Early diesel freight and passenger locomotives had distinctive full-width enclosed body styles, as opposed to the later "hood units". While the EMD E and F units are the ones commonly called covered wagons, there are ALCO and Baldwin units similar in design that they could be called "covered wagon" locomotives too. And although they may not use the term "covered wagon" abroad, variations on this classic design have been manufactured in both Australia and Denmark.
EMDThe EMD E, F, and FP locomotives were manufactured between 1937 and 1950. All in all, 1,338 E units (A and B units), 60 FL units, and 468 FP units were produced for passenger service. The F units for freight amounted to 7,110 A and B units.
ALCOThe American Locomotive Company (ALCO) produced three types of covered wagons between 1939 and 1959. The earliest of these were the DL passenger units, which amounted to 81 total units. The later, more prolific passenger units were designated the PA/PB units. Of these 297 were made. But, as with the EMD locomotives, the most numerous were the freight units. ALCO's production of their FA/FB freight units totaled 1,354.
BaldwinThe Baldwin Locomotive Works manufactured their DL series of covered wagon style locomotives from 1945 through 1950. Most of the DR-6 and DR-4 series locomotives were very similar in general appearance to EMD's E and F units respectively. The DR-12 "Centipede" locomotives were notably different in that they had 12 axles where the others were 6 axle and 4 axle units. However, beginning in 1949 the last of the DR-4 locomotives received a significant change to the shape of the locomotive's nose. The rounded design of earlier units was designated the "Babyface" design. The new angular nose section with a blunt end was designated the "Sharknose". Baldwin's RF series of engines manufactured from 1950 through 1954 were also Sharknose design.