Access ladders and walkways for tiled roof

My local school has a tiled roof which slopes to a box gutter which requires regular cleaning. The box gutter abutts another wall, so falls from the roof are not a hazard. However, there are a number of pieces of air conditioning equipment on the roof which mean that the cleaner must go up and around this equipment to reach all areas of the box gutters.
Apart from the risk of slipping, there is the great risk of breaking tiles.
I am contemplating a permanent arrangements of ladders laid on the tiles(either by hooks over the ridge or with their bases resting in the gutter or against the wall) and lateral walkways (fixed to the upper ends of the ladders). I would appreciate comments on the appropriateness of this approach, suggested materials, component manufacturers , etc. Remember it is school without much money.

affordability doesn't come into it
the roof's a work place
under OH&S whoever directs the cleaner onto the roof or designs and installs the access system is liable

buy and properly install an off the shelf system or seek professional design and construction advice


ian

Don't think you have WorkCover in Victoria do you? but I'm sure as ian said it will need to meet OH&S requirements.