Japanese firm Mitsubishi Electric isn't the only manufacturer of spiral escalators in the world – but there aren't many. Now, a shopping centre in Shanghai has opened up two new iterations, each of which reach seven storeys up into the building.
Spiral escalators are still fairly rare and these new ones, at the New World Daimaru Department Store, are truly amazing: the 12 curved escalators form two huge spiral staircases, dominating the central atrium.
Mitsubishi Electric first developed the spiral escalator in 1985, and has delivered 103 units to customers in Japan and across the world since then. The Shanghai shopping centre was the largest order for a single project to date.
Building a curved escalator is incredibly difficult, as Mitsubishi Electric explains:
Horizontal speed decreases as it moves along the slope, making circular designs impractical. Mitsubishi Electric's engineers overcame this dilemma by inventing the Centre Shift Method, shifting the centre of the circle around which the escalator rotates in response to the degree of gradient, realising smooth rotational movement in perfect harmony with vertical movement.
The escalators achieve smooth movement through specially designed chains that can respond to various angles of motion and rails and handrails made with proprietary processing techniques for optimal flexibility, yet the increased range of motion does not sacrifice precision, as the final processing accuracy is 0.1mm.
Here's the original concept image of the design:
A pretty incredible feat of engineering, even if you have to go to hang around a shopping centre to see it.