This is the second cache that I've placed near the abandoned right of way of the Central Mass. Railroad, the first being Central Mass Railroad. A short history of the Central Mass is discussed there.
You must visit three locations and gather some numbers that will be used to calculate the coordinates of the final cache. There are plans to develop this section of the Central Mass right of way as part of the Bay Circuit Trail at some point in the future.
The first location is the restored section house at the given coordinates above - N 42° 21.692 W 071° 25.068. The section house was built to store tools and equipment that were used for maintaining this section of the railroad. The section house was built in what year? Take the last two digits of the year and call them A and B.
The second location is at N 42° 21.583 W 071° 24.818. There is some tricky footing for little feet here, so keep a close watch on the kids. Here you will find just two of the approximately twenty-five date nails driven into a single railroad tie when the cache was hidden. Date nails have a two digit number on the nailhead. Date nails were used by the railroad to indicate when a railroad tie was last replaced, with the two digit number indicating the year. What are the two digits on the oldest date nail you see here? Call these digits C and D.
The third site is an old signal which still stands at N 42° 21.577 W 071° 24.574. This signal may have been an approach signal for the interlocking signal that protected the crossing of the New Haven Old Colony line next to the South Sudbury station. You will find on the signal box a five digit number. This number is of the form 13EFG. Use the last three digits for E, F, and G.
Now using these formulas, calculate the values of H, I and J:
H = D - (C + E)
I = F + G
J = D - C
Use these values to calculate the final coordinates:
N 42° 2 F. E A B
W 071° 2 G. H I J
You almost certainly will need to read the hint to find it.
The final cache is a small plastic jar which is very well hidden. No stones need to be moved to find it. Only small items can be traded. There is a GeoCoin for the first finder, and a few other small items for trade.