Anthony Thompson <thompson@...>
Mike Del Vecchio wrote:
As for the tank car -- this image to me looks posed so as to place both people in the scene at once. The pole up top is for gauging, but often when a scale isn't present what they're measuring is the distance from the top of the fluid to the top of the dome so that the actual volume in the car can be calculated before emptying the car.No. The standard method was to load "shell full," meaning to the top of the tank shell. The dome is for expansion. The number of gallons lettered on the end of the car was based on actual car measurement (since cars were not identical), and played the role of the "light weight" on a house car. And BTW, "shell full" was also intended to minimize sloshing in transit.
The tempurature of the product is also recorded as that is a component of the volume calculation -- a thermometer on a chain is lowered into the car. Loaders need to record these items so the customer can be billed for the contents.The usual in the steam era was that the "official" end lettering volume in gallons was THE basis for charges. If it said 8022 gallons, then the customer was billed for 8022 gallons. My understanding is that temperature adjustments were only made if ambient temperatures were unusually hot or cold, and this was subject to prior agreement between shipper and consignee.
Depending on how this facility operates, any quantity could be unloaded at a time and both men may be participating in that. Where I work tank cars with raw materials are often partially unloaded to make blends without having to fill a storage tank. A scale isn't practial, so volumes are calculated via gauging as was done in the steam days, both for inbound and outbound loads.This is pretty much my theory of the photo also.
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