Worcester Consolidated Street Railway Company's New In two ways the new power-plant of the Worcester Consolidated Street Railway Company is notable in size and in efficiency. The power-station is situated on Providence Street, Millbury, and is in effect a new plant, although the equipment of two 300-h. p. reciprocating engines and direct-connected generators previously located at this point is incorporated in it. The building was formed by using the power-station previously located at this point and making extensive additions and alterations. The materials used were largely brick and concrete and the work of construction was done by the Geo. W. Carr Co. of this city. An addition was made to the boiler-house, measuring 100 feet in length, 15 feet 6 inches in width and 40 feet in height with monitor roof. An ash tunnel 145 feet long, 13 feet 6 inches wide inside and 10 feet deep was constructed of reinforced cement concrete and thoroughly waterproofed. This terminates in an ash pit 10 feet by 16 feet inside and 25 feet deep, constructed in the same manner. Other additions consisted of a pumproom of brick and concrete, 18 by 54 feet and 24 feet high, and a coal conveyor house 33 by 20 feet and 24 feet high: A coal trestle was built of hard pine timber. Its length is 350 feet, including a bridge over the Blackstone River. There was also constructed of cement concrete a turbine engine foundation, foundation for the stack, foundations for boilers, bridge abutments for coal trestle, a discharge tunnel for turbine room, a smoke flue leading from boilers to stack, hot well and reinforced concrete floors of various thicknesses and areas. The concrete work called for approximately 2500 cubic yards of material. Incidental to the above construction various brick and con crete walls and foundations were razed and in some cases dynamited. All the excavation three feet below the natural grade consisted of a most difficult material to move, namely, large boulders nested in coarse gravel, with constant flowage from springs and siltage from river, three steam pumps being used night and day during the whole time operations were carried on. While only one new unit, as hereafter described, is now in place, the plans are so drawn that four more may be added as the need arises. 5500 K. W. GENERATING UNIT AT MILLBURY When one enters the building the first object that meets the eye is the big generator just installed. This is a General Electric 5500 k.w. horizontal Curtis turbine generator, which furnishes current at an energy of 13,200 volts. This is the largest horizontal turbine yet constructed by the General Electric Company, and is the first, or more correctly the only, one of this type it has built. This turbine has seven stages, each stage having two sets of revolving buckets and a single set of intermediates or stationary buckets. Steam is admitted through a strainer to the combined emergency and throttle valve, thence to the steam chest, where it is admitted to the first-stage nozzles through hydraulically operated controlling valves, there being ten valves, with one nozzle to each. From the nozzles the steam passes through the first row of revolving buckets, through the intermediates and then through the second row of revolving buckets on the first stage wheel, and in the same manner through the nozzles and buckets of the succeeding stages and finally to the exhaust. By the time the steam has reached the exhaust. the pressure has decreased from 200 pounds to a vacuum of 29 inches. The stages are separated by diaphragms, which are not bolted rigidly, but are fitted against the ledges of the casing. The difference in pressure on the two sides of the diaphragm maintains a steam-tight joint. Studs which are screwed into the diaphragms and have a sliding fit in the recesses of the casing are employed for centering. The operating governor is of the centrifugal type, mounted on the upper end of the vertical shaft which drives the gear-pump for force-feed lubrication. This governor operates a pilot-valve, which controls the hydraulically operated valves. An emergency stop is carried on the main shaft which will trip the throttle-valve and shut the machine down if through accident the speed exceeds ten per cent. over the normal. In the operation of a turbine there is no device upon which so much depends, since any steam turbine can accelerate at a very rapid rate and such increase of speed may not be easily perceptible. This unit is self-contained, not even requiring external pumps for lubrication. Oil is kept in circulation from an oil tank cast in the base of the turbine, and the oil is supplied to the bearings at a pressure approximating fifteen pounds to the square inch. The bearings are cooled by water circulating in copper coils imbedded in the babbitt. One of the most striking features of this interesting machine is the great steadiness with which it runs. The almost absolute lack of vibration is so noticeable that the writer, standing upon the top of the machine, found it difficult to believe that within a few inches of his feet were revolving members weighing twentyfive tons and turning at the rate of 1500 revolutions per minute. The condensing outfit is a Worthington surface condenser with a cooling surface of 10,000 square feet, located in an opening immediately under the turbine, connection being made by a copper expansion joint. This condenser is supplied with water by gravity, the water flowing away through a concrete flume into the stream below the power-house. BOILER INSTALLATION AT MILLBURY The generator is of the standard type, three-phase alternating current, made by the General Electric Co., and is direct connected. Excitation is furnished for the alternator by a 75 k.w. Curtis turbine generator made by the same company. The ventilation of the generator is secured by means of fans in the revolving field. Air is taken from outside through concrete ducts in the foundation and is discharged into the building. This is an important point, as the limit of load which it is safe to carry in any electrical generator is determined by the temperature which it will attain when carrying this load. The properties of insulation are impaired by extreme temperatures, and in all electrical apparatus there are losses to be dissipated in the form of heat. The more efficiently and quickly this heat is carried away, the greater will be the load at which any apparatus may be operated without danger of injury to the insulation. The main switch is electrically operated by a push-button, and on a platform back of the switchboard are installed the latest devices in the way of choke-coils and lightning arresters. When one passes into the boiler-room his attention is immediately arrested by the hugeness of the boilers. The present installation consists of four Edgemoor horizontal water-tube boilers of 820 h.p. each, set singly. These are said to be the largest boilers of this type ever installed in New England. These boilers are of the four-pass type and because of the excellence of this type no economizers are used. Ample provision is made. however, for the installation of economizers on top of the concrete flue should it be found necessary at any time to use them. This concrete flue, lined with fire-brick, connects the boilers with a Kellogg patent sectional brickstack 225 feet high and having an internal diameter of 12 feet. Steam is supplied to the turbine at 200 pounds pressure, and its temperature is raised 150 to 200 degrees by means of Foster super heaters. Extra heavy steam pipe is used, with Van Stone joints, and all steam mains are trapped by the Holley system. Steel valves are used throughout. The plant is equipped with double lines of pipe for boiler feed. Wheeler feed-water heaters, of the closed upper coil type, are installed, and the water is pumped to the boilers by two heavy-duty Wheeler pumps. Heat for these boilers is furnished by Murphy automatic smokeless furnaces, which are fed automatically from bins of twenty tons capacity on top of the furnaces. How the terrible toil of the human stoker of other days has been eliminated by modern invention is well illustrated here, and the system of handling coal and ashes is an interesting story in itself. From the time the coal comes to the plant in the car until in the form of ashes it is hauled away on another car, it is touched by no human hand. A siding 1500 feet long has been built to connect with the New York, New Haven & Hartford Railroad, and an electric locomotive hauls the cars over this stretch of track to the elevated trestle which adjoins the power-house. Here the coal, either from the car or from piles, as the case may be, is gathered up, a ton and a half or two tons at a time, in the capacious maw of the bucket of a traveling locomotive-crane and dumped into the upper hopper of a crusher which has a capacity of 125 tons. SWITCHBOARD AND ROTARY CONVERTERS The transmission line is carried, at a height of 45 to 68 feet, over the right of way of the N. Y., N. H. & H. R. R. to a sub-station in Worcester, a distance of six and one-half miles. On the tangents this line is carried on steel "A" frames firmly imbedded in concrete foundations, but on the curves and corners this form of support is replaced by square steel towers. The transmission line is formed by two three-phase lines of No. O stranded wire. The line is built to carry a voltage of 33,000 and the cables are tested to the same potential. After it enters the city the transmission line leaves the right of way of the railroad and enters a brick lightning arrester tower located on Madison Street. Here are installed choke-coils, dis ONE OF THE BANKS OF TRANSFORMERS From the lower hopper of the crusher the coal descends into a Larry car, which runs on tracks over the tops of the furnaces and dumps the coal wherever needed. A rotating grate clears the furnace of ashes and clinkers, which descend into a car that runs in a concrete tunnel under the furnaces. This car deposits the ashes in a receiving pit outside the building, whence it is taken up by the bucket of the locomotive-crane and deposited in cars on the trestle. The total storage capacity for coal is 20.000 tons. The present building will be extended when another unit is installed and an addition duplicating the present building will afford room for three more. The side wall of the building is of temporary nature with this plan in view, and when the plans are completely carried out there will be one building skilfully planned, with equipment to furnish 20,000 k.w. of electric energy, enough to transport the public of Worcester for many years to come, even though the present rapid growth of this live community does promise to exceed the compass of the plans and estimates of the majority of this generation. HIGH TENSION OIL SWITCHES connecting switches and lightning arresters of the latest General Electric models. From this tower the wires pass through underground ducts across Madison Street to a substation. This building is triangular in form, with the apex toward Southbridge Street, with frontages on Beacon and Madison streets. This building is fireproof throughout; the skeleton is of steel, the walls of brick, the interior of brick and concrete and the window sash of steel. No wood was used anywhere in the construction. The building was designed by Frost, Briggs & Chamberlain, and built by the J. W. Bishop Co., both of this city. The length of the building, said to be the largest sub-station in New England, is 144 feet, the width 35 feet and the height 60 feet. There are two floors and a basement. The first floor is 27 feet high and the second floor 26 feet. This gives room for an equipment of electric cranes, a twenty-ton Maris crane in the first story and a ten-ton of the same make in the second story. The wires from the lightning arrester tower enter the basement and in the form of insulated cables encased in lead covering are carried to the top of the building, where they are attached to the bus-bars shown in the illustration of the oil-switches. There are four of these oil-switches with remote control, operated from the switchboard beside the rotary converters on the first floor. A separate room on the second floor contains the transformers. These are arranged in banks of three located over a large concrete duct. Each bank serves a rotary converter and is connected to a motor-driven blower which draws air from the duct below and drives it through the transformers to cool them. These have each a capacity of 550 k.w. and change the voltage from 13,200 to 430, the potential at which it operates the rotary converters. Two of these rotary converters are located on the first floor, as shown in the illustration herewith. They are each 1500 k.w. capacity, and the building is planned to allow for the addition of three more with the accompanying transformers and oil switches. Beside each converter is a switchboard, technically termed a starting panel. On this panel are the main rotary switch, the reactance switch and the push-button controlling the oil-switch. A constant voltage of 600 is planned to be carried from the busbars. Some conception of the size of the main switchboard can be gained by comparison with the figure of the operator as shown in the illustration. This switchboard has twenty-seven panels: one station instrument panel, two main rotary panels, and a separate panel for each section of the feeder system, the entire city having been redistricted for this purpose. Twelve of these panels are "direct ties;" that is, the wires are connected direct to the busbars and to the Fremont Street power-station, making this substation the centre of distribution, whether the current is being supplied from Fremont Street or Millbury. In the basement directly under the rotaries in large open spaces in the foundations are the negative and equalizer buses. Several CONCRETE TERRACE AND STEPS, BEAVEN-KELLEY HOME, HOLYOKE lines of underground returns enter through the basement walls and are connected to the negative bus. A maze of cables carrying the feed wires from the switchboard to the underground ducts are attached to wire racks, where they are easily accessible. In another portion of the basement is located boiler for heating purposes with a coal-bunker under the sidewalk. a The situation of the sub-station is particularly fortunate, as it is very central for distribution purposes. With the completion of this new power system, a long-standing source of complaint against the company is removed. This most important step in the development of the city's transportation problem is but one feature in the plans of the company's officials to give Worcester adequate and satisfactory car service. George W. Carr Company A reputation for good work, in other words "Worcester excellence," has brought the George W. Carr Co., 518 Main Street, a large increase of business in the last few years. Starting from a small concern laying sidewalks and applying tar and gravel roofs, the business has expanded until to-day all forms of cement concrete work are handled expeditiously and successfully. The company is particularly well-equipped to handle contracts requiring careful construction in cement concrete and, with the skill and knowledge secured by the experience of years, to produce work that will be permanently satisfactory. The head of the company, Herbert C. Wilson, says that the efficiency of the company, as shown by the results obtained on work done under unusual difficulties, such as the recent construction work at the Millbury Power Station of the Worcester Consolidated Street Railway Co., where boulders and the inrush of water due to soil conditions made both excavation and cement construction especially difficult, is due to the loyalty of the men employed. This spirit of loyalty, built up through years of mutually satisfactory dealings, enables the company to obtain prompt response to unusual exactions and demands when the nature of the work makes them necessary. The same skill and care that has enabled them, through their larger contracts, to add their share to Worcester's renown is exercised in the small contracts, of which the company has many. While the greater part of their work is in cement concrete, they enjoy a large patronage in grading and artistic arrangement of private and public grounds, and the improvement of undeveloped property for residential purposes. As an example of the diversity of the demand upon their ability we cite a few of their contracts completed: Grading of cemetery and resetting of monuments at Whitinsville; grading of grounds and construction of walks and drives at Clark University, State Normal School, and the Tatnuck Playgrounds in Worcester, and at the Cluett, Peabody & Co. factory in Leominster; the reconstruction of the freight yards in Leominster for the N. Y., N. H. & H. R. R. Co.; excavation and foundation for new school building of Our Lady of the Holy Rosary Parish in Clinton; excavation and construction of two collecting wells on the shore of Henshaw Pond in Leicester for the Cherry Valley and Rochdale Water District; excavation and construction of sewage purification plant in Easthampton; construction of lake and dam in Hubbardston for Mr. Horatio Gates; construction of ornamental concrete terraces at Beaven-Kelley Home in Holyoke, ornamental concrete base for monument at Mercy Hospital in Springfield; sanitary floors and pens in cow stable at " Brightside" in Holyoke, at Col. S. E. Winslow's in Leicester, at Mr. H. V. Prentice's in Tatnuck, and Harry Payne Whitney's on Long Island; construction of fireproof dairy building for the late Mr. George Mixter in Hardwick; foundations for power plant, coal pockets and 250,000 square feet of reinforced concrete roof at the Cuyahoga plant, Cleveland, Ohio, of the American Steel & Wire Co. Large recent contracts have been: construction of lightning arrester house and underground feeder system for the Worcester Consolidated St. Ry. Co.; excavation and foundations for transmission line towers from Millbury to Worcester; construction of the Millbury Power Station addition; ash tunnels and pit, coa trestle, bridge abutments, etc.. for the Worcester & Blackstone Valley St. Ry. Company at Millbury; street development work "Lenox " one of the largest contracts of its kind ever let in this section and a large number of fire and acid proof floors in factories and industrial plants throughout New England. at |