VADODARA, GUJARAT, INDIA — Hirva Anwesha Infratech Limited (HAIL), a Vadodara-based mechanical, civil, and EPC contractor, has successfully completed India's first ammonia storage tank decommissioning using the reverse jacking method at the Birla Copper Ltd. facility in Dahej, Gujarat. The project, contracted through Ostwal Phoschem (India) Ltd., involved the complete dismantling of a double-wall ammonia storage tank and a 55-metre-high flare stack — achieving a zero-incident safety record throughout the operation.
The Challenge
Decommissioning an ammonia storage tank is among the most hazardous operations in the industrial EPC sector. Anhydrous ammonia is toxic at concentrations as low as 300 ppm, flammable above 16% concentration in air, and the cryogenic inner shell operating at minus 33 degrees Celsius poses a brittle fracture risk during uncontrolled warm-up. Traditional top-down dismantling methods require workers to perform cutting operations at heights of 25 to 30 metres for weeks, using full external scaffolding weighing approximately 600 metric tonnes.
The Solution: Reverse Jacking
HAIL deployed the reverse jacking method — a technology that inverts the conventional dismantling sequence. Instead of cutting shell rings from the top down at extreme heights, hydraulic jacks lift the entire tank structure while each shell course is cut and removed at ground level. The result is a 90% reduction in working-at-height man-hours and a 35% faster project schedule compared to conventional methods.
The operation followed a rigorous safety protocol including:
- A HAZOP study conducted in consortium with RINA Consulting
- Controlled ammonia drain-down and nitrogen purging
- Scrubber-controlled venting
- Cold cutting techniques to eliminate hot work risks in vapour zones
- Continuous downwind ammonia monitoring throughout the entire dismantling process
Key Results
- Zero major safety incidents throughout the high-risk operation
- 90% reduction in working-at-height exposure (approximately 1,400 hours vs 14,000 hours conventional)
- 35% faster completion than conventional top-down methods (16-20 weeks vs 26-32 weeks)
- Complete elimination of full-height external scaffolding requirement
- All hazardous waste handled under manifest and transported to authorised TSDF facilities
Significance for Indian Industry
HAIL is currently the only mechanical contractor in India with a documented, audited methodology for reverse jacking decommissioning of double-wall cryogenic and ammonia tanks. For operating refineries, fertilizer complexes, and chemical plants across India, this technology represents a step-change in safety for clearing aged infrastructure.
"The reverse jacking method completely removes the working-at-height risk equation from ammonia tank dismantling. For an industry where conventional methods have historically resulted in incidents at elevation, this is a fundamental shift in how decommissioning should be approached."
— HAIL Spokesperson
About HAIL
Hirva Anwesha Infratech Limited (HAIL) is a Vadodara-based mechanical, civil, and EPC contractor serving the Oil and Gas, Refinery, Petrochemical, Fertilizer, and Chemical sectors across India and eight overseas markets. With a track record of 2,000+ storage tanks and 300+ mechanical projects, HAIL holds ASME U-Stamp, API 650, PESO, and ISO 9001 certifications. The company operates as a single-point contractor handling all mechanical, civil, electrical, and instrumentation disciplines under one contract.
Media Contact
Hirva Anwesha Infratech Limited
Phone: +91-9510034854
Email: info@hail.ltd
Website: hail.ltd
CIN: U45309GJ2022PLC135084 | Vadodara, Gujarat, India