Harumi Triton Square

A large-scale mixed-use complex completed in October 2001 in Harumi, Chuo City. Its four office towers, anchored by the 45-storey, 194.9-metre Tower X, employ a world-first seismic-control structure that links the three main towers with viscous dampers — an innovation that earned the 43rd BCS Award.

Use

Office tower

Area

Chuo City

Completed

2001

Floors

45 above ground, 4 below

Height

194.9 m

Developer

Urban Development Corporation (now UR Urban Development Corporation)

Architect

Takenaka Corporation JV (Tower X); Nikken Sekkei, Kume Sekkei, Yamashita Sekkei JV (Towers Y and Z)

Four Towers in a Stepped Silhouette

On the north side of Harumi-dori in Harumi 1-chome, Chuo City, four towers rise in a tiered silhouette that opens toward Tokyo Bay. Harumi Triton Square, completed in October 2001, was the product of a first-category urban redevelopment project in the Harumi 1-chome district, led by the Urban Development Corporation (now UR Urban Development Corporation). A commercial area within the complex opened in April 2001, ahead of the tower completion.

The tallest of the four office towers, Tower X, reaches 45 storeys above ground (with four below), at a height of 194.9 metres. Tower Y rises 40 storeys to 174.9 metres; Tower Z, 34 storeys to 154.8 metres; and the lower Tower W, 19 storeys to 90 metres. Together they step down in sequence, forming a graduated composition that reads as a single ensemble from a distance. The combined gross floor area of the four office towers reaches approximately 383,300 square metres; including the residential building, the complex extends to around 580,000 square metres.

A World First in Seismic Control

What gives Harumi Triton Square a place in the history of structural engineering is the linked-damper system connecting Towers X, Y and Z. The three main towers — each at a different height — are joined at an intermediate level by viscous dampers designed to transfer and dissipate lateral energy between the structures. When one tower sways, the dampers channel that motion into the others, reducing the peak response across all three. At completion, this was reported as the world’s first application of this multi-tower damper-linked configuration. Tower X was designed by a Takenaka Corporation joint venture; Towers Y and Z by a joint venture of Nikken Sekkei, Kume Sekkei, and Yamashita Sekkei. The innovation earned the project the 43rd BCS Award for outstanding building construction.

Summary

Harumi Triton Square was completed in 2001, with Tower X standing 45 storeys and 194.9 metres as the tallest element of the complex. The damper-linked structural system connecting the three main towers represented a world-first achievement in seismic engineering at the time of completion. The Harumi waterfront has since been transformed further by the opening of Harumi Flag on the adjacent site; seen together, the two projects trace the long arc of reclaimed-land development along Tokyo Bay. For hotels in the Harumi and Tsukishima area, Rakuten Travel offers a range of options.