Working with Velocity of Detonation to get the best from your blast design


What is Velocity of Detonation

Velocity of Detonation (VOD) is a measure of the strength and performance of a bulk explosive. It is the velocity of the detonation front as it moves through a column of explosives. VOD is an industry-approved measurement of explosive performance.

Measured in meters per second, a typical range for gassed emulsion-based explosives is 3200 to 6000 metres per second.

Working with Velocity of Detonation.

Every bulk explosive has a velocity of detonation or VOD range that is specified by the supplier. When we purchase bulk explosives from a supplier, we assume that the explosives are performing within this range but do we ever check to confirm this? The answer is typically NO, we rely on the supplier on site to test the VOD of the product.

Bulk explosive is very expensive and we need it to perform to ensure we are getting the best from every blast. If a bulk explosive is not performing within the specified range, it can produce poor blast results which in turn increase rock breaking, digging costs and crusher throughout costs.

What is the first thing we do when we get poor blast results?

We reduce burden and spacing, put more bulk explosive in the hole and increase powder factor. Straight away our drill and blast costs are increased and maybe for all the wrong reasons.

What if the problem was that the explosive did not perform?

Maybe the VOD was lower than expected due to incorrect mixing or issues with the supplied product. Measuring VOD is a vital part of drill and blast engineering and shot firing. It is critical to understand what the explosives we buy are doing when they are detonated.

The issue with this previously was that VOD testing was expensive to do and complicated. But that’s no longer the case.

ShotTrack VOD units

The ShotTrack VOD system is designed to be extremely portable and simple to use. Using standard COAXIAL cable and a ShotTrack unit that has only one button, it has become easier to get it right every time.

Other VODs testing units on the market today require the user to be trained on how to use the unit, these units are complicated and can lead to wasted time and money due to incorrect setups.

We’ve also made the unit very affordable. Once you purchase a ShotTrack VOD, there are no maintenance costs associated with annual calibration, our unit is designed to calibrate the coaxial cable, therefore, removing the need for unit calibration.

All that is required for a VOD test is the VOD unit and standard COAXIAL cable, cable that can be purchased locally for minimal cost.

Moreover, the ShotTrack VOD system means VOD testing can be self-managed taking the control back into our own hands and ensuring our product is performing well and providing the very best results from our blast designs.

Get in touch with the ShotTrack team to find out more about our VOD unit and other products.