TT and TNC-S next to each other

[UKPN]

We are currently doing a market square this involves in-ground lighting and providing sockets for the market traders. This involves two metered single phase boards The spec asks for the sockets to be on TT and not connected to PME. As the boards are metal. Am I correct that I shouldn't be able to touch both boards at the same time (they are both next to each other) due to the P.D. between each. In the spec, they are referring to the regs for caravan sites I think the thought is that of metal shell burger vans and the loss of neutral although it is all block paving.

Independent earthing only.

The thought had crossed my mind but they want a S.P&N type A metal Memshield 3 D.B. with meters and these are on site now. Thes things are always left for us to sort out no one sits down before handing the job to us and designs these things.

It doesn't matter if the design was to the 14th Ed. A metal fuse board must be protected by a plastic rcd. (on a tt system)