Aurora, Elgin & Chicago Railway glass insulators replaced with Locke 307

Some Operative Features of the Aurora, Elgin & Chicago

Railway Co. II.

Power House.

The generating station is at Batavia on the Fox River, which location is practically the electrical center of the 200 miles of track for whose operation is furnishes current.

The principal features of this plant were fully described in the "Review" for August, 1902, but further data on some special points will be of interest.

The operation of the auxiliary apparatus is for the most part by electric motors. The auxiliary units comprise: Two horizontal flywheel type vacuum pumps direct connected to 25-h. p. direct current motors, two vertical triplex feed pumps with 8-in. bore direct connected to 35-h. p. direct current motors, four triplex circulating pumps with 19-in. bore direct connected to 35-h. p. direct current motors and two 10 x 6 x 10-in. duplex steam pumps.

The electrical control of the motors driving the auxiliaries is well arranged. A single panel board mounted on the wall nearby controls each motor. These boards are fitted with a circuit breaker, starting resistance and a main single-pole double-throw knife switch. Current for all these motors is controlled from the auxiliary board. This current supply is taken from the 125-volt exciter bus-bars and led through circuit breakers and line switches to the respective control boards near the motors. Single-pole double-throw line switches are so connected that any individual motor, pump or group of pumps can have its current metered by a recording watt-meter on this board. A set of double-pole single-throw switches is also mounted on the board and used for controlling the current fed to the crane, stokers, elevator, compressors and lighting circuits throughout the power station. The cables from this board to the auxiliary apparatus are rubber covered and sheathed with lead protected by woven jute, so that the flooding of the auxiliary pit up to the level of the motors themselves would in no way impair continued operation.

Wheaton Yards and Shops.

Close by the auxiliary board is a 4-h. p. air compressor set with two storage tanks of 10-cu. ft. capacity. The automatic governor which controls this motor compressor set keeps the pressure on the storage tanks at 40 lb. per square inch. This air is used for forcing the cylinder and journal oil from the stock room to the pumps of the oil feeding system and is also put to other various uses, such as cleaning switchboards, etc.

There are three main generating units each consisting of a 1,500-kw., revolving-field generator and a 32 x 64 x 60-in. Cooper-Corliss compound engine operating at 75 r. p. m. with 175-lb. admission pressure and generating 2,300-volt, 3-phase, 25-cycle alternating current.

Between the two sides of each main engine and facing away from the generator are instrument boards for each generating unit. These boards are made of a single sheet of wrought iron with an angle iron riveted on the edge to furnish the proper stiffness. On each of these boards are mounted compound gages, speed counter, recording vacuum gage, steam pressure gage, pilot lights and an indicating wattmeter showing the rate of output of the generator.

On the lower part of these boards at a convenient height is a steel shelf of ample proportions for holding oil cups, small wrenches and similar tools.

Space and foundations have been provided in the north end of the building for the addition of a fourth unit. This space, at the present time, is being utilized for repairing the high potential transformers, which work the company carries on with its own employes. This space is readily adapted for such use because it is served by the engine room traveling crane which can unload damaged electrical apparatus from the cars running directly into the engine room and easily load and unload all heavy material for transportation between the power station and sub-stations.

In the center of the engine room floor and between two of the generating units are the exciter units and a 500-kw., 600-volt rotary converter which was installed last fall and is used for feeding the railway circuits near the power house. In ordinary operation exciting current for the main units and auxiliary uses is furnished by a motor generator set, consisting of a 450-h. p., 2,300-volt induction motor, connected to a 300-kw., 125-volt direct current generator.

The west side of the building throughout its entire length and fora width of about 20 ft. is occupied in the basement by the bus-bar compartments, oil room and a workmen's room with bath, toilet and lockers; on the engine room floor by the chief engineer's office, the step-up transformers, blower motors, work shop and store room for the electrician; two galleries at the ends of this side of the building and above the latter named parts are utilized, one for visitors, the other for the main switchboard which controls the output of the station.

The method used in interconnecting a generating unit and its step-up transformers and motor operated oil switch with the high potential bus-bars is simple. All the current from the main generators is switched on the high potential side of the raising trans-formers. The bus-bar compartment is kept under 8-oz. air pressure. Its length is 150 ft. along the west side of the basement and no inflammable materials of any sort are to be found in it.

Wheaton Machine Shop.

The path of the current from generator to line is as follows: From the generator the 2,300-volt current is carried to the bus-bar compartment by three asbestos covered cables. Immediately below the three step-up transformers, which stand on the engine room floor and over openings in the ceiling of the bus-bar compartment, are the primary connections for the transformers. On the 26,400-volt secondary side of the transformers, the wires are all bare copper mounted on standard line insulators supported by a grounded steel rack. These leads, after passing through current transformers and choke coils, again pass up through the ceiling and through the double sets of contacts of the Type H, motor-operated oil switch. From the opposite side of the switch the high potential bare wires drop directly to the three main bus wires. These three bus wires are of hard drawn copper and extend horizontally in brick and concrete three tier cells throughout the length of the bus-bar compartment. This same scheme is used for connecting all three generating units to the bus wires and these wires are sectionalized by single-pole line switches mounted on glass bases inside the fireproof compartments. The bus wires are carried on standard line insulators held up by steel pins bedded in the concrete which forms the bus wire cells and each wire is kept under tension by heavy springs at its ends "dead ended" to porcelain strain insulators mounted on rods also bedded in concrete. These bus wire compartments stand about 4 ft. from the west foundation wall of the building and suitable openings are provided in this side of the compartments for making taps from the buses to line switches standing on the floor above and operated by electrical motors and a system of remote control with operating buttons in the switch-board gallery the same as the switches in the generator circuits between the step-up transformers and the bus wires. From the lower side of these line switches the high potential wires enter stone and brick chimneys built as a part of the west wall of the power station and rise vertically to a point near the eaves of the building. The tops of these chimneys are covered with a 5-in. slab of concrete and the wires pass vertically through three 6-in. holes in this slab and vertically through standard glass line insulators set over the openings in the concrete. It was necessary to drillholes through the tops of these insulators and thus string them on these wires so that they would cover the 6-in. holes in the concrete and not permit the passage of air under pressure from the bus wire chimneys to the exterior. The weight of these vertically hanging wires is sustained by standard insulators so that at all times the wires hang clear in their respective chimneys.

From the lightning arrester banks at the tops of the chimneys the line wires are led through openings in the wall of the building and out to line insulators mounted on a steel rack on the outside wall of the building. At this point the copper conductor used in the interior wiring connects with the standard aluminum feeder used throughout the distribution system. Opposite this exit of the wires and across the track parallel with the west side of the building is a strain structure which cares for all tension in the dead ending of the distribution circuits as they enter the building.

The average monthly output of this station is 1,600,000 kw. hours.

Sub-Stations.

Power from the generating station is distributed on three-phase high potential lines to six sub-stations having a rotary converter capacity of 5,500 kw. General Electric 500-kw. rotary converters are used and the machines are distributed as follows: 1,500-kw. capacity at Maywood, 11 miles from Chicago; 1,000-kw. capacity at Lombard, 20.5 miles from Chicago, these two installations are on the Wheaton-Chicago double-track branch; 1,000-kw. capacity at Clintonville, 2.7 miles from Elgin, and 500-kw. capacity at Ingalton, 11.1 miles from Elgin, on the Wheaton-Elgin single-track branch; 1,000-kw. capacity at Aurora sub-station, 1.5 miles from Aurora and 500-kw. capacity at Warrenville 9.1 miles from Aurora on the Wheaton-Aurora single-track branch; 500-kw. capacity at the power house. The six sub-stations in this distribution system supply 600-volt direct current for 200 miles of electric railway track, made up of the Aurora, Elgin & Chicago third-rail line, the Elgin city line, the Elgin, Aurora & Southern Traction Co's, line which extends along the Fox River for a distance of 40 miles and connects Elgin with Aurora, the Aurora city lines and one half of the track between Aurora and Joliet on the line of the Joliet, Plainfield & Aurora Railroad Co.

No changes have been needed in any of the sub-station buildings and the operation of the apparatus, even though at times under severe overload has occasioned but the ordinary amount of trouble. The changes in the general plan and the extra demand for direct current at certain portions of the distribution system have made it necessary to move some of the rotaries from their original sub-stations, but as all sub-stations were built with foundations for extra machinery little trouble was occasioned by these changes. The output of the 11 rotaries for the first three months of the present year was as follows: January, 1,398,900 kw. hrs.; February, 1,328,000 kw. hrs.; March, 1,170,000 kw. hr.

As originally placed, the storage battery used for operating the oil switches in each sub-station was located on the main floor, in a wooden case with glass doors, near the rotary and switchboard. This arrangement proved unsatisfactory on account of the spilling of acids and the escape of fumes. A portion of the basement under the ticket office is now used as a battery room. All the walls are of concrete and brick and outside ventilation is provided so that no trouble is anticipated from acids.

All sub-station rotaries have been equipped with a speed limiting device which is placed on one end of the shaft and so constructed that when the armature, in event of failure in the alternating current supply, exceeds a set speed, the direct current supply is cutoff from the rotary and running away prevented.

A blank is used for recording the daily performance of the sub-station machinery. The original size of these sheets, which are perforated for loose leaf binding, is 8½ x 14 in. Each sheet is a complete record for the operation of a single sub-station during a period of 24 hours, and as a similar record is used for the generating machinery, any error in the recording instruments or their reading can be readily noticed and adjusted while yet fresh in the memory. The daily consultation of these records also furnishes assurance against continued heavy undiscovered feeder or third-rail leakage.

Distribution System.

The three-phase 26,400-volt wires which distribute current to these six sub-stations were furnished by the Pittsburg Reduction Co. They leave the power house as three separate lines, one extending cross-country to the Ingalton sub-station and on along the track to the Clintonville sub-station, one along the track to the Warrenville sub-station and then on to the Lombard sub-station, and still farther on to the Maywood sub-station, one cross country to the Aurora sub-station. A standard line also connects the Ingalton and Lombard sub-stations, thus forming a loop from the power house through Ingalton, Lombard, Warrenville and back to the power house, assuring the continued feeding of sub-stations even though one branch of the high potential line be down. The high potential lines are carried on 40-ft. cedar poles with 7-in. tops. These poles are spaced 80 ft. apart on straight tracks and extra poles are set at all sharp angles in the line. The style of con-struction as originally built had two cross-arms 4½x5½ in. in sec-tion spaced 24 in. apart, the top arm being 30 in. below the top of the pole. This gave room for two three-phase lines with three insulators on either side of the pole and holding the wires at the corners of an equilateral triangle 30 in. on a side. Glass insulators 7 in. in diameter and 4½ in. high were used in the original construction. These were mounted on a combination wrought iron and wooden pin which held the wire 9 in. above the cross-arms. During the first months of operation many breakdowns occurred throughout the entire high tension system, due principally to the puncturing and breaking of the glasses. The display on these occurrences especially at night was at times startling and many freaks of burning took place. In some cases a small hole was pierced through the seat in the top of the insulator, the current passing through the wrought iron insulator bolt and into the cross-arm. No effect could be noticed at the top of the pole except a small glow, perhaps a half inch in diameter at the point where the aluminum wire rested on the top of the insulator, but a serious effect often took place near the base of the pole or wherever there was a crack or deep knot hole in the wood. At such places the poles would first begin to burn, the flame coming forth from the knot holes very much the same as the blaze of a gasoline blow torch and accompanied by the same roaring sound. In some cases the poles burned in this manner until they toppled over when the short circuiting or breaking of the high potential wires first gave notice of any disorder on the line. It was also noticed that many poles first began to burn at those points where bolts or lag screws broke the dry outside surface of the wood, the leakage in some places being heavy enough to melt the galvanizing from the bolts. When these breakdowns began, the disorders appeared so often that no opportunity was given for resetting the burned poles, so a pole which had had its top burned beyond usefulness would be chopped down and the wires allowed to hang free for a double length span. These interruptions necessitated a change in the pole top arrangement which was soon made.

The top wire which formerly was supported on one side of the pole on the upper cross-arm was moved to a new position at the top of the pole, using a wrought iron pole pin fastened with one through bolt and one lag bolt. The pole wire on the lower cross-arm was moved to the extreme end of this cross-arm but on the opposite side of the pole. This makes an isosceles triangle with abase of 90 in. between the two wires on the lower cross-arm, and sides 70 in. between the upper wire and the lower ones. The lines were thus rearranged throughout the entire system except between Wheaton and Lombard where it is necessary to carry a double line of three-phase feeders in order to preserve the loop system of feeding. The glass insulators have been replaced by Locke porcelain insulators, No. 307. This type is a three-piece cemented and glazed porcelain insulator with a diameter of 7 3/8 in. and a height of 6 3/8 in. Since thus reconstructing the line but little trouble has occured [sic] occurred and this has been caused by lightning. There are in all 67 miles of high potential three-phase pole lines.

Power for the third-rail line is fed to the rail at seven points on the system; power for the Elgin city lines is taken from the third-rail at several appropriate points in the city of Elgin. At the southern limits of the city feeders are led from the third-rail across the Fox River to supply power for the trolley line between Elgin and Aurora. This feeding point is about one mile from the Clintonville sub-station. At Batavia the Fox River line is also fed from the third-rail. The tap is made just outside at the generating station and current is carried across the river by two sets of four feeders each, one set feeding north, the other set south. A third set of feeders taking current from the third-rail near the Aurora sub-station also extends across the Fox River and feeds the south end of the Fox River line at a point near the north city limits of Aurora. Current for the Aurora city lines is carried to a distributing station near the center of the city, part way by the third-rail, and part by overhead cables. A separate set of cables has been installed from a meter on the switchboard in the Aurora substation to a connecting point with the feeding system of the Joliet, Plainfield & Aurora line about a mile distant.

There are in all 81 miles of third-rail which is used throughout the entire system except for a short distance in the city of Aurora. The third-rail itself has caused no trouble during operation, but the third-rail cables which electrically join the two ends of the third-rail where it is necessary to leave a break for road or other crossings have often broken down their insulation and burned themselves out. In many cases it is thought that this was caused by moisture creeping through the cable head and destroying the insulation.

Wheaton Shops.

The repair shops for the entire road is centrally located on a large piece of ground about one-half mile west of the Wheaton station and at that point where the double tracks from Chicago to Wheaton separate, one going southwest to Aurora, the other running northwest to Elgin. This location is about the geographical center of the system. The accompanying illustration of the track outlay in the yards clearly shows the great flexibility for shifting cars from any one of the main lines to the different storage tracks or bays of the repair shop.

Track Layout, Wheaton Yards .

The repair shop building has one main bay with three tracks and two adjacent bays with two tracks each. The front of the building faces east. The construction throughout is fireproof with no inflammable material in its details except the planking in a small portion of the floors. The walls are of brick and the roof is of corrugated sheet iron, supported on steel trusses and lattice girders. Rolling steel doors, seven at each end of the building, close the openings over all tracks.

The north bay has two tracks extending through the building. This room is used for washing and cleaning cars. The floor is of brick with suitable drainage to rapidly carry away the wash water. For one-half the length of the bay the brick floor is on a level with the top of the rails, the other half of the floor is depressed to a level about 16 in. below the rails and added height is thus furnished for more easily inspecting and making slight repairs to the trucks and apparatus under the sides of the cars. Pits are built under the two tracks throughout this half of the bay. These pits are built of brick laid in cement and are provided with iron steps at each end, thus making the entire construction fireproof. Along the walls of this bay and at a height of about 5 ft. from the floor extend water and compressed air mains. Frequent taps with suitable valves are provided along the mains so that every facility is offered for lessening the amount of labor necessary for cleaning and washing cars. This north bay has track room for eight standard cars and is separated from the main bay by a fireproof wall with but one connecting door.

The center or main bay is occupied by the machine tools and general motor and truck repair appliances. The middle one of the three tracks in this bay extends throughout the length of the building and the two parallel tracks at each end extend but one-third of the distance from the ends of the building towards the center. The entire bay is spanned by a Whiting Foundry Equipment Co. 20,000-lb. capacity electrically operated crane. For one-third of the length of the building from either end, pits are provided under all tracks, being similar in design to the cleaning-room pits earlier described, and the floor between the pits is depressed. The middle portion of the bay is planked over and arranged as the machine shop for doing all repair work. Installed upon this floor are two Reed lathes, one wheel turning lathe, one hydraulic wheel press, two emery wheels, one drill press, bolt cutter, blower fan and power hack saw. These tools are belted to two lines of shafting held on brackets along the two walls of the bay. Each line of shafting is driven by a motor.

Control Board for Auxiliaries.

The south bay of the building is of the same general dimensions as the north bay and is also separated from the center bay by a fire wall. Brick partitions divide this south bay into five separate rooms. The west one of these rooms is used as a paint shop. It is lighted by a row of windows on the south side and has no doors opening into other parts of the building. This room has two tracks, each long enough to hold one car and the floor throughout the whole room is planked on a level with the tops of the rails. At one end of this paint room the space has been arranged for varnishing doors and windows and the entire end wall of the room is fitted with a rack for storing the extra windows and doors.

Another portion of the south bay has been equipped with tools for forging and blacksmith work. In this room is the horizontal fire-tube boiler which furnishes steam for heating the entire repair shops. The blacksmith shop is connected to the machine shop by a large double door so that heavy work can be brought by the overhead crane and placed close to the anvil.

Another portion of the south bay is set apart for armature re-winding and the repair of all small electrical parts, such as arc head lights, heaters, etc. Adjacent to this room is the office of the master mechanic, and a store room for all the small supplies used in his department.

The east end of the south bay is the carpenter shop. This room has two tracks, each of sufficient length for one car and an added space at the end of the tracks is fitted with carpenter's benches, a grindstone and band saw. A single door connects the carpenter shop with the machine shop.

The general arrangement of this shop with its tracks extending throughout the building, having their end openings fitted with steel doors, and the placing of the numerous smaller shops along the sides and connecting with the central bay, furnishes an economical and compact arrangement for the handling of the repair work on the company's cars, which need very careful watching and timely repairing on account of the exceptionally severe service to which they are subjected.