Prototype 20 tons built in the early nightees [Permalink](https://concretesubmarine.activeboard.com/t49529137/prototype-20-tons-built-in-the-early-nightees/? | context: ||| Ellmer Group ||| Dr Ehrmann Agentur ||| Ruediger Koch ||| rixrewards.com ||| concrete floating structures of a much simpler kind …
