Hi,
You really need to know some more about the cradle - before you undertake the risk of getting into it.
You will need to see the full maintenance check, when was it carried out and by whom? There are timescales for this.
Many cradles are very different to operate, different mechanisms are used, to cover yourself and the building owner/ manager, you will need to obtain training for the piece of equipment you are going to use.
If you need any help and advise - please give me a call.