The following information is from the San Francisco Trains Organization which has worked to get the Bayshore Roundhouse registered as an historic landmark building:
Bayshore Roundhouse
Built in the early 1900's, Brisbane's brick roundhouse has many stories to tell.
The railroad between San Francisco and San Jose was completed in January 1864, but the northernmost section was not the direct route Caltrain travels today. Instead trains ran over hills west of San Bruno Mountain thru Colma, Daly City and the Mission District. Extra "Helper" engines were required to pull trains to the top of this grade in Daly City. It was common at that time to see as many as three engines pulling a train through the residential neighborhoods of San Francisco's Mission District.
A faster route would be built, but not for forty years. Railroad financier E. H. Harriman acquired control of the Southern Pacific in 1901, and initiated many improvements. By the beginning of the 20th century, San Francisco had grown into vibrant center of industrial production and shipping. Harriman wanted to bypass the troublesome line into San Francisco, and had a new route surveyed to the east of San Bruno Mountain. This new line would travel along the bay, but it would require five tunnels, extensive earthwork, and would ultimately cost a million dollars a mile.
Construction began in 1904, and the route later came to be paralleled for much of its length by U.S. 101. From San Bruno the new line was laid northeast to a tunnel at Sierra Point. From there, it continued north to Visitation Point (by the future town of Brisbane), and then along 2 mile long trestle and fill from Visitacion Point to Candlestick Point. At the foot of Visitacion Valley, wooden pilings supported two sets of tracks along the bay. Four more tunnels, fills and trestles brought the rails north through San Francisco's Bayshore and Potrero Hill districts to the terminal at Third and Townsend streets. Delayed by the Great Earthquake of 1906, the new "Bayshore Cutoff" opened for service on December 8, 1907.
The shoreline of the bay had been where Bayshore Boulevard is now. Debris from the 1906 earthquake and the Visitacion Point cut were used to fill in the marshlands west of the railroad. This reclaimed land was named Bayshore by the railroad, and new facilities, including a large switching yard, were established here to serve the railroad's growing operations on the peninsula.
A brick roundhouse and 90' steel turntable were finished at Bayshore around 1910. They served to stable the steam-powered freight engines used on the peninsula. Locomotives required constant maintenance, and most of this work took place in roundhouses. Engines were serviced, and kept warm in such places between runs. Additional shops were later built to perform heavy maintenance on locomotives, passenger cars, tenders, and all other manner of railroad equipment.
While the Mission Bay Roundhouse in San Francisco handled passenger train engines close to the railroad's South of Market terminal, Bayshore was the point where longer, heavier freight engines were hostled and serviced. A four story high erecting hall was built for heavy repairs, and a transfer table was installed to move equipment between repair bays and the new tender/ and boiler shop across from it. Bayshore's facilities grew to include a massive freight yard, scale tracks, shop and store buildings, and an employee hospital. Also, an icing facility for produce-carrying boxcars was built a mile to the south. Bayshore was a complete industrialized facility and employed hundred of people on a daily basis. Goods and produce shipped worldwide passed through Bayshore, shaping many lives and economies until the decline of freight railroads and the closing of the Bayshore yards in the 1980's.
Diesel engines require considerably less maintenance than steam engines, and steam-facilities such as roundhouses were largely obsolete by the late 1950s with the end of steam. The railroad still continued to use the Bayshore roundhouse for another 25 years, but the facility began to suffer from neglect and age. Completely abandoned in 1982, the Bayshore rails were taken up, and most remaining buildings torn down. The erecting building and car shops were already gone, and the transfer pit was only recognizable by a berm of debris.
Despite these losses, several significant buildings have endured. The tender & tank building survived and is currently used by Lazzari Fuel, makers of seasoned cooking charcoal. The icehouse to the south supports Machinery and Equipment Company of Brisbane, and of course, much of the original roundhouse and turntable pit survives as well. A fire in 2001 took away half the remaining roof of the roundhouse, but the brickwork is mostly intact, the doors that remain hanging at odd angles from their hinges. Yet despite the condition, the city and landowners recognize the significance of the building and its site.
San Francisco Trains is working with the landowner and the Community of Brisbane to develop preservation plans as the redevelopment of Brisbane Baylands begins.
I took the following pics of the roundhouse as it looks these days. Hopefully, the goal of restoring it and making it into a railroad museum will come to fruition some day.
I hope they are able to restore it to its former glory.