Spiral escalators are not exactly commonplace, but that didn’t stop Mitsubishi Electric from building the largest in the world in a Shanghai shopping mall.
Essentially, 12 curved escalators form two huge spiral staircases in the middle of the mall, a design first credited to Mitsubishi Electric back in 1985.
While the Shanghai mall project represents the biggest spiral escalator order to date, the company has delivered 103 units to customers all over the world since first introducing the unique concept.
Below, Mitsubishi Electric explains exactly what its engineers have to go through to construct a spiral escalator:
Horizontal speed decreases as it moves along the slope, making circular designs impractical. Mitsubishi Electric’s engineers overcame this dilemma by inventing the Center Shift Method, shifting the center of the circle around which the escalator rotates in response to the degree of gradient, realizing 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 0.1 mm.
Here’s the original concept image of the mall: