The Huck BobTail 12,14,16, 20mm and 1in diameters, after lengthy and vigorous independent testing, has gained the prestigious Allgemeine bauaufsichtliche Zulassungen (German national technical approval) from the world renowned DIBt (Deutsches Institut für Bautechnik) for use in both static and dynamic applications in civil engineering.
April 1886: the Brunkebergs tunnel
First ever example of a ground source heat pump?