For direct burial, SWA is the "normal condition" provided for in Regulation 522.8.10, so it could be argued there is no enhanced protection against mechanical damage, particularly as the cable may be damaged by ground heave or excavation (which does not minimize risk of danger to persons).

Perhaps SWA in a suitable duct, N450 or N750, the duct buried at a suitable minimum depth to minimize damage from frost heave for foreseeable ground compression etc., would be a more appropriate for this requirement?

hmmm ... perhaps it is one of those engineering 'common sense' assessments one might suppose   

SWA as the "normal condition"  * if * the cable is not in a duct/conduit of equiv protection etc  - perhaps therefore the "normal condition" of SWA is enough to meet (i) ...  although anything for extra protection may be worth it if feasible.

of course it may be possible to affect with a different protective device and remove the issue altogether  :-)

psychicwarrior said:

SWA as the "normal condition"  * if * the cable is not in a duct/conduit of equiv protection etc  - perhaps therefore the "normal condition" of SWA is enough to meet (i)

I did think about that, but I then thought that underground service strike is not an uncommon occurrence, and if there's a prosecution, what might an expert witness consider?.

psychicwarrior said:

of course it may be possible to affect with a different protective device and remove the issue altogether  :-)

And CDM design risk assessment would lead you down that path too. Remove or reduce come earlier up the decision tree than ancillary protection in the hierarchy of controls.

psychicwarrior said:

SWA as the "normal condition"  * if * the cable is not in a duct/conduit of equiv protection etc  - perhaps therefore the "normal condition" of SWA is enough to meet (i)

I did think about that, but I then thought that underground service strike is not an uncommon occurrence, and if there's a prosecution, what might an expert witness consider?.

psychicwarrior said:

of course it may be possible to affect with a different protective device and remove the issue altogether  :-)

And CDM design risk assessment would lead you down that path too. Remove or reduce come earlier up the decision tree than ancillary protection in the hierarchy of controls.