March 12, 1915. THE COLLIERY GUARDIAN. 541 current cannot be applied to the winding motor while ithe 'brake is “full on,” and also the brake cannot be •applied whilst the full current is flowing in the motor. An interlock is also provided so as to prevent the trip geai: of the emergency brake being reset unless the main control lever is in the “ off ” position, and the brake control lever in the “ full on” position. (a) The main control lever, which is connected to the main controllers and depth indicator, is controlled by cams on the latter, so that the winding motor cannot be accelerated beyond a predetermined rate. Should the driver neglect to operate the control lever, the winding motor is automatically retarded, and brought to rest. brakes being capable of pulling up and holding at any point in the shaft a lowering load of eight tons. In addition to a hand-operated band brake, each flywheel is provided with an electro-magnetic brake acting on the rim of the wheel, and capable; of bringing the con- verter set—with one flywheel—to rest from full speed in eight minutes/ The time taken by the same set to come to rest when. running free is about one. hour. During the sinking period each winder was operated by one motor, the drums being of 14 ft. diameter. The loads consisted of men, rubbish, building material, and water, the maximum unbalanced load being eight tons. On completion of the sinking to 750 yds., operation was continued with the 14 ft. parallel drum, with one motor by a direct-coupled induction motor is erected at the Abercwmboi Colliery. The duty for which it was designed when fitted with a tail rope of equal weight to the winding rope is as follows.:— Depth of shaft ................... 240 yards. Output of coal per hour .......... 180 tons. Net load of coal per wind ........ 50 cwt. Number of trams per wind ......... 2 Time of wind ..................... 35 sec. Time of each complete cycle ...... 45 ,, The three-phase motor is wound for 3,000 volts work- ing pressure, and has its. rotor mounted on a continua- tion of the drum shaft. The continuous rating of the motor is 375b.h.p., the maximum horse-power irgencu npressor JBrahe engine ccuplLng ~enci Crane girders C.C. e-eri sStarter §s 'Flexible dutch' . coupling Transformers , _^jq,ooo to^3,qoo Y°l t5/ -NJ L Air compressor ..... 3.,............ E T 3^nQto5Soyolt5 1: 3,ooo-volC switchboard :; :----'■ '•—; ■ LLLlLI-LLLi-J 500-volCswitch] Emergency .-Switches _ Depth indicator-— ^St^chion _ g________________, L©_1©_ 1©J @_____i© J ! j lopoo-volt switchboard ; ; rx © ■ ©; ■ _ ~ r -© ’'S"© | '•'•yfatt7rpbgrbdard'~~~l~~-L~ -' Fig. 19.—Arrangement of Electric Winding Plant at Britannia Colliery. ioz 3 *15 k—iz'10^"—— 15' o'-----*| ,_______15" Fig. 21.—Electrically-driven Winder, Britannia Colliery. UY E 7777 w L '■2 -'ll '»,4....... Milin :___-------- ■...v/ZiSiw b ill r 34U 28" T rVpipe to control frame (5) The brake control lever is connected to a cross shaft which is coupled to the operating valve on the brake engine. (c) The emergency brake is applied by either of the following means:—(1) By hand; (2) by the current failing; (3) by the air pressure failing; (4) in‘the event of.overwind by either cage; (5) in the event of excessive overload in the winding motor. The drum shaft is of 24 in. diameter and 3 in. bore, with' journals 22 in. x 40 in. The shaft is forged with solid half-couplings at each end for coupling to the motor shafts, the couplings being fitted with cross keys to relieve the bolts of the shearing stresses. The drum is fitted with two. sets of post brakes, the raising two trams of coal or rubbish. Following the partial opening out of the colliery, as the cylindro- conical drum could not be erected for some months, a balance rope has been fitted on the winder with the 14 ft. drum, thus enabling one motor to raise four trams of coal (six tons). Working under these conditions, with 19 winds per hour, and a winding t:me of 80 seconds, the number of kw.-hours taken by the Ilgner set averaged over one hour is 3-7 per ton of coal.wound. On completion, of the cylindro-conical drum, -when winding 390 tons, of coal per hour,, the input into the Ilgner; set will be 1,360 units per hour, or 3| units-per ton of coal wound from 730 yds. ' ' . (b) Main Winding—A.C, Motor,—A winder driven developed during the acceleration period being 700, with a power factor of 0-75. A liquid controller is pro- vided for starting and regulating the motor, and is inter-locked electrically with the oil break main and change-over switches for reversing the motor. The resistance in the rotor circuit is determined by the height of the liquid, which is varied by a sluice valve connected to the controller. The liquid is cooled by pipes in which water is circulated, and is pumped from a storage tank in the base of the controller by a small electrically-driven centrifugal pump. The winder is controlled by one lever, which is connected to the main stator switch, the controller, and the brake engine. The controller can maintain a minimum motor speed of 2-5 revolutions per minute with one-tenth normal torque for 15 minutes for rope examination, etc. The drum brakes are of the post type, and are weight- loaded air-operated, with the Whitmore patent self- adjusting and variable load appliances, by which the driver can apply any desired load upon the brake accord- ing to the amount that the foot lever is pressed down. The air supply for the brake cylinder is provided by an electrically-driven compressor set. This set consists of a compressor direct-coupled to a- three-phase motor, with automatic starting and stopping, controlled by the pressure in the receiver, the working value of which is 60 lb. per sq. in. Should the power supply fail either through failure of the main supply or the operation of the overload main switch relays, the brakes are auto- matically applied, and the winder drum brought to rest. A dial depth .indicator is used, with which is incor- porated the overwinding gear. The latter in case of an overwind applies the brakes and cuts off current from the winding motor. This winder has been in satisfactory operation for the last six years. The “ peak ” due to the sudden appli- cation of a load of 750k.v.a. every 45 or 50 seconds is satisfactorily dealt with at the power station by the Tirrill regulator. The number of units per ton of coal, wound without a balance rope, is 1-6 when winding 25 cwt. of coal. (c) Pumping.—When steam was used for the main pumping, the principal pumping stations for the Aber- dare and Rhymney Valleys were at Middle Duffryn, Elliot Pit, and Bargoed. At the former, two pumps, each capable of delivering 80,000 galls, per hour, were erected, the engines being on the surface and driving the pumps through reciprocating beams. At Elliot lit the equipment consisted of a triple expansion engine and a Reidler pumping engine for 80,000 galls, per hour, erected underground in a large chamber near the pit bottom, steam being brought from the surface through a steam main about 1,600 ft. long. A beam pump with engine at the surface was used at Bargoed. The above plant has now been supplemented or dis- placed bv single-lift centrifugal pumps, and in place of pumping continuously the main pumping is now con- fined- at the Elliot Bit to 8-12 hours out of the 24 by enlarging the lodge rooms, the pumping in the other valleys being confined where possible to the night shift. This has a marked effect on the load factor of the power houses, and in the Rhymney Valley it has provided the continuous load necessary for the economical use of gas engine plant. The quantity of water now pumped has largely increased, and is now dealt with by the following main pumping plant :—■ Aberdare Valley.—(Abercwmboi) : Three pumps each driven by a 600b.h.p. three-phase motor. Head .................. 1.015 ft. Capacity .............. 70,000 gallons per hour. Speed and type of pump Sulzer 5-stage, 1,480 r.p.m. (Aberaman) : Two. pumps each driven by a 350b.h.p. three-phase motor. Head ...............722 ft. Capacity .............. 60,000.gallons per hour. Speed and type of pump Sulzer 5-stage, 1,480 r.p.m. (Ysyborwen) : One pump driven by a 120 b.h.p. three- phase motor. Head ................ 200 ft. Capacity .............. 40.*>00 gallons per.hour. Speed and type of pump Willans and Robinson, 3-stage, 1,440 r.p.m,