Hawk & Badger Railroad Forum

Russian SZhD Eel2 in Kiev (1924)
A boxcab for the Long Island RR (1926) - fatuously claimed to be the first to enter actual service. I'm pretty sure the Russians might say otherwise.
Boxcab #50 was the first diesel locomotive on the Reading system and the second diesel locomotive in the United States (Alco, 1926).
A pair of 2-D-2s converted to diesel for the Canadian National RR (1928)
NYC #1547 (1928)
NYC #1550, first diesel to be designed and used for freight (1928) - image from New York Central's employee magazine "Headlight".
NYC #1550 (1928) - artist's rendering.

Just Crazy Jim wrote:

earlydiesels_9000-1.jpg

A pair of 2-D-2s converted to diesel for the Canadian National RR (1928)

Yeh! two more new locomotives in RT3 please. either doubleheaded 2D2 or this diesel electric variants released in the mid 1928. Remember that many railroads did dieselize BEFORe the second world wars. including the Royal State Railways of Siam (today State Railways of Thailand)