Tense Moments with a WP Round

In the August 2016 UXOInfo.com monthly newsletter, the "Munition of the Month" is a U.S. 3.5-inch, M30 WP Rocket. I had an experience in dealing with this piece of ordnance when I was stationed at the 176th Ordnance Detachment (EOD), Fort Richardson, Alaska during my tour there as an EOD Supervisor. It was in the spring of 1986, when the ranges were clear of snow and Range Control was conducting their annual range clean up. Each unit on post was assigned ranges to clean up. First, the unit representatives came to a meeting at Range Control to go over what was expected and what not to do. We gave a safety briefing that stated no one was to go into the impact areas or go forward of the firing lines. All brass and ammunition components were to be dropped off in barrels next to Range Control. Anyone who found dud ordnance or abandoned munitions was to call us (EOD).

During the cleanup we got a call from Range Control that there is a 3.5-inch rocket lying next to one of the barrels. The first thing I noticed was this was a dud fire rocket as the safety band and the bore-riding safety (ejection pin) were missing. The second thing I noticed was the groove around the forward section of the fuze where it joins the warhead. This indicated that this was a M30 white phosphorous (WP) munition. The munition's paint had deteriorated, so you could not use that as an identification feature. Another feature to tell the difference from a 3.5-inch M29A2 Practice and the M28A2 High Explosive Anti-Tank (HEAT)/M30 WP munition is that the practice munition has a round hole where the bore riding safety was and the HEAT and WP munition has a square hole.

Reference Image - Close Up of bore-riding pin - 3.5 Inch Rocket

Reference Image - 3.5 Inch WP Rocket Cut Away

Because the 3.5-inch WP rocket was next to Range Control's building, I could not blow in place (BIP). The EOD manual calls for attacking the M404A2 fuze with a slug that is fired from a .50 caliber dearmer. If the munition is WP you can't do this because of the possibility of cracking the warhead and exposing the WP to air. Once exposed it will ignite, and when hot enough, it will cause the burster to function scattering particles of WP. The alternate procedure is to make a mix of Plaster of Paris and pour it into the hole that once held the bore-riding safety. This will prevent the plunger and actuating sleeve from moving forward and making contact with the firing pin lever. I made a watery mix and poured it in as the hole is very small. I waited to until my test sample became hard.

Next I picked it up and carried the munition to a sandbagged trailer (a very tense and slow operation). We then carefully drove the munition to our demolition range. I next placed a Composition C-4 charge underneath the warhead. We wanted to blow WP up into the air in order to make all the white phosphorous to burn out. If you counter-charge it into the ground you will bury the WP and contaminate the range. Then, if you move some dirt and expose the WP it will start burning. That is something you don't want to happen on a demolition range.

We never learned who moved the WP rocket to Range Control. That person was very lucky to survive. Fortunately the dried plaster was enough to stop the fuze. If not, it could have been a real bad day for me. This was my first and last render safe procedure (RSP) on a 3.5-inch rocket. Today the Army EOD unit at Joint Base Elmendorf-Richardson (JBER) is the 767th Ordnance Company (EOD).