ALLIED : Gustav Line BETA AAR Round Two - Eye of the Elefant

[GreenAsJade]

In other good luck news, the centre right M10 reversed successfully out of the line of fire of the two far-right PzIVHs.

I'm moving it back, now, to a position that has some teeny view holes near to where the PZiVHs are...

... and a good view of the next little valley that Bil has to cross on the way from Hill 109 to Hill 126....

[GreenAsJade]

Elsewhere, further adjustments continue...

I've been resisting committing an M10 to the deep right, but I realised that the compromise positioning was the worst of all worlds - face on to the line of approach, and exposed to the centre ridge overwatch. So he's going deep.

The centre freed M10 is now heading forwards, with a choice of going right over the road/ridge to have a go at PzIVHs, if they move forwards and expose sides, or of continuing to watch over The Spur, on my left. There has been no noise from there for a while: I guess Bil is making sure I have nothing lurking over there. It's strange that he'd pause his push on this side, though, because that frees me (at least creates an impression of freedom) to use resources on the right, wheras if he were coming at the same time on the left it'd be ... more pressured. Maybe he's ready for full attack, behind The Spur, and is waiting till he gets properly engaged on the right before making a nasty move on the left? Who knows but, I need to keep an eye on there for sure.

GaJ

[Michael Emrys]

I'm really quite relieved to report that the trapped left rear M10 ran the gauntlet of the Hill 130 JgPz succesfully: it is still alive and now free to roam the midfield with far more options.

[snip]

This is the sort of move that I would normally put in the category of "crazy, don't risk it, you think it's a calculated risk, but it will go wrong". I've lost track of the number of times I've said to myself "I'll chance it, it's worth it", and then wished I hadn't.

This is one of those situations where the extra speed and maneuverability of the M18 might be nice to have. I'll be interested to see what happens when we get some of those to play with.

Michael

[c3k]

Nicely done! Now, go shoot something!

[General Specific]

This is one of those situations where the extra speed and maneuverability of the M18 might be nice to have. I'll be interested to see what happens when we get some of those to play with.

Just the thought of M18's running around at top speed guns blazing just made me drool a little....

actually alot.....

[Vinnart]

Just the thought of M18's running around at top speed guns blazing just made me drool a little....

actually alot.....

Me too!! The "Hellcat" was my favorite allied armor in CMAK. I always bought a few for QB to run circles around it's nemisis the "Hetzer" which my old army buddy used to always buy when we played. I hope it makes a debut to CMx2 soon.

[MikeyD]

Just the thought of M18's running around at top speed guns blazing just made me drool a little....

I got a small taste of that in CMBN Commonwealth being greatly surprised by the Cromwell's blazing speed. Something I hadn't been expecting at all.

[John Kettler]

Michael Emrys,

It's not just the speed, but the size and the height. So it's much faster, smaller and lower than an M10, yet hits every bit as hard. Am fairly certain it's got a better power to weight ratio than does the T-34/76. Additionally, the M18 has such a low ground pressure it can operate on ground where infantry can't go. Remember "Hellcat Ridge" from CMBO?

General Specific,

Since you like M18s, I believe you'll enjoy this. Restoring an M18 and (don't want to spoil the surprise).

The secret of using the M18? Never get hit by anything larger than 7.92mm fire and try to avoid that if possible.

Regards,

John Kettler

[GreenAsJade]

Movie 35, 0:36-0:35

Not a lot to report this turn.

The centre M10 reversed into it's new position as planned, but none of Bil's forces made a move on the right flank, so he didn't get any HTs to fire at.

As you can imagine, I was watching the PzIVhs closely throughout this. The rear one was definitely tracking the M10 between the trees - it's aim adjusted 2 or 3 times, but apparently he couldn't get a lock as the M10 moved.

The other PzIVh reversed back into very close proximity of the rear one, and took up station guarding theirs sides that are exposed to the centre ridge. Wise move, because my other M10 had been psyching up for a push over the ridge for just such a shot. The good thing about this is that Bil therefore really only has one barrel, not two, facing off the centre right M10.

[GreenAsJade]

The centre-right M10 will stay put for one more turn where it is - since Bil knows that it is there, he has to start thinking about how to get rid of it, and that presumably will be mortars, because I'm pretty sure the Elefant and its friends can't find an LOS into here, and it seems unlikely he'll go into a direct face-off hoping his PzIVhs can manouver and re-spot me before I spot him. That means I have at least a turn (of mortar aiming etc) where I can sit menacingly over the HT route to Hill 126 before I have to move again.

I am also pulling the second M10 over to support this action. It is looking for another path through the trees that can see the HT push route, but is shielded from the current PzIVH location.

This may force the HTs to go further out towards the edge of the map, where the ground falls away, and the west spur that they are on will block LOS from the centre ridge. That would be a good thing for me, because it takes them further away from Tit overwatch, and into the teeth of the right M10.

I have some other minor tweaking going on, including a couple of minor units moving forwards once again to try to re-connect with Bil's centre and left forces, which have been uncomfortably out of touch for a while...

GaJ

[dieseltaylor]

I was wondering if you had checked PZIV gun range/penetration to your M10's armour. It may be a useful thing to know particularly if there is added height difference.

Great escape though: )

[GreenAsJade]

I'm always up for a lesson on CM... how do you check that sort of thing?

[CharlieMike24]

Put it in view of Bil's PzIV and he'll check it for you!

[dieseltaylor]

The safe way is to actually dummy up the current distance on a non-flat map and dook it out. The quick method is to look up the armour penetration figures and the angled armour. Unfortunately looking through Slat's collected penetration gigures gives a range of choices and in the end all of the figures are for flat shooting.

In the end though is how did BF model it and that is the final answer. I suppose this could be trialled in CMBN but that will have to wait until toniggght - assuming M10's are present!

[Marco Bergman]

M10 almost safe at 2000m. Pz IVH unsafe at 2000m. But the range is much less than that, so both are in danger.

[GreenAsJade]

Ah yes - looking forwards to putting mods back in Particularly that one

GaJ

[dieseltaylor]

Is that the armour thickness accounting for slope? I bet the Hetzer looks pretty innocuous : )

Apparently the T34/85 had to get within 400 metres to penetrate the Hetzer armour rather than it bouncing off. The Hetzer armour was 60mm at 60 off vertical so not dissimilar to the M10 and I was hoping that the firing from below would increase the apparent angle for the armour. The Hetzer armour is quoted as effectively

around 100mm of vertical - but does also obscure the idea was to bounce the shot not stop it.

I think GAJ was almost perfect in angling his M10 so the chassis was not straight on to the enemy.

Too late now for testing.

[Marco Bergman]

Is that the armour thickness accounting for slope? I bet the Hetzer looks pretty innocuous : )

BFC uses the slope effect calculations from the Bird/Livingston book WWII Balistics: Armour and Gunnery. I have used a majority of these calculations in the spreadsheet used to generate the silhouette figures, assuming equal elevation and a 75mm gun firing.

Figures for the Hetzer are:

176, 26, 18

176, 26, 18

88, 20, 20

Side angle can be estimated as increasing the armour figure by the percentage equal to the angle, at 30 degrees. I.E. at 30 degrees offset, armour value is approx 130%. Below 30, the effect rapidly drops away to zero. Above 30 the effect is parabolic, increasing with armour thickness. Just assume that hits on the side at 60 degrees should deflect.

Changes in elevation can have a big effect on sloped armour. M10 hull front with 5 degree elevation goes from 82 to 99. However, vertical armour isn't really affected. Pz IVH hull front at 5 degrees elevation goes from 81 to 83.

[Marco Bergman]

The Hetzer armour was 60mm at 60 off vertical so not dissimilar to the M10

38mm at 55 degrees is far less armour than 60mm at 60 degrees. Effectively 82mm vs 176mm, roughly half.

[MikeyD]

M18 Hellcat had considerably less (25mm at 23 degrees) and the Germans were terrified of them.

[John Kettler]

Standard Ordnance Items Catalogue, Vol. 1, page 142

http://www.scribd.com/doc/13810463/Standard-Ordnance-Items-Catalog-1944-Vol-1

lists the Turret Front armor basis as a most impressive 4.5" (114.3mm) and the Hull Front as 3.25" (82.55). IOW, the effective thickness vs Direct Fire from ground level dead front.

Regards,

John Kettler

[Freyberg]

I've found M10 hull down a pretty tough tank against a PzIV. And it can often survive a first hit.

[dieseltaylor]

BFC uses the slope effect calculations from the Bird/Livingston book WWII Balistics: Armour and Gunnery. I have used a majority of these calculations in the spreadsheet used to generate the silhouette figures, assuming equal elevation and a 75mm gun firing.

Figures for the Hetzer are:

176, 26, 18

176, 26, 18

88, 20, 20

Side angle can be estimated as increasing the armour figure by the percentage equal to the angle, at 30 degrees. I.E. at 30 degrees offset, armour value is approx 130%. Below 30, the effect rapidly drops away to zero. Above 30 the effect is parabolic, increasing with armour thickness. Just assume that hits on the side at 60 degrees should deflect.[Diesels bolding]

Changes in elevation can have a big effect on sloped armour. M10 hull front with 5 degree elevation goes from 82 to 99. However, vertical armour isn't really affected. Pz IVH hull front at 5 degrees elevation goes from 81 to 83.

Interesting to know the basis of BF calculations. Is there any WWW research on the likelihood of a shell glancing off inclined planes? I assume from the sentence I have bolded that this also means hits to the front glacis at 60 degrees will also bounce which is what I have been trying to see would occur in GAJ's case.

Do you know if BFC model shatter-gap and ammunition variation? I may easily believe that would be going too far in terms of playability but cannot see how it can really be avoided if one is trying for complete realism.

For more see here

http://spwaw.com/lholttg/penetration.htm

[Marco Bergman]

I assume from the sentence I have bolded that this also means hits to the front glacis at 60 degrees will also bounce .

No, I'm trying to give a useful rule-of-thumb from a parabolic data set that varies with a whole heap of variables.

Do you know if BFC model shatter-gap and ammunition variation?

yes, and, don't know.

If you wish to delve into arcane mathematics we should do so elsewhere instead of hijacking this thread.

[GreenAsJade]

Movie 36, 0:35-0:34

I wonder if you guys are still reading, now you have your own Gustav's to play with?

Bill seems to be making a serious push on the right. I think the two new armour contacts in the middle right are the other two PzIVhs. In addition, his Elefant moved this turn. It's all a bit tense, because at the same time I contacted his inf on the centre right ridgeline (in full view of his right PzIVhs) and inf on the left near the Spur. It will be interesting to see if his PzIVhs get distracted by the infantry game, allowing me some free shots at them...

GaJ