In June 1890, engineers started collecting data for harbor expansion, with surveys conducted on local terrain, geology, water depths, tidal conditions, climate, and soil movement. The survey was completed within a year. At that time, the harbor covered 66,000 square meters, with a 3m water depth, width of 160 meters, and a current speed of four knots. In 1904, the Japanese began to install pilings for coastal warehouses, dredge outlying sandbars, and reclaim more than 132,000 square meters of land used for the railway building at Takangpu. In April 1905, Japan colonial administrators established an agency in charge of expansion work and conducted a second detailed survey. The work was completed the next year.