Tower section and a method for a tower section

A method of assembling two tower sections with respective annular flanges with through-holes for bolt-and-nut connection of said two tower sections, comprising the steps of:

• providing one of the tower sections as a tower section having a first end and an opposite second end, with an inwardly directed peripheral flange at said first end, said flange having a plurality of through-going holes extending from an inner face to an opposite outer face of said flange, an indicator device for indicating alignment of one of said through-going holes with a hole of a flange of another tower section, said indicator device including a body mounted in said one of said through-going holes, said body having a first body end and an opposite second body end, a portion of said body including said first body end projecting from said outer face in a first configuration of said indicator device, said indicator device including means allowing for said indicator device to assume a second configuration wherein said first body end is located closer to said outer face, said means urging said indicator device to assume said first configuration;
• lowering one tower section towards the other tower section,
• contacting said annular flange of one of said tower sections with said first body end of said indicator device, to bring said indicator device towards said second configuration, and
• rotating said one tower section until said indicator device indicates said first configuration, wherein said holes of said one tower section are aligned with said holes of said other tower section, said indicator device being mounted to said other tower section.