This has prompted a rationing of chassis in nearly a dozen eastern US rail terminals to control supply, according to intermodal marketing companies (IMCs).
The two Class I railroads, which own their chassis, are having the toughest time, while DCLI customers such as CSX Transportation have not been affected.
'Due to increased import transloading and thus, higher demand for 53-foot container capacity - coupled with the longer customer unloading times - cycle times on chassis have increased 11 per cent versus the peak months in 2020,' UP said.
'This creates a shortage of chassis that can only be addressed by introducing more or having the entire transportation supply chain become more efficient,' said a spokesman.
NS also attributed the shortage to a slowdown in turning rail-owned containers and the chassis underneath, but the railway declined to provide specific metrics around container turn times.
'Capacity challenges in the global supply chain, particularly with local drayage and [distribution centre] throughput, have resulted in longer cycle times for containers and chassis. Combined with strong volumes, this has resulted in tight chassis supplies at various intermodal terminals,' NS said.
The effects of the 53-foot chassis shortage aren't limited to the railways and their customers; however. JB Hunt Transportation Services and Schneider National, two of the largest trucking and intermodal providers in the country, recently increased accessorial fees on shippers holding onto containers too long.