From weeks of surveying to just days: ROCO is reshaping Antwerp’s future with Propeller

On Belgium’s biggest infrastructure project, TM ROCO rebuilt its surveying and planning workflow around a single, shared digital environment — powered by Propeller, enabling excavation tracking, compliance, and collaboration across 600+ users.

A project too big for traditional surveying

The Oosterweel Verbinding is unlike anything Belgium has attempted before. By 2033, Antwerp’s notorious traffic will run partly underground through a new network of tunnels, freeing space for parks, bike lanes, and improving air quality.

ROCO is leading construction on the right bank — a massive stretch of canal tunnels, sunken highways, and underground crossings. The scope is staggering: vast amounts of concrete and steel to install, and strict environmental checks at every stage.

Trying to keep up with this using traditional surveying? Impossible.

A team of seven or eight surveyors could spend a week in the field – and data would already be outdated by the time it hit the desk.

Propeller turned that bottleneck on its head

Today, a single drone flies over the entire site in two days. Once processed in Propeller, the data is immediately accessible to hundreds of team members. Because of its ease of use, weekly drone flights now provide accurate site progress and keep all users aligned.

Engineers review progress without walking the site
Designers verify if plans work before digging begins
Project managers track excavations and machine access from their screens.

Every meeting, someone says: ‘Let’s take a look at Propeller. It’s our shared reference point.’
— Bert Limbos, Survey Manager.

Proof that pays off

For ROCO, Propeller isn’t just about speed. It’s about protection.

Compliance: Historical imagery shows exactly where soil and materials were placed, demonstrating that no pollution occurred.
Dispute resolution: When machines blocked access on a narrow stretch, drone flights every few hours provided undeniable proof of delays
Accurate billing: With Propeller’s visual record, invoices are based on facts, not assumptions

Propeller gives us visibility into the site’s history, present, and future — all at once.
— Bert Limbos, Survey Manager.

Collaboration at the scale of 600 users

At ROCO, Propeller is not limited to surveyors. More than 600 people across diverse disciplines – from crane planners to environmental managers – rely on it.

Workspaces keep things tidy, so each group sees only the information relevant to their role. That makes adoption stick: about 70% of users are actively uploading designs, measuring and planning.

If you walk through our office, you’ll see Propeller on every display. It’s part of our daily business. — Dave Wels, Drone Pilot.

The tools that matter most to ROCO

Weekly site mapping

Challenge before Propeller: Traditional surveys required seven or eight surveyors over a full week, and data was outdated by the time it was ready.

Solution with Propeller: Processes drone flights in Propeller to map the entire site in just two days.

In practice at ROCO: A single pilot delivers fresh, accurate maps for every team, replacing weeks of manual work.

Design overlays

Challenge before Propeller: Identify and resolve design conflicts early, ensuring smoother collaboration and streamlined workflows.

Solution with Propeller: Overlays CAD files directly onto drone surveys to check if designs match real-world conditions.

In practice at ROCO: Designers and engineers validate feasibility early and adjust before construction begins.

Proof for compliance and billing

Challenge before Propeller: Provide clear proof of compliance and usage, ensuring transparency and smoother workflows.

Solution with Propeller: Creates a historical visual record of activity across the site.

In practice at ROCO: Documents compliance with pollution regulations, supports accurate invoicing, and provides indisputable evidence during disputes.

Vertical imagery

Challenge before Propeller: Inspecting large installations and structures was time-consuming and inconsistent.

Solution with Propeller: Generates vertical imagery for detailed inspection and documentation over time.

In practice at ROCO: Records building and installation conditions at handover, and years later, to prove quality and prevent disputes.

Workspaces for large teams

Challenge before Propeller: Hundreds of users across different disciplines needed access to data without being overwhelmed.

Solution with Propeller: Tailors platform views so each department sees only what matters to them.

In practice at ROCO: More than 600 users, from crane planners to environmental teams, use Propeller daily with streamlined access.

Results at a glance

600+ users across every discipline
2 days of flights replace 1 week of traditional surveys
70% active users uploading designs, measuring, planning
Full compliance record to protect against disputes
Propeller integrated into every project meeting

Final word

Through the Oosterweel project, ROCO is defining best practice for integrating Propeller into day‑to‑day workflows ensuring that survey, design, and delivery stay in sync.

Propeller isn’t just another tool. It replaces traditional surveys and is the way we run this project. — Dave Wels, Drone Pilot.

By using Propeller we have a weekly update over the entire construction site. This allows all our disciplines to work with the latest situation on site. Mapping flights is an indispensable part of our processes. — Bert Limbos, Survey Manager.

About ROCO

TM ROCO leads delivery on the right bank of the Oosterweel Verbinding, combining deep civil expertise with a digital execution model. Our teams integrate design, surveying, and construction in one shared environment to build safer, faster, and with full accountability.