Thermal lances are the work‑horse of underwater demolition, using a high‑temperature flame to cut through steel and concrete. Because the operation occurs beneath the surface, the consumable (usually a steel rod or fuel gas) must be managed carefully; its burn rate directly influences how long the lance can stay active.
The cutting time can be predicted by relating the length of the required cut to the amount of consumable burned per hour and the cutting speed that each kilogram of consumable can achieve. In practice, the faster the burn rate and the higher the cutting speed per kilogram, the shorter the overall operation.
L = length of cut (meters)
R = burn rate (kg/h)
S = cutting speed per kg (m/kg)
When planning an underwater cut, divers must also consider water pressure, visibility, and safety margins. The calculated time provides a baseline, but real‑world factors often require adding contingency time to ensure the operation is completed safely.
How do I calculate the burning rate of consumable in an underwater cutting operation?
What factors affect the cutting speed of a thermal lance?
How do I determine the required length of consumable for a specific underwater cut?
Can thermal lances be used on all types of metal?
What safety precautions should I take when using a thermal lance underwater?
How do I extend the cutting time of a thermal lance?
What is the typical range of underwater cutting speeds for thermal lances?
Results are for informational purposes only and do not constitute professional advice.