Issue link: https://pma.uberflip.com/i/1355890
Millions of "Weighted" Tons '05 '10 '15 '20 '00 '05 '10 '15 '20 '00 '05 '10 '15 '20 '00 0 5 10 15 20 25 0 50 100 Millions of Tons Millions of Hours 150 0 50 100 150 200 30 35 40 350 400 250 200 300 250 300 "Weighted" Tons = Containerized + (Auto & Trucks)/6 + Lumber & Logs + General Cargo + Bulk/50 Coast Total Hours Paid 2000-2020 Coast Total Tonnage 2000-2020 Coast Total Weighted Tons 2000-2020 Noncontainerized Cargo Containerized Cargo Calculation of Total Tonnage and "Weighted Tonnage" Cargo moving through West Coast ports is manifested in a variety of ways, but when reported it is ultimately distilled into revenue tons or revenue units (TEUs). General Cargo is reported by weight or measure; Lumber & Logs, by 1,000 board feet to the ton; Automobiles (and light trucks) by measure; Bulk Cargo by weight; and Containerized Cargo, as number of boxes that are converted into Revenue Units, or TEUs. A Revenue Unit, by definition, is equivalent to 17 revenue tons. From this collection of data, PMA constructs a variety of tonnage statistics that are used for many different purposes. Some of those uses require adjusting, or "weighting," one or more of the cargo sector tonnage values to develop useful indices for comparisons over time or among ports or port groups. One such tonnage "weighting" is used in this section. Total Tonnage The most commonly used tonnage statistic is Total Tonnage. This measure is constructed by multiplying the number of container TEUs by 17 revenue tons, adding General Cargo revenue tons, Lumber & Logs revenue tons, Autos revenue tons and Bulk tons. The "Total Tonnage" data for each port table shown in this section is calculated by this method. "Weighted" Tonnage For the purpose of comparing the volume of tonnage handled in a port or group of ports to the corresponding number of hours paid, a "weighted tonnage" statistic is used. Only two of the cargo sectors are altered to "weight" the total tonnage: Autos and Bulk. Applying a "weighting" factor to bulk tonnage has been a common approach to measuring productivity for decades. Bulk tonnage is currently weighted at 50 to 1. The reason for greatly reducing the amount of the Bulk tonnage used in studies about productivity is that Bulk Cargo, because of the methods of loading and discharging it, requires far fewer payroll hours per ton than the other sectors of cargo. Automobiles are reported by measure: each 40 cubic feet of volume is reported as one ton. For example, a popular mid-sized sedan measures 460 cubic feet and weighs 3,330 pounds. This vehicle is reported as 11.5 revenue tons even though it weighs just over 1.6 tons. New imported automobiles arrive on specialized auto carriers and are driven off the vessel and parked. This operation generally takes much less time than handling general cargo or lumber and logs. To offset this difference in labor requirements, auto tonnage is weighted at 6 to 1. Total "Weighted" Tonnage Thus, the "weighted" tonnage statistic that is used in the graphs on this page and in calculating the "Weighted Tons" per Hour data in the following tables is the sum of container TEUs x 17, General Cargo tonnage, Lumber & Logs tonnage, 1/6 of Automobiles & Trucks tonnage, and 1/50 of Bulk Cargo tonnage. Coast Hours and Tonnage '02 '04 '06 '08 '10 '12 '14 '16 '18 '00 0 2 4 Tons per Hour 6 8 10 12 14 '20 Coast Total "Weighted" Tons per Hour Paid Coast Total Tons per Hour Paid Total Hours have been annualized for 2004, 2009, 2015, and 2020 since these years have 53 payroll weeks, for the calculations of Coast Total Tons per Hour Paid and Coast "Weighted" Tons per Hour Paid. S TAT I S T I C A L I N F O R M AT I O N 71 71 PACIFIC MARITIME ASSOCIATION