Separate charge in this case meant shell and casing (powder in brass). URL in above post states this was specially done to accomendate submarines.

Line of sight? or direct fire.

I wonder who was spotting for them. They seem to be hitting the target.:up:

Kurtz - Sorry, it was my impression you were talking land ordnance - you mentioned 105mm. I'm no expert of sub guns, sorry. Unless you are talking of that dead-end concept, the submarine cruiser, with big guns, I would go with thannon's comments.

Howitzers and mortars have a high trajectory, which offers flexibility to the gunners as they can, in effect, shoot over hills. Most land artillery fire missions use indirect fire, in which the round lands in a place where the crew has not a hope of seeing it. Such shoots depend on an observer to correct the fall of shot or else, recently, some highly impressive (and expensive) wiggly-amps kit. To give the flexibility in trajectory, the propellant charges need to be variable, which leads one back to the charge bag concept, allowing the gunners to vary the muzzle velocity. Mortars and howitzer muzzle velocity is generally pretty low.

Standard naval gunnery has generally been more direct fire in nature, with the gunners (or at least somebody in fire control) being able to see the fall of shot. As with tank guns, a high velocity is most useful for this. The main reason for separate ammo would be simple weight (the big boys are heavy enough without having to try to load everything at once) and size (imagine having to design a battleship ammo handling system for 16" fixed rounds, with the projectile permanently fastened into the casing!).

Of course, really big naval guns could fire very long distances and aircraft were often carried as spotters. In a shore bombardment role, observers again might be necessary. In general however, what I said above is, while not universal, almost so.

In short, with smaller-bore high-velocity rounds, fixed ammo is standard as, among other things, it gives you a higher rate of fire. With small-bore howitzer, semi-fixed is the norm. Anything above a certain size (much above 5" or so) tends to be separate due to handling constraints. Again, there are exceptions to every rule.

As to our starting video clip, they were shooting in the direct fire role, something land gunners practice but rarely get to do for real. (In general, this is usually considered a Good Thing as if the gunners can see the target, the Bad Guys have been allowed to get waaay too close. There are exceptions to this too.) Fire a round, watch where it lands, correct your own fall of shot. Lotsa fun.

piersyf - I understand your arguments and have sat in on the odd meeting on whether or not to provide protection. From my point of view however, blast pressure (and thus danger) drops off very quickly (the cube root of the distance) and is thus a very short-range threat, whereas fragments are dangerous to much greater distances. To my way of thinking, if you have the time, it is therefore a no-brainer if you are concerned about your troops and assets. The dangers of containing a blast are far outweighed by the dangers of not containing shrapnel. However inaccurate the bad guys may be, Chicken Little only has to be right once. As an old sergeant instructor once told me (as I was sweating my first trench-digging lesson), all the sweat you expend in your entire career only has to save your life once to be worth all the effort. I 'm not much concerned with trying to maintain appearances - macho posing gets people killed and I'm with Patton on such things. Different case if it's shoot-and-scoot, of course.

WRT the rate of fire of mortars and such. While the Taliban have used them, sitting in one place and firing a sustained barrage against an established base is a good way to meet 72 young ladies in a hurry.

There is probably also a definite safety risk in keeping your high-explosive rounds in the same room as your powder. Even after the rounds and powder were aboard they were typically kept in seperate magazines.

Fatty - Very true. One should never store the two together or in any place other than a proper magazine. That does not apply, of course, to fixed ammo. By NATO standards, the risk factor in such munitions is taken as the highest - in the case of a fixed HE round, the entire mag would be rated IAW the HE in the projectile.

Incidentally, one theory WRT the high Royal Navy losses at Jutland is the suggestion that ammo was being stored in places other than magazines so as to be able to carry more. If that happened, it would explain a lot.

shoot and scoot
 

Hey Trex. Yeah, no argument about blast being local, but a genade in a pit is worse than a grenade in the open. Arty's biggest threat in a conventional fight is counter battery and air. In both cases digging in is counter productive. In the first case you need to move as soon as you shoot, and the old Soviet concept of moving to an alternate prepared position has been shown not to work, not least because the position can be seen and marked, so you get pounded all the way between 2 known locations and once you get there. As for air, it is a bit easier to hide a gun than the pit as well. Western armies have largely moved as far away from prepared positions as they can except where they are a deliberate blocking force or being dangled as bait.
Another way of looking at it is somewhat fatalistic; the dispersion for an average mortar shooting from around 3k is about 20 to 25m. A round going off in the clear space would tell everyone they are under attack, so they wouldn't just stand there, they'd do whatever they were told to do in that case. The frag radius might be large (50m +) but the space between fragments increases over distance. The odds of being killed or even injured are not all that high, especially with the flack gear and helmets. Look at the casualty figures for rocket and mortar attacks and you'll see a pattern of a small number of rounds and a handful of injured, maybe a death except for the 'lucky' shots. The risk is there, but not really as high as many people think. To give a hard figure, during the opening bombardment for operation veritable (end of ww2) the brits were putting 6 TONS of ammo onto every known command post, mortar and gun position(which had varying levels of protection) over a 2 1/2 hour period. People running in the open you can kill, but just simply lying down and not moving increases your chance of survival 10 fold.

Good argument. I have heard it before and, in many situations, I agree with it.

There is however little threat in Afghanistan (to us anyway) from either air or CB.

I think the 'grenade in a pit vs grenade in the open' concept is generally greatly overstated. Regardless if you are at the bottom of a mine or on top of a mountain or even floating in mid-air, if you are within the grenade's lethal radius, you are dead, period, full-stop. The only way a barrier will can (not necessarily will, but potentially may) cause more problems is WRT blast, and that is within a very short distance. (Indeed, with the exception of low-frag munitions like FAE, if you are within the lethal radius for blast, you are almost always within the lethal radius for frag). In short, the main danger, the main casualty-causer, comes from fragmentation and barriers provide a positive benefit there.

While moving around from AMA to AMA is good protection in most circumstances, looking at the video, I get the distinct impression that these guys are firing from an established base of some sort. Note the large tents. Also, somebody has had time to fill and place a bunch of Hesco-Bastion (or equivalent).

Fatalism is great and my hat's off to the King of Battle, but I am a professional pessimist. Like I said, Chicken Little only has to be right once. If there is any way I can up the chances of sending one more of our troops home with a full set of body parts and no extra navels, I'm all for it.

I agree on most but the accuracy issue. The practices can differ from country to country but here we can hit a point target with mortars in 1-2 shots atleast 99% of the time, from any range. In a normal situation the target isnt visible from the fring position. This isnt a infantry vs artillery thing for me as i love both and long range artillery/MLRS, is what i usullly have in use in recon missions. We dont have fixed units under one FO, FOs are in the platoon level, he buddies with the platoon commander in the infantry and artillery has some of their own. The units and (tulenkäyttöoikeutta, dont no the term) amount of firepower in your use, is given to you based on the situation by the FO commanders in company, batallion etc. level. So in theory a situation could come that i could be commanding several batteries at one time, as was the case in last war where the Soviet invasion was stopped with massive concentrations of fire. Ofcourse i can only give my word but we have both artillery and mortar units that can do what you described. But if your ever in Finland i can take you to have a look, you being ex military and me having connections it shouldnt be a problem.:)

Happy Times - I am a great fan of both guns and mortars. They are, I think, complimentary. In Afghanistan however, lacking the sophisticated survey and rangefinding equipment needed for a first-round hit in rugged terrain, correction would have to be by old-fashioned '50 Up, 75 Left' method - and around built-up ISAF bases, that's unhealthy. Fortunately.

I would love to be able to visit Finland sometime. Beautiful women, a remarkable history and climate that's never 140 in the shade - what's not to like?

Well said, they ARE complimentary.:up:
Off course we have here first rate maps but i think i could do hit just as well with 3 81mm mortars, some pen and paper stuff i dont know how to translate, GPS for all, optical rangefinder http://www.mil.fi/maavoimat/kalustoe...pup.dsp?id=326 and "käsisuuuntakehä"http://www.mil.fi/maavoimat/kalustoe...pup.dsp?id=320 to get the direction. Comms could be a problem, frequency-hopping radios would be great to have. 30-60 second strike (30-60 grenades)and out, using weather as your friend maybe, if they could do it theyd probably take the risk.:hmm:
Im also happy of their level of current training.:lol:
Thanks for the compliment, USA is very high on my list of places to visit, especially the East coast with its rich history.:up:

These are all good point if we are talking about the sense on attacking a firebase, having fun isnt a reason enough.:lol: Of course you would have to have large numbers of troops in the open or unprotected otherwise. 82-81mm would be the largest mortars you could use in that terrain so they are no bunker busters.
Ofcourse if you plan to overrun a base the idea of suppressing gets an meaning.

mortars and artillery
 

Hey to both Trex and Happy Times. I include the following War Office memo from WW2 regarding the 3" mortar. Note that the effective area given is 3200 sq feet but that for 100% kill ratio it has to land within 10ft. Even then there are documented cased of mortar rounds landing between two men having a conversation and both surviving.



Also, a favourite tactic of the US Marines in Vietnam when counter attacking a NVA assault was to throw fragmentation grenades then turn their backs and hunker down and take the frag in the back of the helmet and flack jackets. OK Marines are crazy, but they still trusted their equipment. As an artilleryman I can say I would NEVER want to be under an arty barrage regardless of my knowledge of the statistics. I would also NEVER want to try to assault a gun position over open country. The vid showed a firemission (direct) at a bit of range. When I first read the thread (didn't see the vid) I wondered why they weren't in 'Killer Junior' mode. After seeing the vid I realised the Taliban were not close enough to warrant that response. Frankly, lucky Taliban...

And Happy Times... Dude, I have the utmost respect for the fighting quality of the Finns. I have absolutely no doubt you guys can do exactly what you claim, but most armies cannot. I still stand by my comments. Let's face it, we have our own experiences, and like I said, I'm speaking as an Australian, and we haven't had the same sort of opponents as the Finns have (although a very long stretch connection might be made between WW2 Russians and WW2 Japanese for crazyness):p

WO 291/129 Lethality of 3" mortar HE bomb.

The cast iron (Mark IV) bomb is about 70% better than the steel (Mark III) bomb, due to finer fragmentation.
Stick fuzes would probably add 65% to the effectiveness of the cast iron bomb, 25% to the steel.
Time-fuzed HE was considered "practically valueless" due to the zone of the fuze and the steep angle of descent.
"Jumping" mortar bombs might perhaps be up to ten times more effective against entrenched troops, whereas the stick fuze would be no more effective.
"Preliminary results obtained by AORS7 show that the reduction in overall lethality by small bumps may be as much as 6 times for men lying down."
Vulnerable areas are given as 3,200 square feet for the steel bomb, 5,500 the cast-iron.
Probability of incapacitation (%) for each type of bomb are given as:
It is suggested that these can be usefully presented in two ways; either as percentage chances, or as odds.
As percentages at different ranges (yards):
As ranges (yards) at which different odds apply:

Estonia is a better choise, cheaper alcohol and better looking women ;)

I am more and more thinking I need to do the Grand Tour.

Hmmm, what can I tell Mrs Trex?

Very interesting, i have these same type of tables in finnish somewhere.:hmm: And thats probably one reason the jäger companies use 120mm mortars, the 81mm are with infantry companies wich are not as mobile and have older equipment. The thing here is that we have to make do with what we have. We have world leading high tech, but we also have things some would consider obsolete. The lack of air support for the ground forces has lead to one of the biggest artillery corps in Europe, with some 3500 guns and mortars. The accuracy and speed has been a must, but in the future we need to get more of those self-propelled. And with the air to ground capabilities introduced in the air force and new ammunition for artillery and MLRS its likely to reduce in size. It also seems UAVs are taking a major role in the long range recon and directing fire.