AT Fire Immobilize Historical Results?

[Timotheus]

I have recently retired from a career of 30 years on main battle tanks. My speciality was always Gunnery. I have fought in the sand on two tours etc. So, I would like to help where I can from the technical aspects of tank gunnery etc. My aim, always to help.

Bearing in mind it’s at least a six week full time course to become a basic qualified Gunner - then years of experience to gain a fuller knowledge.

Dadlamassau has his finger on it with his explanations.

The jump in technical quality from WW2 to present day is staggering , yet we still cannot aim at a certain point on the target and hit it there - not possible at any range because of dispersion. When everything is lined up correctly, the gun sight relationship is boresighted 100 per cent and range is spot on - even then you cannot pin point your fall of shot. The main reason is because of the Gunner aims at the centre of the observed mass in order to overcome dispersion. That variation in lateral and vertical movement cannot be made consistent due to manufacturing tolerances and therefore in Gunnery terms cannot be compensated for by the fire control computer. In tank gunnery consistency is far more important than accuracy.

I will pause here and if any interest I will answer any questions but overall you lads have pretty much got it covered. Not bad for a bunch of ‘Civvies’

Congratulations on your retirement. I had to leave after 10 years (4 of that being university and training in the Summer) due to medical release myself, but my service was all peacetime/Cold War and mostly on the 6 wheeled Cougar pieces of crap we had in Canada as opposed to Leopards.

I'd be really interested in your thoughts and experience are on the frequency of immobilize results?

My training also emphasized aiming for the centre of visible mass and I never tried anything else during my own gunnery training and neither did any of my gunners at the regiment and on the range or live fire exercises. But I've since read and listened to WWII vets who claim they did try to aim for certain areas, but as Faustnik has pointed out, there were in desperate circumstances against Tigers or Panthers. In the 1990s, I was shocked to hear our former honourary commandant of the Armour School on a documentary describing how he instructed his squadron's (company) gunners to aim for the very small area of the lower part of the Panther's mantlet.

[ianrs54]

Memory seems to indicate that at least 2/3's of hits were on the turret, which is why it has the heaviest armour. If you want to go into the detail have an optional table for special effects. Personally I no longer think it's worth the effort - an immobilised vehicle would normally be abandoned, PDQ, since the next round is going to kill. I very much doubt that a vehicle crew would be able to tell what had just halted their vehicle.

IanS

[Bob_Mackenzie]

Hi Ian

I fear you have it the wrong way around, its 2/3rds on the hull



From ORO T-117 - which is a $1.99 download and worth every cent

https://www.merriam-press.com/surveyofa ... warii.aspx

Cheers

Bob

[Timotheus]

Hi Bob,

Dadlamassu mentioned a world of tanks article on p1 which has a similar picture (http://ftr.wot-news.com/2013/12/26/on-a ... n-the-eto/).

$1.99 is not bad, I'm downloading your suggestion now, thanks so much!

[ianrs54]

Figures were taken from action reports. Empirical evidence would also indicate more hits on the turret than the hull, hence more armour there !

[Timotheus]

Figures were taken from action reports. Empirical evidence would also indicate more hits on the turret than the hull, hence more armour there !

[EDIT] Sorry, looking at what I wrote below, it could sound like I'm being a tool. I'm really not trying to be but often end up sounding that way. I'm just very interested in any sources I might be able to go in an read this. Sorry again.

Is there a list somewhere of the empirical evidence or somewhere on line that mentions the numbers you spoke about? Barring that, a book?

I used to think that the turret would be hit a lot more, especially late war when the concept of taking a hull down where ever possible when halting to fire. But then a lot of tanks will get hit on the move, too, where the whole profile is exposed. Plus you can't always take a proper hull down. I know the Germans uparmoured hulls first before turrets, at least in the development of the Panzer III and IV, as did Patton's tanks that had chopped up armour (versus sand bags which Patton didn't like for some reason) received the hull front as well, though I think I've seen pictures of some of these Sherman 76s with armour welded on the side of the turret.

[ianrs54]

AP rounds fly flat and will hit the upper hull/turret. IAT and possibly towed guns should hit the hull, but super-elevation (jacking it up a bit to reach the target) will tend to raise the hit location. At close range and in close quarters there would be more hull hits, and hits from artillery bombardment would be random. Crews using the 17pdr though that Sabot was inaccurate because they kept applying the same elevations they had used for APCBC. The Sabot being much faster did not require this. To give some idea of the sort of ballistic drop that a sabot round has the L7 105mm drops by 2m in 3000m, ie it's flat. The long german guns - L70's are too long, and the barrel eiher droops slightly, under its own weight, or whips on firing.

Bear in mind that this is a very complex topic.

IanS

[SABOT]

It is a very complex subject but in a nutshell Bob has got it spot on. In general the hull represents approx 2/3rd of the target size so therefore if hit in the open you would expect approx that percentage to hit in the hull area. It’s down to dispersion as I pointed out earlier and what is known as Standard Deviation (SD) .

Sorry Ian but you are a bit off in your explanations. If you elevate higher you generally miss . The graticule pattern is applied by range to ammo type. It takes account of the trajectory at all known ranges , taking into account the drop of the projectile. In that sense the projectile will perform correctly to the quadrant elevation applied - that’s the final angle of the gun at the point of final lay immediately prior to firing . That angle incorporates the Angle of Sight (AOS) that will be either positive or negative and also Tangent Elevation.

In simple terms it reads like this. You need to get the range correct - lay the correct aiming mark on the centre of the observed mass. At least 80% of your rounds fired will hit the target allowing for dispersion/SD . Two thirds are likely to hit the hull area when target is side on. 50% between hull and turret when head on or oblique.

Obviously then, being hull down reduces the chances of being hit because the lay of the gun taking into account the observed mass means you alter the MPI ( grouping) of the rounds as more will now miss. You can adjust your percentage chances of a hit in line with the percentages above. Not as simple on a moving target as it is harder to hit both side on and head on movers with oblique movers the hardest of all to hit.

So, as a wargamer what is more important is to recognise that the fighting compartment is made up of the turret and the hull. The turret floor is only just off the hull floor on a turntable . So in a modern MBT a hit in the hull does not always mean it affects mobility.

Do crews dismount when hit once? You will read lots of different historical accounts that vary. Crews are at least trained to fight their tank as it degrades but morale is always the decider in my experience.

[Bob_Mackenzie]

Hi Bob,

Dadlamassu mentioned a world of tanks article on p1 which has a similar picture (http://ftr.wot-news.com/2013/12/26/on-a ... n-the-eto/).

$1.99 is not bad, I'm downloading your suggestion now, thanks so much!

In a similar vein (and free)

http://lmharchive.ca/the-ronnie-shephar ... gust-1944/

http://lmharchive.ca/wp-content/uploads ... alysis.pdf

http://lmharchive.ca/?p=1326

http://ww2talk.com/index.php?media/albu ... -1945.205/ (be aware that the pages are in an odd order on this one)

Cheers

Bob

[SABOT]

Great references Bob. Many thanks.