横浜みなとみらい21中央地区における開発方式の時系列的分析

抄録

 Minato Mirai 21 (“MM21”) is a waterfront redevelopment scheme that blends offices, residential and commercial uses in the center of Yokohama. It is regarded as one of the most courageous attempts at waterfront redevelopment in Japan. It started with a proposal in 1964 by Akira Tamura, an eminent Japanese urban planner. This work was commissioned by Ichio Asukata, a liberal socialist mayor of Yokohama city. They envisaged the relocation of an aging but operational shipyard, harbor piers and railway freight yards in order to create a new site which would connect two existing central districts that had been separated by these industrial estates.
 Besides MM21, Tamura proposed other novel structural plans as “six spine projects” for Yokohama, which was then under population influx pressure from Tokyo. Because of the city government's financial constraints and limited planning power, Tamura initiated a paradigm shift in planning principles towards ceasing reliance on paternalistic support from central government. He strongly advocated a local planning approach with local government initiatives and also the introduction of privatization. Tamura wrote numerous books detailing his peerless experiences as a leader of the new urban planning and coordination bureau of the city for ten years. However, a chronological study of his work based on historical facts has not been attempted previously. This research aims to clarify the detailed process for planning and negotiation of MM21. The roles and positions adopted towards the MM21 scheme of the concerned bodies such as the City, Mitsubishi Group, Japan National Railways (“JNR”), the Yokohama maritime industry, Japan Housing and Development Corporation and national ministries have also been explored.
 Mitsubishi Heavy Industries (“MHI”) owned the old shipyard, and Mitsubishi Estate acquired most of the shipyard land, becoming the major landowner in the area. JNR operated huge freight yards within the planned area. As the area was exclusively a harbor district, the maritime industry of Yokohama wished to protect their interests. Tamura prepared a new industrial estate in a newly reclaimed area to relocate the shipyard which made it possible for MHI to expand its production. Tamura negotiated and reached a deal with MHI, but they could not make a decision on relocation due to the extremely volatile economic situation surrounding the ship industry. At the same time, Tamura persuaded JNR to either move or abandon their freight yards, which caused a strong movement of community opposition to the relocation. Tamura envisaged an appropriate size for redevelopment of the Mitsubishi Estate in terms of private investment by minimizing the volume of reclaimed land. By allowing the company to make decent profits from the redevelopment, the construction of public infrastructure and facilities was planned mostly through private contributions rather than public investment.
 Tamura was later required by the new mayor to relinquish control over the second stage MM21's execution, but Tamura's successors were able to successfully execute the second stage of MM21. Regarding the privatization aspect of the project, Keiichi Ozawa as the new chief urban planner made a breakthrough by persuading the Mitsubishi group and the maritime industry to introduce a land readjustment scheme in the area and also provide a new maritime development area within it. After Ozawa left his role, Ryoichi Hirose, as the next chief planner, helped concerned bodies to reach agreement on the final implementation plan in 1983. Both Ozawa and Hirose were reliable staff members of Tamura's group. Although the redevelopment area was eventually expanded due to pressure from concerned parties, the continuity of dedicated chief urban planners made the project successful over a longer term.