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OCR for page 44
44 Truck Drayage Productivity Guide The direct customers of the drayage firms are usually the importers and exporters. (Although so-called "store door" drayage is theoretically controlled by the ocean carriers, in practice, the importers and exporters often chose the drayage driver.) The primary goal of importers and exporters is to obtain their import goods (or ship their export goods) at their preferred time at low- est possible cost. Customers see the cost, time, and uncertainty associated with drayage and seek to minimize all three, but are first and foremost concerned with the cost. The direct customers of the marine terminal operators are the ocean carriers. Although marine terminal operators do pay attention to the needs of importers, exporters, and drayage firms, the ocean carriers pay the bills. Many marine terminal operators, such as Eagle Marine Services and APM Terminals, are ocean carrier subsidiaries. The primary goal of the ocean car- riers is to turn the ship (unload import boxes and load export boxes) on schedule at lowest pos- sible cost. Carriers will pressure terminal operators (even their own subsidiaries) to handle the vessel on schedule at lowest possible cost, regardless of impacts on other terminal functions-- notably drayage. As a result, drayage queues lengthen and turn times rise while a vessel is being worked. Although the ultimate customer pays the entire cost, that customer does not see all the compo- nent parts or the tradeoffs between them. An importer with a "store door" rate will receive a sin- gle bill from the ocean carrier, with no breakdown between ocean, terminal, and drayage costs. An importer or exporter with a "local" rate will pay for drayage separately, but will not see a break- down between terminal and ocean costs. Need for Buffers Vessels arriving at the terminal unload a large number of containers in a relatively short time. The vessel arrival therefore creates a backlog or stockpile of import containers on the ter- minal, which draymen will pick up and deliver over the next few days. Vessels departing the terminal likewise load a large number of outbound containers in a relatively short time, clear- ing the terminal of a backlog that draymen created by delivering export loads and empties over the previous week. The desire and ability of import customers to receive containers may bear little relation to the pattern of vessel arrival. One customer may want "hot" boxes immediately, while another may want arrivals spaced out over several days. At most ports the typical pattern is for import pick-up demand to peak on the day of first availability (usually the vessel arrival day), and to taper off thereafter. Empty container returns will lag import pickups by a day or more. Export loads typically build up in the week prior to vessel arrival, often peaking the day before the out- bound cutoff. The flow of containers between vessel and landside customer is therefore anything but smooth. Rather than a steady conveyor-like stream, the flow is a series of surges. Any system that must accommodate uncoordinated flows and surges requires buffers-- intermediate stopping or storage points that allow parts of the system to operate at different rates or on different schedules. As a buffer, however, the gate queue is costly, inefficient, and envi- ronmentally unsound. Each container in a terminal gate queue is being attended by a driver, chas- sis, tractor, and diesel engine burning fuel and emitting pollutants. Best practices should conserve some or all of those resources by minimizing the time in the queue. The potential for uneven arrivals, the fixed throughput capacity of the gates and the terminal, and the relative difficulty of adapting the number of open gates together imply the need for a buffer in the system. The marine terminal gate acts as a metering device, with the queue outside serving