Timelkam railway accident

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Amstetten derailed on October 19, 1875

The Timelkam railway accident was the derailment of the Amstetten locomotive on October 19, 1875 on the Austrian Western Railway , the then Empress Elisabeth Railway , at the Timelkam station between Linz and Salzburg after a wheel tire broke .

the accident

In a mixed train the leading derailed steam locomotive Amstetten the Series I , together with a Tender for a Radreifenbruch on the locomotive. Since the coupling behind the tender broke, the remaining vehicles on the train remained on the track . The locomotive plowed its way up an embankment and came to a standstill standing upright. People were not harmed.

consequences

The cause of the tire breakage was not a material defect , but the fundamental nature of the choice of material. The fact that a material subject to alternating stresses has a lower load capacity or service life than a statically loaded material was not yet known. This material fatigue was only discovered a few years later by August Wöhler .

Wöhler, who had already done intensive research on this topic, was employed at the Borsig company and then railroad director and member of the general management of the Reichseisenbahnen in Alsace-Lorraine in Strasbourg. With the conversion of steel production to the new Bessemer and Siemens-Martin processes in the early 1860s, the steels of that time were harder than the old puddle iron , but also more brittle . It was not until the Timelkamer accident that it was recognized that the brittleness of steel was a great risk for wheel tires - and for the railways of the time - in terms of both safety and economy. The memorandum published by Wöhler and Johann Bauschinger from Munich on the occasion of the examination of the accident and the discussion with the steel manufacturers on the introduction of a state-recognized classification of iron and steel is regarded as the beginning of modern material testing and standardization .

At the beginning of the 1880s, at the instigation of Wöhler, the Association of German Railway Administrations introduced a first classification for steels in the railway industry, in which the sum of tensile strength (from the tear test ) and transverse contraction as a percentage of the original cross-section served as a quality number . Ludwig von Tetmajer , Zurich, published the quality number c as early as 1886 (as the product of tensile strength and elongation at break ), and also gave specific guide values ​​for wheel tires. Since then, the deformation and failure behavior of materials under cyclic loading has been determined in the Wöhler test , which is named in honor of Wöhler as a pioneer in materials testing.

literature

Individual evidence

  1. Another photo in: Stockert, Vol. 2, Fig. 85.
  2. See Lit. Krankenhagen: Materialprüfung , 1978 - the sinking of the Titanic is based on a similar reason ; there, too, the rivets that failed in the collision were not poorly manufactured, but only from an inappropriately chosen type of steel, which was used in the cold water temperatures of the North Atlantic became too brittle
  3. The original endurance test machine for tensile load of Wohler in 1860 is at the Deutsches Museum in Munich; Fig. In Lit. Krankenhagen: Material Testing , 1978, p. 51 (pdf p. 6)
  4. a b Krankenhagen: Material Testing , 1978, p. 48 (pdf p. 3)
  5. Technical Commission of the Association of German Railway Administrations (ed.): Memorandum on the introduction of a state-recognized classification of iron and steel. In: Journal of the Association of German Engineers Vol. 21, Issue 11, 1877, Sp. 518–523; republish in: Organ fd Fortschr. d. Railways , 7th supplement volume: The properties of iron and steel , Wiesbaden 1880
  6. Quality number . In: Otto Lueger: Lexicon of the entire technology and its auxiliary sciences , Vol. 7, Stuttgart, Leipzig 1909, pp. 312-313.
  7. Ludwig von Tetmajer: Communications from the institute for testing building materials in Zurich , 3rd issue, 1886, pp. VIII, 13, 56, 103 ff .; 4th issue, 1890, pp. 5, 30, 115 ff.
  8. Ludwig von Tetmajer: The applied elasticity and strength theory. Leipzig and Vienna 1904, pp. 27, 218

Coordinates: 48 ° 0 ′ 29.7 "  N , 13 ° 35 ′ 41.5"  E