Icelandic shipping company Eimskip will add four trips to Portland this year – a 13 percent increase in port calls over 2016 – continuing growth at Maine’s sole container terminal. Eimskip has increased port calls to Portland from 26 in 2013 to 35 planned for this year. The increased visits are being driven by a 20 percent growth in shipping volume, said Larus Isfeld, managing director of Eimskip USA.