Say, did I ever tell you about the time I almost killed my buddy with a 25mm cannon?
The Bradley Fighting Vehicle has an all-electrical turret, with power drives for both azimuth and elevation. This is a system with two modes: normal, slow speed for fine tracking and aiming, and “slew” mode for high speed traverse and elevation of the gun. In slew mode, the turret will move at 60 degrees per second in both traverse and elevation. There is also a manual system of handwheels in case drive power should be lost.
The driver’s hatch at the left front of the vehicle pops up to about a 60 degree angle. Because the gun is mounted so low above the deck of the Bradley, turret is traversed to the left while the hatch is open, the gun would strike the hatch. Well, banging a $100,000 gun against the hatch at high speed would be bad for the gun, and would also tend to cause undesirable stresses on turret drive mechanisms. Accordingly, the Army, in its wisdom, included a microswitch* into the driver’s hatch. If the switch is open, meaning the driver’s hatch is open, the turret will traverse normally throughout most of the spin around the vehicle. But as the turret drive approaches the driver’s hatch, the gun will automatically command an elevation of about 3o degrees at the highest rate. That is to say, the gun will jump over the driver’s hatch. **
It was a beautiful autumn day in the early 1990s. My battalion was in Pinion Canyon Maneuver Training Center to provide support to another brigade. While that brigade was training, we acted as the Opposing Forces for them. OpFor was always far more fun that being the Blue Forces. The atmosphere was a good deal more relaxed. While many good training opportunities were to be had, we also weren’t being graded by outside observers. The roles and missions we performed tended to be a bit more varied and interesting. The platoons and companies of the OpFor would be shuffled around to tailor a force to a given scenario.
I forget what people had to be shuffled around and why, but one week I found myself on my usual Bradley, A-12, but with my regular driver and gunner replaced with two of my favorite people. SGT M was my roomate, and was a very intense, wiry young man of Greek descent from California. SPC O’C was a young, large, friendly, if somewhat quiet Irishman from Philly. Very different people, but we’d been friends for some time. Normally, the stress of operating in the field frays nerves and can cause friendships to strain. But as OpFor, we weren’t under any great pressure, and the conviviality was nice. Both SGT M and SPC O’C were pretty easy to lead, being quite professional themselves.
Since Uncle Sam frowned on us shooting real missiles and bullets at our fellow troops, even if it was those jerks in 1-8 Infantry, we used the Multiple Integrated Laser Engagement System, or MILES, as a training aid. MILES is like the worlds largest game of laser tag, with lasers and harnesses not just for people, but all types of vehicles, especially tanks and Bradleys. The laser for the Bradley’s main gun clamped onto the barrel of the gun. And just like the sights of a rifle have to be zeroed to ensure a hit, the laser had to be adjusted (at least daily) to ensure hits on distant targets.
Since all three of us on the crew took great pleasure in sticking it to the chuckleheads of the BlueFor, we took every reasonable measure to prepare for the morning round of battles. High on the list*** of chores was to zero the MILES system, so we could cause blinking lights and anguish in our victims.
Most Bradley crews were quite familiar with setting up the MILES system on their vehicles. I’d actually attended a one week course on post to become my company’s subject matter expert on the system, and had grown quite proficient at tweaking the system for optimum performance. Zeroing the MILES box on the gun was fairly simple. There was a cheap little telescope coaxially mounted to the laser itself on the box clamped to the gun. SGT M would look through the scope, find a discrete object roughly a mile away, and direct me to traverse and elevate the turret until the crosshairs were direct aligned with the object.**** Then, with the laser aligned exactly to the target, from the gunner’s seat, I would move the sight reticle of the Bradley’s main sight (the Integrated Sight Unit, or ISU). Much like windage and elevation knobs on a rifle sight, this would move the reticle without moving the gun itself. Once both the laser and the sight reticle were both on the same target, the system was zeroed.
Normally, to get the most precise control possible, when zeroing the system, the turret drives are switched off, and the gun is aligned using the handwheels. This morning, while I was focused on helping to zero the gun, I was also on the radio getting updates about our mission, and answering important questions like “does you crew still have all its sensitive items, have you lost anyone in the last 24 hours, how much fuel do you have onboard (which, the entire company had just topped off tanks less than an hour before, just like every morning) and just generally being pestered by the higher ups. So I cheated and was using the turret in powered mode, in the slow rate. SGT M had found a nice target to align on, and SPC O’C was up on deck lending a hand and moral support. SGT M bent over barrel of the gun to look through the telescope, and directed me to scooch the gun a little to the left to get on target. I did so, completely forgetting the driver’s hatch was open. And sure enough, it hit the cut-out arc, instantly jumped up, and smacked SGT M right in the face. He was knocked back quite violently, tumbled into SPC O’C, and they both fell the 6 feet or so from the vehicle to the ground.
In the end, it came to nothing more than some scrapes and bruises and a fair amount of (rather legitimate) butthurt, but I was mortified that I had forgotten such a basic safety rule, and could have seriously hurt my friends.
Naturally, that was the last time I tried to zero in power drive. And of course, for the rest of that particular trip to the field, I was the one putting my face next to the gun, and SGT M got to sit safely inside.
*This mircroswitch is functionally identical to the little push switch in your refrigerator that turns the light out when you close the door.
**There is a similar “cutout” switch in the back of the vehicle for the missile loading hatch over the rear troop compartment.
***Other key parts of the Pre Combat Checklist included making sure all our thermoses were full of fresh hot coffee, and that sufficient snacks, Top Ramen, beef jerky and cigarettes were loaded, and a supply of paperback books on hand for the lull between battles.
****Any object would do. It didn’t have to be another MILES equipped vehicle. Objects with a right angle, such as a building or a chimney worked very well. Of course, if you had another vehicle to use, that was fine too. That way you could instantly test how well you’d aligned the sights to the laser by simply shooting at them. If they blinked, you were good.