It was started (at least in planning, not necessarily in construction) Around March of 1859, and finished in 1861. It's final depth was 318 feet, and its dimensions were 14 x 8 feet. The purpose of this shaft was to circumvent the weak demoralized rock that made tunneling from the West Portal so painfully slow. Once the shaft was sunk to grade 2 new headings could be made. One heading going towards the West Portal, and the other going east into the mountain. Its location was literally as far east as you can go before the mountain grows too much in height and in angle.
Several shafts were sunk between the West Portal, and the West Shaft. Four exploratory "wells" were dug to grade so workers could tell what sort of tunneling conditions miners would meet along the way. More specifically the shafts were dug to tell the amount of water that miners would encounter. It was determined that the West Shaft west heading could proceed 1000 feet towards the West Portal before the pumps would become overwhelmed. Of course once the adit broke through water could freely flow out the West Portal, then through the Haupt Tunnel and into the Hoosic River. Three of the exploratory Hockin's wells have completely mysterious locations, and are supposedly filled In. However the Shaft known as Hockin's well #4, and the Supplementary shaft to the West shaft (known as the Baby shaft) have well archived locations. Hockin's Well #4 was located exactly 950 feet west of the West Shaft, or contemporarily a few feet east of a small parking spot on West Shaft road (on private property do not trespass! You have been warned!). This shaft is filled not just with dirt, but supposedly with 3 Model Ts. The Supplementary shaft was 264 feet west of the West Shaft, it is also filled in. The West Shaft however is not fully filled in.
The final point of interest in the West Shaft vicinity is the Nitroglycerin Factory. Built by George Mowbray, A professor who had expertise in the process of making nitroglycerin. The factory was completely built and running by December 31, 1867, making it the first nitroglycerin factory in the US. It was located about one hundred feet south of the West Shaft. The building nicknamed "the Acid House" was about 150 feet in length, and contained several troughs used in the manufacturing process of nitroglycerin.
The West Shaft, Nitroglycerin Factory remains, and spoilage piles are all located on private property. There are a lot of houses nearby so if you think you can trespass and not get spotted think again!
The pictures below should be more than enough to keep your appetite for adventure satisfied.
Do not trespass on the West Shaft road residents property no matter how tempting it may be!