Part Two

URNING from the subject of

T maintaining elements of the gen

eral roadway, described in October Bulletin, we may consider the maintenance of special facilities:

It is likely that no other facility attracts more attention and interest from the traveler than the signal system. These silent mechanical watchmen- the semaphores - unceasingly and with absolute precision protect the various track conditions where they serve. They are of two typesautomatic and interlocking block signals. The former are actuated by the trains as they pass through the protected section of track known as the "block." When the train enters the "block" an electric circuit is made through the rails and the semaphore arm raises to indicate that the track is occupied; when the train leaves the block the circuit is broken and the arm drops. Thirty-five hundred miles are protected by this type of signal. The interlocking type is controlled by the operator of an interlocking plant. These interlocking plants have the additional function of handling switches and crossings of complicated track conditions, together with the accompanying signals. The name "interlocking" is derived from the fact that the switches and corresponding signals are all "interlocked" for the clear movement of a train so as to prevent interference of other trains. We have 63 such plants on the System.

The System has 108 freight yards, of which 20 are main terminals, incorporating about 3,000 miles of track. The rapid increase of freight movement, together with the necessity for greater efficiency in car mileage, has required constant improvements in these yard facilities. They were originally built in large open territories which gave unlimited freedom but in subsequent years have become surrounded by industrial plants and city developments and the problem of improving them has become increasingly more difficult. In many cases it requires the greatest ingenuity and study to accomplish the

desired improvement with the limited areas available. During 1923 extensive yard changes were made at Los Angeles, Calexico, Bakersfield, Roseville and Roseburg, with many minor changes in yards over the entire System.

pose.

While dealing with the subject of terminals it is well to mention turning facilities required for locomotives. We operate 99 turntables for this purThese devices occupy a particularly critical point at the heart of engine houses; they are the single unit by which the many radiating tracks can be reached; their failure to function seriously ties up the terminal operation. With the rapid increase in length and weight of locomotives, it has been necessary to increase the proportions of turntables from the old 50-foot wooden type to those of steel, some of which now are 100 feet long. The replacement of a turntable must be accomplished as expeditiously as possible for the reasons cited above. In former years this commonly took a full day, but by careful development of practice this has been greatly reduced. A remarkable record was established by the Portland Division on April 15th of this year, when they replaced a 70-foot by a 100-foot turntable at Roseburg in one hour and forty-six minutes.

Importance of Sidings

Passing sidings perform a most important function in the operation of single-track railroad with traffic moving in both directions. Placed at proper intervals, according to the frequency of train movements, they virtually

create a facility equal to that of double track, and save the cost of constructing and maintaining long sections of what in reality would be unnecessary second track. Double-track is built gradually wherever single-track proves inadequate, but until this is necessary the passing siding serves all requirements. When these units were originally built, they were made to accommodate the longest trains in operation at the time. The increase in length of trains has been approximately in proportion to locomotive tractive effort or pulling power. For the old locomotives of the '60's this was about 15,000 pounds; today it is as much as 86,000 pounds or about 6 times as great.

In the course of 60 years fuel has been issued successively by the cord. ton and gallon. Each facility required for these fuels has been built, developed and then replaced by an entirely different type; coal could not be handled as wood, nor oil as coal. The result of adopting new fuels has caused much new construction because of the great number of units involved.

Oil facilities have undergone marked improvement. Those originally built consisted of elevated tanks to which the oil was pumped and from which it flowed by gravity to distribution points. All the oil was under constant gravity pressure and might escape if breaks occurred in connecting lines. Our latest plants eliminate the elevated tanks; the service tanks are depressed below ground and have no outlet through which the oil can flow by gravity. Instead, it is delivered to distribution points by means of auto

matic pumps which begin to operate the moment the outlet valves are opened. In other words, the delivery force is that of the pumps which can be immediately controlled instead of gravity.

Today we issue oil at 107 fuel stations which include 164 storage and service tanks, having a total capacity of 80,000,000 gallons. In the heavy season of 1923, about 2,000,000 gallons were used per day for all purposes. The water problem is one of our greatest,

for good quality is necessary, and every possible source must be utilized to secure the great quantities required. The West Oakland Yard alone uses as much as 1,500,000 gallons per day. In the heavy season of 1923, mentioned above, we issued about 24,000,000 gallons per day on the System.

In the development of steam power, about twelve times as much water is required as oil. Since the average locomotive tenders can only carry about three times as much water as oil, and with the required ratio of 12 to 1, it follows that they must be supplied with water four times as often as oil. This is reflected by the fact that we operate 408 water stations as compared to the 107 for oil. We have progressed from the old style facility of wayside points in which the water was perhaps syphoned from an adjacent stream, ог run from a tank through a log with a hole bored through its center, or in a "V" shaped wooden trough-to the modern facility with an elevated steel tank holding thousands of gallons and connected by an ample pipe line to a modern water column.

The Central Pacific Railroad of 1865 had twelve tunnels under construction with proposed aggregate length of about 5,600 feet. Today we have 153 with a total length of 155,000 feet, or an average of 1,000 feet each.

In the course of time the number of tunnels has varied because of changes in the location of the road; in some cases it has been considered advisable to add them and in others to abandon them. For example-recent

line changes have caused the construction of tunnels at Elk Rock on the Portland Division, and at Rocky Point on the Coast Division, and have caused the abandonment of two tunnels between Marcel and Cable on the San Joaquin Division, of one between Wickes and Floriston and one near Emigrant Gap on the Sacramento Division. As a point of interest it may be added that the new double tracking work over the Sierra which is being done by the Engineering Department will include 8 new tunnels and 21 will be included in the Natron Cut-off.

Tunnel Maintenance

Tunnel maintenance is accomplished with considerable difficulty for the reason that it must be carried on without interruption to traffic, and in a very limited working space. About 68 per cent of our total tunnel length is lined with timber, which must be renewed periodically.

Tunnels are particularly important elements if anything occurs to block them the line is usually effectively cut and traffic tied up. Our line over the Tehachapi Mountains is the only southern outlet from the San Joaquin Valley. It is a particularly difficult piece of road and is used jointly with the Santa Fe. In order to protect it from interruption of traffic, all the original timber linings of tunnels from Ilmon to Cable have been replaced with reinforced concrete. Similar work is carried on elsewhere whenever required. In a short time we shall finish enlarging and relining the San Fernando

tunnel-6975 feet long-the second longest of the System.

This relining with concrete is accomplished by means of some novel special practices, all arranged so that the entire project can be carried out without interruption of traffic. The forms and reinforcing bars are prepared for a short section, so that the concrete for the section can be completely poured during a working day. A concrete mixing plant is set up near one of the tunnel portals and the concrete delivered pneumatically through a pipe to the working point. This pipe is laid along one of the side ditches and occupies but little space. When it reaches the point where concrete is to be poured it is directed into the various parts of the forms, and readily forces the material into small difficult places where other methods would be ineffective and slow.

One of the great obstacles in the building of the original line over the Sierra was the winter snow. It played an important part in the selection of the route, the effort being made to choose a location where this element would be minimized. Many people seriously believed that operation would be impossible during the winter. The problem was-and still is a serious one, but continuous traffic has been accomplished through valiant efforts of snow plows and the construction of snow sheds. These latter are all of timber and now total 29 miles in length. When the Central Pacific Railroad started out from Sacramento it was necessary, within the first few miles. to build over the American River one