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The crane on the southern tower was throughout centuries the symbol for Cologne. There are no reports about its' construction, but it can already be seen on the pictures of the Ursula legend which were painted around 1450. At this time it had already been out of use for quite a long time. Therefore it is rather unlikely that it was built as late as the 15th century-which was formerly beleived. It is more likely that it was erected around 1350 when the building of the southern tower began.
Once built on the ground it probably went up with the tower. Its' basic square consisting of four solid oak beams was cleverly positioned on the middle of the four sides of the tower, so that each beam only had to be 9,65m long in order to cover a square of 13,6 x 13,6m width.
In order to raise the crane on the next level, it only had to be lifted -corner by corner- for the thickness of a square stone block by the aid of wedges. When this easy procedure was gone through the crane stood - in accordance with the proceedings of the building- between 40 and 50 cm higher than before, at last at a hight of about 45m. (AW)
The actual carrying structure of the crane was about 12,70m high and narrowed from 9,95m to 4,70m , so that its' slate covered sides inclined by about 12°. In its' centre was the "Kaiserstiel", a huge oak trunk of 15,20m hight and - at its' upper end (the thickest part of the trunk)- about 1m in diameter. There it posessed a thick thorn - held by four iron bands - which rested on an iron resting shell. Thus the whole construction could easily be moved.
The part which stuck out of the carrying construction, was an octagonal slated tower cover. It had a hight of 5,40m in itself. From it stuck out the jib,built of three heavy beams, which protruded the tower cover by 7,20m. The overall length of this jib was 13,15m, its' projection from the axle of the "Kaiserstiel" had a length of 10,55m. All in all was the construction about 25m high and its' peak lay more than 70m above ground. (AW)