Don’t forget that the “NEW” date limits the use of the car, for a covered hopper, to a period of 30 months following the “BLT” date. In other words, if the car was built in Jan. 1960, “NEW 1-60” would appear on it only until the car was re-weighed, probably somewhere around June, 1962. At that time, “NEW 1-60” would be painted over, and the letters representing the station doing the re-weighing (for L&NE, it was PA, for Pen Argyl), along with the date, would be re-stencilled in the same place. If the weight of the car had changed, the numbers following “LT.WT.” and “LD.LMT.” would also be change accordingly.
“BLT” is the “Built” date, and generally doesn’t change unless the car undergoes a major re-building, usually involving changes to the underframe.
“NEW” refers only to the “LT.WT.” (light, or empty weight) of the car when it was built. After a certain time period, which varied for different car types and different eras, the car had to be reweighed, as outlined above. After the initial re-weighing, “NEW” would no longer appear.
Here are a couple of cars that demonstrate the lettering changes. I model the “late '30s”, which gives me a bit of leeway on the exact dates. Occasionally, cars from the '40s or even '50s have been reportedly seen by railfans. [:-^]
This car just made it, built in Oct. 1939:
This Erie boxcar, built in 1930, was re-weighed at Meadville, Pa. in May of 1935. The data in the black patch on the sidesill, above the right truck, indicates that the journals were re-packed, probably (