SJ, Swedish State Railways, has over the years used a lot of different locomotives; steam, electric and diesel. SJ, like most other railway companies, uses a system for classification of their rolling stock. In SJ's case this system uses a capital letter which can be followed by one or more letters or digits (eg. Ma, X2, T66, L). To get to the location of this geocache you will have to identify the locomotives below (the capital letter is enough).
Convert each locomotives capital letter to a number ( eg. A=1, B=2, .........Z=26).
The coordinates of the cache are N59 04.pqr E15 06.xyz
where p=a-e, q=c, r=f-d+b, x=a-b-c, y=d-a and z=d-a+b