TUNNEL CRITICAL SECTION MONITORING
Tunnel
convergence,
measured continuously
A compact camera that tracks the same prisms in your tunnel and reports sub-millimetre displacement to the cloud every 5 minutes. It fits where an automated total station can’t, and it runs without site visits.
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Read the UK case study
≤2 mm
Agreement with an automated total station in a live UK tunnel
>95%
Uptime across three months of unattended monitoring
0
Manual site visits needed during the deployment
5 min
Between readings, around the clock
WHERE IT’S USED
Metro & railway tunnels
Watch lining convergence and lateral movement while adjacent excavation, piling or dewatering changes the ground around an operational line.
Road tunnels
Watch lining convergence and lateral movement while adjacent excavation, piling or dewatering changes the ground around an operational line.
Utility & service tunnels
Monitor tight, hard-to-reach galleries where a total station is not set up, with LTE-M or Ethernet connectivity depending on what’s available underground.
Automated total stations are the established solution for continuous monitoring, but they require sufficient space, regular maintenance, and ongoing site attention.
THE OPERATOR’S PROBLEM
Nearby works change the stress state of the subsoil, and your obligations don’t pause while they correct foundations. Traditional instruments make continuous monitoring harder than it needs to be.
Clearance is non-negotiable
Bulky equipment inside a live tunnel competes with the vehicle or train envelope.
Every maintenance visit is a shutdown
Each calibration trip means a site visit, a permit and a safety plan.
The critical sections are the tightest
Monitoring from a position where an instrument fits, not necessarily where the risk is greatest.
HOW IT WORKS
TotaLite captures standard survey prisms and converts sub-pixel changes in the image into displacement. Convergence is computed automatically between the target pairs you define.
Prisms on the lining
The same standard survey prisms you’d use with a total station, fixed toward the sensor. Typically five per section.
Sensor on a bracket
Mounted rigidly, powered on site, and set up in about an hour. One sensor measures 15–25 targets at once.
Readings in the cloud
Relative displacement arrives on the TotaLite platform every 5 minutes, with alert thresholds set on each chart.
WHAT MAKES IT DIFFERENT
Why TotaLite?
Our device measures all points at once and keeps going between survey rounds, so movement shows up as it happens rather than at the next site visit.
Plan a monitoring session
Capability
Footprint
Measurement
Operation
Connectivity
TotaLite benefit
Installs in about 1 hour and fits where space is limited
Direct relative displacement measurement
Autonomous 24/7 operation
LTE-M or Ethernet connectivity
CASE STUDY
Matched an automated total station to within 2 mm, next to live construction
Academy Geomatics was commissioned to design a monitoring solution for an operational UK tunnel while excavation, pile driving, and dewatering activities were underway nearby. Continuous tracking of lateral movement and tunnel convergence was essential to meet the operator’s regulatory obligations.
≤2 mm
>95%
3 × 5
INSTALLATION & COMMISSIONING
These three stages are typically completed within a single visit, keeping your on-site time short and predictable.
STAGE 1
Preparation
•
Project assessment: device count, positions, sections and thresholds
•
Choose a standard or custom bracket
•
Choose connectivity: LTE-M or Ethernet
•
Verify the planned setup before the visit
STAGE 2
Installation
PRISMS
•
Installed as for a total station, minimum 2° separation
•
Typically 5 prisms per cross-section, facing the sensor
•
The TotalLite app guides target naming, LED power and measurement interval
SENSOR
•
Mounted rigidly on its bracket and powered on site
•
Recommended: a total station survey for slope distances to sensor and targets
STAGE 3
Commissioning
•
Create the baseline in the TotalLite app
•
Enter slope distances for each target
•
Define target pairs; convergence is computed per pair
•
Set alert thresholds on the displacement charts
SPECIFICATIONS
POWER
9.5–24 V DC, min. 18 W (sensor + shield)
CONNECTIVITY
LTE-M or Ethernet
PRISM SPACING
Minimum 2° angular separation
FIELD OF VIEW
60° horizontal · 45° vertical
TARGETS
15–25 standard survey prisms per sensor
SETUP TIME
About 1 hour per sensor
CABLING
Daisy-chain Ethernet, up to 200 m
READING INTERVAL
Every 5 minutes, 24/7
CERTIFICATION
CE · UKCA · FCC · IC
BEYOND THE SENSOR
The real bottleneck
is the data silo
Most tunnel movement data stays with one contractor, on one project, often in one shift’s logbook. It is rarely compared across tunnels or pooled across organisations, which keeps tunnelling on fixed inspection schedules while rail, aviation and automotive act on continuous signals.
Closing that gap starts with monitoring that can be deployed everywhere it’s needed, including the tightest sections of a live tunnel. Continuous data turns many monitored sections into an asset early risk signature, so issues are spotted before a threshold is crossed, on the next tunnel as well as this one.
“Because what we can’t see, we can’t manage.”
From the TotaLite manifesto
Have a tunnel section that
needs watching?
Tell us about the asset, the nearby works and your thresholds. We’ll scope the sensors, positions and connectivity with you.
Talk to TotaLite team ›