PF Geomatics is a London surveying and site engineering specialist, led by Managing Director Paolo Fernandes (TCInstCES). It supplies precise data to contractors, steel fabricators and rail teams across London and the South East, on a “right first time” promise. Rail possessions are short and hard to secure, so mistakes are costly.
The key tool is a Trimble X9 3D laser scanner, bought from KOREC just over a year ago. It captures highly detailed point clouds of rail bridges and tunnels, which become accurate Revit models. Fabricators can then design strengthening plates and new components faster, with fewer clashes.
The challenge: bridges and tunnels
Many of London’s bridges and tunnels are over a century old. Surveying them means capturing millimetre-level detail of rivets, plates and flanges as well as the wider structure. Traditional total station surveys record only selected points, so fabricators and designers end up working from incomplete information.
Time is the other constraint. Teams contend with short possession windows, passing vehicles, low light, restricted access and the repetitive geometry of tunnels. Clients still need data they can design and fabricate from without clashes, delays or rework.
The solution: Trimble X9 scanning
After a KOREC demonstration, Paolo invested in the X9 and Trimble Business Center (TBC) processing software. For bridge and tunnel work, these features count most:
| Feature | Benefit on site |
|---|---|
| Auto-calibration | No downtime; scanning starts at once |
| Image quality | Clients call it “mind-blowing”; bolts and rivets show clearly, even in low light |
| On-site registration | Instant proof that scans overlap and connect |
| Range & low light | Suits tunnels and bridge undersides |
| Pause Scan | Stops and resumes when vehicles or people block the view |
| Perspective & TBC | Smooth tablet-to-office workflow, or Trimble RealWorks when working with Bidston Draughting |
| Trimble ecosystem | Helps clients on Tekla Structures, whose point cloud handling reduces errors |
The X9 on site
Camberwell Railway Bridge
Camberwell Grove Bridge is a Victorian structure, around 150 years old, that crosses the railway and has been closed to motor traffic for several years over safety concerns. Working for McNealy Brown, a contractor known for collaborative rail delivery within tight possessions, PF Geomatics had to capture every structural detail to support components for the upcoming strengthening works.
During a full night-time possession, Paolo scanned the top and underside of the bridge, including every flange, gap and rivet line. The X9 sat on an elevated tripod secured to a scissor lift, which held it steady against strong winds in restricted areas.
Afterwards, Jack Bidston, Director of Bidston Draughting, worked alongside Paolo with a Trimble X7 scanner. The two datasets were combined in TBC, and the resulting Revit and 3D DWG models are now being used to fabricate the strengthening components.
Lambeth Bridge
Opened in 1932, Lambeth Bridge is a Grade II-listed, five-span steel arch bridge over the Thames, now being upgraded. A small protective wall at the bridge edge meant careful scanner positioning, so that deck data could be tied to underside scans of the same location in one complete Revit model.
On-site registration reassured Paolo that everything had been captured, and the client was extremely impressed by the point cloud and imagery. Pause Scan proved its worth whenever local noise interrupted the scan.
Tunnelling work
Tunnels are among the hardest places to scan: uniform surfaces, repetitive features and changing site conditions. PF Geomatics specialises in them, and the X9 has helped the team build a streamlined, efficient process.
- Establish strong control. Prisms every 100 to 200 metres, with multiple sets of angles observed.
- Place plenty of targets. Black and white targets link each scan to the next, giving one point cloud rather than isolated local scans.
- Register on site. Paolo confirms straight away that scans connect with enough overlap.
- Break the sameness. If a uniform tunnel defeats registration, he rotates the X9 to break the link and connects one target to the next.
- Pause, don’t restart. When a vehicle intrudes, such as a van clearing gutters, the scan is paused and resumed without losing registration.
The client benefits directly. On bridge and tunnel panel projects they need accurate panel sizes and clear identification, and a single registered scan makes their spray-marked panels easy to pick out.
The results
For McNealy Brown, the PF Geomatics workflow has been a game changer. Weeks of manual templating with Perspex sheets, followed by office draughting, now take one or two shifts. The X9 scan holds the detail needed for an accurate Revit model, so McNealy Brown can start producing new components almost immediately.
“The onsite registration is brilliant – you know straight away if you’re right or wrong. The image quality is mind-blowing for my steel clients. In rail work you don’t have time to mess about, and the X9 lets me crack on and deliver the detail they need. My clients have great confidence in the end deliverable and even those new to laser scanning are convinced after seeing the clarity of the X9’s imagery.”
