How to draw a German Eisernkreuz

Martin Héctor Afflitto Echagüe found this description in an old german book in an Argentine Aeronautical library. It describes the dimensions of a german Eisern Kreuz.

Diagram (reproduced)

Martin reproduced the diagram by hand.

Accompanying Text

The text in German is as follows:
Hoheitsabzeichen
An den Enden der Oberseite der oberen tragflächen an der Unterseite der unteren Flächen, beiderseits in der Mitte des Rumpfes und auf beiden Seiten des Seitensteuers erhalten die Flugzeuge in größtmöglichster Abmessung die deuchen Hoheitsabzeichen in Form des "Eisernen Kreuzes ", in schwarzer Farbe. Das Kreuz erhält eine etwa 5 cm breite weiße Umrandung. Für die Abmessungen bezw . Formen des Kreuzes sind die in Fig. 114 angegebenen Abmessungen zu wählen. Der flugzeugrumpf erhält außerdem beiderseits neben dem Kreuz die Typenbezeichnung und Flugzeugnummer.

Translation (bei Hans Trauner)

National Markings
The German national markings are applied to the very ends of the uppersides of upper wings, on the underside of the lower wings, on both sides of the middle of the fuselage and on both sides of the rudder. The markings are in maximum possible dimension in form of the 'Iron Cross', in black colour. The cross has a white border of approx. 5 cm width. For the measurements and form, the measurements of Fig. 114 are used.
In addition, the type designation and Aircraft Serial number (Flugzeugnummer) are applied to both sides of the aircraft.

Hans notes:

This Figure 114 is taken from an order of July 25th 1916. Interestingly in this order the ratio of radius to height is given as 1:1.4, despite the given measurements. This 1.4 ratio included the white border!

Alternate instructions

Tom Solinski offers:
I found the same information (dimensions) in newer form in an issue of Flying Scale Models two years ago. Great numbers but constructing it is a draftsman's nightmare. For those of you who want to practice drawing these "Iron Crosses" may I suggest the following process using a straight edge, ruler and compass?
  1. Draw a vertical line the desired height of the cross. This forms the vertical "H" in the sketch.
  2. Draw a horizontal line the same length as the first line that bisects the first line. The horizontal "H" in the sketch.
  3. At the end point of each of these lines draw two perpendicular lines that are one-fourth the length of the original vertical lines one running in each direction away from the base line. These form the vertical and horizontal "B"s in the sketch. 1/4H + 1/4H = 1/2H=B)
  4. Label the endpoints of the "B"s as (working clockwise): top left, top right; right top, right bottom; bottom right, bottom left; and left bottom, left top.
  5. Draw and extension of the original lines from steps a & b above out at least one "H" unit long.
  6. Take your compass and set it to 1.3 x "H" wide, this is the dimension "R" in the sketch.
  7. Set the point of the compass on the "top right" endpoint from step d above and strike an arc on the extension line to the right of the cross.
  8. Move the compass to the intersection just drawn on the extension line, and strike an arc from the "top right" to the "bottom right" end points in step d above. Now you have the first curve established.
  9. Repeat steps g & h for the other three legs of the cross.
  10. Erase anything that doesn't look like a cross.
That was easy wasn't it?

Reference

Title : Das Flugzeug Und sein Aufbau, Bibliothek für Luftschiaffahrt und Flugtecchnik, Band 17
Author : Knut Anacker ( Ingenieur und Flugzeugführer)
Publisher : Richard Carl Schmitdt & Co., Berlin W 62, Januar 1918