The takeover by the Huanchaca company saw the first of a fleet of 2-6-0 locomotives built by the Baldwin Locomotive Works arrive in 1889. The relationship quickly developed, and Baldwin supplied an outside-framed 2-4-2 in 1890. This was the first outside-framed loco on the FCAB, and the first application of outside frames to a narrow gauge locomotive by Baldwin. The use of outside frames allowed construction of larger locomotives, and by 1892 Baldwin were supplying large 2-8-0 locomotives.
