Radio tower Berlin

The Berliner Funkturm or Funkturm Berlin (Berlin Radio Tower) is a former broadcasting tower in Berlin. Constructed between 1924 and 1926 to designs by the architect Heinrich Straumer, it was inaugurated on 3 September 1926, on the occasion of the opening of the third Große Deutsche Funkausstellung (Great German Radio Exhibition) in the grounds of the Messe Berlin trade fair in the borough of Charlottenburg-Wilmersdorf. Nicknamed der lange Lulatsch ("the lanky lad"), the tower is one of the best-known points of interest in the city of Berlin and, while no longer used for broadcasting purposes, it remains a protected monument.

The tower is built as one large steel framework construction, similar to the Eiffel Tower in Paris. The 150-metre-high (490 ft) and approximately 600-metric ton radio tower was originally planned strictly as a transmitting tower, but later additions included a restaurant at a height of approximately 52 m, and observation deck at a height of approximately 125 m. Visitors reach the restaurant and the observation deck by an elevator which travels up to 6 meters per second.

The radio tower has two very notable structural characteristics. First, it sits on a square surface area merely 20 meters to a side. Its ratio of surface area to height is 1:6.9. For comparison, the Eiffel Tower sits on a square 129 meters to a side, giving surface-area-to-height ratio of 1:2.3. Second, the radio tower is probably the only observation tower in the world standing on porcelain insulators. It was designed as the support tower for a T-antenna for medium wave, and the insulators were intended to prevent the drain of the transmitting power down through the tower itself. However, this was impractical, because visitors would have been vulnerable to massive electric shocks, so the tower was later grounded via its elevator shaft. The insulators used were manufactured in the Koeniglich Preussische Porzellanmanufaktur (Royal Prussian Porcelain Factory).

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