A Mineman's Recollections
 of Southern California Duty

A Mineman's Recollections of Southern California Duty

My tours of duty at the Drill Mine Preparation Facility (DMPF) and MOMAUPAC, Long Beach, CA, were interesting and scary-funny at times. With COMINEPAC just down the street, you didn't know what off-the-wall thing you would be doing each day, where you would be going, or what out of the ordinary thing would happen.

SHORTEST ASSIGNMENT?: One morning at the front office, I saw a glum-looking MN3 report in from Japan and within 30 minutes or so the lucky guy had been offered and gladly accepted transfer orders back to Japan. I'm not sure why he got a crack at this assignment before anyone else knew about it. Quickie-orders like that were usually offered-up at quarters or at a gathering of the rates required.

WHEN THINGS WENT BANG: One evening the duty-section off-loaded a truckload of recovered Mk 49 drill mines inside the old aircraft hangar. A few hours later, the quietude of the relic hangar was shattered by a very loud bang and the sound of something metallic that ricocheted off the ceiling and clattered to the concrete deck. Apparently, no one had read the "Pass-down Log" which probably read, "When the recovered Mk 49 drill mines are returned, check to make sure all the clock-delayed recovery flares have been fired or rendered inoperable."

Mexican/Hispanic fishermen, loved the drifters from Long Beach mine plants that ended up South of the Border. A stencil on the mine case indicated that there was a $50 (U. S.) reward for their safe return.

One day, my boss asked me to help him actuate ten Mk 66 parachute control units so they could be used for training by the Air Force. The Mk 66 used a thermal battery to fire an explosive fitting that opened the parachute at a preset altitude or after a short time-delay. We were a little leery of activating the thermal batteries, so we took the control units inside the detonator test & installation cage. Face shields and safety goggles were plentiful, but neither of us thought it necessary to actually use them. My partner wore thick glasses so his eyes were somewhat protected as he placed the first control unit, battery down, into the vise and pulled the pin. The round battery got hot enough to melt the solder holding the quarter-sized metal bottom plate in position. After activating the batteries on units 1 though 9 (one at a time), my partner turned the Mk 66s upside down and placed them on the workbench without incident. But on the last one, when he turned the unit upside down there was a loud bang when the thermal battery exploded. I thought he would be injured as his head and shoulders disappeared in a cloud of thick, white smoke and smoldering confetti-like material. I heard the round, metal bottom-plate bounce off the overhead and drop back onto the workbench. What caused that particular battery to explode & not the others was a mystery. We figured the melted solder allowed the high pressure, built-up by the very hot materials inside the battery, to straighten out the narrow metal rim of the battery forcing the bottom-plate skyward at high-speed.

Since I could transport explosives, I was often tasked to drive a 6X6 truck to Seal Beach to pick up small boxes of detonators and explosive-fittings and return them to DMPF by a slow route off the main thorofares. One sunny morning when faced with one of those onerous trips to Seal Beach, I called the Boat Pool and asked if I could use one of their LCMs to make the trip. I had no problems, coming or going. However, a few weeks later when a buddy set out by LCM to Seal Beach he encountered a dense fog-bank. Instead of returning to the Boat Pool to wait-out the fog problem, he kept going, possibly in circles, until several hours later he ran out of fuel. After the fog lifted someone spotted the LCM and it was towed back to the Boat Pool. I think that was the end of the LCM trips to Seal Beach.

DMPF issued close to a thousand drill mines each year. Surface plants were usually made by the YFU (an LCU fitted with mine rails). On one of these surface plants, everyone was amazed when a large bottom mine popped back to the surface like a cork. The charge case was empty, so it had to be recovered and returned to the shop.

One day when a dozen or so recovered bottom mines were sitting on the hangar deck, someone noticed that one was leaking water from a mysterious, small hole in the mine case. The 3/8-inch diameter hole appeared to have been "burned" through the metal case. At first, we thought lightning may have struck the mine. Then I theorized that an MSO's minesweeping electrode (short leg) may have been dragging along the bottom and touching the mine case when it was zapped with up to 7,500-amps. What do you think happened?
One day when an 18-wheeler was transporting a load of drill mines down Route-5, another trucker keyed his CB-mike while passing and a flare was ejected from one of the drill mines. Up until that moment we didn't know that our drill mines had a RADHAZ problem. WO Putnam asked me to assist in designing an aluminum foil shield for the drill kit. We plugged every orifice with aluminum foil and cut a circular wooden disk on which we stapled aluminum foil for the aft end of the drill kit. Putnam came up with an ingenious way to test "our" design. We put a small transistor radio that worked fine before putting it inside the drill kit. A thin string attached to the tuning dial allowed us to make sure we got absolutely no reception from the radio. I left the project before it was tested "on the road."


Big problems encountered during the YFU's recovery of inert Mk 57 mines, caused DMPF to make some "can-do-spirited" but very bad decisions. After recovering the buoyant mine case, the YFU's crew lost some of the 900-lb. anchors due to them being dragged along the sea floor on a thin and very long steel cable. The yucky mercury-based anti-fouling compound on the cable created a messy and very hazardous problem for all concerned. The "solution" was to take the anchors out beforehand and cut off 800-ft. of the offending cable and dispose of it into the "metal disposal bin.". When the much wiser "metal bin" people refused to take the stuff, a big hole was hastily dug and the mercury compound-coated cable was buried.
Minemen were called onto the thick red carpets when an inert Mk 57's case & anchor separation occurred inside the torpedo tube right before it was launched by a U. S. submarine. The anchor did a "Newton" and headed for the bottom while the buoyant mine case just had to rise up in time to have the sub's bow planes snag the mooring cable. How in the world did this happen, one might ask?
While loading the Mk 57 into the torpedo tube, without an MN looking-on, a TM pulled the safety pins too soon and the spring-loaded caps on the aft-mounted "HAS" forced the safety bar off. This allowed the "locking pawls" inside the caps to drop freeing the pistons to move as soon as hydrostatic pressure was applied. The TMs pulled the mine out and (without noticing that the pawls were lowered) reinstalled the safety bar over the top of the HAS's caps. When the torpedo tube was flooded the HAS started the 1-hour setting on the delay mooring clock. After several time-consuming practice runs over "the drop zone" the Mk 57 was launched and the "unheard of before" happened. Luckily for the MNs on the red carpet, a razor-sharp MN in the sub's galley overheard the TMs discussing the problem they had loading the Mk 57. Henceforth, black marks on the Mk 57's xpl-section indicated that the mine should be inserted up to that point before pulling the safety pins.

Bill, I probably should give a couple of examples of COMINEPAC's last minute requirements by its staffers.

One day while preparing Mk 6 mine cases (inert w/no components; just something for the sweepers to sweep), we got an urgent/last minute request, from a staffer at COMINEPAC, to put 50-ft of fire hose over the mooring cable right below the mine case. This was an attempt to thwart efforts to sweep the mines easily, i.e., an impromptu anti-sweep device. We didn't get any feedback on the effectiveness or lack thereof provided by the fire hose.

One day while loading Mk 52/55 Mod 2 (magnetic) drill mines equipped with "red flares" to indicate a magnetic mine fire during sweeping, we got a frantic call (some mines were already loaded on the semi) from COMINEPAC to remove the red flares & replace them with a different color. Reason: The mines were to be laid off San Diego & red flares were used by submariners to indicate they had an emergency & needed assistance.

Staffers at COMINEPAC & elsewhere couldn't easily grasp the fact that sterilization settings needed to be greater than the delay arming settings.

Don Jones, MNCM, USN (Retired)




Derick S. Hartshorn - 2009-present
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