01 May 2013

7YW Artillery – FRANCE continued

After having started to study howitzer design of the period with my first illustrated Prussian samples, I now have a better understanding which now enables me to also present the single genuine French howitzer piece fielded during the Seven Years' War.
Source regarding this design are scarce. Once more numerous bits from various records had been brought together.
Next image shows an original 1:3 scale model of the barrel. It is attributed to the famous Swiss/French founder Jean Maritz, hand made in 1748. The piece is made of gold-plated bronze and richly decorated. The barrel comes with the button and cascabel sculpted quite similar as the Vallière 8-pounder. My draft just reproduces the non sculpted button variant.
Source: copyright restricted
Image Collection of the Paris Musée de l'Armée, France.
It is published here for purely academic use without any commercial intention.


Source: copyright restricted
Image Collection of the Paris Musée de l'Armée, France.
It is published here for purely academic use without any commercial intention.

Below contemporary draft of the carriage from Struensee's book served as general guide for my scale drawing, including its associated tutorial for dimensioning a howitzer carriage. Struensee designs a 6 shots barrel, that is longer then the French 4.5 shots piece, which, in consequence  results in slightly altered figures with my draft. He accounts for 12 inches of space from the top front edge of the bracket cheek to the front of the trunnion cut-out, while mine accounts or only 8 inches or 1 shot, for the muzzle swell of the true shorter French barrel would otherwise get jammed between the bracket cheeks. Struensee's original illustration also includes a rather major flaw as it does ignore the true angle of the carriage's trail. With his illustrated angle, the carriage would have been fitted with absurdly low wheels, since the trails lower face was in any case meant to be level with the horizon line. But apart from this, all other figures do make a good fit with other drafts for howitzers of the period. Also his illustrated carriage of the French 24-pounder cannon includes an albeit minor figure-wise deviation to its associated tutorial.
I should note that there are also other takes regarding the design of the carriage. See below illustration found in the French Esquisse Historique de l‘Artillerie Française, by A. de Moltzheim, Strasbourg 1866. 
I don't know if his illustration is based on thorough research at all. Again, we cannot see the barrel. The visible bits seem to be based on a Gribeauval M1765 6-inch howitzer, really. The carriage seems to be designed with straight bracket cheeks, omitting the otherwise custom angle. Not sure here. The English contemporary John Muller, director of the London/Woolwhich arsenal and foundries, had the following to say – quoting: "It is true St. Remy, a French author, published in 1723 [sic. – read 1693], the most complete and extensive Treatise of Artillery, in two volumes in quarto, that is extant; which has since been much improved in the last Paris edition, in three volumes, published in 1745, containing all the improvements made in the artillery since the first edition… … All the authors that wrote since have done no more than copied his works in an imperfect manner, even the German authors follow him; though it is plain that the French have chiefly copied [the German] Dilichius: for their field carriages are exactly the same to this day as he has delineated them in his first work…" (John Muller, A Treatise of Artillery, London 1768, introduction pp. iii ff.).
With this German ‘Dilichius’, Muller refers to the classic work by Wilhelm Dillich or the latinized Wilhelmi Dilichii, Hochvernünfftig gegründet- und aufgerichtete, in gewisse Classen eingetheilte, bisher verschlossen gelegen, nunmehr aber eröffnete Krieges-Schule [sic.], Frankfurt 1646 (more widely read, it seems, was the 2nd edition of 1689). Dillich describes the standardized carriages first introduced by Maurice of Nassau's  Dutch at around 1620. The design was soon universally adopted across Europe and remained basically unaltered till well into the 19 hundreds.
Really, all contemporary publications concerning French artillery I know of would repeat presenting St. Remy's 1693 coppers, even the 1755 first volumes of the Encyclopédie do so. As a result, we do not know if anything essential had changed meanwhile. I have the single fragmental evidence, from the Malinowsky & Bonin source on Prussian artillery, who state Prussians introduced straight carriages from 1759 on "based on a design so much favoured by the French at this time". Two pages later, they aren't so sure anymore by stating it may have been only in 1761 or even 1766. Further information on French designs for this period should be the general direction of any further research. Possibly with period between 1760-1765 such models may have been found. Initiated by marshal Broglie, the French really undertook some measures in the attempt to lighten her cannons in order to reduce the ever growing want of draught horses. The Vallière 8- and 12-pounders were re-bored to 12- and 16-pounders, all insignia as well as the figure sculpted buttons were omitted. Also a lightened carriage was introduced for at least these converted pieces, which seem to have seen first service with the campaign of 1761 - not before this year. Oddly enough, Gribeauval's 1765 introduced new ordnance continued to be mounted on carriages with a considerable angle.

06 April 2013

The 2nd Battle of Bergen – Easter Friday, WWIII Central Front 1985

Here are a selection of shots taken from our Easter Fridays Game. Odd purists may object the scenario won't fit in this dedicated Seven Years War Blog, but, I must say it does bear a compelling connection, really. That's why I chose to share it anyway.
Soviet T-80's attacking


To me and our group in Frankfurt/Germany, Easter Friday has been the anniversary day of the SYW April 1759 fought battle of Bergen for years. This year, I made it a "Cold War turned Hot" scenario settled in around 1985-86. 
A Soviet reinforced tank regt (T-80's & BMP-2's) supported by 4 flight's of Mi-24 Attack-helos under the command of colonel “Brunswickov“ launched a deliberate attack on a NATO W-German battle group under overall command of a W-German general-major named "Breugler", drawn from 15th Armoured Brig/5th Armour Div with Leopard II & Marder IFV's (each 1 reinforced battalion plus 1 AT coy Jaguar II HOT and a battalion of 155 mm SP howitzers). NATO defended the high grounds to the east of Frankfurt - in fact the historic grounds of the 7YW battle of Bergen in 1759. Recon and AA platoons were also included on both sides. 
A great battleground to the present day, as it turned out. Google maps provided the basic layout for the terrain. Worked excellent. An embarrassing lot of build-up-areas, rally. I need more buildings, I guess.
The Terrain (table size 2 x 1.9 m)
View shows end result with initial FEBA outlined red


For my scenario, I used the original set of Frank Chadwick's Combined Arms rules (long out of print) which I haven't played for years. Yes, it's still alive. I wonder if anyone else is still using this set of rules?

My Scenario Planning
We were 4 players. Two on each side. I played on the WarPac side. 
NATO mission: Hold and defend
Part of the W-Germans were supposed to start in prepared positions, while a reserve of armour was to reinforce only later entering from NW direction of Nieder-Erlenbach.
Bergen-Enkheim and Bad Vilbel surroundings seen from the South

WarPac Mission: seize Bergen and Lohrberg heights
The Soviets approached from E on two axes. Most armour plus 2 Mot-Rifle coys approached from Schöneck while a Mot-Rifle bataillon approached along the A 66 Interstate tasked to seize Bischofsheim and attack NATO positions along A 66. 1st Bn/28 Armour following behind and tasked to assault Bergen from front the minute the northern group started its assault across the heights just S of Gronau. A single massed simultaneous strike was planned. That should do it, I thought. Part of NATO positions to the W of Bischofsheim were to be blinded by smoke to reduce defensive fire, to be delivered from the Regt Arty group of 3 battalions deployed behind the Hohen Stein high ground (each 1 bn SP 122 mm and 152 mm howitzers and 1 bn BM-21 missile launchers).
Soviet 3 bn Arty Group deployed to support the attack

Forward Edge of Battle Area (FEBA) was found by a pre assault recon action by all players operating with a company sized force to get a feel for the rules. The positions gained here could then serve to place forward elements onto the table. This, I did for the first time. To my feeling not so bad an idea to play out a prior mini game simulating the pre main action recon part, and then start the real game anew. It helps to avoid having an entire Arty battalion gang up on a single unsuspecting BRDM recon platoon the moment it comes into sight. I had all this in other games before.

How did it all work out?
Very different to my initial planning. The W-German reinforcing armour elements choosed to be already in position instead of coming in later. I somehow missed to tell this bit right after issuing the troops to my opponents. Soon later, while I was busy explaining our force to my partner, they had all deployed & I didn't bother to interfere. The heck. Won't make much of a difference, I thought. While the Soviet were deploying for the assault, W-Germans launched a smallish spoiling attack on Gronau, held by only a single BRDM recon platoon. Soviet plans remained unchanged, nevertheless, except Gronau was now also to be regained, which absorbed about 2 coys strength. Gronau now became the scene of a murderous close combat with both sides arty elements also joining in.
The fighting in Gronau
Soon later, 3 Soviet tank bataillons started the assault head on the Bergen position. I failed to fire the planned smoke mission, but instead decided to attack several spotted enemy with regular HE. Not a good decision, as it turned out, for it did little damage. Now basically all W-German elements in  position opened fire on Soviet tanks. The result was an outright massacre.
Too many tanks now received hit into their flank armour from the direction of Gronau and South positions in the woods behind Bischofsheim (the area that was to be blinded by smoke). This brought the game to a soon end with the Soviets taking a decisive defeat. Our Mi-24 Helos now could do no more then cover our retreat.
Finale seen from the South
W-German positions in Bergen. Most being 2/152 PzGrenBtl. – the unit I served in between 1984-1986. It suffered no casualties. I must have survived the day, I guess :-) 
W-German M-113G A2 artillery Forward Observer. The model being a self-made conversion

10 January 2013

Prussian SYW Artillery scale drawings – part 2


In order to illustrate Prussian ordnance of the Seven Years' War with its true distinctive features and dimensions, it is necessary to have a look at the 1717 designed ‘new range’ of ordnance, which laid out most of the basic characteristics of all that can be entitled distinctive Prussian in relation to other nations ordnance for the decades to come. The below two sheets have been arranged to give an insight here.
I took the effort to also illustrate the 3-pounder field gun, for it is believed some pieces to this design did see service during the Seven Years’ War, despite being obsolete ‘old school’ by that time. The next sheet will give some insights to the general design of the carriages. I am particularly happy to have unearthed an illustration of the M1717 wedges (Schusskeile). The design is explained in Malinowsky & Bonin, but only with another rare paper authored by Malinowsky, the so much needed illustration could be found. The written description, only, with its many outdated technical terms was found impossible to understand. Source is the periodical Archiv für die Officiere der Königlich Preußischen Artillerie- und Ingenieur-Corps, vol. 8, Berlin 1839. The Darmstadt State- and University Library keeps a copy including the appendix foldouts that are missing with the Google library copy. I hope my English wording is ok. Any corrections and improving suggestions to English wording of the technical terms are highly welcomed. I’m no engineer.

This carriage design remained in use till well into the Seven Years' War. The carriages were furnished blue, and the metal fittings were painted black. The tools and other equipment, such as rammers, wedges, etc. were instead furnished odd grey. Constructors and cartwrights kept modelling about minor details throughout the period, but in general, this is how the guns looked like. The paired spokes arrangement was found with the 3- and 6-pounders. The heavy guns had wheels with spokes in ordinary arrangement. Only during the course of the Seven Years’ War, a new carriage design seemed to have been introduced. I will get back to this issue with the sheets to come. For the period up to 1759 and beyond, Prussian carriages looked as illustrated. Below, I added a contemporary illustration of the M1717/1722 3-pounder, found in a gunners’ manual dated approx. 1745 (source is the collection of the Rastatt Army Museum/Germany).

This carriage is of the M1717 design, but with bracket cheeks overall 5 D longer than my above illustration (+1 for the trail and +4 for the centre section [Z]). My illustration is based entirely on the details from Malinowsky & Bonin.
The below photo shows – to my understanding – the single original Seven Years’ War carriage that survived to the present day.

Its a 2-pounder piece of 1758 and belongs to the collection of the Stockholm Army Museum / Sweden. From Hans Bleckwenn’s, Die friderizianischen Uniformen 1756 - 1786, we learn only this single piece was fielded – i.e. a solitaire non-royal ordnance design. The barrel was cast and its carriage assembled in Stettin. It was the private effort of a captain von Seebach in an attempt to equip his militia bataillon with a cannon. Apparently, the king refused to give Seebach’s unit a piece of his own royal ordnance. It was soon lost in a combat against the Swedes. Bleckwenn also provides the scale drawing to this piece. I don’t know the origin of Bleckwenn’s sketch, so that I cannot tell the hen from the egg. The sketch, at least, does give us the dimensions.

Most details of the carriage make a good fit with afore described M1717 carriages. Just the non-rounded trail and the use of only a single horizontal bolt near the centre transom deviate from the regulations. Also the wedge design is somewhat special.

From 1738 on, a significant transformation in Prussian gun construction took place. Prussian field cannons became much lighter, thus, more mobile than the M1717 heavy ordnance. This was contrived by reducing the charges, overall barrel length, and metal strength of the gun tubes. 


The Holtzmann 24-pounder served as master-design to which all other calibre pieces were to be proportioned. Several variants seem to have been cast and tested between 1738 and 1744, for the records give several different overall barrel weights for the pieces actually fielded. The below image from the Gohlke booklet served as the template for my illustration.  

It took me a while to realize its caption is complete nonsense. The drawing is absolutely fine, and accepting it is really the 16 shots 24-pounder all dimensions start to make a lot of sense. The signifficant reduction of weight is quite obvious compared to the older early 18th century European standard ordnance illustrated with the two sample barrels. The new design was based on the widespread believe a chambered bore design created much more gas pressure to the round then an ordinary bore design. Based on this observation, Prussians concluded one could arrive at the same power with less charge. Less gunpowder also allowed for the reduction of the barrels metal strength. This way, the same number of guns could be fielded at much less cost, or alternatively, the number of guns could be increased at same cost. Indeed, a best price arrangement hard to resist, for it so much suited the only now evolving Prussian battle tactics. Prussian infantry drill had arrived at outstanding battlefield mobility. All that was missing was a numerous and equally mobile artillery for best close support. Frederick was so enthusiastic about these light pieces, that within a decade, all of the old heavy ordnance was rigorously melted to provide the gunmetal for new casts, or expelled to the arsenals to serve as fortress or siege cannon. By 1756 all Prussian field guns were chambered bore pieces of mostly 16 shots length, a new 12-pounder 14 shots long, and a super light 24-pounder only 12 shots long. The Beauvrye 3-pounder (see below) was the single ordinary bore design remaining, and it can be considered the master design of yet the next transformation of ordnance to come.
The below sheet examines such a light chamber bore barrel design in somewhat more detail. I felt the need to have a closer look, do a very close reading and recreate the true dimensions. The date of introduction varies with the sources. Apparently, the guns were designed in 1738, but first serial casts commenced only in 1740.


Bataillon Guns


I will try to focus on those guns that were most important either for their design or because they were fielded in larger numbers. No less than six different models of 3-pounders were fielded during the course of the war, including the old M1717 piece as well as around 38 Saxon "Quick-Firer" barrels captured at Hohenfriedberg (1745) and adapted to Prussian style by end of 1750. Captured Austrian models are not included here. For easier identification, all pieces – i.e. more precisely the barrels – are commonly named after their designer/constructor along with the date of construction and/or its first serial casts.

On the eve of the war, summer 1756, Prussians mobilized 240 bataillon guns for a total of 126 bataillons (incl. Pionniers and some bataillons tasked for garrison duty not issued any pieces). 62 were newly cast 6-pounders replacing the same number of Holtzmann 3-pounders with a cylindrical chamber bore. The remainder were all 3-pounders. In terms of numbers, the Holtzmann M1740 conic chamber piece was the most common, amounting to near 100 out of the 178 total. Its new and particular light construction replaced the heavy M1717 long barrel pieces from 1740 on. The construction was indeed found to be too light as the campaigns of 1744/1745 revealed. Its' shot hardly carried 1.000 paces. With the widening of the chamber in order to take a larger powder charge, its shot now carried up to 1.500 paces. Nevertheless, after 1745/47, no new pieces were cast to this model, it seems. New designs were given the preference instead. One such new design was the Beauvrye M1746 piece, which seems to have been designed in response to the shortcomings of the Holtzmann M1740 piece. It had a longer barrel, but was still much lighter then the old M1717 piece. From this model, only 18 casts at the Berlin foundry are documented. Some more pieces may well have been cast, for these tables are incomplete, but this model was fielded in much fewer numbers as the Holtzmann piece. Also in 1746, general Linger designed a conic chamber barrel 20 shots long and somewhat lighter then the Beauvrye piece. Apparently, now this new Linger model was given the preference, as around 60 pieces are believed being cast up till 1756. The light barrels seemed to have been mounted on an equally lightened carriage. Bracket cheeks were shorter, and also the wheels were scaled less high. The illustrated 42 inches wheel is based on the Beauvrye piece illustration found in Gohlke, Geschichte der gesamten Feuerwaffen bis 1850. The Holtzmann 24-pounder had 51 inches wheels. Therefore the 2 remaining 6 and 12-pounder calibres must have had wheels scaled between these two extremes. See also below near contemporary painting “Seydlitz at Rossbach”.

The gun seen here can be identified either as the Beauvrye or the Linger 3-pounder. The uniform details look all rather authentic. The cannon may well be just as authentic. Note the gunners ‘flail-rammer’ as well as the bricoles slung around the gunners’ shoulders. This gun also comes with rather small wheels.
The Beauvrye piece is of interest because according to a paper by Hans Bleckwenn it is quite certain that it was attached to the Berlin region infantry regiments Prinz Heinrich (IR 35), Münchow (IR 36), Fredericks' own Praetorians ( IR 15/I. Leibgarde), and possibly also the other Guards bataillons in 1756. They had them with all their Potsdam exercises during the early 1750’s, as it is recorded in a diary of the Guards officer von Scheelen (see: Hans Bleckwenn / Engl. translation by Digby Smith: Prussian Field Gun Models in Relation to General Tactics. Original articles in the Zeitschrift für Heereskunde, 1957, Numbers 154, 155, 156, 157. 1958/1 Jan-Feb.)

As I am discussing the Prussian range of early Seven Years’ War bataillon guns, this chapter can be completed with also presenting the M1754 light 6-pounder by Dieskau.




Holtzmann’s M1740 range also included a 16 shots 6-pounder, but only few have been fielded during the campaigns of 1741 and 1742. It was only little more effective then the 3-pounder but requiered more horses for it’s draught. For this reason it was removed from the field inventory. The remaining Linger 3-pounder had a 20 shots barrel (144 cm) and should have looked much like the Beauvrye piece.

The sole type of bataillon gun not disscused being a 1-pounder Amusette. Such a piece was initially allocated to the Prussian Frei-Bataillons raised during the Seven Years’ War at a ratio of 1 piece per bataillon. From 1759 or 1760 on, they all received 3-pounders instead. Moreoften captured Austrian pieces. Little information could be found here. The first pieces used were really captured Saxon models found in the arsenals of Dresden and Freiberg. With near certainty, the carriage was a `wheelbarrow` type, in which a horse could be harnessed between the shafts. This type of carriage was known all across Europe and fielded with many armies. In Britain it was entitled Galloper gun.

Also of interest may be the innovative limbers, that came with the Prussian bataillon guns. A combination of limber and ammunition cart.


Position Guns

In 1756, and all through 1757, Prussian heavy or ‘Position Artillery’ consisted of chamber bore 12-pounders, either 16 or 14 shots long, and a super light 24-pounder. Furthermore several 10/11-pounder howitzer models. The first sheet presents the 16 shot barrel 12-pounders.

Once more an image of the ‘real pieces’. Above image shows a number of barrels on display at the Vienna Heeresgeschichtliches Museum (HGM). No 1 is a Dieskau M1759 ‘Austrian-type’ 12-pounder, 18 shots long. A cast of 1781 it seems, as per the little information I was able to aquire from the museum. This would be confirmed by the shape of the rounded button which started to appear with casts of 1774 and later. No 2 could be identified as the M1758 ‘Austrian-type’ 12-pounder. A 16 shots barrel (182 cm) Apparently a cast of 1758. It's weight, as per the barrel's engraving is 1,680 pounds (785.4 kg). No 3 behind is a Dieskau 6-pounder M1768/71, 18 shots long (or more preceisely 18.2). Again a cast of after 1774 because of it’s rounded button. This piece came without holds/griffins. And to the rear No 4 we have a mighty 24-pounder. As per it’s mouldings, the piece should be either M1754 or the earlier M1717. Both were quite similar. No 5 is an Austrian 6-pounder. The non sculpted holds and the rounded button would also make it as a 1770 or later cast. The barrel in the left foreground is a Russian Unicorn (date of cast unknown). the bore is larger then the Prussian 12-pdr next to it. Should be a 15 cm class calibre, roughly equalling a 24-pdr bore. As one can see with this rather random arrangement of barrels, the Prussian barrels do have a presence of their own, and do stand out from the crowd by the sheer size of the sculpted griffins. In particular the 24-pounder looks awesome.
The next piece I like to introduce is the rather special design ‘super-light’ 24-pounder M1744.

With the available written record I was able to recreate it‘s true dimensions, for not a single image could be found so far. The principle dimensions of the barrel as well as the carriage should be all rather authentic, and about as close as you can get it. Just some of the minor issues are speculative. Do not pin me down to the exact height or width of applied iron metal sheets, nor the actual number of nails, recommended to fit all to the carriage. Next to the 12-pounders, this piece, along with the equally eccentric 10/11-pounder ‘howitzer-gun’ designed the same year were meant to be the mainstay of the Prussian ‘heavy’ field artillery with the early Seven Years‘ War campaigns, all through 1758. Both were fielded for the first time with the Prussian invasion of Bohemia in 1744.
The 24-pounder is said to have done particular good service at the battles of Hohenfriedberg (1745) and Roßbach (1757). From 1758 on, it gradually became out of use, as it was replaced by the introduction of a new range of more powerful 12-pounders. Next is the 10/11-pounder ‘howitzer-gun’. Both pieces just belong together. They have been designed the same year, and their special construction, along with Holtzmann‘s Klemmkartätschen entitled grape rounds – especially designed for these two pieces – can be deduced only from an understanding of their intended tactical employment. 
Frederick was a great promoter of cannister and grape, in favour of ordinary shot, to be employed with the guns in a given action. To his observation, with the early Silesian Wars‘ battles, cannister and grape did far more damage as roundshot. But cavalry could not really be harmed with conventional cannister rounds at medium ranges. It was the Austrian cavalry, that had been the biggest threat to the Prussians in the battles of Mollwitz 1741, and Chotusitz, 1742. This shortcoming of Prussian 1740 ordnance must have been the inspiration to create a range of ordnance capable of firng destructive grape rounds out to longer distances. The naked figures expressed with the two illustrated barrels leave no doubt to the intention of their design. Frederick‘s 1749 tactical instructions gives the most evident hintsight. He advised to place a battery of 4 24-pounders and 4 10/11-pounder howitzers on the wings of the infantry line. From this position they were tasked to aim at the oposing cavalry in particular by employing Holtzmann‘s Klemmkartätschen.
In addition to the long barreled 10/11-pounder howitzer, also shorter barrels of approx. 6.5 D length were designed.




Above image shows a Prussian 10-pounder howitzer barrel on display at the Vienna Heeresgeschichtliches Museum (HGM). It should be the 'heavy' M1766 for the siege artillery, which is revealed by the rather massive dimensions of the first reinforce. The barrel was approx. 6.5D long (108 cm).

Of less importance is below 18-pounder. The principal howitzer piece of the pre-1740 period. The last 10 pieces to this design were cast at the Berlin foundry in 1744, it seems. A few were mobilized during the SYW. However, the mainstay of howitzers was the 10 or 11-pounder during the early campaigns and the light 7-pounders fielded in growing numbers from 1758 on.
I needed to do the piece in order to understand the method of proportioning a howitzer carriage in relation to it‘s barrel. Most turorials of the period simply state they were quite similar to the proportioning of a cannon carriage, and that would be about all that is said. Also below illustration is part of this research work. It is based on the single draft of a Prussian howitzer, I was able to find. In fact, 2 such pieces must have been part of Feld-Maréchal Lehwaldt‘s East-Prussian Corps of 1757 – after the battle of Groß-Jägersdorf – as replacement of the 10-pounder howitzer pieces lost in this battle.


more pieces to follow …

16 June 2012

7YW Artillery – the Prussians are coming

I finally managed to get started with the Prussian ordnance fielded during the Seven Years' War. It is a most interesting subject to me, for there is so little image material found with the commercially available books on the Prussian army. Even with rare ones, long out of print. 
I'm so fond with the first results, that I thought of sharing it in advance.
The below first illustration, therefore, is a sort of sneak preview, as I worked off-scale my regular sheet format. More details are to follow with my next completed sheet.

More information on Prussian artillery will soon be available in English language published in the Smoothbore Ordnance Journal by Digby Smith and Stephen Summerfield. Digby Smith has also done a wonderful translation of a rare paper by Hans Bleckwenn focusing on Prussian 7YW artillery.

At this point I wish to thank all who have supplied me with this wealth of material. I have received great support from many countries ranging from the US, UK, Denmark, Italy, France, and Germany. I have also received the official permission of the Stockholm Army Museum to use their image material.
My initial decision, to do this project in English language rather then in German turned out to be a good one. The audience grows so much larger.
My special thanks to David Morfitt ("Not by Appointment" Blog at nba-sywtemplates.blogspot.de ), who has contributed the nice illustrations of the Prussian barrels and carriages insignia.
Regarding the 'source situation’ on Prussian artillery which enables me to reconstruct the 7YW period pieces, I will draw most heavily on the single most valuable 4 volume work by Malinowsky & Bonin, Geschichte der brandenburg–preussischen Artillerie, vol. II, Berlin 1841. It provides most detailed descriptions on the evolution on barrel and carriage design, but comes without images. Regarding images, most authors work with the same four of five illustrations again and again, which implies not much has survived WWII. The former Berlin Zeughaus Museum owed a large collection of scale models of which but few pieces survived. Also the Potsdam Heeresarchiv had loads of scale drafts of about all pieces ever fielded or designed in Prussia. All was lost with a devasting air raid April 1945, it seems. Some scale drawings did survive in Germany or other collections, such as Denmark. Most are post 7YW, but are of good help nevertheless. 
To make matters worse, some glaring errors are found with correctly identifying some of the images. None of the more recent Historians such as Dr. Hans Bleckwenn, Die fridrizianischen Uniformen, Osnabrück 1987; or Martin Guddat, Kanoniere Bombardiere, Pontoniere, Herford 1992 seem to have noticed. The flaws start with the 1911 published little booklet by Gohlke, Geschichte der gesamten Feuerwaffen bis 1850. Gohlke comes with 3 sample images of Prussian guns. Two of the three have false captions. Bleckwenn, at least, was more cautious with presenting his 12-pounder illustration "claimed" to be mounted on a M1762 carriage. Martin Guddat less so. He presents several images of a 12-pounder scale model, a black and white photo of another 12-pounder unlimbered and a 24-pounder limbered, and fails to notice that it is all different photographs of the same piece. It's a scale model of the "Austrian-type" 12-pounder designed by Dieskau in 1759, 18 shots long, and mounted on a M1774 carriage. Bleckwenn illustrated the piece in his book. The barrel design is equally the model for the casts of 1774 or later. The carriage is of similar design as with the heavy 12-pounder nicknamed "Growler" (German: Brummer) on display at the Paris Musée de l'Armée to the present day. A barrel 22 shots long and first cast in 1761. The famous "Growlers" first fielded at Leuthen in 1757 were heavy fortress or siege guns with 24 or 26 shots barrels, not the model on display in Paris. It's dimensions was rather close to the French Vallière 12-pounder found in my January 2012 post.