Show NORTH MOUNTAIN POWER CO COS S PLANT WRITTEN FOR THE MINING REVIEW among the power transmission systems of the pacific coast that have been constructed ted with an eye to the future rather than the present needs of the communities which they serve one of the most interesting is that of the north Aloun mountain tain power company this plant is located in the central part of trinity county california two miles below the town of junction city where canon creek from which the water used for power is obtained flows into the trinity river weaverville Wea verville the county seat is twelve it required eighteen to twenty animals to pull each of the larger pieces weighing 18 pounds up the grades and when mud was encountered it was necessary to hitch eighteen animals to the fall of a block and tackle fitted with steel cables despite these difficulties however no mishap occurred to any of the machinery watershed the water used at the plant is diverted from canon creek which has a drainage area of fifty two square miles above the di these have been utilized as storage reser doirs part of the watershed is heavily timbered and lies within the boundaries of a government forest reserve this will insure the preservation of the forests which arp are so effective in steadying the runoff run off the average annual rainfall for the last thirty three years at weaverville Wea verville twelve miles from the plant has been inches at the higher levels of the watershed the precipitation is much greater but no re records are available for that region because A 7 i k ud pla f I 1 j 1 ao 4 M ll 11 18 horse team hauling the lower half of stator of K W bullock alternator over 60 miles of mountain road from the nearest Pail railway way station niiles miles distant by road the nearest railroad point is redding on the shasta route of the southern pacific railroad humboldt hay bay on the pacific pacific ocean with eureka the chief coast city of northern california lies almost due west distant fifty nine miles in a straight lines the altitude of the plant is 1400 feet A all ll 11 r material nat erial cement and machinery were hauled in over sixty miles of the severest mountain fountain roads across three distinct divides or summits viz trinity mountain browns mountain and oregon mountain averting dam the upper part of the basin is rugged glaciated granite country extending up to an altitude of from to feet above sea level where some snow remains throughout 1 the year the higher parts of this basin are in the nature of an immense amphitheater lying on a flank of thompson peak which is a characteristic feature of all elevated glaciated topography and as is so often the case the converging and descending glaciers have scooped out immense immen 1 A se holes with almost perpendicular 1 cular sides which now form the beds of two lakes the country is absolutely uninhabited and without even trails except for the one to the above mentioned lakes ditch Sy system stern the dam is small and serves merely for diverting the water it is of the usual rock filled crib form which has been the type used for many years in mining operations on the pacific coast the ditch system consists of alternating sections of ditch flumes blumes and ajie one tunnel part of the di ditch is cut in solid rock but the most of it is dug in the side hill soll soil which stands welland well and puddles well the flumes blumes are nineteen in number and vary in length from thirty to 1200 feet those immediately below the dam are laid upon a solid bedrock bed rock bench and equipped with adequate spill ways waste gates and sand boxes the total benl length th of the flumen flumes is feet A tunnel 1821 feet long has been driven to replace a temporary flume which was unavoidably built upon treacherous sliding ground this tunnel is heavily timbered throughout its entire length and tightly lagged except where the rock is usually hard the dimensions of the main tunnel are four feet nine inches by five feet ten inches in the clear the total length of the ditch flumes blumes and tunnel is seven and one fourth miles the average grade of all is or 3 1 feet per mile the ditch is provided with waste gates and sand boxes at suitable locations phones can be readily connected at any point and as a result any along the ditch can have prompt communication with the power house the forebay is excavated out of the solid rock of 0 the hillside ten feet deep fourteen feet wide and sixty feet long the ditch is provided with a a gate at its entrance to the forebay and the latter contains a gate and grizzley at the intake of each of the two penstocks pen stocks provision has been made for a third penstock when a third unit shall become necessary in the plant suitable trash racks are provided just above the forebay the penstocks Pen stocks the penstocks pen stocks two in number are each 1165 feet long under a total head of feet there is an effective head of feet or working pressure of pounds per square inch there is one complete independent pen stock for each of the two units each con bay walls to allow air to enter when the forebay gat gates es are closed and thus prevent collapse of the pipe they are also provided with air valves and manholes man holes at suitable points buildings the plant proper consists of the power house the transformer house and the high tension switch house in addition there is the shop the operators dwelling and the stable at the forebay is the forebay tenders cabin and at the dam is a house for the tender of the head gates power house each of the two hydraulic units consists of a pair of 44 inch pelton wheels under one sheet steel housing provided with ring oiling self aligning bearings coupled to the generator through flexible leather link couplings the nozzles are of the deflecting type with the largest tips in service the wheels are capable of driving the generators at 25 per cent overload the wheels are controlled by type F 71 NOR WON 1 k I 1 w oil filled water cooled K V A bullock transformers view in power house showing waterwheel Water wheel housings generator etc the capacity of the ditch is eighty cubic feet per second which is sufficient to operate at full load three units uni ts like the two which are now installed near its lower end the ditch passes through a gap in the narrow ridge separating canon creek from trinity river and terminates in a forebay on the river side of the divide thus is secured a head due not only to the fall in canon creek in the seven miles through which the creek and ditch parallel each other but also to the additional fall aall in a further course of two miles to the creeks junction with the trinity river and to the added fall in two miles of the rivers course between the junction and the plant A telephone line extends from tha power house along the entire course of the ditch to the head dam instruments are placed in the station the forebay tenders cabin the he adgate tenders house and at several other points along the line portable tele 0 fists of a line of 36 inch and 28 inch and at the lower end two lines of 18 inch all riveted steel pipe of various gauges according to its position in the line at the Ys or points where the single 28 inch pipe branches into in 0 o two 18 inch lines the penstocks pen stocks are enclosed and anchored in a massive block of masonry laid up with imported portland cement mortar at their lower ends just before entering the power house they are secured by a similar form of construction and at various points they are held by bands and anchor bolts leaded and sulphured into the bedrock throughout their entire length they are laid in trenches and covered by back filling except at their lower ends where the profile of the hill is such that it was best to lay each in a separate tunnel after completing and testing the penstocks pen stocks the tunnels were walled up and backfilled back filled the penstocks pen stocks are each provided with an 18 inch standpipe stand pipe just outside the fore lombard governors using oil the pres pressure sura and vacuum are maintained by oil pumps belt driven from the wheel shafts the governors are not fitted with any form of switchboard speed control but a single operator has no difficulty in synchronizing ron izing a generator under the load conditions which exist in the plant the tail race is six and one half feet wide and excavated for feet through bed rock cock to the trinity river the genera generators two in number are of the bullock type furnished by allis chal mers company of milwaukee being three phase K W R P M 2200 volts 25 cycles rev field 6 pole two bullock exic volts 45 K W R P 11 are driven by belts from the generators the switchboards are of marble and have wagner instruments the power house feet is built of OE concrete made up with sand and gravel taken from the river bars a few rods from I 1 the site 0 of f the plant and with imported portland cement A special bay or alcove has been provided to give ample space behind the switchboard the roof is of corrugated iron supported on steel trusses A cyclops hand operated crane spans tile the main part of the building and is fitted with a triplex block this easily handles the heaviest piece of machinery the leads between the generators ex citers aiters and switchboard are lead covered cables laid in conduits within the concrete and cement floor transformer house the transformer house is and also built of concrete it is fifty feet distant from the power house it contains seven step up transformers viz two banks rails which are imbedded bedded im in the conc concrete kete piers thus any transformer can be quickly rolled out upon the far car removed and another reconnected in its place in case casa of accident the penstocks pen stocks are each tapped in in the power house and after passing through shutoff shut off and throttling valves under the control of the operator water is delivered into a cylindrical steel tank 36 inches diameter by 24 feet long this storage tank is set upon a little knoll about twenty feet above the level of the transformers from this tank the water circulates through the cooling coils of the transformers by gravity the transformers are connected in delta on the low voltage side and in Y on the high voltage side with ungrounded neutral fifty miles of 0 its length lie in a heavily timbered country requiring a tremendous amount of clearing the trees ranging from two feet to four feet beet in diameter etwas it was necessary to construct a trail nearly the entire length of the line afe route deviates from a straight line only slightly and only where the topography made it unavoidable it is a thorough transmission so to speak there being no taps on the line anywhere between the plant and the substation sub station at eureka the line is a single circuit three phase averaging thirty five poles to the mile the poles are redwood at the western end in the inaccessible stretches the native red fir was the only wood available insulators are loca locke two piece single pet oil T 11 ir W L V 7 ilia N A 4 AR n view in power house showing two K W bullock alternators of three each and one in reserve they are of bullock make K V A water cooled oil insulated 2200 volts 25 cycle each bank is located in a separate room and the seventh or spare transformer is in a third room they stand upon rollers which in turn rest upon three rails set into concrete piers the spaces between the piers are filled with gravel and provided with so as to allow oil to rapidly escape in case of leakage or accident the water piping is connected up with unions and so arranged that every transformer is interchangeable with every other one as far BS as water and electric connections are concerned A track runs the entire length of the building and at such an elevation that the floor of a car is at the same height as the the high tension switch house the high tension switch house is feet a frame structure covered with corrugated iron twenty feet distant from the transformer house in it are two banks of MT alt al M T single throw air brake switches and G E alternating current multiplex lightning arresters connected up for the three phase circuit pole line the pole line extends almost due west from the plant to the substation sub station in eureka th the e length is sixty five miles of this fifty five miles are over a severely rugged mountainous country the altitude of the plant I 1 is only 1400 feet and E ureka eureka is at sea level but the line passes over several summits ran ranging ginA from 0 to feet in altitude porcelain eight an and d one half in diameter in the fog belt a larger insulator of similar design is used pins are sun dried eucalyptus oiled one and one half inches diameter the spread of wires on the standard length spans is 40 inches wire is no 4 copper except on some long spans where stranded cable is used the length of spans varies from fifty to 1400 feet according to the conditions and topography of the country the telephone circuit is no 30 10 B B galvanized wire carried on glass glas s insulators telephones telephones stromberg carlson are connected to the line at severa several I 1 of the cabins which have been built for the accommodation of the patrolmen and at frequent in are pole boxes con consisting of mag neto generator and batteries into which the patrolmen plug their pocket sets and thus have long distance loud talking instruments the potential at present used on line is 10 20 J kilovolts substation sub station at eureka the substation sub station at eureka includes an auxiliary steam plant as follows two B W water tube boilers fitted with peabody patent oil burning furnaces duplicate oil pumping system goubert auxiliary feed water heater wheeler admiralty surface condenser with self contained steam driven air and circulating pumps cooling water being taken from humboldt bay and a mcintosh and seymour tandem tan dem compound engine of nominal rating of I 1 H P A running at R P M is connected to engine by rope drive A bullock rotary converter K W R P M 6 pole 25 cycle volt is ar vc I 1 OR 4 switch board in power house ranged for direct connection to this by a jaw clutch and so driven by the engine this permits of carrying the loal load by steam when necessary to shut down tho the transmission line for repairs the engine is fitted with a switchboard speed control device the clutch has a synchronism indicator inthe in the nature of a lamp so that the engine may be connected to the rotary while ic is running at full speed on the power transmitted from the trinity river plant for the rotary converter there are three bullock transformers K W water cooled 25 cycle volts for stepping down for the local distributing system are three G E transformers K W water cooled for furnishing power to the 60 cycle in candescent cand ascent and are arc lighting circuits of tha city of eureka a three phase 60 cycle generator is driven by the rotary acting as a synchronous motor thebus the substation sub station Is fitted with switch boards boards and H T switches suitable for handling this equipment A fuel oil tank fifty four feet in diameter by twenty five feet deep holding barrels has hai been b een built near the substation sub station an I 1 is connected to a dock on ba bay by a pipe line the substation sub station is thirty one feet by b ILI feet built in the marsh on waterfront of eureka heavy concrete foundations rest on the redwood piles cut off below low tide level load the load at present consists chiefly of lights in the city of eureka some kotcis are aheady connected to the circuits and the motor load is being rapidly developed local transmission lines are being constructed ted about the shores of bay and in a very short timer time the company will be supplying power to the local companies in Eu suburbs not only for light but for motors in the various industries ol of that rapidly developing 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