By Keith Reid
Bottom loading fuel tanker trucks at the terminal or bulk plant are now so common they are almost ubiquitous. But that wasn’t always the case. Seventy-three years ago, the February 13, 1952, issue of National Petroleum News (NPN) magazine highlighted the point at which bottom loading became a proven technology in the article, “Bottom Loading of Oil Tank Trucks.” As the magazine’s Midwest editor Leonard Castle, noted, “…bottom loading as now developed represents a revolutionary improvement over present loading methods.”
The article reported on a test by Standard Oil Co. (Indiana) at its Rochelle, Illinois, pipeline terminal. The company had recently built a state-of-the-art fueling terminal, which operated efficiently until a new, larger transport truck entered service that required a complete reworking of the loading dock platform. This provided an opportunity to explore a new approach that would not only minimize similar future issues but also solve a variety of challenges related to top loading.
The extensive testing process ran from 1950-1951 though the range of seasons with some extreme weather. The system proved to be highly successful with only a few minor bugs still to be worked out.
While both top and bottom loading manage to fill a tank, bottom loading was rare but had potential. From the article:
Advantages–Bottom loading can achieve these benefits:
- Installation costs are much less because no superstructure—no rack is necessary. This factor is of even greater importance during a period of war mobilization because of the considerable saving in materials. [Note, the Korean War was ongoing at the time.]
- Safety conditions are vastly improved for truck drivers and terminal employes. In fact, when the system finally is perfected, loading rack accidents hazards will be all but eliminated because no one ever should have to leave the to mount the dock or scale a transport truck.
- Vapor losses during loading are cut virtually to the irreducible minimum.
- Ground space is conserved, and trucks have more flexibility in parking than at the conventional loading rack where they must fit into a limited, specified space.
- Increased loading facilities can be added without making existing facilities obsolete.
A significant, universal changeover to a long-established way of doing business can be a considerable undertaking for an industry. But the benefits from bottom loading were obvious and tangible. On the financial side, the capital conversion costs were balanced against the long-term savings potential with new construction and upgrades.
As the article noted: “Indiana Standard was unable to say in dollars and cents what the financial savings would be on the installation of bottom loading as compared with the construction of a conventional loading rack. It was pointed out, however, that a major investment is required to change the capacity of a conventional dock within the pumping limitations. But to add new bottom loading facilities, all that is needed is a ‘T’ off the product line, so as long as the pumping capacity is behind it adding new loading facilities is just like plugging in on a water main for a new house.”
The big financial savings came with the elimination of the rack superstructure, although the required valve for bottom loading was typically less expensive than the conventional counterweighted top loading device. The cost of equipping a truck or transport with the needed loading nozzle adapter for bottom loading was small, an estimated $40 to $50 (equivalent to $480 to $600 today).
Top loading has not completely disappeared. It is still common in many chemical applications and in petroleum fueling applications in some regions of the world. In the United States, there fuels top associated with rail applications and some tank wagon applications (home heating oil and wet hosing delivery trucks, for example)—but even in those cases bottom loading options exist as well.
Keith Reid is the Editor of Fuels Market News.
