Stonne 2: Set Up

Looking at the landscape around Stonne and possible table sizes, I decided on using just one 35" x 22" wargaming table which, if using what is now my usual 1.5" = 100m ground scale, will give me a 2.3km x 1.5km battlefield. This is enough to recreate all from a little West of Stonne village all the way over to Les Cendrières Farm and including the Northern approaches to the escarpment and Mont Hébreu and the Terre des Dix Cents.

Stonne plateau, 2.3km x 1.5km

I found the insulation foam landforms that I had always used for fictional games a bit restrictive for recreating an actual landscape, so I had to chop them about a bit. Fortunately I had some old river bend sections which were geographically too extreme for most wargames tables, so they got customized for this scenario.

Le Bac de Stonne, below the escarpment

Les Cendrières Farm

Terre de Dix Cents

This will be the scene for a series of encounters, recreating the various attacks and counterattacks on Stonne village, involving elements of:

• Großdeutschland infantry & other regiments
• 37mm AT units from the 14th PzJagr Abt
• Panzer IVDs of the 8th Panzer Regt and attached PzJgr Is
• Stuka air attacks
• Panhard 178s of the 6th GRDI
• Char Bs of the 41st & 49th BCC
• Hotchkiss H39s of the 45th BCC
• FCM36s of the 4th BCC
• 25mm AT pln

I will be making significant use of Walter Moore's Armoured Fist Stonne scenario booklet (which is available on Wargame Vault here), as he has done much of the organizational work already.

The only delay might be in putting highlights on a few Panzers for photography reasons.

Pondering Tanks 'At An Angle' and the 'Glancing Off' Effect

There is usually a mechanism in rule sets covering AFVs & anti-tank fire to determine whether front or side armour should be targeted. In simple terms, attackers want their AP rounds to impact the target AFV as close to perpendicular as possible to reduce the chance of glancing off.

I have seen rules where a line is drawn from the further rear corner and through the nearer front one and extending towards the attacker. Depending which side of the imaginary line the attacker finds itself decides if front or side armour is targeted.
The problem with this is that the proportions of length and width determine the frontal arc: long, thin AFVs like the SdKfz 232 or Churchill to some extent, are penalised by having a smaller frontal armour arc but more square AFVs benefit from a wider frontal arc. This is in spite of most tanks having front & side armour at an angle of about 90° to each other but this method is not often used.

More satisfactory is the common 45° rule applied to the nearest corner of the target AFV. Again, a line is projected forward, this time at 45° to the front & sides and attacker placement in relation to the line determines which face of the target AFV is more 'flat on'.

Both methods treat the target AFV as metal boxes, with no rounded corners such as on the Sherman or Somua S35. By rights, if a rounded corner is hit, the face of the armour may well be perpendicular to the direction of the shell travel but where armoured faces meet may however be effectively thicker and stronger.

In any case, until recently there was a penalty in my rules if aiming at armour presented at shallow angles. This was to penalise attackers aiming at weaker side (and rear!) armour which may be at a far from ideal angle for penetration, thus simulating the 'glancing off' effect. At the same time, although I do not plot the fall of shells as such (or even take sloped armour very much into effect), I did not want to disallow targeting weaker parts of AFVs on some arbitrary principle of angles, if such shots might have been attempted in real engagements.

So in bed the other night, I got to wondering if there was a geometric formula or mechanism to decide the issue once and for all, obviously taking into account the target position/angle and also the relative thickness of front & side or side & rear armour but not the sloping of glacis plates and so on which would be another matter.

As expected, it is a very complex subject.

High velocity rounds (I suppose this could include the 2pdr and 37mm L45  as well as the 88mm Flak, during the France 1940 period) generate a good deal of heat on impact and can penetrate due to the softening of armour and grooving caused by the shell.

If we look at a Panzer III, which had a nominal 30mm of armour front & sides, one of the two faces is going to be presented at somewhere near to 90° to the LOS from attacker, so it doesn't make a lot of difference whether front or side is targeted, using this model. A Panzer IVD with 30mm of armour on the front and 20mm on the side is a different prospect. You would think that having 30% thinner armour on the sides means that shots would be able to strike at slightly more oblique angles and still be somewhat effective. Although there are exceptions, many tanks seem to fall like the Panzer IV into the 1.25 to 1.3 front to side armour ratios (at least in France 1940) but is that enough to justify taking shots at armour which is going to be angled at 45-60°?

I would say for game balance, it is not:

• I haven't done the maths for obvious reasons but my gut feeling is that thinner side armour would only allow 5-10° of extra shooting angle
• There would be yet another stat to look up on the charts, or a ruling could be applied across all AT weapon muzzle velocities and variations of front, side & rear AFV armour
• The game would be slowed down with more fiddling about with odd-angled triangles, t-squares and other obscure implements

Perhaps it would be possible in some 28mm or 54mm 1:1 wargame but on reflection, it's not something I would want to simulate!

Activation Test Skirmish

I've been activating units by drawing counters up until now, which was nice and random and helps the solo player keep track of what hasn't done anything yet in the turn.

However, after a test run of some of Robert's rules at the 2D6 Wargaming HQ, I wanted to have a go rolling for activation for a couple of reasons:

• although I am not sure what, if anything it is replicating in the real world, player selection of unit activation priority gives the gamer a feeling of some control over activation
• it is easier to tweak activation rolls with simple adjustments for unit type & quality and other tactical considerations than it is with card or token based draws, where you can only add extra tokens to increase probabilities

The skirmish itself consisted of PzII, PzIII & PzIV troops plus Schützen platoon vs AMR33, Panhard 178 & S35 troops plus motorised infantry platoon and 25mm AT section. Entry points were diced for and I used the 2D6 Wargaming objective cards (now available in three colours) to generate the German objective of the road junction and elimination of an infantry platoon for the French.

The Panzers swung left immediately to take the dominating high ground as a base to give support to the assault on the hamlet with the road junction. The rest of the German column and the French column (spearheaded by their armour) met head-on at the outskirts of the town, the Panhard armoured cars plugging the gap for most of the game but sacrificing themselves in the process.

The Somuas started a flanking move and found the Panzers. 25mm ATs were sent to the farm to secure the right flank for the Allies, forcing the Panzers into the path of the S35s.

Eventually, the PzIIs made a dash along their right flank distracting a screen of French infantry away, while the Schützen attempted a left hook around the battlefield to drive off the anti-tank guns and to secure the objective. Two thirds of the Allied infantry fell back to the cottages at the road junction.

Morale now starting to crumble, the Panzers were unable to support the Schützen who, although outnumbering the poorly-shooting defenders, could not get a foothold in the hamlet.

Final positions

I will probably now stick to dice activation as it provides more scope for adjustments, is no more time consuming than drawing tokens and makes the game just that little bit more involving for the player(s).

Engagement Distances

The ground scale in my rules has always been 1" = 100m, which is a throwback from the WRG rules I used for a number of years back in the day. It is nice to get more than a square kilometre on one terrain tile but there is compromise between 'getting more area on the table' and units and elements being a bit too close together for convenience, not to mention aesthetics.

Mark Luther's Hannut

In this Hannut game, the ground scale for larger figures (possibly 28mm) was used in an IABSM game with 6mm miniatures and the effect is undeniably realistic-looking. I know I don't think too often about how the real life battlefield translates to the wargaming table or consider what a target 500m away actually looks like but this is easy to do in your own local area.

If I look across the fields to the lane on the horizon, vehicles there are pretty much tiny specks among the hedgerows. Comparing the view on Google maps tells me the T-junction over there is about 1km away, almost the maximum effective range for most small calibre tank guns in 1940.

Another location where I first did this comparison was Harlow Common, which is an open bit of land bordered by country lanes and houses. I sometimes looked across and wondered how it would translate scalewise onto a wargaming table. Calculations indicate that the width is around the extreme end of rifle fire effectiveness.

My direct fire chart goes all the way out to 2,000m for anything over 75mm, although even at 2286m, the 88mm apparently could still penetrate 6" of armour but when you look at ranges in the real world landscape you can understand why it can be a 2% chance to hit. 

"If It Ain't Broke" Scribblings

Analysing Hit Probabilities

Some time ago I was trying to work out a way of having simpler range brackets, by the looks of my jottings here, as well as the possibility of going over to D20 dice. As it happens it became a thinking out loud on paper exercise into deciding I didn't want to change anything after all.

As it stands, I measure the range, go to the combat chart, get the penetration %, adjust the % for the usual reasons, then roll the dice. As you can guess, very few guns are similar enough to group together in such a chart if you look at their stats closely enough but three categories of weapons did fall into line with each other somewhat: small arms; 13.2mm-47mm; & 75mm-150mm.

Don't get me wrong, I am reasonably happy with the eight range brackets I currently use (Point Blank, Close, Short, Intermediate, Medium, Long, Distant & Extreme). The WRG WW2 rules I used to use felt wrong when either side of a certain range gave a vastly different hit probability. I just wanted to see if I could work out a simplification without increasing the probability steps noticeably or bending the penetration data overmuch by using Point-Blank, Short, Medium, Long and Extreme ranges.

Having not quite ironed out very many of the wrinkles in that idea I then wanted to see if I could devise a way of rolling a handful of D6 for however many attackers were firing within these simplified range brackets, getting back to a long-abandoned group suppressing fire concept I toyed with a few years ago. I am sure it has been done in other rule sets.

Imagining that hit probabilities tail off rapidly towards the end of a trajectory's arc and increase alarmingly at point-blank ranges, I surmised that there might be a largish section in the middle where although, percentages are changing, they are more gradual than at the extremes. Not being a ballistics expert, this was going to be something which was merely required to work in a gaming context, not give very silly results and make everything simpler.

Having decided on PB, S, M, L & X range brackets for the three categories of direct firing weapons and that the M bracket was going to be some kind of norm where, in theory, most of the firing would occur, that left the extremities just needing some adjustment factors and eventually some new adjustments for other combat factors (cover, movement, etc).

All well and good but although the possibly easier to remember range brackets might have resulted in slightly less range table checking there was now going to have to be a roll for penetration, something I did not really want. It could never be factored into the one dice roll, not without, off the top of my head, probably a hit chart for every gun.

Quite an enjoyable bit of noodling about with ideas, nevertheless, if only to conclude I like things how they are.

Rules Tweak: Armour Penetration

I am grateful to TTH on the WW2 Talk forum for his link to All Gun Penetration Data, a comprehensive list of WW2 AP data, as far as I can see. Certainly it amply covers the France 1940 period.

The datacharts show penetration for Rolled Homogenous Armour as well as Face Hardened Armour, which reminded me that that my AP combat charts in places uses a mixture of data. This was principally because I had only been able to find figures for German guns against RHA although there were a few other anomalies as well. The new information has enabled me to create a more level playing field for AP gun combat vs FHA only.

That just leaves me to have another look at the AP data for the 18 pounder and 75mm IG, as I came to the conclusion that the CS tank gun could be ruled out on the AP front as the only offensive round carried (if any!) was HE.

Logically, I suppose one day I will have to look into which tanks had RHA and which had FHA and on what part of the vehicle but hit plotting isn't something I intend to get involved in!

Plenty to keep me off the streets!

Meanwhile, back in the conservatory, there is a whole load of odds & sods to finish painting: foot figure faces, weapons & helmets and basing-up of these new strips and other figure group bases to flock, etc; minor detailing of 20-30 vehicles; completion of camo repainting on 20 -odd French tanks; and adding decals to a dozen aircraft.
After that, I will begin repainting another batch of tanks and tank unit identifiers, applying decals to tanks & vehicles and draping Swastika flags onto certain German AFVs & vehicles.