Johann Heinrich Ehrhardt

Johann Heinrich Ehrhardt, also Erhardt, (29 April 1805 - 29 April 1883) was a German locomotive manufacturer and inventor.

Early life

Ehrhardt was born on 29 April 1805 in Zella St. Blasius.

He was the son of a poor gunsmith who, as a day laborer by the guild free mastermind, worked in the Jäger'schen wire drawing plants. During a visit from a master gunsmith with his parents, the man became aware of the technical skills of Ehrhardt and allowed him to become an apprentice gunsmith. His first job as a journeyman was at the mint in Gotha.

Le Belge

With his recommendations, mint master Ehrhardt went to Belgium in 1831. He worked only half a year at an optician in Brussels before moving to Seraing with the John Cockerill company so he could go Maschinenfabrik to work in steam engineering. [1] As a fitter from dewatering machines, he invented 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 locomotives, Le Fleche, opening soon, the train from Brussels-Mechelen needed to be done. To acquire theoretical knowledge for future work, Ehrhardt went to the Polytechnic Institute in Düsseldorf in November 1833. Three months later he left 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, the locomotive was derailed "due to malicious tearing up the rails". [2] The Stephensonlok was not damaged. In 1835, Ehrhardt mounted the Le Belge, [3] the first steam locomotive made in continental Europe. [4] This was the end of the regular service in 1835.

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

Saxon engineering company

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

Shortly thereafter, Ehrhardt was transferred 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 prevailed 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. At the time, the only two locomotives built by this company were ones developed under Ehrhardt assembly line 1839/1840. They were the TEUTONIA and the 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 was sold to the Magdeburg-Steamship Company. They rebuilt the ship's engine. The PEGASUS was, after one year of probation by the Leipzig-Dresden Railway Company, acquired. They operated 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, Ehrhardt worked 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."

Later years

The long list of his students contains 18 names of intended machine masters of other railway companies and professors of Gewerbschule Chemnitz and Freiberg. It also includes 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, as well as an industrialist and entrepreneur.

In 1869, Ehrhardt went to live in Radebeul to rest. He died there 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