Power

Industrial Access performed a drone inspection on a decommissioned brick chimney. The structure was found to be in very poor condition, with brickwork severely cracking and crumbling, posing an active falling object hazard. Later, the client contracted Industrial Access again to perform chimney demolition services. The drone inspection allowed Industrial Access to safely and quickly determine the structure’s situation and help the client develop the best strategy for the chimney moving forward.

A power generation plant in the Eastern USA was looking to conduct a visual inspection for their decommissioned, 195’-tall brick chimney and adjacent abandoned building. Industrial Access (IA) team was set to perform a ASCE Class I inspection utilizing a UHD video camera drone to determine the current condition of the failed structure and provide expert recommendations for the facility and its chimney moving forward.

A drone inspection is an excellent solution for structures and job sites with limited/difficult access or potential safety hazards that may pose a risk to workers. A drone can collect data and photographic evidence from areas of a structure or site that were previously inaccessible, dangerous or expensive to access—all from the comfort and safety of the ground. By using the data collected from the drone during a preliminary inspection, our team can identify areas of concern and create a plan to address any deficiencies or need for repairs utilizing our rope access methods, overall saving a lot of time and money to the client while ensuring the safety of the personnel.

Since the brick chimney was in hazardous condition, carrying out a drone inspection was the recommended option for its safety and efficiency. The drone was able to capture high-resolution footage of the entire structure’s exterior without needing to spend resources to create proper, safe conditions for crew access.

During the demolition, a crane was utilized to carry a man-basket around the chimney during the removal of the upper 50’ stack section, the platform and its ladders. Then, some portions of the breeching ducts were eliminated to provide better access for demolition equipment and periodic debris removal. Manlifts were used to carry out the rest of the chimney demolition.

The inspection confirmed that a big portion of the chimney’s brickwork has almost or completely failed. The top 20’ of the stack was in the worst condition with large areas of missing bricks, separation between wythes and courses of the brickwork, missing mortar, and severe bulging of stack between steel tension bands. Visual data gathered from the drone revealed anomalies such as multiple large cracks along mortar joints, snapped steel band, oxidation of steel appurtenances, and more. The crumbling brickwork as well as the fallen bricks on the platform and doghouse roof were posing an active falling object hazard around the base of the chimney. This evidence of severe deterioration confirmed that the platform is not safe to use, and that the top section of the stack had reached failure beyond repair.

IA’s team of experienced engineers and technicians determined that the top of the chimney and the existing platform could no longer be repaired and thus should be demolished to mitigate the safety hazards. Meanwhile, the remainder of the chimney could potentially be salvaged with extensive costly repairs on brickwork, mortar joints, and steel bands; however, both IA and the client agreed that the most sensible long-term solution was to demolish the chimney to its entirety. Several months later, IA mobilized on-site to carry out the demolition.

During demolition service mobilization, the site was prepared by clearing the area off of vegetation and large debris, barricading the area and setting up safety rigging and devices in accordance with appropriate regulations. The breeching ducts were partially dismantled for demolished brick removal access. Demolition began by first carefully removing top bricks in small sections using a handheld hammer and electric or pneumatic demolition hammers. The bricks were then dropped down the interior of the chimney. Steel bands were cut off, existing doghouse enclosure was removed, so were the platform, ladders, davit, and other appurtenances. IA crew continued pulling bricks apart until the chimney was completely demolished. The brick rubble and metal waste were collected for disposal. Before leaving the site, IA sealed off the four open breeching ducts with metal plates.

The installation of the new refractory system was completed successfully and on time. This repair will help ensure the longevity of the structure and maximize its operational efficiency. It is important to protect the steel plate of smokestacks from their harsh interior environment in order to preserve their structural integrity and safety. Performing regular inspections and timely maintenance on steel stacks and their liners will help identify signs of deterioration early and take preventive measures before extensive damage occurs.