Mobile equipment and Ice Cream

My dear and beloved mother in law informed me of her intention to buy a 3 phase ice cream machine for her food kiosk. She owns a patch of land and has a food kiosk on it. Naturally she thinks electricity is stuff of wizards and witches and it all just works with harry potter spells.

When inspecting her land and power supply I found that she has a 3 phase supply. Two of the phases each feed old unused consumer units that fed various commando sockets for old leisure equipment. Her third phase feeds the kiosk, which consists of two piggy backed 16mm 3 core armours that run along the land and are fed directly into the kiosk and into an old consumer unit with a 30ma rcd. The run itself is an estimated 30 metres.

Obviously the problem is the kiosk has no 3 phase points, further inspecting the land I found both piggy backed armours are dangerously jointed half way through the run and have an IP protection of plastic box and sandbags. Did I also mention this ground is prone to flooding?

I'm proposing ripping it all out and running a new 3 phase armour to the kiosk. But what options can I use in regards to mobile equipment and not directly feeding an armour into the kiosk? I've not much experience with kiosk/caravan installation but is a sort of system that could be arranged to allow me to upgrade the consumer unit to 3 phase while maintaining some type of socket-like connectivity to the kiosk?

Or is the option of simply running a direct 3 phase cable with isolator directly into the kiosk to feed the machine acceptable? I'd much rather have a single supply feeding the kiosk entirely. The kiosk from estimate has all the usual equipment you'd expect such as friars, fridges and candy floss machines.

Thank you. Look forward to replies! 

I should also point out this kiosk while technically being a mobile catering unit is essentially a fixed building that hasn't moved in 20 years  so I don't know if that voids vibration issues.

Does it have wheels ?      I'd have to mug up on the requirements for mobile units myself but I think after being stationary for  20 yrs  I'd declare it officially a fixed installation ,  once you install a cable  it won't be moving anywhere soon .   Treat it as you would  a shed. 

If you want to call it a mobile  kiosk  you 'll have to mug up in the mobile section of the Regs . Can't say I bothered to read it to be honest , as with Fairgrounds . 

Its probably a load of bonding , RCDs & rods . 

I would say the pertinant thing here is what is it made of?  It it is a metal structure, then I would treat it like a caravan, e,g TT earth etc.

Don't use a SWA gland at the kisok end, use a plastic gland so the SWA armour is insulated, and provide a TT earth for the kiosk.

Starting "again" from the incoming supply seems to make sense - as it stands do each of the phases supply the separate CU's / switch fuses?

Yes, each phase has been feeding a consumer unit, two which are now unused and one which feeds the dual 3 core armours to the joint and then to the kiosk.