The Joseph D. Lovell Locomotive Rosters constitute a partial roster of Pennsylvania Railroad steam, electric and early diesel locomotives to 1946. The collection also contains seven small ledgers listing the production of not only the Juniata Shops, but also the earlier Altoona Machine Shops (1866-1904) and locomotives purchased from outside builders, principally the Baldwin Locomotive Works. His lists include rosters for both the Pennsylvania Railroad proper and its predecessor lines.

There is also a folder containing copies of letters and notes by Robert B. Watson documenting the provenance of the records.