Alter Kranen (market width)
The old crane in Marktbreit (also called Mainkran ) on the left bank of the Main is a house crane (freight crane) made of stone and wood based on the principle of the pedal crane of the 18th century and one of the few cranes that have survived from its time.
description
The cylindrical crane house is a round building made of approximately one meter thick masonry, 9.25 m in diameter and 6 m high up to the protruding roof. The base consists of six layers of rounded limestone blocks, two conical base layers and four cylindrical layers, the second and fourth indented by about 5 cm. The other outer wall is made of ocher-colored, rounded sandstone, also indented alternately. In this way, eleven circumferential approx. 28 cm high annular grooves are formed in the outer masonry with its 24 stone layers, including a conical base wall and protruding edge to the roof. The flat conical roof (total height: 7 m; 5.8 m to the tower ball without a lead tip, inclination: approx. 40 °) consists of the fixed lower part and the rotatable upper part with a small dormer window as access to the boom and for monitoring the loading operations above the lead-clad wooden boom with chain, ball and double hooks (total length: 12.5 m, 9.4 m of which protruding from the roof , 50 ° boom angle). The chain runs from the treadle axle over a roller at the foot of the boom attached to the crane column over the roller mechanism at its tip to the leveling roller with hook (bottle), the end is anchored at the boom tip. The rope greaser had to climb the 18 climbing clamps of the jib to the Keranich beak, the end of the jib, and grease the chain rollers well. The wooden roof structure rests flush with the topmost stone layer, supported by 14 support beams resting on the inner wall and about 3.5 m high on a wall recess, which in other cranes reach the floor. The arched entrance (~ 2.9 m high) with a rectangular stone staircase and wooden door is located on the west side about 1.60 m above ground level. In representations from the beginning of the 19th century, the entrance was covered. To protect against the immense pressure of drift ice and floods, an icebreaker made of shell limestone was firmly attached to the outer wall on the upstream east side of the crane house , above which the elaborately designed coat of arms of the founder, Prince Johann I Nepomuk from the Schwarzenberg family, was attached . Two opposite barred windows facing the Main and the city provide some light. The sign-shaped notice board near the entrance says: “Rebuilt in 1784 after being destroyed by floods by Prince Johann I zu Schwarzenberg. Inside there are two connected pedal bikes. On the east side icebreaker, above it the coat of arms of the Princely House. In the 18th and 19th centuries, the crane was used to load and unload ships in the wholesale trade with local products and imported colonial goods. "
The almost 13 m high crane (16 m at the end of the jib) has the original oak and fully functional double-wheel drive mechanism (chain winch, cable winch), which was a common feature for most of the pedal cranes. The drive wheels, about 5 m in diameter, sit on the chain shaft in a wooden frame. It was attached to a horizontal crossbeam (drawbar) running between the wheels at both ends of each of the two crane workers around the central axis of the square, pointed oak trunk connected to the wheel frame on the one hand and the conical roof with the boom on the other, the crane column ( also called Kaiserbaum), rotated. The crane needed a sworn crane master who was in the service of the crane leaseholder and for the payment of the employees in and on the crane, for the course of the crane business and for the winch servants running in the wheels, a 15-25 man team from their own guild who belonged to the "Aufläder" was responsible. The loader or sick hand - not to be confused with the winch hand, the winch driver, the cyclist, the crane treadmill or the crane worker in the treadmill or on the drawbar in the crane house - worked outside the crane on the crane load, be it on the quay or in the Main ship. The original 50 m long and with a specific mass of 4.00 kg / m total weight of 1,690 kg had a tested load capacity of 3,190 kg or 3.2 metric tons .
The old cranes has a certain resemblance to the Andernacher Old Krahnen Stone-rotunda (here without a roof cornice superior), conical roof with dormer on the boom, icebreaker in the upstream direction, crest.
history
Today's harbor crane is the successor to the previous building, which was destroyed in the centuries- old ice course at the beginning of March 1784 , and whose crane house, which is also round, had a timber frame construction comparable to the Lüneburg crane . It was Joseph I. Adam , 4th Prince of Schwarzenberg, probably built from 1745 to 1755. It offered hardly any resistance to the strong ice flow with floods and floating logs and was swept away as a whole by the floods. In the same year, Johanns I Nepomuk , 5th Prince of Schwarzenberg from 1782 to 1789, had the current house crane rebuilt as a "crane made of wood and stone [...] with a boom" by master mason Johannes Michel by decree . The construction of such a loading crane always required the permission of the sovereign. It was used to transfer goods from the Main ships to carts and wagons and vice versa.
In 1806 Marktbreit became Bavarian , and the crane and its warehouse came into Bavarian ownership in 1814. The crane was in operation until 1899/1900 and has since been an industrial monument for the rich and extensive trade relationships and activities on the Main and a landmark of Marktbreit. With the port cranes in Andernach, Trier (2) and Würzburg, it is one of the last five remaining stone house cranes with a rotating roof.
On special occasions, guided tours with a look inside the crane are possible.
See also
literature
- Hans-Liudger Dienel , Wolfgang Meighörner: The Tretradkran . In the series: History of Technology (published by the Deutsches Museum ). Munich 1995; ISBN 3-924183-33-3
- Hans-Joachim Krause, Richard Scharnagel: The pedal crane in Marktbreit am Main . A consideration of the hoist from 1784, its load-bearing capacity and performance in stationary operation and the risk to its crane treads in transient operation. Self-published, Marktbreit 2004.
- Michael Matheus : Harbor cranes. On the history of a medieval machine on the Rhine and its tributaries from Strasbourg to Düsseldorf (Trier Historical Research 9), Trier 1985.
- Michael Matheus: Medieval harbor cranes . In: Uta Lindgren (Ed.): European technology in the Middle Ages 800-1400 , 4th edition, pp. 345-348. Berlin 2001; ISBN 3-7861-1748-9
- Monika Stöckl: Fixed harbor cranes: Crane buildings from the 15th to 18th centuries on the Rhine, Main and Moselle ; Term paper for obtaining the academic degree of a Magister Artium. University Press, Mainz 1986.
Web links
Coordinates: 49 ° 40 ′ 8.4 " N , 10 ° 8 ′ 37.3" E