Impressive, I picked a random one and it had a multi-pages The Martian spoof in the middle with a moral of doing regular maintenance procedures and reading technical manuals !
Skimming the Preventative Maintenance comics just a little made me realize that our military heavy machinery is incredibly terribly badly designed. Like it's blindingly obvious from these manuals that these machines have been designed to funnel money from the military to the "industrial complex"! ( https://en.wikipedia.org/wiki/Military%E2%80%93industrial_co... for those too young to have heard it yet. https://xkcd.com/1053/ )
> Your M119A2 howitzer’s M137A2 panoramic telescope doesn’t travel well. If you leave it installed during travel, the telescope won’t be working for long.
> Stow the M137A2 for travel. If it’s installed, vibration damages both the telescope and the M187A1 mount.
> Install the canvas fire control telescope mount cover, NSN 1240-00-819-4527, before you tow. That protects the M187A1 mount from debris.
> After you remove the M137A2, install the plastic quick-release protective cover, NSN 5340-01-042-1330. Without the cover, the quick-release handles can loosen and fall off.
Basically, the thing is junk, and has lots of ways to break such that you need to replace (no doubt expensive) subsystems regularly.
Would you want to fight a war with a howitzer like this?
It doesn't strike me as a design flaw that a carefully calibrated item like a panoramic telescope used for accurately firing artillery at ranges up to 20 kilometers would need to be protected before the howitzer is towed along a muddy, bumpy road.
I don't have any experience with howitzers, but I had a couple of years on a M1A1 tank, and you have to remember that heavy combat vehicles are designed to fill a particular role under insane circumstances. These things are min-maxed to a degree that just doesn't compute in everyday life.
The general priority (with US equipment) is usually: get the job done, save the crew, be fast to repair battle damage. So while there are blast doors and blow-off panels to (usually) prevent an ammo cook off from killing the crew, there is no system that will stop the turret from rotating if a crew member is crawling between the turret and the hull; laying the main gun on it's next target is given absolute priority.
There are similar things with tracks; they'll wear out and need more maintenance that tires, but when the contest is between tracks and an obstacle, the tracks almost always win. (Or you throw one off the sprockets, which is a royal pain. Mud is terrible for that). That's one of the reasons they haul tanks around on flatbed trucks whenever possible, tracks will eat a road, given the slightest opportunity.
There are videos on youtube of tanks driving over car bombs, and shrugging off the explosion. Not something you'd do if you had a better choice, but...
It's really a case of the operating environment being so different from what we're used to that some of the engineering choices look insane, but it's the battlefield that's insane, not the engineers. ;-)
First of all, thank you for your service. My dad was in the Army. (Briefly. He was too nuts.) Respect.
And thanks for the detailed reply.
There are trade-offs, yes, but that's not really what I'm getting at. It's more that these machines require a huge and intricate supply chains (not to mention supply lines) to function. If anything were to cut them off they're going to be out of commission soon.
Ever wanted to learn how to disassemble and clean a 240B machine gun? You can do that! Examples:
https://www.psmagazine.army.mil/Archive-Index/