A few historical notes on freight cars ...
Steel framed freight cars replaced wood before the First World War in new construction. The all wood cars had a 15 yr lifespan in hard daily use - most were scrapped during the boom of the 1920s or for sure during the Great Depression. The standard 40 foot steel AAR boxcar was introduced c 1927 (but had many forerunners) and remained with only minor mods the car of choice in new construction through the 1950s. Most were gone by the 70s though a few lingered perhaps as late as 1990.
Fifty foot boxcars for special uses have been around since steel underframes were introduced. Shipment of automobiles was big business in the 1920s and all went in 50 foot cars. By mid century, fifty foot cars replaced 40 footers in new construction. Most of these cars were not general purpose boxcars but had specific uses for hauling various commodities - special suspensions, inside bulkheading, clamps etc.
For hoppers, steel hoppers were de facto the standard in new construction after 1905. Dual hoppers were the norm and as coal is modestly heavy (but much lighter than iron ore or other bulk quarried commodities) the length was initially set at 34 feet and 30 ton capacity. Over time, as technologies for couplers, brakes and track improved, lengths grew to the 100 ton hoppers of the modern era. Hoppers had rough use so even steel cars had a relatively short life of 20-25 years. Depending on the era and locale, the fleet could be predominantly smaller 30 ton cars or progressively larger cars.
In the Canadian context, coal was mined only in Cape Breton and in the west (southern Saskatchewan/Alberta/BC). Accordingly, most coal in central Canada was imported from the US. Residential and industrial use of coal ended shortly after the Second World War leaving the railways themselves as the last big user. This use tapered down in the 1950s and was gone by 1960. I have not personally seen a hopper of coal in central Canada for most of my adult life although a very few coal fired power plants have been running.
For other cars, stock cars have always been composite - steel underframes and wooden bodies. The last stock movements in Canada by rail were phased out during the 1960s. Similarly, reefers were mainly wood on steel frames cooled by ice until the 1950s. They were replaced by steel reefers with cooling units and these were in turn mostly gone by the mid 70s. The odd reefer hung on in specialized service but haulage of perishables today is a truckers business not rail (Tropicana Unit trains being the exception that proves the rule)
Grain moved traditionally in boxcars with grain doors. This mode of haulage prevailed until the 1970s in Canada where vast fleets of Fowler boxcars (outside braced composite cars) were in use. Eventually covered hoppers displaced the boxcars. In Canada, those covered hoppers were the "Trudeau hoppers" built mainly by Marine Industries and they looked nothing like the modelled covered hoppers produced in large scale today.
I could go on but will conclude with a remark on eras. The 40 foot boxcar is really a product of the first half of the 20th century. A few carried on after diesels were introduced but the diesel era really marked the beginning of much larger cars. The last 50 years have seen fairly remarkable advances in technology and cars built for use early in the diesel era look very dated when run with more modern diesels. In fact, even 50 foot cars are pretty small in the most modern trains. Go trackside and watch a few trains rumble by to see what I mean. The mix of cars has changed and as well, the cars are huge. Tank cars of all sorts as well as covered hoppers predominate in most general purpose trains while intermodal cars make up a good percentage of the rest. Depending on primary industry in your area, you may see hoppers of coal, jennies of ore or boxcars of newspring and so on.
As in all areas of model railroading, the more you watch the real railroads, the more discerning your eye will be with models.
Regards ... Doug
