PMRR Hazel Mine - Prototype Research
I have a separate article on this web site about the general information about the PRR's Chartiers Branch. Here, I want to share more detailed information about the Hazel Mine itself.
Once model railroaders get an idea of what they want to model, they really become experts in that area. However, to nearly everyone else, there is not enough context provided to draw that person into the miniature world the modeler has created. I hope to change that, so let's start off with orienting ourselves to which part of the world I am modeling.
Canonsburg is a small town (a "borough" in Pennsylvania-speak) of about 9,000 people located southwest of the city of Pittsburgh, Pennsylvania. Pittsburgh is on the far western side of Pennsylvania (near the border with Ohio). In 1950 Canonsburg had around 12,000 people. It is well-known for its elaborate July 4th celebrations and parades each year.
Canonsburg is about 18 miles southwest of Pittsburgh. It was one of the major towns along the PRR's Chartiers Branch. The Chartiers Branch connected Carnegie (just outside of Pittsburgh) with Washington, PA. The railroad tracks followed the Chartiers creek, from where it obtained its name.
Canonsburg neighbors Houston, PA and Strabane, PA. Within Pennsylvania, a "township" is generally an area outside of a borough (town) or city. Canonsburg had a lot of big industry, such as coal mining, steel and iron manufacturing, pottery, and lumber. The single-line railroad tracks you see in the modernday map below is still the original PRR Chartiers Branch line, although in the time period I model, it was double-tracked.
The map below shows, approximately, where the Hazel Mine would have been. In the 1970s the people got tired of having nearly annual flooding in the area, so public funds were gathered, and the Chartiers creek was moved. In this particular area of interest, it was straightened out to run along side the Chartiers Branch railroad tracks. After the mine closed (I still don't know when that was), state highway 79 was built in the area.
Here is a satellite view of the same area. Part of the original Fort Pitt Bridge Works building remains (the three large rectangular buildings on the left-hand edge of the photo). These are always a good reference for locating the Hazel Mine. I have highlighted the approximate location of where the mine used to be.

Updated: April 21, 2016

The diagram below, from 1945, shows the overall track arrangement in the area. The Chartiers creek itself is shown in the thick, shaded line following the branch line, and going below the coal tipple mine yard. The Chartiers Branch was double-tracked in this area, which you can see in the two parallel tracks going from lower-left to upper-right in this diagram. The Canonsburg passenger station and freight house were just to the left of the diagram. The large structure labeled "11" in the diagram is the Fort Pitt Bridge Works company. Its track comes off of a siding, while the Hazel Mine coal tipple yard track comes off of the branch line itself and crosses the Fort Pitt line. The coal tipple yard consisted of 5 tracks, and it later on merges back into the siding.
This scaled diagram comes from The Engineering and Mining Journal, dated December 22, 1900. It clearly shows the entire Hazel Mine facility's trackage, the Chartiers creek, and a portion of the Chartiers branch main line. My guess is that this is the as-built layout, since the tipple extension over track #5 isn't there yet, and neither are the buildings on the other side of the yard from the creek. However, it is the best diagram I have found showing the location of the turnouts in the yard. The track nearest the creek was track #1. There are crossover turnouts between the left two tracks, and a number of crossover turnouts between the right three tracks before the tipple. Shortly after the tipple, the left-most track (#5) merges into track #4. Much further down the yard, tracks #1 and #2 merge into each other and into track #3. Not shown in this diagram, shortly before merging back into the siding of the Chartiers branch line, tracks #3 and #4 merge into one. A total of 75 cars could be stored in the yard. The rectangular structure below the tipple indicates that it contained a boiler, a power house, a dynamo, and a machine shop. This diagram also shows the coal-car track of the tipple and mine entrance as well.

Updated: August 31, 2014

External Reference:
The diagram below (from Sanborn insurance maps) shows the mine and its surrounding features. This was from a survey done in November 1913. In the upper left corner of the diagram are three parallel tracks. The top two are the Chartiers branch's main lines, while the bottom one is a siding. Note how this diagram shows the Hazel Mine lead coming off of the siding, while the two diagrams above showed it coming off of the main Chartiers branch line. Track diagrams of Sanborn insurance maps may not be accurate, because their primary interests were structures and access to water sources (to deal with possible fires). So, this diagram is very useful in figuring out the various structures making up the coal tipple area, their relative placements, and their sizes, but not so much the track arrangements. Note that this diagram clearly shows a track coming off of track #5 leading to an engine house. This was not part of the original construction of the mine complex, but eventually the mine was so busy that the railroad placed a permanent switcher in the area, and this engine house provided storage and basic repair facilities. The mine had its own power house (the pink, rectangular building to the left of the tipple in the diagram), which housed the air ventilation and electricity generation systems that operated the mine, the tipple, and the yard. The traditional company-owned employee houses were all around the tipple, and apparently expanded up on Buffalo Hill over time. At the north end of the tipple, to its left, are a set of water towers.

Updated: January 03, 2015

External Reference:
The Hazel Mine employed over 600 men at peak times. The tipple was the outside building of a long collection of tunnels into the hill behind it, known as Buffalo Hill. The image below came from the 1903 book titled "The Successful American", where on page 280 this mine is described in full detail. Apparently when this mine was built, it was built with the absolute latest in technology and safety for its employees. The local newspaper reported that this mine was the most productive single mine in the U.S., producing 4,500 tons daily, with work going on around-the-clock (of course, we all know how unbiased and factual newspapers are!). It was originally created by the Pittsburg & Buffalo Co. (note no "h" in the name), but ownership changed hands a few times. In 1936 it was owned by the Canonsburg Coal Co., in 1940 it was listed on a survey as being owned by Chartiers Creek Coal Co., and in 1942 it was apparently owned by National Mines. Originally gondolas and box cars were used to capture and transport the coal, but those were later replaced by the more conventional open-top hopper, both two-bay and four-bay varieties. Pittsburg & Buffalo Co. had over 500 of its own hopper cars, and between all the mines it owned, it had a total of four steam locomotives. It was a fairly young company at the time, but it was well-funded because it was created out of the combined effort of several previously successful businessmen. The photo below shows the tipple in its as-built configuration (no extension over track #5, the one on the right-hand side of the image).