Leonard unveils Descender Duo, a dual-head robotic demolition arm designed to improve industrial safety and reduce shutdown time by up to 50 per cent.
Industrial robotics and refractory services specialist Leonard has launched Descender Duo, a dual-head robotic demolition arm designed to improve safety, accelerate maintenance and reduce shutdown times in hazardous industrial environments. The system made its debut at Lisahally Power Station in Northern Ireland, removing 25 tonnes of slag material within hours.
Developed for the cement, metals, waste-to-energy and petrochemical industries, Descender Duo enables remote-controlled refractory demolition, anchor cutting and welding, and refractory spraying inside boilers, calciners and silos. Its vertical-access design eliminates the need for personnel to enter confined, high-risk spaces during these operations.
Weighing less than two tonnes, the pre-assembled system requires an access opening of just 1.2 m². Supported by an external overhead hoist, it uses electrically operated hydraulic stabilising legs to secure itself inside vessels. The robotic arm offers 360-degree rotation and is suited to vessels approximately 9 m in diameter, with its operating reach extendable through strategically positioned access points.
Equipped with two independently controlled robotic heads, Descender Duo can perform identical or different tasks simultaneously, including refractory demolition, anchor cutting and spraying. Its remote-control system incorporates live camera feeds, allowing operators to monitor operations without entering hazardous environments.
According to Leonard, the technology can deliver time savings of up to 50 per cent compared with manual methods. Its ability to operate at temperatures exceeding 100°C allows maintenance to begin as early as 24 hours after burner shutdown. An all-electric power supply further supports cleaner and more cost-efficient operations.
First Deployment Demonstrates Shutdown Efficiency
The system was first deployed at Burmeister & Wain Scandinavian Contractor’s (BWSC) Lisahally Power Station in Londonderry, Northern Ireland. The facility generates electricity from grade C waste wood, supplying approximately 40,000 homes and businesses.
Leonard and BWSC collaborated to develop a customised solution for the plant’s 26-metre furnace, where extensive external pipework created significant access challenges.
Mark Leonard, Managing Director, Leonard, said, “It required new thinking and rather than step away from the problem we were committed to solving it for the customer, with the customer. We’re relentless in our approach to tackling complex challenges, head-on. We took our years of cement plant experience, coupled with our working knowledge of the BWSC plant, and designed, engineered and tested a completely new vertical solution within just seven weeks from that initial conversation with the customer. That solution was the Descender Duo as we know it today.”
Traditionally, the furnace required a cooling period of up to 36 hours before preparatory work could begin, followed by manual slag removal using rope-access personnel. With Descender Duo, work commenced just 24 hours after shutdown, reducing downtime by up to one day.
The deployment removed 25 tonnes of slag within hours, eliminated the need for at least six workers to enter the hazardous furnace interior and saved 26 hours in the shutdown programme.
“The effectiveness exceeded expectation,” said Martin Doran, Plant Manager at Lisahally Power Station.
“When the Descender Duo concept was first discussed, we had to spend some time with the team from Leonard looking at how it was going to be moved into the furnace. Every site is different and that presented its own challenges, but nothing that the team couldn’t overcome. Once it was installed we were hugely impressed by its efficiency.”
Expanding Industrial Robotics Applications
Descender Duo joins Leonard’s existing portfolio of robotic maintenance solutions, including the Axis horizontal-access arm, Nano confined-space access arm, Charger cement mill media recharging system and Calibre cement mill media grading system.
Headquartered in Northern Ireland, Leonard provides robotic refractory demolition, installation, inspection and industrial maintenance services across the cement, metals, energy, biomass, glass and civil engineering sectors.
Formerly known as G Leonard, the company has more than 35 years of industry experience and operates across Europe, North America, the Middle East, Africa and Asia-Pacific.
The latest innovation reinforces Leonard’s focus on replacing hazardous manual processes with robotic systems that improve workforce safety, enhance operational efficiency and minimise industrial downtime.