Shippers could face congestion surcharges for containers passing through Europe’s top ports as the peak season approaches.

Most ports are working at near capacity and have little slack to handle the expected surge in pre-Christmas containerized imports, particularly from China.

Inland carriers, whose barges carry more than one million TEUs a year on the river Rhine alone, say they face delays of up to 24 hours in Rotterdam, and fear the situation will worsen as terminals focus on deep-sea ocean carriers.

Contargo, a leading barge operator on the Rhine, imposed a flat congestion surcharge of $20 per container at Rotterdam and Antwerp terminals this month. Effective October 1, the surcharge will be $20 for every 12 hours that inland shipments are delayed.

The company said it is experiencing delays of 24 hours at the APM and ECT Delta terminals in Rotterdam and 12 hours at the ECT Home facility. Barges face four-hour delays at Antwerp terminals.

Contargo also reserves the right to unload containers at other terminals if its barges are delayed by more than 36 hours.

The 20 percent surge in container traffic on the Asia-Northern Europe route this year also is pressuring short-sea shipping lines that feed containers into main ports such as Rotterdam. Delphis, one of Europe’s biggest feeder operators, warned that shippers likely will face congestion surcharges in autumn.

While congestion has eased from the 80-hour delays that barges experienced at Rotterdam early this year, it is still playing havoc with sailing schedules, mainly on short-haul routes.

The round trip between Hamburg and St Petersburg that once took a week now can last up to 14 days. Inland barge transits also have been impacted, with Contargo extending the turnaround time for its service between Antwerp and Worth, a Rhine river terminal, to 10 days.