A Thermic Lance is a steel pipe packed with mixed metal wires.

Pure oxygen gas is passed through the pipe from an oxygen cylinder and regulator. The end of the pipe is lit with a high temperature source, e.g. an oxy-acetylene torch. The iron in the steel burns in the oxygen coming down the pipe to produce enormous heat and a liquid slag of iron oxides and other materials, which dribbles and splashes out, just like an enormous firework sparkler.

The temperature reached in the centre of the combustion zone is approx. 4000 degrees Celsius, greater than the melting point of any substance on earth. By the way of comparison, concrete melts at 1800 - 2500 degrees Celsius and steel at less than 1500 degrees Celsius. Also, because it runs on oxygen, the lance can cut underwater.