Come visit the Whippany Railway Museum, where New Jersey's Railroad history is being preserved. Take a leisurely stroll through the historic railroad yard, complete with the historic Whippany train depot, coal yard, wooden water dank, and dozens of historic railcars and displays.
The cache itself is not on the railway museum property, but it is located nearby. The Whippany Railway Museum buildings are currently only open on Sundays from April thru October from noon - 4:00. There is a $1 admission fee to tour the grounds if you choose to visit while the museum buildings are open and the ticket booths are staffed. The information needed to complete the field puzzle may be accessed at any time, but the CO requests that you please not enter the museum grounds after dark.
To complete this cache, you must explore around the museum grounds and locate the answers to a series of 20 questions about the various historic railroad displays set up throughout the area. This is not intended to be a cache-and-dash. The coordinates for each of the answers have not been given, so it may take you some time to locate them all. That being said, none of the questions are meant to be overly difficult. All of the answers should be easily found if you take the time to enjoy the displays and pay attention to your surroundings. Have fun, and enjoy your visit. 
Locate the information and perform the indicated mathematical operations to find the missing coordinate numbers.
A: First digit of the Texaco steam locomotive
B: Third digit of the chunk ice capacity of the Union Refrigerator Transit Line car
C: The Chicage Broadway Limited train departs from which track?
D: Miles to Paterson (2 digits)
E: Miles to Lk. Hopatcong (2 digits)
F: First digit of Southern engine number
G: Cost (in cents) of 1 quart of milk (2 digits)
H: Miles to Netcong (2 digits)
I: Rahway Valley RR engine number (2 digits) (It seems there may be two answers to this now. The two choices are sequential numbers, but the one you need is evenly divisible by 4.)
J: Mile marker number to the left of the museum stairs
K: Morristown & Erie RR "Bobber" Caboose No 1 was originally what number on the Delaware, Lackawanna, & Western RR?
L: Number of letters in the name of the Sante Fe Diner car
M: Fourth digit of Whippany Railway Museum Roseland car number
N: Coca Cola. Yes sir! Ours is Ice Cold. Serve below how many degrees (2 digits)?
O: Minimum penalty (in dollars) for spitting on sidewalks
P: Fourth digit of Whippany Railway Museum Morristown car number
Q: Last two digits of Lackawanna Radio car number (2 digits)
R: Last two digits of Lehigh New England caboose number (2 digits)
S: Last digit of the year the "Jersey Coast" was built
T: Last digit of the New York, Susquehanna, and Western RR industrial switching locomotive number
The cache is located at N 40 49.UVW W 74 24.XYZ.
U = A + B - C
V = D - E - F
W = G - H - I
X = (J/K) - (L*M)
Y = (N/O) - P
Z = (Q - R) - (S + T)