Complex sentence: At Colton they were pushed to the 2 ft gauge tracks described above, then tipped onto a stockpile then gravity-fed into 2 ft tipplers which were taken to the standard gauge line, tipped again then lowered down the original incline.
Split into simpler sentences: At Colton they were pushed to the 2 ft gauge tracks described above. The ore was tipped onto a stockpile then gravity-fed into 2 ft tipplers which were taken to the standard gauge line, tipped again then lowered down the original incline.