Carl Ludwig Fresh

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Carl Ludwig Frischen (born July 20, 1830 in Bremen , † May 8, 1890 in Berlin ) was a German electrical engineer.

Life

Carl Ludwig Frischen was born in Bremen as the son of a merchandiser. He learned the mechanic's trade in a local machine factory and studied mechanics and mechanical engineering at the Hanover Polytechnic from 1849. On July 1, 1851, he entered the service of the electromagnetic telegraph of the Royal Hanoverian Railway. In early 1854 he became a telegraph engineer . In March 1854 he invented a method for two-way communication on telegraph lines. In 1856 he was honored for the "efficient and strenuous service rendered in the construction of the new telegraph lines".

He made a name for himself in specialist circles with the closed-circuit circuit he developed in 1864, which enabled a telegraphic intercom procedure on a single line. In mid-1865 he became head of the Royal Telegraph Inspection. In 1867 he was appointed chief telegraph engineer and promoted to the telegraph administration of the North German Confederation in Berlin, which was founded in 1866.

From 1868 to 1870, on behalf of Siemens & Halske, he played a key role in building the approximately 11,000-kilometer Indo-European telegraph line between London and Calcutta for the British Commonwealth.

Werner Siemens, who was working on a similar intercom procedure, became aware of him. In January 1870, Frischen retired from civil service prematurely and went to Siemens & Halske as a chief engineer, where he developed safety and signaling systems for the emerging railway industry for the next 20 years. He was also responsible for the test drives with the Elektromote - the world's first trolleybus .

The train protection on rail lines was initially designed as security for a period of time , which was sufficient for trouble-free operation, but led to problems in the event of irregularities. Sensor, monitoring and signaling technology were required for securing the space (distance securing , see section block ). For this purpose, in mid-1870, Frischen developed the block apparatus (block factory; later block station) and rail deflection contacts.

Bells were first used to communicate between the blocks, then Morse code machines and later telegraphs. The blocks or signals were locked and released from the interlocking by means of electromagnets that were controlled by rail deflection contacts.

From 1877 to 1881 he worked on the cabling of the German telegraph network under the guidance of Postmaster General Heinrich von Stephan .

At the Berlin trade fair from May 31, 1879 in Moabit, he demonstrated the world's first electric locomotive, a dynamo-electric train , a miniature locomotive with around 3 hp built for the Cottbus lignite district.

While experimenting with Bell telephones, he invented a forerunner of the loudspeaker.

At the beginning of 1930 the former private street in the Berlin settlement Heimat was renamed after him in Frischensteig . On November 23, 1931 it was renamed to today's Natalissteig .

literature

  • L .: Carl Frischen 1830–1890 . In: Erhard Born (ed.): Pioneers of the Railway System, Darmstadt: Röhrig [1962], pp. 99-104.

Individual evidence

  1. ^ Wilhelm Brix: Telegraphing on the same wire in opposite directions. In: Polytechnisches Journal . 137, 1855, pp. 172-179.
  2. ↑ Omnibus history: The first trolleybus in 1882

Web links

personal data
SURNAME Fresh, Carl Ludwig
BRIEF DESCRIPTION German engineer
DATE OF BIRTH July 20, 1830
PLACE OF BIRTH Bremen
DATE OF DEATH May 8, 1890
Place of death Berlin