SO here’s how it all works.

Articulated lorries reverse up to the rear of the warehouse and drop off the stock, which is loaded onto booms that staff can use to send the goods, by hand or by machine, onto conveyor belts known as ‘receive lines’.

These lines head towards rows of employees on the left-hand side of the warehouse who check the goods are in good condition then place them into black tote boxes.

The totes are then whizzed upstairs where the items can be scanned, stowed and sorted before the final packing stages.

Each of the three floors above the ground one have the same layout.

An enormous yellow-fenced rectangular space known as ‘the field’ is in the centre, where tens of thousands of little blue robots placed underneath yellow pods which look like a cross between a bookcase and a tic-tac-toe square move the blocks from worker to worker and side to side.

Despite the machines zipping around each other closely and constantly, there is little chance of a collision.

On the off chance something does go wrong - perhaps a product falls out or the ‘bots bump into each other, an employee wearing a special top which repels the machines can step into the ‘field’, to address the problem then return back to their station safely.

One one side of the ‘field’, people pick up random products from the black totes and scan them and are then told where to stow them in the yellow shelves.

Each shelving unit moves horizontally down the line until it’s full then heads across to the other side of the space where it queues to be seen by another row of people.

These workers pick out stock according to customers’ orders, which appear on a display, and send them back down in another tote box. A supervisor checks this is being done quickly enough to avoid a log-jam.

The boxes return to the ground floor - on the right-hand side this time - for yet another team to collect them and put them in suitable packaging before dropping the parcels onto one more conveyor belt.

Address labels are added further along by a machine to protect customer privacy, then the parcels drop down a chute for employees to collect and sort into delivery stations which send the fulfilled orders off to hundreds of different destinations.

FULL STORY: Rare peek inside Amazon fulfilment centre

See how I got on when tasked with preparing and packing a customer's order: