60mm+ Free-tubing Too Easy?

[Bullethead]

The US 60mm mortar, and as far as I know all mortars from other countries of the same or greater size, is designed to be fired from a bipod. This is because they were originally intended to give advancing grunts portable arty for use on stationary, fairly hard rifle targets such as dug-in machineguns. When attached to the bipod, the mortar tube has very limited traverse, but that's OK because the target isn't expected to be moving and you need a sturdy mount to give consistent accuracy on a point target. However, this makes 60mm and bigger mortars less effective against rapidly moving targets, such as vehicles.

To get around this problem, real experts with mortars free-tube it. This means they disconnect the bipod and hold the tube in their hands (with a thick rag for heat protection), pivoting the tube on the baseplate ball joint to track the moving target. This ain't something you get much training on at mortar school, especially in times of major wars and massive draftee armies like in WW2.

Free-tubing is an art form. The mortarman has to not only be a good judge of lead with his looping trajectory shot, but also has to simultaneously hold the tube at the correct elevation for the amount of charges attached to the fins of the big stack of unpackaged mortar rounds he has lying beside him. He needs a pile beside him because he can't let go of the tube to reach for more, and he doesn't have time to jack with adjusting the charges. All this means that effective free-tubing is beyond the abilities of the bulk of mortermen and even the experts have to do some preparation first. And all this is has to be learned OJT, especially in situations like WW2. In other words, it's for sure not something you see every day.

Which brings us to the infamous effectiveness of mortars vs. moving vehicles in Combat Mission. I quite often see vehicles being tracked by mortar bursts where either the vehicles' movement exceeds the traverse limits of the mortar bipod, OR the vehicles' bearing rate exceeds the tube traverse rate supplied by the traverse crank on the bipod. IOW, the only way these shots could be happening is if the mortars were being free-tubed.

I have a problem with this. In demo scenarios, all the mortarmen are regular or even green. From the docs, these troop qualities mean very little or no combat experience--IOW, they very likely never got much if any free-tube training in school and ain't had the chance to learn it in combat. Yet they're free-tubing like expert old salts.

And that's just the 60mm mortars. These are small enough for free-tubing not to be too big a PHYSICAL problem in terms of strength required. 81mm mortars are different beasts entirely.

IMHO, this needs to be addressed. Regardless of the question of whether a regular or green mortarman could hit a small, STATIONARY vehicle at 400m with the frequency shown in CM, having them be able to track "fast" moving vehicles is a pretty serious accuracy problem. Hell, even "fast" moving grunts can out-run most mortars in real life.

-Bullethead

[Hunter]

Good point bullethead</p>

Mortar strikes will generally be a number of rounds hitting the one spot, with minor correction to 'walk' onto the target point. It is odd to see these 'dynamically rolling barrages' going on</p>.

Maybe one for the CM2 list?</p>

Bruce

[Moon]

Very interesting read, Bullethead. You'll be happy to know that this has already been fixed.

[SimonFox]

Damn I wish I knew about this 'bug' I've been only targetting stationary halftracks or areas where I think they will go and wondering why I can't get as many kills as people say. Anyway, good post bullethead nice read your clearly well informed comments. Though I must admit I find it hard to keep a straight face while making a response to a post from that nom de plume

[This message has been edited by SimonFox (edited 11-19-99).]

[Los]

First off I agree with what Bullethead is saying about tracking *fast* moving targets. (Infantry generally can be tracked.) Mortar shoots should be aimed at locations not moving vehicles or what not. Yes you can make adjustments to the firing arc within reason but that's something we have to figure out. The way to hit a moving target is just like in real life, you need to predict where it's going to be by the time of TOT and place your fire mission there.

That being said, it is much easier to move a 60 or under around to hit moving targets than a larger mortar. And it's most often doen without free tubing. With a direct lay site attached, one guy kneels in front of the mortar and lifts the legs, shifting them a little left of right and sets them down while the gunner makes minute corrections with the site. But I would say if you are firing at a vehilce so close htat you actually have to move the tube to track it (like a PF) the youa re way to close and it's an incredibly rare circumstance, plus other then the occasional oopeon topped target or unbottoned tank you are using the wrong weapon for the job.

RE: "Freetubing" Actually this is very far from common. I had a discussion about this with several ex-mortar platoon leaders (I have two in my company)a while ago. In fact the current 60mm has a trigger device that will allow you to drop the round and then aim and fire it but it's something that has to be set up ahead of time. (We were screwing with free-tuing a 60 this summer, good for a lark but not really what the weapon is meant for) WHile it can be used in an emergency situation it is not as accurate, nor will it support a high rate of fire or indirect fire.

A couple of points about mortar crews. The guy who drops the rounds (be it free tube or regular) is not the guy that aims the mortar (the gunner). One guy sits there and levels the bubbles after each round dropped down the tube (or at least he tries too). The ammo bearers set up a production line of prepping and passing rounds to the AG (assistant Gunner) who drops them down the tube, or if you want to get fancy each guy gets in a line and drops his own round in a choreographed fashion. There's a lot that goes into prepping the rounds for firing at a particular target you can't just pull them out of the container and drop them.

I think ore a concern _may_ be the speed with which a mortar goes into action after they have been moving but I haven't done a real study of the times in CM yet.

Cheers...

Los

[Herr Oberst]

*Beware unsubstantiated claim* 'cause I can't find the reference on it, but the Germans did "free-tube" the 50mm.

I have watched video of a 50mm team walk a mortar barrage. One "gunner" free-handing the tube, and three "loaders". To make the gunners life a tad bit easier, the variability in range was limited (I'm assuming this was so the loaders could use consistent powder count). The gunner did need to be able to see where the rounds were impacting, but the results seemed quite effective.

I suspect that this ability decreases dramatically as tube size goes up.

[Bullethead]

Good points, Los.

Los said:

>>>>>>>>> That being said, it is much easier to move a 60 or under around to hit moving targets than a larger mortar. And it's most often doen without free tubing. With a direct lay site attached, one guy kneels in front of the mortar and lifts the legs <<<<<<<<<

Right. But this makes for more punctuated bursts of fire, setting up a series of beaten zones for the target to move through, instead of the continuous stream of bursts on target we see now. And like you say, this is something possible for 60mm but doesn't work as well with the bigger tubes.

>>>>>>>>>> RE: "Freetubing" Actually this is very far from common ...... WHile it can be used in an emergency situation it is not as accurate, nor will it support a high rate of fire or indirect fire. <<<<<<<<<<<<

I think free-tubing was much more common in **some** countries in WW2 than it is today. For instance, neither the Japanese "knee" mortar nor the Brit 2" mortar had bipods at all; free-tubing was the only way to shoot them. So troops used to this type of mortar would be better at free-tubing 60s than say US or German troops and even regulars would do it because they were trained that way. But this is why I titled this thread "60mm+,"

because these light mortars had to be free-tubed anyway.

However, this still assumes the mortarman is really school-trained. In prolonged wars, the trained mortarmen are usually long dead and the infantry company's weapons platoon's mortars are mostly crewed by guys pulled from the rifle squads. Generally guys the company topkick was mad at, too . So even in the Brit army, I'd expect a good free-tuber to have been a rather rare and valuable commodity. Just like how in Viet Nam a good M79 gunner (very analogous to free-tubing a light WW2 mortar) was a prized asset.

That all said, in the Gulf War I actually saw an Iraqi mortar being free-tubed against a Hummer that was haulin' ass. Looked just like it does in CM, a continuous stream of bursts following the vehicle. And they got a direct hit on the Hummer, too, with their 4th or 5th shot. Very impressive. But with all the thousands of mortar rounds I saw fired over there, that was the only example of free-tubing I could really identify.

>>>>>>>>>>>> There's a lot that goes into prepping the rounds for firing at a particular target you can't just pull them out of the container and drop them. I think ore a concern _may_ be the speed with which a mortar goes into action after they have been moving <<<<<<<<<<<<

Quite so, at least for 60mm+ tubes where you had to jack with the additional charges on the fins and such. Most lighter mortars didn't have this complexity.

-Bullethead

[Bullethead]

Moon said:

>>>>>>>>> You'll be happy to know that this has already been fixed. <<<<<<<<<<<

Thanks for the word, Moon. Can you please elaborate a bit as to how the fix changes things?

-Bullethead

[Los]

Just because the 50mm or 2" doesn't have a bipod doesn't mean they are "free tubing". The 50mm comes with a handy dandy all in one suitcase design so in effect it's not free tubing. All you have to do is rotate the whole suitcase-base and the tiny little mortar moves. That isn't free tubing per se. It's firing the mortar on its mount. I've never fired it (The German one) myself but have seen two examples set up one at Benning's Infantry museum and one at Aberdeen Proving Grounds.

I have not seen a 2" so don't know if it has a bipod or not but if it doesn't have some sort of fixed tube then there is hardly a reason for its existence since the whole point of a mortar is high angle INDIRECT fire. So I suspect that it is a fixed tube similar to a German model in some way. I'll check my Iann Hogg resources for more details when I get home (I've seen it a ton of times but right now at work can't recall a thing about it!)

As far as the Japanese "knee" mortar as US troops erroneously called it. That thing is hardly more than a rifle grenade launcher in capability. But in that role it was probably handy dandy. (Did the Arisake have a rifle grenade cpability? If not that's probably the genesis of that thing.) Funny aside a number of US trooops broke their thighs using that thing since the baseplate thing was curved roughly around the shape of a guy's thigh and everyone who tried it broke a femur.

"Quite so, at least for 60mm+ tubes where you had to jack with the additional charges on the fins and such. Most lighter mortars didn't"

Yes the sixty has cheeses (and I've seen WW2 footage with cheeses) though at least the German 50mm mortar has no cheeses. I don't know about the brit 2"? BTW as an aside the WW2 Russian 2" equivalent has a small bipod (A fixed thing that's maybe 6 or 7 lbs and half a meter in height.)

Cheers...

Los

[Moon]

I don't know the details, Bullethead, but in the current full beta hitting moving targets with mortars is MUCH more difficult. I also noticed that mortars can fire within a certain angle of their facing, and if the target moves out of it laterally, they have to rotate. I hope this sheds some light. Steve or Charles would have to give any more details.

[Guest Scott Clinton]

The British 2" mortar did not have a bipod or a fixed mount. It was basically 'free-tubing' all the time if the data I have is correct.

I have read references of the 2" being used in at a near-horizontal angle in house clearing during the Market Garden camp. It was able to hit the FIRST floor of a multi-story building. That is a pretty flat trajectory for a mortar.

------------------

The Grumbling Grognard

[This message has been edited by Scott Clinton (edited 11-19-99).]

[Renaud]

For what it's worth, you can see what looks like a Brit 2" mortar being free-tubed in the movie 'Bridge Over the River Kwai'. Of course it's just a movie but it looks plausible to me.

-Ren

ps: The mortar did not seem to have any kind of optional stand available.

[This message has been edited by Renaud (edited 11-19-99).]

[This message has been edited by Renaud (edited 11-20-99).]

[Los]

Yeah there's only one cryptic picture of the 2" mortar in Iann Hogg's grenades and Mortars. And it's kinda from behind but it looks like the guy is holding it up and there definately isn't a sight on it. In fact Hogg calls it "more a grenade projector than a proper mortar", and in fact the rounds that they are feeding into the thing look like cylindars or "beer cans" instead of mortar rounds.

If there isn't a site or proper stand for this thing then it definately isn't capable of anything other than direct fire in anything other than the most rudimentary way.

Los

[Bullethead]

Moon: thanks for the word. That sounds like exactly what was needed.

-Bullethead

[Mikeathome]

There were many different types of mortar - America used 2 different types of 60mm - the Mortar M2 on Mount M2 was the "standard" bipod fired version based on a design from Brandt (as were most mortars in the world at the time). There was also the mortar M19 on Mount M1 which was much like the Japanese "Knee" mortar - ie only a barrel mounted to a small curved baseplate.

The Bipod mounted version had no means of holding the mortar on target appart from the bipod - it just had the ball mount on the base plate, so any "free tubing" as discussed would probably have been horribly inaccurate.

The notes I have for the M19 mortar say it wasn't bery accurate and had limited range, and was limited to small numbers issed to airborne and special purposes units.

The Russians had 4 versions of 50mm mortars - 3 of them had "standard" bipods but were much lighter than the US 60mm (19kg vs 9-16kg). Their final one did away with hte bipod for an all-in-one baseplate/traverse mechanism. There were only 2 elevations - 45 or 75 deg, range being varied by venting exhaust gasses forwards from a tube under the barrel.

The Brit 2" was mostly used for smoke than HE support (BTS note!! ), was triger fired and indeed could be fired horizontally - but not loaded that way!!

Perhaps the most bizarre light mortar was the Italian 45mm which was breach loaded and the propelling charges came in magazines of 10. A lever opened the breach for the bomb, and closing hte breach automatically loaded a charge. Apparently hte rate of fire was very high, and accuracy excellent, but the bomb only weighed 1 lb, which was only 1/2 to 2/3 the weight of other light moratrs - the Polish 46mm for example weighed 1.5 lb, the British 2" 2.2 lb, the Jap 50mm grenades 1.17 and 1.75 lb. The French 60mm had a havy bomb weighing 4.5 lbs.

Almost forgot the Russian 37mm spade moratr - imagine a simple spade with a square blade and a simple straight handle - well the blade was the baseplate, the handle hte barrel. A monopod was formed by the plug that closed the barrel when configred as a spade!!

Hope this has all amused and informed.

Mike

[Kazom]

It is a good post Bullethead and I shared your observations about mortars. Its also good to hear the issue is being addressed. The only comment I would like to make is that I heard in another post that boresight pre-plotted artillery firepoints were being added to the game. I think if you could set up pre-plotted ambush points before the senario begins and the mortar did not change targets during the senario then moving vehicles which crossed the ambush markers might indeed receive some nasty mortar fire. This seems to me the only way they could have a good chance of hitting a moving target - and I hope this is the plan for the final game.