The up to 7.25-metre-diameter (23.8 ft) steel pressure pipes (penstocks) with a total weight of 26.600 tons were supplied and installed by the German NOELL company (today DSD NOELL).
Pipa baja bertekanan ~7,25 m (penstocks) dengan berat total hingga 26.600 ton disuplai dan dipasang oleh perusahaan German NOELL (kini DSD NOELL).