On a decommissioning project, we severed a tank wall – 4.5 m diameter, 12 mm carbon steel – in a single cold-cutting pass, with no dismantling and no heat input.
The Challenge: The Tank Stays Put – the Machine Travels
A tank measuring 4.5 metres in diameter presents more than 14 metres of circumference to cut. It cannot be chucked, rotated or loaded into a machine tool. The only practical answer is to bring the machine to the workpiece.
On a recent decommissioning project, we were contracted to fully sever a tank wall: carbon steel, 12 mm wall thickness. The requirement was a clean, straight cut – cold, no heat input, no angle grinder, no hot-work permit needed.
The Equipment: Self-Propelled Trav-L-Cutter
The tool of choice was a Trav-L-Cutter – a self-propelled orbital cutting and machining unit. The system clamps to the outside of the tank wall using a tensioning chain and drives itself around the full circumference while machining continuously.
The chain drive compensates dynamically for out-of-round geometry – a common condition in tanks that have seen years of service. There is no slip, no loss of position.
Key parameters for this job: - Tank diameter: 4,500 mm - Effective cut length (circumference): > 14,100 mm - Wall thickness: 12 mm carbon steel - Process: cold mechanical cutting (zero heat input) - Passes required: 1 - Mobilisation: no crane, no fixturing of the vessel
Why Cold Cutting?
In process-industry decommissioning, thermal cutting methods – plasma, oxy-fuel – are frequently ruled out by hazardous-area classification, residual contamination inside the vessel, or proximity to adjacent equipment. Mechanical cold cutting with the Trav-L-Cutter generates no sparks, no heat-affected zone and no slag. The result is a defined, largely burr-free separation plane.
Conclusion
On-site machining is not a compromise solution. With the right machine concept – self-propelled, chain-guided, adaptive to geometry – large-diameter vessels can be severed precisely and safely: no removal, no hot work, one pass.
For further information on on-site machining capabilities: www.hsos.eu