Hinc calidi fontes

Inside the heat storage tank, things happen that we cannot see from the outside: water is heated to a temperature of 115 degrees Celsius and carried to consumers through a widely branching network of pipes. There, the thermal energy dissipates through the heated rooms in all directions. Besides generating heat, the water heated in the tank can also be used to generate electricity via a steam turbine; the electricity then reaches households through a widely branching cable network. In its purely geometric form, the tank gives no hint of the internal currents and processes just outlined. This gave Gerhard Lang the idea of expressing the tension between the discrete geometric shell and the hidden dynamic life inside through a graphic design.

With his lively graphics, Gerhard Lang points to the thermal and dynamic processes connected with the tank. In this way, a connection, an exchange, arises between the internal processes of the tank and the city of Frankfurt.

For this, Gerhard Lang uses a sign that is particularly suited to depicting currents, processes and dynamics: the arrow, made of a line and a triangle – a sign that is recognised across linguistic, cultural and professional boundaries. The arrows on the tank, pointing in all directions, take up something that happens inside it: thermal energy that does not rise straight upwards, but first spreads out across the city and finally dissipates beyond it.

The arrows, visible from far around, sit on the surface of the tank, yet in our imagination they move beyond the boundaries of the building. In their liveliness, the arrows thus take away the tank’s geometric hardness and give it a special, living breath.

C. N.