Ocean Carriers Brace for Orders Surge Ahead of Potential New Tariffs

The push to get goods to U.S. shores brought an early peak season for seaports, while raising costs for importers and adding distribution complications that could grow across supply chains in the coming months.

“After the section 232 and 301 tariffs were announced back in March, we started to see cargo moving ahead earlier in the year,” said Gene Seroka, executive director of the Port of Los Angeles. “We did see companies looking to put their purchase orders in and advance those inventories.”

Loaded import containers at the Los Angeles port, the nation’s busiest seaport and a major entry point for goods from China, rose 6.6% from the year before in September but also declined on a monthly basis for the second straight month.

Overall goods imports to the U.S. rose 10.3% in the third quarter, according to the Commerce Department, and private inventories contributed more than 2 percentage points to the third-quarter gross domestic product growth rate. That drove strong third-quarter results at many cargo-handling operations as demand for their services surged, driving up prices.

“July was one of our biggest months we’ve seen in terms of both demand and constrained capacity,” Douglas Waggoner, chief executive of freight broker Echo Global Logistics Inc., said on a conference call with analysts last week.

Many companies brought in goods without the clearer view on demand that comes with shipping later and have had to push more goods into increasingly crowded logistics channels, adding costs and other challenges.

According to real-estate brokerage firm CBRE Inc., the rate of available warehouse space—properties that are vacant or soon to become vacant—fell for the 33rd straight quarter, to 7.1%, during the three-month period ending in September.

The frenzied freight market started to cool down in September, after the pretariff orders were fulfilled. But some operators say their customers have started to adjust their global supply chains in response to new potential tariffs.

President Trump and his Chinese counterpart, Xi Jinping, are scheduled to meet in November amid a standoff over trade and possible new tariffs.

“In working with our customers largely in Asia right now, we are seeing some movement in decisions around where they’re actually manufacturing and moving supply chains in anticipation of what January may bring,” United Parcel Service Inc. Chief Operating Officer James Jay Barber said in an investor conference call last week.

That prospect has shipping lines that work trans-Pacific trade lanes maintaining their capacity during the traditionally slower last weeks of the year. Shipping research group Alphaliner said in a report that trans-Pacific carriers are even adding extra container-handling equipment “to cope with the additional volumes and to take advantage of the strong spot rates on the route over the course of the coming weeks.”

Trade analyst Chris Rogers of the Panjiva research group said the likely Jan. 1 increase in tariffs on more Chinese goods “suggests we’ll get another pop upwards in imports in the November-December time frame,” once holiday-season goods start clearing out of warehouses.

Panjiva said seaborne import volume from China into the U.S. declined 0.8% year-over-year in August, after rising 12.5% and 6.5% in June and July. But September import volume from China was back up 5.5% year-over-year.

The rate to ship an ocean container from China to the U.S. is now roughly twice as high as it was this time last year, shipping analysts said, as demand is picking up. “Capacity is insufficient,” said Philip Damas, director of Drewry Supply Chain Advisors Ltd. “Importers are not very happy because they’re struggling to get their cargoes moved in time [and] the prices are twice what they usually are.”

Write to Erica E. Phillips at erica.phillips@wsj.com