Hi Boston

I don't think that the PC has to be ever present to fulfil each of the duties placed on them.

Imagine a road maintenance contract requring traffic management. It would be rare for the PC to be on site throughout the setting up and removal of TM. The might do some intermittent monitoring of the performance of the TM sub-contractor but would be unlikely to attend each and every location when TM is put in and removed and might not even visit each and every location when maintenance works are being done.

How much monitoring needs to be done during physical presence would depend to an extent on the PC's reasonable level of confidence in how sub-contractors perform.

This is not really any different to the situation on a typical building site. The PC will have some site staff mostly sitting in the offices, with some supervisors moving around from location to location but not being constantly watching over each sub-contractor by standing on the spot.

Fire Safety - not according to HSE.

From L153:

Principal contractors do not have to undertake detailed supervision of contractors’ work. [My bold throughout] Monitoring 129 Standards should be checked regularly given the rapidly changing nature of a construction site. Effective monitoring involves: (a) time and effort (with sufficient resource having been set aside for this at the planning stage – see paragraph 123); (b) treating health and safety in the same way as other important aspects of the business; (c) taking prompt action where necessary; and (d) using a mix of performance measures – both active and reactive in nature, eg: (i) routine checks of site access and work areas and plant and equipment, or health risk management to prevent harm (active); (ii) investigating near-miss incidents and injuries as well as monitoring cases of ill health (reactive).

All of which suggests a proportionate approach.

If a specific activity were to be e.g. critical to programme or quality, it would probably need someone from the PC to be present for most of all the time it takes to complete the activity.

Conversely, if the PC has confidence in how a subcontractor will do their work, their level of oversight could be lesser, particularly when the subbie knows much more about what they are doing than the PC.

To return to my previous example of traffic management, it would not be the norm for the PC to have staff trained to the same standards as the TM supervisors.

If we expected the PC to have such a level of skills and knowledge, then the same would apply to any other specialist subbie that they take on - so that the PC team would have to be superheros.

CDM is NOT supposed to about massively increasing the cost of construction.

FireSafety - of course those tendering will factor in for an appropriate level of supervision.

But one foreperson on a site one km long is going to be stretched. [As infrastructure projects go a 1km long site could be relatively small!]

They (how ever many theys) have to make decisions as to how much time to spend where.

Exactly the same would apply to a conventional building site. The foreperson is not going to be ever present to check how the roofing works are going. Might even not be competent to be up there with sufficient safety, if e.g. the works are such that full edge protection +++ is not reasonably practicable.

Once upon a time, there was legislation demanding a safety supervisor to be employed by any contractor with 20 workers (on one or more sites). It was recognised that one size doesn't fit all and this legislation was done away with - without much dissent.

For the historians - Regulation 5 of the Construction (General Provisions) Regulations 1961.