sorry guys, i'm not trying to be defensive or offend, but you are breaking cdm regs by not having a cscs operating at heights. however this only applies if you are doing work at ANY height above or below ground level "where there is a risk of injury or death from falling". this even applies if you just stand on a chock of wood to gain a stretch. i've done loads of work on balfour beatty sites and they won't even let you on site without one. you even have to have the ipaf harness license. the only reason i can see that you were allowed on site was either an over sight or incompetent manager. if you have an accident, just watch you insurance run a mile. it is impossible to satisfy a risk assessment to work at heights without having bog standard safety training. therefore should an accident occur, it will be you as the owner of the company in the dock, not the site manager.