With the increasing size of the ground based telescopes, the lines used to carry and distribute cryogenic gas or fluid to instruments need continuously to be longer. Cryogenic transfer lines of a few 10 meters will be common in future infrastructures. Transfer cryogenic fluid requires highly insulated lines in order to minimise the coolant consumption and keep the temperature of this coolant as low as possible. This level of thermal insulation can only been obtained by a vacuum insulation. After a short introduction presenting the conventional designs used for our liquid nitrogen lines, the paper presents and analyses performances measured on different lines.