scanny77:
I work a 4 day on 4 day off shift this comprises of two 9 hour day shifts and two 15 hour night shifts. This job is not govened by the driving hours rules, but still accounts for a 48 hour week.
Ah “Squirter’s” shifts. 
Occasional mobile workers
These regulations are primarily for the benefit of commercial drivers and crew of vehicles participating in road transport activity under EU drivers’ hours rules. However, it is possible that non-mobile workers (for example warehouse workers, mechanics, drivers of light vans) will drive vehicles within scope of EU drivers’ hours regulations on an occasional basis.Any worker who only occasionally works within the scope of the EU drivers’ hours rules will be subject to the Working Time Regulations 1998 (as amended), rather than these Regulations. You are an occasional mobile worker if you:
n work fewer than 11 days within scope of EU Driver’s hours rules in a reference period that is shorter than 26 weeks
n work fewer than 16 days within scope of EU Driver’s hours rules in a reference period that is 26 weeks or longer.
As now, limits under the EU drivers’ hours rules will still apply to occasional drivers.
Therefore you are not governed by these new regulations provided you do not drive under EC Regs on no more than 10 days during any 17 week period.
It appears that you can adopt either the set periods or a rolling 17 week pattern subject to a Workplace Agreement, confirmed in writing by your employer and renewable every five years. The employer in this case would appear to be the Agency, but as I’ve said before, I can’t see how an Agency can set up a workplace agreement because it is not a ‘Workplace’. 
However, I feel that this is an oversight on the part of the legistrative draughts person, rather than an intended restriction. 
Note that the Working Time Regulations 1998 may still apply in the context of your principal occupation.
A link to the 1998 Regulations HERE