[Rules] Can non-personnel units dig in?

[treadasaurusrex]

I feel bad going down the rabbit whole again, once it looks like you extricated yourself from it, but the rules for digging in aren't all that great.
     Beginning dug in makes sense for many scenario's.  But I do have two major objections.

     1) Time -  According to rules it takes only 30 minutes to dig in provide one is not interupted. 
         a) No one digs in that fast - certainly not a foxhole.  As an infantrymen I can tell you that you, that soil and root system dependent, one can spend most of a night digging a foxhole.  Granted that is you and your battle buddy rotating in 15-30 minute intervals (one digging and one providing security).  It is exhausting.  God help you if you hit the water table before you can get at least 4 feet down.  
         b) The best you can do is Hasty Fighting Position (aka Hasty Grave) -https://www.google.com/search?client=safari&rls=en&q=hasty+fighting+position&ie=UTF-8&oe=UTF-8.  Does provide some protection from both direct and indirect fire, and better than nothing, but it is not what most of you probably envision when you think about digging in.
         c) Mortars, Guns and Tanks would take a hell-of-alot of effort to dig in.  Even with a larger crew it would take time to do it and do it right. Best thing to do if use the terrain (some natural low ground or berm) and quickly reinforce it with some extra digging.

    2) Once fox holes or hasty fighting positions are dug - they don't go away unless you fill them in.  Why do they disappear when you leave the area.

Mike

I think what you are considering digging in to be more of entrenching. The rules seem to follow that as well. It made even more sense WAAAAY back in the day when there were 3 levels rather than 2: dug in, entrenchment, bunker.

      I have been playing. PG since 1999 (1st Edition).  I don't remember there being three levels to digging in.
      Also, in U.S. Military we consider entrenching something akin to digging actual trenches and defensive works.  Entrenchments are manmade fortifications.  Digging in is more temporary in nature.  The longer you are in the defense the more robust it becomes.  Hasty fighting positions become fighting Positions (fox holes), Fighting positions become built down fighting positions with overhead cover.  Eventually you will  dig in alternate and supplementary positions, and start tying in positions with communications trenches.  Eventually you can and will construct trenches with pill-boxes, or walls with towers.  Given time, your hasty's can become a virtual fortress which can be surrounded by obstacle belts including land mines and wire.  
      Even from a WW II perspective, fox holes aren't really entrenchments.  For game purposes you may be right.... it takes about 15 minutes to carve out a hasty fighting position for an infantryman, 30 for him and his battle buddy (one securing while the other digs).  Not sure how long it would take to build a berm around a tank or a gun.  I would imagine it would take quite a bit of time if building it on a flat surface, and a little less if using natural folds in the terrain, or man made walls/fences to obscure at least part of your vehicle/gun.

    Mike

Similar experience.
Having been an armored company and battalion XO, my tank had a blade in front and my crew could create initial (hasty) enfilade positions for a whole platoon (17 tanks) in about 75 minutes with my tank's dozer blade. That was in peacetime maneuvers, and not under hostile fire. No overhead, or rear protection, and typically minimal buildup on the flanks of each tank. These "dozer push enfilade positions" were created in appropriate -- usually desert --  terrain. Creating secondary firing positions for each track would have taken an additional 75 minutes, or so.

Felipe