Western Trips

Western Trips

Monday, February 20, 2012

Rail Roads / Electric Interurban Railways

Today's commuter to and from San Francisco from the East Bay communities rides on a modern system called BART. The Bay Area Rapid Transit uses electric power from a third rail. No overhead wires. It's fast, sleek and travels to San Francisco and back within tubes put under San Francisco Bay. In the earlier years of the 1900's, getting around the Bay Area was a bit more complicated. The building of the massive San Francisco-Oakland Bay Bridge in the 1930's changed all that. Before getting into the story of how the interurbans built and operated their electric trains across the San Francisco Oakland Bay Bridge, I should point out that there are many excellent museums to visit in the area where you can learn much more about the subject. The history of the railways also includes the successful operation if urban electric trains. These were not the great steam locomotives but electric street cars.

Restored 1900's streetcar
If you have the opportunity to visit or vacation in the San Francisco area, the the Western Railway Museum located on Hwy 12 between Fairfield and Rio Vista California is a must see. The location is about an hours drive northeast of Oakland. Another is the San Francisco Railway Museum which is located near he south end of the Ferry Building. If your California vacation or weekend trip takes you to Sacramento, then a stop at the California State Railroad Museum is time well spent.The Museum is located at the corner of Second and "I" Streets in Old Sacramento. You will also be interested in the story of the Texas Electric Railroad which explains the power conversion needed to provide DC current. Also the unique story of the how cities grew from horsepower to electric power.

san francisco streetcar
San Francisco Streetcar (author's collection)
The San Francisco Bay area is geographically unique. Boats and bridges were and are quite necessary. Before the San Francisco Bay Bridge was constructed in 1936, ferry boats were the way to travel into the city. The ferry business on the bay was booming. Within the communities in the East Bay area as well as in San Francisco proper people used streetcars. These were simply electric street cars. As part of the history of railways, the consolidation of the electric street car linesiturned them into interurban rail lines. When the Oakland Bay Bridge (this name is also used) was built an entirely new method of trans-bay transportation would begin and the electric trains were a big part of it.

The three years of San Francisco Bay bridge construction started in 1933 and cost $77 million dollars to build. Prior to the bridge's completion there had been electric interurban railroads on both sides of the bay. With the bridge completed in 1936, it was time to connect the east bay with the city of San Francisco with a rail track directly across the bridge. A new page in history was in store for the Bay Area electric trains.

Actually, the early designers of the bridge specifically made space along the south side of the lower deck for two tracks. It was a given that the bridge would handle electric train traffic. The rail facilities for the bridge line was financed with $15 million of bonds through the Reconstruction Finance Corporation. This line was put under the direction of the California Toll Bridge Authority. The line extended just under seven miles from the east side of San Francisco Bay to a terminal in San Francisco.

oakland bay bridge construction
Oakland Bay Bridge under construction
It was evident that construction of this line over the bay would have to be flexible. The reason was that the electric railroads that ran in the area used different voltages. There was not one standard voltage. The Interurban Electric ( a subsidiary of the Southern Pacific Railroad ) which ran in the east bay communities was using 1,200 volts whereas the Key System, was a consolidation of several smaller streetcar lines assembled in the late 1890s and early 1900s line and was using 600 volts. A third system operating, the Sacramento Northern,whose lines spanned all the way from Oakland through Sacramento and up to Chico California, used three voltages, 600, 1,200 and 1,500. It should be noted that over the previous years there was a good deal of consolidation of various interurban lines and some ownership changes. The Key System went through many changes with various names used but the line was mostly referred to as the Key System, even after some reorganizations.

When construction started on the tracks, which was after the roadway sections were completed, it was evident that a multi-voltage system would have to be installed. How to deliver different voltages on the bridge was the question.  Several options were outlined and studied. Some consisted of multi-voltage overhead lines plus a third rail. In other words, overhead lines that would be delivering different voltages to different railways. Quite complicated and expensive to build and operate. The option chosen was a combination third rail with an overhead line to deliver one voltage. The third rail was to deliver 600 volts and the overhead wire 1,200  This option was the less costly and also made it easier to bill each rail line for the power used..

The next step in planning was to devise a routing system for all three lines which would bring them together into the bridge yards. The Sacramento Northern cars were using the Key System tracks making that part much easier. The Interurban Electric was eventually rerouted to a curving elevated track going over the Southern Pacific mainline tracks and joining existing tracks in Emeryville.

san francisco oakland bay bridge
San Francisco-Oakland Bay Bridge
Before the cross bay system got up and running there was a control system put in place which told the engineer his maximum allowed speed. All three electric rail systems operating over the bridge had these systems installed in their cars. The control system was essentially a signal panel with illuminated numerals which gave out the maximum allowed speed for each section of rails. To guard against over speeding the control panel had an "NS" on it's lower part with a white light below it that went on when the train was operating at maximum or beyond the maximum  allowed speed. There was also a low pitched warning whistle that would go off on the GE manufactured control systems if the maximum speed was exceeded. The cars with a Westinghouse made control system would hear a bell. Keeping the rail cars at a safe speed was obviously very important. Failure of the engineer to slow down when necessary resulted in having an emergency brake applied.

As far as the history of railways is concerned, the entire control system was, for the era, was fairly advanced in design. Sensors were placed on the rails at various intervals. The sensors were able to detect passing trains and send coded information to receivers on the train cars. The train receivers just transferred the information into the control panel of each train. The control panel then adjusted speed limits.

Another interesting and very necessary item was the "train describer". This feature of the control system identified every destination for every train. When a train left the San Francisco station for, example, it's destination would be sent to the Bridge Yard Interlocking Tower. The operator in the tower would then know how much time would elapse before the train entered the interlocking yard area. The "train describer" would be able to show the destinations of the first three approaching trains as well as the presence of up to seven additional trains behind those. It was very important to know which trains were where at any given time. With this information it was then possible for the tower operator to plan all of their routes accordingly. This was necessary since trains were enroute to many different places after crossing the bridge. The "train describer" was also very helpful at the west end of the San Francisco-Oakland Bay Bridge because the Key System trains had to be separated from the other two lines because it was using a separate terminal lead track. all of this may sound a bit confusing but when three different lines were all crossing the bridge, sorting them all out was absolutely necessary. Very similar to what an air traffic controller does today. As a historical side note, it's interesting to learn that all of the train designations for the Interurban Electric line were in numerals. The Key System trains all were assigned letters and the Sacramento Northern cars were all assigned the letter "N". These identifiers were placed on the left front end of the car on a metal disc.

modern street car
Present day San Francisco streetcar (author's collection)
The standardization of all rail cars traveling over the San Francisco-Oakland Bay Bridge included more than just the signaling equipment. In addition, all cross bay electric train cars had to have special coupling apparatus for the rapid adding and cutting off of cars on the bridge. The standard coupling in use wouldn't be enough. Window wipers were installed on all 86 cars using the bridge as well as the 15 control trailers. Also added to these cars was an emergency lighting system with their own generators.

The San Francisco Terminal building was planned as far back as 1932. The structure selected was a state sponsored plan and was built was facing Mission Street between First and Fremont Streets, The cost was about $2.3 million. The first "official' test run for the bridge crossing was held on September 23, 1938. a group of Southern Pacific and Interurban Electric officials went on a special train from Oakland Pier. They then transferred to a Key System car for the trip across to San Francisco. The Key System car was used in this instance because at that time the power system that was energized was only at 600 volts of overhead power. This was about the only time that the Key System ran over the bridge with it's pantograph raised for power. Several more test trips over the bridge occurred over the next several weeks using various configurations with baggage cars, etc. In the middle of January 1939 all testing was completed and the cross bay interurban service was ready to start carrying passengers. As with all new systems, some problems emerged during the first several weeks and months. Some were of a technological nature and others were simply due to the inexperience of some trainmen. As is always the case, the problems were eventually remedied and the new cross bay train route was a great success.

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