Johann Heinrich Ehrhardt

Johann Heinrich Ehrhardt , also Erhardt, (* 29 April 1805 in Zella St. Blasius ; † 29 April 1883 in Radebeul ) was a German locomotive manufacturer and inventor

Life and work

His career began in the son of a poor gunsmith as day laborers by the guild free mastermind worked in the Jäger'schen wire drawing plants. During the visit, a master gunsmith with his parents this was aware of the technical skills of the Son and allowed Ehrhardt still an apprentice gunsmith . His first job was finished the journeyman in the mint in Gotha .

LE BELGE With his recommendations mintmaster Ehrhardt 1831 went to Belgium. He worked only half a year at an optician in Brussels before moving to Seraing to John Cockerill could go Maschinenfabrik, to work in steam engineering. [1] As a fitter from dewatering machines he invented there a rear cargo compartment. Ehrhardt moved in by Konrad Pastor Gustav led locomotive Cockerills as 1833, the preparations for the construction of its first along the lines of Stephenson's locomotive ROCKET in continental Europe manufactured steam locomotive LE BELGE began. With two of Stephenson's locomotive ( LE Fleche [franz .: THE ARROW ] and STEPHENSON ) opening should train Brussels-Mechelen done. To acquire theoretical knowledge for future work, Ehrhardt was in November 1833, the Polytechnic Institute in Düsseldorf . Three months later he left it with the "Certificate No. 1 of Prof. Carl Shepherd ". [2] In order to be able to open up the railway line with two locomotives, twelve trials from July 1834 were provided by Ehrhardt each locomotive, then carried the acceptance by the Royal Commission. The decrease journey took Robert Stephenson on August 2, 1834 in person, Ehrhardt accompanied him in the cab. Halfway to Mechelen derailed the locomotive "due to malicious tearing up the rails". [2] The Stephensonlok was not damaged. 1835 mounted Ehrhardt then the LE BELGE, [3] , the first steam locomotive made in continental Europe. [4] This took the end of 1835 the regular service.

In 1836, Ehrhardt visited the Arts and Crafts School in Düsseldorf to enhance his theoretical knowledge as well as his skills in the technical drawing. Then he returned to his home in Zella.

Products of the Saxon engineering Compagnie According to one source Ehrhardt met at a trade fair in Leipzig in October 1838 one of the directors of the Saxon engineering Compagnie in Chemnitz know who hired him the same for the construction of steam engines and locomotives. [2] According to another source [1] Ehrhardt worked brother as an engraver with the publisher Friedrich Brockhaus, Leipzig. This he told of the experiences of his search of work, brother. Brockhaus had participated in the Saxon engineering Compagnie in Chemnitz and was interested in the reorganization of business activities on the acquisition of the company by Carl Gottlieb Haubold followed in 1836. Since Brockhaus there was planning to enter the locomotive, he had a conversation with Ehrhardt and then sent him with a letter to Director Kaden to Chemnitz, there to check the work on its suitability for the locomotive. The report was very sobering. The Technical Director of the Saxon engineering Company, Justus Preuss, Set Ehrhardt, because he was satisfied with his time head of the locomotive design, director Friedrich Overbeck man, not.

Shortly thereafter transferred Ehrhardt on 14 October 1838 before its occupation, the at Kirtley in Warrington / England purchased locomotive pattern STORM country roads from Leipzig to Chemnitz. This led to the first fight between Ehrhardt and Over husband. After further examinations of this Ehrhardt prevails in his advocate Brockhaus that Overmann lost its responsibility for the Locomotive. Ehrhardt built as a foreman the intended mounting area the way you want to and ordered some of the parts already supplied by the company's own foundry due to poor quality new, this time with the brothers Jacobi in Buschbad in Meissen . Later Ehrhardt redesigned the company's own foundry. Then the only two built by this company locomotives developed under Ehrhardt assembly line 1839/1840 TEUTONIA and PEGASUS, [5] using Ehrhardt statement on the design plans of Director Preuss. [6] [7] The TEUTONIA was for the Magdeburg-Leipzig Railway Company provided, however, could not be taken for their rail line into operation of this because it was too heavy for the superstructure. The locomotive was instead at the Magdeburg-Steamship Company are sold, they rebuilt the ship's engine. The PEGASUS was after one year of probation by the Leipzig-Dresden Railway Company acquired, they operate on their route to 1861. The verdict on Ehrhardt in the German Commercial newspaper was positive: "The work on the locomotives was excellent, the machines, pumps, etc. worked as good as it was only to want.." [2] As more projects are not successfully designed, be transferred to the Company the construction of boilers until it went bankrupt in 1852.

Ehrhardtsche scale

Lokomotiv cylinder boring machine of Ehrhardt From 1843 to 1868 was Ehrhardt as chief machinist ("with upper machinist were referred earlier to the current secret Baurat to him, everything revolved Technical") [8] in the service of the Saxon-Silesian railway company or by its nationalization in 1851 the Saxon State Railways in Dresden, He made many outstanding services to the rail industry. He invented the two-sided braking with oscillatory waves (1847) and the portable Ehrhardtsche scale to control the axle loads of vehicles [9] (patent no. 71: Apparatus for controlling the load of locomotives, tenders and axles, 1879). From the patented in many countries pioneered by control apparatus [10] which built Sächsische Maschinenfabrik of Richard Hartmann between 1865 to 1873 a total of 1,235 pieces; Royalties went to each Ehrhardt, for the attainment of this support from his friend Louis Schönherr had received a rival of Hartmann. Ehrhardt come the invertible cast steel frogs for switches and crossings and comprehensive the rail tabs. He made contributions to the improvement of the Adam's arc springs and for preheating condensation devices. These maintenance devices are used, such as the locomotive cylinder boring machine. "He is considered a master of railways . "

His 18 names long list of students contains the intended machine masters of other railway companies and professors of Gewerbschule Chemnitz and Freiberg also factory owners and directors of major German and Austrian machine and textile factories.

Ehrhardt's nephew Heinrich Ehrhardt (1840–1928) was also a successful inventor, to an industrialist and entrepreneur.

In 1869, Ehrhardt continued in Saxony Radebeul to rest, where he died at the age of 78 years in 1883.

Literature

Jochen Haeusler: The Ehrhardt family of cell or how did that locomotives know-how to Chemnitz? . In: museum courier, Issue 18 December 2006.

Dietmar Delicious: Johann Heinrich Ehrhardt. A universal industrial and railway skilled in the art of his time. In: Courier Museum of the Chemnitz Industrial Museum and its association. June 2009, p. 10 f.

Günter Metzeltin: Ehrhardt, Johann Heinrich. In: New German Biography (NDB). Volume 4, Duncker & Humblot, Berlin 1959. ISBN 3-428-00185-0, p 580

Ehrhardt : In: Röll, Freiherr von: Encyclopedia of railways, volume 3. Berlin, Vienna, 1912, p 494. Ehrhardt

Body for the progress of the railways, 1883, p 197th