SP&S number 525 was the only steam locomotive in SP&S class O-2.
In the early 1920s the SP&S had experienced an increase in traffic, especially logging traffic off the Portland, Astoria and Pacific and United Railways west of Portland, Oregon
. To help handle this tonnage, several locomotives had been leased from the Great Northern Railway
and Northern Pacific Railway
. To offset these costs, several of these locomotives were sold by the parent roads to the SP&S. Number 525 was one of these locomotives.
SP&S locomotive 525 was originally built for Northern Pacific by the Schenectady Locomotive Works. Builders Number 46878 was built in February of 1910.
Number 525 was officially bought by the SP&S on November 30, 1925. She was used on the mainline because she was able to haul heavier eastbound trains upgrade out of Pasco WA. Over time, as newer locomotives were obtained by the SP&S, Number 525 was demoted to local or work service, or used on doubleheaded mainline trains. By late 1942 and Early 1943 she was assigned to the Vancouver WA yard as a switch locomotive. She was finally scrapped in 1947.
SP&S number 525 was originally NP number 1698, in class W-1
SP&S Number 525 was dismantled on October 31, 1947