(1) Sometime ago on the what remains of IC’s line South of Springfield I saw a coal drag. Right after the enqine was a very unique car. It looked like a flat car with a little house on it. The car was very short–probably even shorter than a cabose. The “house portion” probably was tree feet wide and ten inches tall. I saw this car on more than one occassion, always on the same coal drag.
(2) Two days ago, I was in Indianapolis, and I saw a train go over CSX’s double main near the white river. It had three huge GEs on it, lead unit CSX the last two UP. It was a unit train of what appeared to be steel gondolas. Aside from never seeing a uniform unit train of steel gondolas, this was kind of different, because every gondola was covered with a cover that I had never seen before and the gondolas were slightly longer and slightly higher sides than normal.
(2) " Tin foil gons" (regular gons converted to take rolls of alluminum or other light metals from steel mill to finishing plant somewhere else) …More of these out there than you would think, especially with shortages of covered steel roll cars. Also have seen the used with rolled plastic and fiber products. The covers on these are either two piece steel or fiberglass composite. Wait till you see some of the slab car moves!
I obviously can extrapolate from the term, but could you give me more information about a Scale test car? Is it something that just shows how much weight is being applied to the drawbar?
If I may, I had some responsibility for the testing of the scales used to weigh coal cars at the various mines run by Old Ben Coal Company. All of our scales were electronic and designed to weigh the cars coupled while in motion at slow speeds over the scales. Obviously, the scale test car is of a fairly precise known weight. I don’t recall the tolerances, put maybe within plus or minus a 100 pounds or less.
The first step in the test is to set the uncoupled test car on the scale and if necessary make adjustments to bring the scale reading to show the weight of the test car. The second step was to then put the car in a train to check the scale reading under “as used” conditions making several runs over the scale. I believe the allowed tolerances on elelctronic scales are plus or minus 5% for any given car in the train, but in testing and adjusting the scale, the object would be to get an average on the reading of the scale car weight very close to the actual weight of the car. The reason for seeking the average is that in use the forces caused by the cars being coupled can slightly lift or weigh down the car being weighed.
As a further note, mechanical scales use leverage to provide the weights as a reading on the balance bar. An electronic scale is actually a bridge with load cells that measure the very slight deflections that result when the bridge is under load.