This is a bonus cache linked to the Adventure Lab - The Island of Sodor.
The cache is not located at the co-ordinates given.
Sodor is a fictional island featured as the setting for the Railway Series of books by the Rev Wilbert Awdry, begun in 1945, and for the popular television series Thomas the Tank Engine and Friends since 1984.
It is depicted as being located in the Irish Sea just off the English mainland near Barrow-in-Furness, Cumbria; between Barrow and the Isle of Man – an enlarged Walney Island. Sodor is much larger than the Isle of Man. The island is roughly diamond shaped, 100 km wide east to west and 82 km long north to south.
The actual cache can be found at : N54 AB.CDE W003 FG HIJ
The numbers are revealed as you complete the Island of Sordor Adventure Lab and are stored in the associated journal.