Re: Hoppers from early 20th century
It seems as though this thread has gone "off the rails" discussing what those extra tracks on the left side of the image are, rather than focusing on the FAR more interesting and important (and in-scope) freight cars to the right. Considering that it's far more likely that there are more general pre-WWI modelers here than there are DL&W Scranton Division modelers, we really should be focusing on that FASCINATING string of coal-carrying cars instead of a small stretch of very specific right-of-way.
Here are a few notes about what I "think" I'm seeing in photo C1106 (which was taken just west of Scranton on 5/2/1912):
1) There are three types of cars in view: hoppers, solid-bottom gondolas, and hopper-bottom gondolas. Each car is a specific car type, built to do different things for different reasons.
a) Hopper cars have slope sheets and rapid discharge doors on the bottom.
b) Solid bottom gondolas are just open-topped boxes with a flat bottom and NO doors, and come with several different side heights, especially when dealing with wood construction freight cars.
c) Hopper-bottom gondolas are a hybrid, and are a good example of the frugality of early period railroading. They're more similar to solid-bottom gondolas in that they "mostly" have a flat bottom, with between two and four "hopper-like doors" cut into the floor. Hopper bottom gondolas specifically lack slope sheets for true rapid discharging, and require a lot of man-muscle to empty (manpower is cheap in 1912. Steel and specialty car are expensive, and automatic unloaders are basically H.G. Wells-inspired fiction).
2) All of the cars in this photo APPEAR to be DL&W equipment, which is no surprise: before the 1920s it was far more common to see nothing but home road cars in large groups like this. And while this is a "staged" photograph, it's not very staged: chances are extremely good that all the photographer did was to tell the security agents to "stand over there", and that the car selection was 100% random and "natural".
3) The steel hoppers seem to be mostly DL&W 72000-75999 series cars (built in 1905) with one or two 69900-69999 series cars (built 1900).
4) the DL&W 5/1915 ORER capitulation lists 2,528 gondolas and 10,368 "coal cars". A more precise breakdown of the cars is as follows:
Gondola, all-wood, 31'5" OL, low-side: 196 cars
Gondola, all-wood, 31'5', high side: 1 car
Gondola, all-wood, 31'5", "conventional duty": 838 cars
Gondola, "steel" (with all-wood sides). 36'5": 495 cars
Gondola, "steel", 40'5", four drop doors: 1,000 cars
Gondola, hopper bottom, all-wood, 30'6" to 36'4", 4,245 cars
Gondola, hopper bottom, all-steel, 30'6", 10 cars
Hopper, all-steel, 30'6" or 34'6", 6,113 cars
31' all-wood gondolas: 1,035 (8%)
40' composite gondolas: 1,495 (12%)
All-wood hopper bottom gons: 4,245 (33%)
all-steel hopper bottom gons: 10 (0%)
All-steel hoppers: 6,113 (47%)
5) I count 21 cars in this photo: 13 steel hoppers, six hopper-bottom gondolas, and two plain gondolas. Statistically, if these really are all DL&W cars there should be far more of the all-wood, hopper bottom cars; steel coal-carrying cars are over-represented. (that said, "statistics" really don't mean a thing in the real world, and this mix is most likely "normal")
6) ALL of these cars have archbar trucks. The Archbar truck ban is nearly 30 years in the future and T-section Bettendorf cast trucks were only introduced in 1904; MOST freight cars will be delivered with archbar trucks for another decade.
7) Archbar trucks under all-steel, "modern" cars like these hoppers is nothing new. Early PRR and B&O all-steel freight cars had them (including X29 and derivitave boxcars), and archbars pop up in AC&F builder's photos through the late 1920s. The NYC was an early and widespread adopter of cast sideframe trucks under everything, but few other railroads were until much later.
(PS: notice that it's May, and there's basically nothing green growing at all. Welcome to the world of no EPA and lots of raw pollution)