I would be interested in hearing people's views around contractual issues and health and safety issues on CDM sites and legal possession of a CDM site. We are currently experiencing a H&S concern on site which is under the PC's responsibility at the moment. We as the client have raised concern around  lack or site management previous times (the sub contractor has been nominted by the PC as site supervisor? - discussion point?!).

I am being told other colleagues that we have no legal/contractual control over the site and it is up to the PC to manage. This particular site has a PD who has been involved in the pre-construction but as this is a design and build contract I feel they should be involved in more than just the pre-construction.(another discussion point!?)

There is concern that as the client we are getting more involved than perhaps we 'contractually' should but my worry is we still have a duty to take reasonable precautions to ensure H&S on site, managing and coordinating sub-contractors etc. Contractual or no contractual responsibility would the HSE take a certain stance against us as the client regardless of contractual responsibility/site ownership?

How CDM works in practice is fraught with complications some of which you have identified. Part of the problem is that CDM Regs cannot determine or define every possible scenario. That said, as the client you do hold the purse strings and if all else fails you could contact the authorities if your concerns are not addressed about how the site is being managed.

The PC is responsible for site safety and security - that's a given. How they discharge their duty is entirely up to them. As a conscientious client it is incumbent upon you to raise any concerns. Getting the PC to address them may be more difficult. If you put your concerns in writing to the PC I believe you will have discharged your duty and insulated yourself. 

I am currently experiencing similar problems with a PD who thinks they are the PC!

to add further point not raised, and whislt not aware fully of the project details and complexity.. It would be permissable for the PC nominate a suitably trained, competent and resourced sub-contractor to temporarily manage the site - but only provided that contractor (or named person/s) have appropriate SMSTS training qualification in addition to any other duties such as first aid and temporary works co-ordination/design as may be required for the contract...