Waterjetting 37a – Removing Explosives

One of the major efforts carried out at the High Pressure Waterjet Lab at Missouri S&T during my tenure related to removing explosives and other energetic materials from different casings. The casings ranged in size from very small anti-personnel mines to the large rocket motors that carry objects into space. The first part of that program dealt with the factors relating to the removal of explosives from warheads. Initially we had to show that this was relatively safe, and we initially thought that we were done when we showed that the explosive did not react as we went up to and beyond the pressures needed to wash the explosives from the case.

“Oh, no!” we were told, “That is not enough, we need to know how safe it is!” Which meant we had to determine, for each explosive we were likely to find, the waterjet pressure at which it reacted. (i.e. went BANG!) This meant that we had to fire water jets at pressures that ultimately reached 10 million psi (at which point all the explosives tested got seriously annoyed) to cover the field of response.

Once that safety level had been established then we could determine the pressures required to wash out the munitions, and from that design a tool to carry out the washout. We called the first one, WOMBAT, and here is a short video showing it in being used to clean out a SPARROW warhead.

Figure 1. Description of a Washout

The program examined a number of different approaches for different munitions, and we worked with Wilkes University in PA to build a full scale washout facility for shells, that was installed at the Navy facility in Crane, IN – but I’ll show that, and movies of the development of a capability to cut into sealed munitions, in later posts.