Sparkasse Hagen Tower

The Sparkasse Hagen Tower (Sparkassenhochhaus Hagen, Verwaltungshochhaus/Verwaltungsgebäude der Sparkasse Hagen ), often referenced as Langer Oskar  (Long Oskar) by locals, was a 101 m skyscraper in the city centre of Hagen, North Rhine-Westphalia, Germany. The building served as the main office tower and part of the headquarters of the resident Sparkasse, Sparkasse Hagen. Built in the early 1970s it was a regional landmark for nearly three decades until demolition in 2004. It was replaced by a lower building complex, called Sparkassen-Karree Hagen, which was inaugurated in 2006.

Construction
Construction began 1 August 1972 and finished on 29 November 1975. It was inaugurated on 29 November 1975. It was named after the director of the savings bank at that time, Oskar Specht. The architect of the building was Karl-Heinz Zernikow from Hagen.

The cultivated surface amounted to 634 m2 the effective area 12634 m2 (office surface: 7.621 m. The building had 22 storeys, of it 2 basements, the building height over the upper edge of the area was 98 m, the building length of 37 m, the building width approximately 18.5 m.

The front consisted of a pre-hung aluminum construction with a surface of 10300 m2. The converted area amounted to 57000 m3. A characteristic was the constant reinforced concrete slab, which served the balance of the building for the elevator pits: 113 by, and 1.72 m thick.

Water leakage penetrated, and damaged building insulation. Repairs would have required further measures, including improvements to the air conditioning system and installation of a second stairway for fire safety reasons. Repair costs were estimated at €42 million. It was estimated that demolition would cost 5 million euro and construction of a new building would cost €16.8 million. Therefore, it was decided to demolish the current building and construct a new one.

Demolition
The building was explosively imploded at 10:53 on 7 March 2004, in the then-largest and riskiest breakup of a multistoried building in Europe. 1,450 explosive charges weighing 250 kilograms were used in timed sequence to cause 26,000 tons concrete and steel to first fold and then collapse into a predetermined 70 m bed without damaging neighboring structures. The successful breakup is considered as master achievement of the specialty firm from Thuringia and receives an entry in the Guinness World Records.