Friedrich Gravenhorst

Heinrich Ludwig Dietrich Friedrich Gravenhorst (born January 3, 1835 in Weide near Großenaspe in Schleswig-Holstein , † June 11, 1915 in Stade ) was a German road construction technician .

Life

Gravenhorst was born on the Weide estate near Großenaspe, which his father, the Hamburg merchant Carl Friedrich Gravenhorst (* 1798, † 1867), had acquired. There is evidence that his ancestors on his father's side had lived in the Braunschweig area since the 17th century . As a teenager, Gravenhorst had received private lessons, among others from his uncle Pastor Mertz in Schönkirchen near Kiel . In a private school in Kiel, he passed the final exam for university entrance qualification. He was interested in mathematics and mechanics , but due to adverse circumstances, he was unable to start university immediately. He first completed a forestry and hunting apprenticeship at a forest ranger's office near Kiel. Here he also took classes in mathematics and surveying . He then passed an examination as a surveyor and land surveyor in Kiel. He then worked in surveying at various locations, including in Uelzen , where he produced a large-scale city map. In this way he acquired the funds for a university course.

He then studied mathematics , mechanics and civil engineering at the Polytechnic in Hanover , which later became the Technical University and is now the Gottfried Wilhelm Leibniz University . After completing his studies, he first took a position at the hydraulic engineering inspection in Celle . He would have liked to return to his homeland, but there was a lack of suitable vacancies there. Therefore he volunteered to work on property tax regulation in Prussia . He came first to Köslin and then to Stolp in Western Pomerania . In Pomerania he met his wife Luise, née Lehmann, a doctor's daughter from the village of Lupow in the Stolp district , whom he married in Lupow in 1867.

After Schleswig-Holstein was incorporated into the Prussian state, Gravenhorst joined the road construction administration. Road construction would then remain the field in which he was successful for 40 years. He returned to his home province, first to Meldorf , then in 1871 to Segeberg . In 1872 he became a district builder in Otterndorf in the Hadeln region . In 1873 he took over the management of the Stade State Building Authority as a road construction inspector. The building district for which he was responsible at that time comprised the districts of Stade , Bremervörde , Geestemünde , Lehe and the state of Hadeln. At that time there was only a railway connection in the area on the Bremen - Bremerhaven line until the Lower Elbe Railway between Harburg and Cuxhaven was put into operation at the beginning of the 1880s . Other stretches had to be tackled by carriage or on foot. During his tenure in Stade, Gravenhorst covered 275,000 kilometers on business trips.

But Gravenhorst was not satisfied with the administrative work and inspection work alone. He was constantly preoccupied with theoretical questions of road construction in the Elbe - Weser triangle, with its poor railways, with its various soil conditions. Gravenhorst was the first to introduce a fundamental innovation in road construction by replacing the previously practiced road reinforcement using boulders of different sizes for the first time in 1885 with standardized small paving. On a test route on the Ritzebütteler Chaussee, km 4.250–4.254, he realized a road surface that was as flat and evenly resistant as possible in the form of a small pavement made of cube-shaped granite stones with an edge length of 4 to 6 centimeters. This new patch performed so well that it was soon used across Europe and overseas. With his pioneering act, Gravenhorst created the road surface that was most frequently used in Europe until the middle of the 20th century.

Gravenhorst's marriage to Luise Lehmann resulted in nine children: four sons and five daughters. His work was later continued by his son Otto (* 1872).

literature

• German Biographical Encyclopedia (DBE), 2nd edition, Volume 4 (Ed. Rudolf Vierhaus), Saur, Munich 2006, p. 114.
• Carl Graf von Klinckowstroem :  Gravenhorst, Heinrich Ludwig Diedrich Friedrich. In: New German Biography (NDB). Volume 7, Duncker & Humblot, Berlin 1966, ISBN 3-428-00188-5 , p. 12 ( digitized version ).
• Georg Beermann: Friedrich Gravenhorst . In: Lower Saxony Life Pictures (edited by Otto Heinrich May on behalf of the Historical Commission for Lower Saxony), Volume 2, Hildesheim 1954, pp. 78–87.

Web links

• Gravenhorst's souvenir in Stade