Dolmen D22 has some striking features. Side stone S2 has its flat side at the outside instead of the inside the chamber. The longitudinal walls of the chamber contain at one side three stones but at the other side two. Because of the concatenation of trilithons hunebedden normally have the same number of stones in the opposite walls. Also the distances between the side stones is rather small and therefore D22 looks like an enlarged dolmen more then like a Dutch dolmen.
During a quick survey of the ground plans of dolmens in Mecklenburg, it appeared there was a similar plan to that of D22 (Serrahn 541). There is no excavation plan available for Serrahn 541 and during the unification of East and West Germany the dolmen has been cleared away by the landowners . Regrettably we cannot have a detailed plan for this dolmen anymore. The chambers of D22 and Serrahn 541 have the same outline, but differ in their sizes. In D22 the gap in the strange double stone Z1' falls together with a deviding wall in Serrahn 541. Besides this, the outside of side stone S2 stands at the same slant line as inside of the comparing stone in Serrahn 541. This uniformaty together with the mirrored side stone can hardly be accidental. Afterwards the chamber pattern of D22 and Serrahn 541 was found with another two enlarged dolmens in Mecklenburg. One as the excavation plan of Serrahn 540 (by Schuldt in 1967), the other produced by own measurements (Frauenmark 632). Serrahn 541 plays a double role. The pattern mirrors itself in its ground plan: Having a side stone like in D22 (the two plans right in the figure below) as well as having a slant treshold (the three plans left).
From left to right: Bronneger D22, Serrahn 541, bis, Serrahn 540 and Frauenmark 632.
Due to the huge distance between D22 and the dolmens in Mecklenburg (over 400 km) it can hardly have been a matter of copied ground plans. It was possible to ferret out a pattern, which was simply enough to be remembered. over a long time (below the figures left). It starts off with the fact, that the slant treshold can be created by a diagonal in a double square. Here the proportion 1:2 leads to an angle of 117º - the same as the angle between the long axis and the treshold. After drawing the diagonal three times in a loop, a right angled triangle evolves. The top of this triangle is clamped by a parallel line to that of its base. This figure determines the plan of the chamber (light red in the figure).
It's a question if the construction of the grid doesn't depend on a circular reasoning. A right angle gets setup by the grid, but from where does the grid get its right angles? In the Sulba sutra (500 BC) the construction of a square is described using a stick and a rope only. When also the 'diameters' from the description are involved in it, one gets the required grid.
When desiring a square, one needs to take a rope as long as a side of the square. Tie a knot at both ends and mark it at the middle. Setup an east-west line with it, having a pole fixed at its middle. Fasten both knots to the pole and draw a circle with the mark. Stick a pole at both ends of the diameter [= intersection of the circle with the east-west line]. Having one knot tied to the eastern pole, draw a circle with the other knot. Draw a similar circle using the western pole. The second diameter [= the north-south line] is obtained from the intersections of both circles. Stick a pole at both ends of the diameter [= intersection with the first circle]. Fasten both knots to the eastern pole and draw a circle with the mark. Do the same at the southern, the western and the northern pole. The intersections of the four circles produce the square.
Of course there are more ways to construct the pattern. For example by means of the twelve-knots-rope as known from
ancient cultures (figure on the right). Steps two and three are executed when first a diagonal is drawn via the proportion
1:2 (blue). For two reasons the construction in a grid is hold forth on this website:
(1) With the dolmens the grid has its own orientation, derived from the 167º and/or 193º axis (green in the figure below).
(2) The construction via the grid can be seen as a starting point of a continuous development up to the earliest writings on math (see the page Math in ancient times.
From the ground plans it appears, that there hasn't been a strict guideline or a uniform formula. The orientations of the dolmens and the grids differ from each other all the time. Also the orientation of the dolmen in relation to the grid isn't fixed. Often the grid has been derived from azimuth 167º and/or 193º (the green lines below), somtimes this counts for the dolmen itsel, but other values are possible (i.e. with G5). Even the slant side under an angle of 117º, may not be seen as law (Barkvieren 92). With almost none of the dolmens the setup is the same and yet everytime there are enough starting-points to recognize the associations. The comparison of the next ground plans shows this well.
From left to right: Serrahn 540, Frauenmark 632 and Barkvieren 92.
From left to right: Heveskesklooster D5, Bronneger D22 and Serrahn 541.
A celestial body rising at 167º sets at 193º (see the page Alignment on alpha Crux ). The three upper dolmens have their grid on one of both directions. Besides that Frauenmark 632 and Serrahn 540 have one of their sides on the other direction. Since the pattern has been drawn into the grid differently, still the chambers don't the same orientation. But the enclosed right angled triangle does appear all the time. With the lower three dolmens this triangle partly falls 'outside' the chamber, for it reaches to the flat exterior of one of the stones. These dolmens give the impression as if the exist of two compartments, while the pattern incorporates the larger one. Dolmens D22 and 541 can be drawn from azimuth 167º, but with modified proportions (resp. 2:3 and 1:3). This doesn't apply to G5. While with D22 the grid is put on 43º/133º, G5 appears to have its long axis on 43º. Therefore the grid gets an orientation of 70º/160º. In their study Gozález-García and Costa-Ferrer find a peak at class 70º-75º and more notable at class 95º-100º . The short side of the enclosed right angled triangle has an orientation line on 96º, which leaves the dolmen between two flattened side stones. The surface of bots planes point in this same direction and can have been markings. Regrettably the dolmen has been cleared away, so this cannot be verified anymore. Orientations on 70º and 96º occur together with markings in more dolmens, but they are too few to come to conclusions.
Although there exist similarities in the setup of the pattern all the time, one clearly cannot speak of a plain systematics. The grid supports the construction of the chamber and this seems all there can be said. Maybe the slant side of the pattern can explain the positioning of the tresholds, but the current data is too minor to judge upon that. In general the pattern seems to be a by-product more then a goal in itself. Perhaps it was utilized to create the enclosed triangle. The basis of the triangle always falls together with a long side of the dolmen. Moreover, the basis has the same length as the chamber wall of the dolmen - also when the triangle partly exceeds because of the exterior of a stone. For the moment the right angled triangle together with some orientations seem to be the main elements in the construction.