The firefighting robot of Notre-Dame

It happened on 15th April 2019, on Île de la Cité, in the heart of Paris. Notre-Dame has been standing there for over 850 years. The iconic gothic building, a stone vessel richly decorated with arabesques and gargoyles, was built between the 12th and 14th centuries. For a very long time, it was one of the largest cathedrals in the world and the highest building in Paris. It has also been the most visited monument in France, welcoming over 20 million people every year.

That all changed on the night of 15th April.

That evening, before the eyes of appalled Parisians and shocked viewers from around the world, Notre-Dame was burning. The alarm was first raised at 6:18 p.m. by the security PC of the cathedral. Due to an incredible chain of events (which are still under investigation), it took 30 minutes before the fire brigade were called. When the first troops arrived at around 7 p.m., it was already far too late. The fire was spreading at an incredible rate through the roof, fuelled by the famed latticework of ancient oak timbers, some of them dating back to the 13th century, so dense and vast that they were referred to as ‘the forest’. Reinforcements were called.

Within the first hour, 400 firefighters tried to save as much as they could of the building. Some crews were even sent inside, risking their lives, to save the artworks and to try and prevent the collapse of the towers. However, a little before 8 p.m., they were all called back, rightly so. The roof had been gradually crashing down in several parts. Temperatures rose to a blazing 800°C inside the nave, the lead contained in the great spire melted and was flowing like lava. The spire itself collapsed a few minutes later. 

As the site became too dangerous for humans, the firefighters sent in their non-human colleague: Colossus.

Colossus is a universal technical support robot. A remotely controlled ground-based drone with an empty weight of 500kg, entirely electric, 1.6m long and a little less than 80 cm wide and high. A 100% French-made design created by Shark Robotics and launched in 2016.

As its pilot, using his reinforced touchpad, guided the drone through Notre-Dame, Colossus was configured in fire extinguisher mode: carrying a fire hose pumping 2500 litres of water per minute, a day/night 360-degree camera with 30x zoom, a thermal camera, gas and temperature sensors. All of it completely watertight and resistant to heat radiation, mounted onto a platform made of aerospace grade aluminium and hardened steel, driven by crawlers. A battle-proven beast. 

“Colossus is the most powerful electric robot in the world”, explains Cyril Kabbara, cofounder of Shark Robotics. “Its two engines, 4000W each, deliver a torque of 300N/m – which is absolutely enormous!”

It is capable of carrying 500kg of material. Or of pulling up to 250m-long and 70mm-diameter hoses full of water, which weigh 1 ton (“you’d normally need about 15 men for such manœuvres”).

There are other industrial robots as powerful as Colossus, admits Kabbara, but they are much bigger in size and, more importantly, equipped with traditional combustion engines. “It makes them impossible to use in fire: the lack of air could choke the engine and the fuel could explode.”

With its six 29.8V/46Ah lithium-ion batteries, Colossus can work for 10 to 12 hours. It moves at 3.5km/h, rolls over 30cm obstacles (stairs, rubble), goes up and down 45-degree slopes. Its radio range is 500m outdoors and 200m indoors. According to Shark Robotics, it takes no more than half a day to learn how to control it.

Colossus is not a single-mission robot, quite the contrary: it was designed from the beginning to be modular. It can be quickly con-figured and reconfigured, to adapt to each situation, thanks to a Picatinny rail interface (the same is used for mounting firearm accessories in a snap) and an ad-hoc connection solution.

Among possible accessories there are all types of fire hoses, smoke extraction fans, a robotic arm to manipulate objects, a motorised ram, stretcher carrying frames, baskets for transporting material or long-distance (5km) transmitter kits.

Thanks to its multiple configurations, it can be used for fire extin-guishing, land mine clearance operations, transporting material or injured people, reconnaissance operations (measurements, collecting information), or even decommissioning nuclear power plants.

All these operations have one common feature: dangerous terrain, which is no coincidence. 

“All our robots are designed to keep people away from hazards”, highlights Kabbara. “We created our company exactly for this purpose.” 

Shark Robotics was founded in 2016 in La Rochelle, on the Atlantic coast. “For historical reasons, but also because the area is highly suitable: major universities and large machining factories bring us their knowledge and expertise.” Cyril Kabbara is a business intelligence specialist, with an army and defence industry background. The other co-founder, his friend Jean-Jacques Topalian, is a mechatronics engineer and, as Kabbara calls him, “the brilliant inventor of the firefighting robots in France.”

Shark Robotics designs and manufactures everything in-house in La Rochelle – including machining and assembly. The SME only develops the hardware. The software is flexible, customers decide what they need to add. 

“From the very start, we wanted to be a profitable company and not a drip-fed start-up” says Kabbara. “We wanted to sell and so we had to propose products that were already mature.” Therefore, Shark Robotics involved potential users – fire brigades, military and industrial special forces and others - from the very beginning. “We told them ‘use our robots and break them if you have to!’ which generated rather high costs, but it also helped us achieve our goal: to provide powerful, reliable, durable solu-tions best adapted to the sector.”

Shark Robotics robots – currently about ten models – are fully standardised. It was necessary for convincing fire brigades, the police, the French army, ArianeGroup, Total, Thalès, Areva… customers that are regular users of their robots: “Our robots are deployed in real-life situations about a dozen times a week in France.” estimates Kabbara. “Which gives us a lot of feedback.”

Among their most spectacular interventions, there was a fire in January 2018 in Choisy-le-Roi, in the southern suburbs of Paris. A massive fire burnt down two levels of an underground parking area, destroying about fifty cars with temperatures rising up to 600°C. Colossus was fully deployed. 

Shark Robotics has 20 employees and regularly strengthens its team. Around 30 robots, including 10 Colossus, have been sold in France and in Belgium. The SME has started shipping to other  foreign countries as well, in the Middle-East, South America and Japan. “We have firm orders worth 5 million euros for the next 2 to 3 years. We are now planning a minimum production of 10 to 15 robots a year.” 

In April this year Colossus was deployed for several hours in the Notre-Dame fire. Its camera and thermal sensors were the “eyes” that made it possible for the firefighters of Paris to estimate the situation continuously and to locate the hottest fire spots to better target their efforts. Its fire hose shot millions of litres of water inside the cathedral, extinguishing fires and lowering the temperature of the nave’s walls.

After hours of exhausting battle, the fire-fighters managed to protect the cathe-dral’s main structure, its two famous square towers, its treasury and the better part of its artworks. A miracle in itself, because Notre-Dame has only narrowly escaped its complete destruction. It was all a matter of minutes, which makes Colossus’ role even more decisive. 

The press acclaimed the heroic bravery of the firefighters. It has also published a number of enthusiastic headlines on Colossus, that Cyril Kabbara is keen on amending. 

“Colossus did not save Notre-Dame! It is merely a tool, the firefighters did the job.” This is true, but if we imagine the robot, working stoically, all alone in the middle of the nave transformed into an inferno, we perfectly understand why journalists have made Colossus a hero worthy of the Marvel universe.