In 1950, SP leased ten 4-8-4s from subsidiary St. Louis South- western for use on the Rio Grande Division. On May 27, 1953 Cotton Belt 4-8-4 No.818 was tested on commute train No. 126. The results encouraged SP to renumber all ten as 4475- 4481 and 4485-4487. One additional locomotive, Cotton Belt No.813, was added later and renumbered 4488. Several of these locomotives were assigned to commute service for a short while. These ex-Cotton Belt 4-8-4s had excellent acceleration for the commute trains. However, they were rough riding and were not popular with engine crews. They were demoted to freight service and assigned to the San Joaquin Valley where they ran out their miles until retirement in 1955-56. 
 

In the early 1950s the commute trains were being handled by a fleet of 4-6-2s on the mid-day and weekend runs while 4-8-2s and 4-8-4s were assigned to the morning and evening peak-hour trains. Servicing of the locomotives was done at the Mission Bay roundhouse in San Francisco and at the San Jose roundhouse (at Lenzen Ave). The occasional heavy repair and shopping were taken care of by the Bayshore Shops in the Peninsula town of Brisbane. 
 

The first diesel to appear on the commute trains was EMD SD7 No.5325, beginning service on September 28, 1953 and assigned to off- peak and weekend trains. While this 1500-horsepower locomotive could handle short trains, its slow transition could not match the get-up-and-go of the fleet-footed 4-6-2s which it was to replace. The steam boiler equipped 5325 was soon reassigned to the Western Division and on August 8, 1954 the unit was leased to the Northwestern Pacific. 
 

However, the handwriting was on the wall and steam would soon be replaced with diesel locomotives. On January 7, 1955 the Coast Division's main line passenger trains were dieselized. On that morning 4-8-4 No.4458 powered the Coast Daylight, No.98, from San Francisco. That evening No.94, the Starlight had 4-8-4 No.4459 while No.76, the Lark had No.4452 for the run to Los Angeles. Diesels replaced steam on the streamliners while 4-6-2s continued to power Nos. 77-78, the Del Monte between San Francisco and Pacific Grove, and 4-8-4s were assigned to the Coast Mail Trains, Nos. 90-91 between San Francisco and San Jose. 

The answer to dieselization of the service was found in the fleet of Fairbanks-Morse Train Masters. These 2400-horsepower units proved to have the speed and acceleration needed for the frequent stop and start schedule of the commute trains. In 1953 SP tested the F-M Train Masters in commute service and liked what it saw. In December 1953 the two demonstrators were purchased and numbered 4800-4801. Between December 1953 and March 1954 SP added fourteen more Train Masters to the roster numbered 4802-4815. All the units were ordered with steam boilers. 
 

Original plans called for the units to be assigned to the California-Texas pool where they could be used in passenger service if the occasion arose. On August 25, 1954 two units were put in service on the commute trains for a series of tests. The units did what other diesels could not do: they were able to maintain speed and acceleration with the heavy trains. 

After spending time in the Sunset pool pulling merchandise and mail trains, the sixteen Train Masters were assigned to the San Francisco commute pool. The big 2400-horsepower F-M's, along with a small fleet of boiler-equipped GP-9s, became the backbone of the commute fleet. A single Train Master or two GP-9s in multiple could handle the heavy peak trains while a single GP-9 would be assigned to the mid-day and weekend trains. 
 

The End Of Steam

On January 22, 1957 the last steam powered commute train with 4-8-4 No.4430 departed San Francisco as train No.146 for San Jose. At San Jose the locomotive was forwarded to Oakland where it finished out its days in freight service before being vacated on September 24, 1958 at Bayshore and sold for scrap to Luria Brothers in South San Francisco. 

While the official end of steam on commute trains ended decades ago, former SP 2472 can still be seen from time to time on CalTrain specials. Such is the case in this 1996 view of the historic Pacific leading the Garlic Train back to San Fracnisco with a long string of Sumitomo-built bilevels on the drawbar. (Ken Rattenne Photo)
 

The official end of steam on SP took place on October 19, 1958 when 4-8-4 No.4460 pulled an excursion train from Reno to Oakland. While it has been almost 43 years since steam was assigned to commute trains, Golden Gate Railroad Museum's ex-SP 2472 makes occasional appearances on the line.