A mould system for moulding a blade shell of a wind turbine blade comprising: - a first mould for manufacturing a first blade shell part of the wind turbine blade, the first mould substantially extending along a longitudinal axis, - a second mould for manufacturing a second blade shell part of the wind turbine blade, the second mould substantially extending along the longitudinal axis, - a turning device configured to reposition the first mould between an open mould position and a closed mould position, wherein the first mould is arranged next to the second mould in the open mould position, and wherein the first mould is arranged on top of the second mould in the closed mould position, the turning device comprising a turning mechanism and a first primary beam connecting the turning mechanism and the first mould, - a first scaffold arranged between the first mould and the second mould in the open mould position, the first scaffold extending along the longitudinal axis, and wherein the first scaffold comprises a first primary scaffold part and a first secondary scaffold part (92") spaced apart in the longitudinal direction by a first primary scaffold opening, the first primary scaffold opening being configured to allow the first primary beam to move therethrough during repositioning of the first mould between the open mould position and the closed mould position, - a first primary movable platform attached to the first mould and being configured to move between an extended platform position and a stored platform position, and wherein the first primary movable platform covers the first primary scaffold opening in the extended position and wherein the first primary movable platform is arranged to expose the first primary scaffold opening in the stored platform position. - a first mould for manufacturing a first blade shell part of the wind turbine blade, the first mould substantially extending along a longitudinal axis, - a second mould for manufacturing a second blade shell part of the wind turbine blade, the second mould substantially extending along the longitudinal axis, - a turning device configured to reposition the first mould between an open mould position and a closed mould position, wherein the first mould is arranged next to the second mould in the open mould position, and wherein the first mould is arranged on top of the second mould in the closed mould position, the turning device comprising a turning mechanism and a first primary beam connecting the turning mechanism and the first mould, - a first scaffold arranged between the first mould and the second mould in the open mould position, the first scaffold extending along the longitudinal axis, and wherein the first scaffold comprises a first primary scaffold part and a first secondary scaffold part (92") spaced apart in the longitudinal direction by a first primary scaffold opening, the first primary scaffold opening being configured to allow the first primary beam to move therethrough during repositioning of the first mould between the open mould position and the closed mould position, - a first primary movable platform attached to the first mould and being configured to move between an extended platform position and a stored platform position, and wherein the first primary movable platform covers the first primary scaffold opening in the extended position and wherein the first primary movable platform is arranged to expose the first primary scaffold opening in the stored platform position.