hipped roof

Hey everybody, ~1950's two storey hip roofed house, with part of the roof extending down through the 1st [UK] floor: The original rafters are suprisingly small (45 x 70mm), despite some of them going nearly 8m to the apex. The main hip section of the house has been insulated for a while, but...

What is the correct and safe way to access a Pyramid Hipped roof for minor maintenance tasks where normal use of a roof ladder is impossible ? The pitch and other access issues make just walking on it unsafe. Any thoughts greatly appreciated.