The presence of a federal mediator to help West Coast longshoremen and waterfront management reach a new collective bargaining agreement has not kept both sides from ratcheting up the rhetoric in their ongoing dispute, with each blaming the other for the increasing congestion plaguing the seacoast's major ports.

Operations at the five major West Coast container ports—Los Angeles, Long Beach, Oakland, Seattle, and Tacoma—are "approaching complete gridlock" due to a deliberate effort by the International Longshore and Warehouse Union (ILWU) to slow operations at the ports, according to a statement issued late yesterday by the Pacific Maritime Association (PMA). For instance, ILWU has withheld the services of 75 skilled yard crane drivers each day at the Ports of Los Angeles and Long Beach, the nation's busiest port complex, according to the PMA statement.

Since Nov. 3, ILWU has reduced the number of yard operators there by two-thirds, PMA said. These workers are critical to clearing congested terminals and ensuring the smooth resumption of container flow, according to the statement.

ILWU countered by claiming the congestion problem has been caused by an overabundance of containers and a worsening shortage of chassis equipment needed to move boxes by truck to and from vessels. Neither of those issues is the fault of the union, it said in a separate statement.

The union took ship management to task for cancelling two of three night shift crews at Los Angeles and Long Beach that would normally be loading and unloading vessels. ILWU said PMA's action will do nothing to ease the congestion crisis and accused management of trying to "gain the upper hand at the bargaining table" by casting the union as the villain in the dispute.

PMA, which took the action at the start of the year, said it made no sense to assign a full retinue of crews to work vessels whose freight wouldn't be discharged anyway.

The war of words, though it might signify little more than a tool to influence public perception, still doesn't make life easy for Scot Beckenbaugh, deputy director of the Federal Mediation and Conciliation Service (FMCS), an independent federal agency that mediates protracted and high-profile disputes such as this one. FMCS was asked by both sides to intervene, and Beckenbaugh, who played a key role in mediating the 2013 contract battle between the International Longshoremen's Association (ILA) and East and Gulf Coast ship management, was assigned to oversee the negotiations. ILWU and PMA have worked without a contract since the prior six-year compact expired July 30.

Meanwhile, the worsening congestion at Los Angeles and Long Beach is having a spillover effect. The Port of Oakland said today that it set an all-time record for cargo volume in 2014, due in no small part to a 20-percent surge in loaded import boxes in December, the most the port had handled in any month since May. A portion of the December increase came from cargo diversions from southern California ports, according to the port. The prior annual record was set in 2006.

Michael Zampa, a spokesman for the Port of Oakland, couldn't be specific on how much of the December surge was attributable to cargo diversions from other ports. Year-over-year import traffic entering Oakland rose 7 percent in September, 9 percent in October, and 3 percent in November, according to port data.

To manage the import surge, Oakland launched in early December special gate operations to process, clear and push out containers on Saturdays and Sundays. Still, the port's fluidity is under severe pressure. As of this morning, between 10 and 15 ships were anchored in San Francisco Bay awaiting berths at terminals, the port said. In addition, some truckers report waiting several hours to pick up cargo due to the escalating congestion, the port added.