#2236
Southern Pacific class AC-4
🇺🇸 United States ·built by Baldwin Locomotive Works· from 1928· class of 10 American 4-8-8-2 cab forward locomotives
what is it?
Southern Pacific Railroad's AC-4 (meaning Articulated Consolidation) class of steam locomotives was the first class of 4-8-8-2 cab forward locomotives. They were intended to improve on the railroad's MC (Mallet-Consolidation) class 2-8-8-2 locomotives with a larger firebox, hence, the four-wheel leading truck (instead of the two-wheel). The AC-4s were the first SP Mallets built for simple expansion.
who runs it
base stats
Bars compare against all trains: 600 km/h (maglev), 1,700 seats; power, weight and number built on a log scale up to 20 MW, 1,000 t and 20,000 built.
fun facts
- First built 98 years ago, in 1928.
- Weighs about as much as 46 African elephants (~6 t each).
- Served for 27 years (1928–1955).
steam locomotive: Burns coal, wood or oil to boil water; the steam drives pistons that turn the wheels.
spec sheet
- built
- 1928
- in service from
- 1928
- retired
- 1955
- status
- retired
- number built
- 10
- kind
- Steam
- traction
- steam
- origin
- 🇺🇸 United States
- builders
- Baldwin Locomotive Works
- operators
- Southern Pacific Transportation Company
- top speed
- —
- power
- —
- gauge
- 1,435 mm standard gauge
- wheel arrangement
- 4-8-8-2
- weight
- 279 t
From the Wikipedia infobox and Wikidata. Blank means the sources don't say.
Sources: Wikidata Q7570297, Wikipedia: Southern Pacific class AC-4 (CC BY-SA 4.0).Updated 2026-10-25.