Burning open S slag tapping holes is only necessary for holes that have been shut down for long periods of time. This particular tap hole is a back-up hole used only when one or both of the other 2 tap holes needs to be shut down or fails to flow sufficiently to keep slag at proper levels. In this image it is easy to see the hose feeding oxygen to the coupler and lance pipe. Look closely and you can see the tapper feeding a steel re-bar into the hole along side the lance pipe as "Fuel" to increase heat to the levels necessary to burn open the tap hole. This procedure produces a fireball at the end of the lance pipe that exceeds 5000 degrees Fahrenheit. Behind the tapper is a dolly bar loaded with a clay plug to close the hole when needed.