At the beginning the Germans worked with an wooden design to start the Natter.
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Later they came up with the steel frame tower which was installed close to Stuttgart in Germany.
Several of these launch towers should be installed to allow a constant start of Natters, but the end of the war came much faster.
So here is the second set with the steel frame tower:
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Both sets can you order online, for example from here:
http://www.1999.co.jp/eng/10526321
Or if you prefer my solution, then you can buy my launch tower here:
https://www.shapeways.com/product/UXTDT7K6F/1-144-natter-launch-tower-steel-version
Or if you prefer my solution, then you can buy my launch tower here:
https://www.shapeways.com/product/UXTDT7K6F/1-144-natter-launch-tower-steel-version