I worked for Corning Incorporated (formerly Corning Glass Works) for a while. Corning has made a wide variety of products from telescope lenses to kitchen ware to optical fiber to catalytic converter cores from silica over the years. The silica (the technical name for sand) has been shipped by covered hopper since the mid or late 1960s. In the 1920s - 50s, boxcars were used. Loss and breakage in this business was always a problem. Corning was the first mass-producer of electric light bulb globes - the glass part of a bulb - and they just loaded them in bulk into a boxcar and allowed 25% breakage.
