MKloby, is it true that mortar fire is more difficult to counter fire?
Kris
It's taking 4 hours now for this post between the baby fussing and people calling...
I have a couple of thoughts on this. Keep in mind, I'm not an artillery officer, and an arty man could probably go into much more detail than I could, especially when it comes to counter-battery fire (which is out of my league).
Due to the short max effective range of mortars, it would be easier to narrow down where the fire came from... talking of a couple clicks rather than miles.
However, it is relatively easy for mortars to dig-in. All you'd need is a few hours, and you would have a nice basic fighting hole. Of course, that's not going to protect that position from a 155mm shell plunging directly on target, but it will offer decent protection with respect to splintering fragments. It will be much more difficult to prepare a defensive position for arty pieces weighing several tons.
Another thing that comes to my mind is that your light (60mm+ mortars) and medium mortars (80mm+) can be easily broken down and manpacked. You available options for choosing your fire support position are not as restrictive as arty, in the sense that you can hump them over rough terrain, across unimproved terrain, across streams and such. Divisional arty, towed by trucks/halftracks, is obviously going to be more restricted in it's choice of firing position.
Also, keep in mind about various methods used for detecting enemy firing positions. Forward observers, recon patrols, aviation recon will all have a more difficult time picking up a mortar position vice massive arty pieces. Not to mention that mortars can move their position in a matter of minutes. This can mitigate the risks posed via counter-bat fire, but can also vastly diminish the effectiveness of your own fire. It can prove advantageous if you position is spotted by, say, a patrol.
I believe in WWII they were able to use radar to identify mortars while in flight, but I am not sure how effective this method truly was in identifying a probable firing position.
In some aspects, mortars are more vulnerable to counter-bat fire, but they also have several advantages as well... Perhaps someone that has served in arty can expand on this.