THE Port of Tacoma has posted a 31 per cent increase in container volume in May year on year to 758,071 TEU, attributing the gain to the commencement of Grand Alliance calls from last July.

Double-digit growth is expected until August when the arrival of the Grand Alliance box numbers last year will kick in and reduce growth data, acknowledged the Port of Tacoma.

Also credited for year-to-date growth were established customers. Without the Grand Alliance contribution, the port's year-on-year volume would have still risen 3 per cent.

Laden container imports increased 45 per cent to 281,145 TEU year-to-date compared to January to May results in 2012. Exports increased 38 per cent to 213,482 TEU in the same period.