Andy Smith
MIne-action specialist

Searching ground with prodders

I was asked whether it is safe to use a prodder to search for explosive hazards and answered as reproduced below. I later looked at the recent accident record and confirmed that the misuse of prodders by professionals is still common - so I wrote a paper for the JMU Journal - published under the title Understanding the use of prodders in mine detection. That paper makes the points with more persuasive detail. Click the title to open it as a PDF.

Q: Although it might take a long time, why not just issue deminers a prodder and save money on other detection equipment? That would surely empower local people and so stop them being dependent on aid?

A: If it was safe to prod for pressure sensitive anti-personnel mines, you could be right. To start with, you have to discriminate between excavating a mine - which is conducted using tools designed to remove the ground so that the mine can be seen - and prodding to try to find where the mine is in the first place. One is excavation, the other detection. So:

  • Excavation is conducted after a detection method (usually a metal detector or MDD) has indicated the presence of something to be unearthed. Use this link to see how an excavation should be conducted.
  • Prodding is conducted in order to find out whether there is anything present to be unearthed.

Prodding onto any device that can be set off by pressure is obviously dangerous. Anti-personnel blast mines are designed to be initiated by pressure on the top, so prodding should NEVER be used to locate them. In theory, prodding could be an appropriate way to detect ERW that is not pressure sensitive, but only if the required depth of search could be achieved.

When it is necessary to locate mines without using metal detectors or dogs, the entire surface of the ground should be excavated. This can be conducted using handtools or rakes as described on pages 29-34 of Chapter 6: Manual Demining.

Experienced soldiers and those with hands-on experience have known that prodding was ineffective and dangerous since the early '90s. This was confirmed by Professor Trevelyan of the University of Western Australia who conducted some prodding experiments in loose sand and found that it was not possible to prod to detection depths without the use of excessive pressure (see Statistical Analysis and Experiments in Manual Demining, 2003.) In ordinary soil, it is usually impossible to prod to 10cm without using excessive pressure. To prod to a 10cm depth at 30 degrees to the ground also requires a long prodder - which many deminers do not have. As part of the GICHD Study of Manual Demining published in 2005, comparisons between methods were made and it was found that prodding with the lowest friction prodder in existence failed to locate mines at 13cm. Worse, all shallow mines that were found had been subjected to excess pressure and would have detonated if they had been real.

In fact, given the information that has been in the public domain for years, it would be mad to set out to prod to locate mines. But prodding is still part of many demining groups' SOPs - usually as an emergency method. While it is more likely to create an emergency than safely locate any missed mines, people want to do something and prodding may be all they can do.

Official UN advice to anyone finding themselves in a minefield to "prod your way out with a pen" is ridiculous. Without any eye protection and with your hand that close to any blast, a simple risk assessment would have to balance the risk of being blinded and made handless with that of losing a lower leg. I know which I have chosen when I have been obliged to balance those risks.

So no, it would be irresponsible to issue prodders for local deminers to use as detectors. If they used them, they would detonate or miss mines - often leaving the people even more dependent on aid.