Throughout France, engineering structures - bridges, viaducts, footbridges and aqueducts - are major components of the public infrastructure network. In Seine-Maritime (76), a densely populated urban and industrial area, these structures support thousands of vehicles, trains and pedestrians every day. Their good condition is therefore crucial to user safety, traffic flow and the resilience of logistics networks.
But these structures are aging. Built for the most part in the 50s and 80s, these structures are subject to wear and tear over time due to loads, weathering, corrosion and ground movement. Regular, in-depth inspections are essential to prevent damage, extend service life and prioritize maintenance operations.
Traditionally, these inspections require heavy equipment: gondolas, scaffolding, rope access, traffic interruptions... Efficient methods, but costly, slow to deploy, and sometimes dangerous for operators.
To meet these challenges Multinnovthe French specialist inrobot and drone inspection, has developed innovative solutions adapted to these complex environments. Thanks to our Stereo2inspection drone, we can carry out high value-added missions, with no contact with the structure, no disruption to traffic, and optimum analysis accuracy.
Presentation of our activities
Multinnov is a French company with a clear ambition: to provide access to complex technical environments without endangering operators or disrupting installations. For over ten years, we have been developing inspection robots and drones designed to intervene in :
- confined spaces (tunnels, tanks, technical ducts);
- areas without GPS signals (underground structures, industrial buildings);
- dangerous or unstable areas (aging structures, active industrial sites, etc.).
We support public and private customers in collecting visual data (photos, 4K videos, ITV reports) in a variety of contexts:
- public infrastructure (sanitation, bridges, roads) ;
- industrial sectors (energy, chemicals, transport, agrifood);
- engineering and diagnostic offices (structural controls, pre-construction inspections);
- post-incident situations (explosions, fires, floods).
Our approach is based on :
- mastery of our technologies (development and assembly in France);
- ability to adapt quickly to the terrain;
- impeccable image quality thanks to our on-board 4K cameras ;
- and, above all, a constant commitment to safety.
Maintenance and inspection of engineering structures and bridges
Bridges, viaducts and other concrete and metal structures are complex structures subject to numerous mechanical and climatic stresses. Water, wind, corrosion, road or rail traffic all contribute to structural fatigue, sometimes invisible to the naked eye... until the critical moment.
Common structural pathologies
Among the most common defects are :
- cracks in concrete or supports ;
- reinforcement coating bursts (internal corrosion) ;
- damage to expansion joints;
- deck deformations;
- or run-off and seepage threatening foundations.
These defects, if not identified in time, can lead to serious failures or even partial collapse. Regulatory requirements therefore call for regular inspections (visual, destructive or televisual) to anticipate repairs.
The limits of traditional methods
To inspect certain sensitive points (bridge intrados, abutments, voussoirs, suspended joints), technical departments often call on :
- telescopic platforms;
- suspended scaffolding;
- or specialized rope access technicians.
But these interventions have their drawbacks:
- significant mobilization of personnel and equipment;
- high cost (transport, safety, lane closures) ;
- human risk (falls, physical constraints, exposure) ;
- traffic downtime;
- difficult access to certain areas (over water or active railroads).
Case study: Multinnov at Infraneo
In 2024, Multinnov was commissioned by Infraneoan engineering firm specializing in structural diagnostics, to work on a railway bridge in Seine-Maritime. The brief was to inspect theunderside of the structure, located above a heavily trafficked road, without blocking traffic or installing a gondola.
Course of the mission
The Multinnov team Multinnov team deployed the Stereo2our in-house-developed inspection drone, capable of flying without GPS, in closed or dark environments.
Here are the key steps:
- Preparing the take-off area, in lateral safety ;
- Hovering Stereo2 under the bridge deck, with lateral inspection of walls and supports;
- 4K image and video capture with motorized camera orientation;
- Powerful integrated LED light for exploring shadowy areas;
- Recording and live transmission to the operator's tablet ;
- Complete survey of visual defects: cracks, seepage, splinters, joints.
Results
- Zero traffic disruption for the duration of the intervention;
- Complete inspection in less than half a day;
- Accurate visual report sent to Infraneo the next day;
- No risk to agents;
- More than 40% lower intervention costs than with a gondola inspection.
With Stereo2, we were able to access 100% of the target zones, without any contact with the structure, while offering analysis quality in line with the requirements of structural design offices.
Bridges and civil engineering structures are crucial elements of our landscape. Their maintenance cannot be left to chance. Yet conventional inspection methods are often time-consuming, costly and risky, and difficult to reconcile with modern traffic constraints.
With the Stereo2Multinnov provides a technological, efficient and sovereign response to these challenges. Our made-in-France inspection drone enables :
- reduce the cost and duration of inspections;
- safety for agents (no physical intervention at height) ;
- collect high-quality images, even without light or GPS;
- avoid any disruption to service or traffic.
In the Seine-Maritime department, but also throughout Normandy and the rest of France, we support local authorities, engineering offices and public works companies in optimizing the maintenance of their engineering structures.
Need to inspect a bridge, viaduct or other hard-to-reach structure? Contact Multinnov for a free demonstration or a personalized quote.
Our teams are ready to intervene in the 76 region and anywhere in France, in complete safety, without compromising on quality.
