Thermal lance
From Wikipedia, the free encyclopedia
A thermal lance or thermic lance or burning bar is a tool which burns iron in an oxygen environment to create very high temperatures for cutting. It consists of a long iron tube packed with iron rods, which are sometimes mixed with aluminum or magnesium rods which increase the heat output. One end of the tube is placed in a holder and oxygen is fed through the tube.
The far end of the tube is usually lit by an oxyacetylene torch. It can also be lit by an electric spark, in which case the tube is connected to one terminal of a battery and the other terminal is connected to a copper electrode. The end of the tube is then rubbed against the copper electrode to produce sparks, which ignite the lance.
An intense flame is produced at the lit end and can be used to rapidly cut through a variety of thick materials including steel and concrete. The tube is consumed, so every few minutes the operator shuts off the oxygen, discards the remaining stub of a lance and starts using a new lance.
A thermal lance does not contain thermite, contrary to popular misconception.
Using a thermal lance for safe-cracking is a popular misconception. A number of lances are needed to cut into even the most basic safe, and make much noise and smoke, making stealthy safe-cracking impossible. Also, they can char and set fire to the safe's contents, such as paper money, which burns easily.
[edit] Appearances in fiction
In the Michael Mann-directed film, Thief, a thermal lance is featured in a scene where the main character must break into an exceptionally dense and secure safe.
In the film $ the bank manager uses a thermal lance to release an employee who was locked into the bank vault.
In the TV series Heist, the character Ricky uses a thermal lance to break into an armored truck.
In the 2001 Frank Oz film The Score, Robert DeNiro's character uses a thermal lance to cut a hole in the top of a safe inside the Montreal Customs House in the climax of the film to steal the scepter inside, to avoid the safe's glass relocker device. However, the television show MythBusters showed that it could not have been done as shown in the film.
The term "thermic lance" is occasionally used incorrectly in science fiction to mean a type of ray gun.