Bonding swa. What method.

Hi all 

Just need your advice, theirs a discussion going on atm on site between a couple of sparks. We have around 50 apartments being fed by 3core swa from a panel room all glanded into the top of a run of trunking, armour isn't used as cpc. One spark is saying we need to run individual 16mm earth's to each gland
Another is saying 10mm to the first of each set and then looping. I would have thought just bonding the trunking near the board adding some bonding tags in-between the trunking sections and bolting the banjos on would suffice. Tbf the trunking is <o.o1 atm anyway to met. So what's your opinion and regs if possible, don't have book with me.

Thank you.

What does the design call for?

The design comes first, but my view is your only bonding the armour so a link to the trunking is all that is needed. The size depends on the supply

Asked around, got drawings but no cable calcs or specs of that sort.

In general,

It would be as @SLIPSHOD & SLAPDASH says,

Unless there is a spec otherwise

think you are learning that many site sparkies talk rubbish.

Have a look in your regs book and see what you can find.