The burning rate of a safety fuse is approximately:

• A. 120 seconds per yard (40 seconds per foot)
• B. 60 seconds per yard
• C. 30 seconds per yard
• D. 240 seconds per yard

Answer: (A)

Burn rate of a safety fuse is the time it takes for the fuse to burn through a given length, and it’s the practical measure you use to time detonation delays along a fuse line. A common approximate rate is about 40 seconds for each foot of fuse, which works out to 120 seconds for every yard. That means a yard-long piece burns in roughly two minutes. This steady pace allows you to predict when each charge will ignite, enabling safe, coordinated timing across multiple blasts. The other rates would imply significantly faster or slower burning than what is typically observed, making timing unreliable. So the best rule of thumb is 40 seconds per foot, or 120 seconds per yard. If you have, say, a 6-foot run, expect about 240 seconds to burn to the end.