Why Does Changing Just the "Seat Fabric" Increase Train Capacity? — How Ounce-by-Ounce Weight Reduction Unlocks Higher Transit Capacity

On Yurikamome, operating in the

Tokyo Waterfront Secondary City

Center area, securing transport

capacity during major events at Tokyo

Big Sight and peak rush hours has

always been a critical challenge.

Within strict vehicle size constraints

and tire load limits, the answer to

safely transporting as many

passengers as possible lay in

accumulating subtle "millimeter-by

-millimeter and gram-by-gram weight

reductions".

Conventional train and bus seats have

long relied on durable, high-pile

"moquette" fabric to withstand

frequent seating. In contrast,

automotive seats typically feature

flexible, highly moisture-absorbent

"tricot" fabric. On the Yurikamome

7300 series, engineers adopted tricot

fabric for the first time in a commuter

train as part of car body weight

reduction efforts.

While the weight saved per seat is

small, it reduces weight by

approximately 50 kg per car (over 20

seats), enabling a transport capacity

increase equivalent to about 5

passengers across the 6-car train.

Yurikamome's weight reduction

strategy extended far beyond seat

fabric. By switching the car body

material from stainless steel to

aluminum, the weight of the body

alone was cut by approximately 10.1

tons (from 69.6 t to 59.5 t).

Combining major structural redesigns

with painstaking weight reductions

down to the seat upholstery, the

capacity per train increased from 722

passengers on older models to 802

passengers—a boost of 80 people

(approx. 11%).

Starting with seat upholstery, this

weight reduction approach was carried

over to other systems facing heavy

congestion, such as the Nippori

-Toneri Liner 330 series, contributing

directly to urban transit congestion

relief.

I hope you look forward to the next AGT Blog!