aligned?
Verify alignment annually, or after any significant event — bearing replacement, shell-section change, foundation repair, or a knock from a crane or vehicle. Operations with high reliability targets often run six-monthly checks on their most critical mills and kilns. Between formal surveys, trends in vibration, bearing temperature and motor power draw are useful early warnings that geometry has drifted.
What is the difference between cold and hot alignment?
Cold alignment is measured with the unit at ambient temperature; hot alignment is measured at or near operating temperature. On a long rotary kiln, thermal growth can shift the shell several millimetres, so the two readings legitimately differ. ISS records the temperature condition and corrects for thermal expansion so the reported geometry reflects how the equipment behaves when it is actually running, not just when it is cold and stopped.
What do I need to provide before the survey?
At minimum: equipment general-arrangement drawings and the OEM alignment specification, any previous alignment or survey records for trend comparison, your site access and induction requirements, and a written scope of work. For shutdown surveys, the shutdown schedule and the survey window — including cooldown time — drive the methodology. The more context the surveyor has, the faster and more valuable the result.
Can a mechanical survey be done during a shutdown?
Yes, and most are. ISS operates 24/7 and routinely works inside shutdown and turnaround windows, often on night shift to stay off the critical path. The constraint is access and cooldown rather than survey time — scaffolding, isolation and a cool-enough surface need to be ready when the crew mobilises. Book shutdown work early, as peak periods (March-April and September-October) fill weeks ahead.
Request a quote
If you have a mill, kiln, crane runway, conveyor or structure that needs precise measurement — or you simply want a baseline before the next shutdown — ISS will scope the work, recommend the right method, and provide a clear proposal. We operate Australia-wide from our base in the Illawarra Region, NSW, with crews mobilising to mine sites and processing plants across every state. Call 0407 057 015 or visit industrialspatial.com to discuss your mechanical survey requirements and request a quote.