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Australia has the largest and most complex water management and hyroelectricity generating system in the world - the Snowy Mountains Hydro Electric Scheme. Built over a 25-year period, it now provides great benefits to the people of NSW & Victoria. By BRYAN MAHER The story of elechical energy, Pt.11 J\ USTRALIA is the world's driest £'l.. continent. Finding reliable supplies of water is more ,important then even the discovery of gold. The western farmers of Victoria and NSW once suffered agonising droughts while fresh water from the Snowy Mountains was wasted, flowing eastward to the sea. The Snowy Mountains Hydro Electric Scheme was designed to alleviate the effects of both flooding and drought and provide electric power at the same time. Seven power stations, including two underground, together generate more power than the largest thermal power station in Australia. The whole 94 SILICON CHIP undertaking is the largest, most complex water management-electricity generation structure in the world. Hydroelectric proposals The catastrophic 1880 drought wrought such havoc that urgent proposals arose to divert water from the Snowy Mountains to the west. By 1908, further examination had produced a threefold proposition: (1) . Diversion of Snowy River waters to the west. (2). Dams to be built to ease both drought and flood conditions. (3). Hydro-electricity generation to supply the proposed national capital. Proposals came aplenty, but the first viable dual large-scale plan came forth in 1947. A joint State-Commonwealth technical committee investigated the whole question and NSW ceded to the Commonwealth the rights for the water to be used as a power source for the ACT. Above: while electricity generation is a key element in the Snowy scheme, less well known is the important part it plays in flood mitigation. Here the sluice gates on the Jindabyne Dam are wide open during late 1974 as they release part of the previous winter's snowmelt. &LOWERING RESERVOIR TOO MA RESERVOIR ,..s..,oo-=-o'-=FE=-cET_ _ _ _ _ _ _ _ _...,JOUNAMA PONOAGE l OGILVIES INTAKE OUTSTATION DEEP CREEK INTAKE p4,,_,00"'-0-----~&LOWERING --i---tTUMUT 3 POWER POWER STATION STATION 3000 2000 TO MURRUMBIDGEE IRRIGATION A R E A - - - - - -- ------ - - TUMUT 1 TUMUT HAPPY JACKS POWER POND PONDAGE --STATION--RESERVOIR - - - - - - - - - - - - - - - - - - ~ Snowy-Tumut Development 70""'0-"-0F'-"E"-ET_ r'- __,KH~~~g:~N MURRAY MURRAY 1 OGONG GEEHI --------.-GILTHEGA - - - - , ISLAND BENO JINOABYNE - - - - - - - , L A K E - - - ~ 2 POWER POWER CREEK RESERVOIR PONOAGE PONOAGE PUMPING EUCUMBENE STATION STATION INTAKE BURRUNGUBUGGE STATION 6000 i=="-----+---+---+---+-----+-----+----..C...,,-T""""-+-------i---------.n,TAKE LAKE JINOABYNE---+---------1 5000 4000 3000 TQ.MlJRRAY GUTHEGA POWER 0 IRRIGATION AREA - - - - - ' - ' = = = - - - - - - - - - - - - - - - - - - " S - " ' T A " ' T l " ' O N ' - - - - - □ ~:1"~~ ~~~~~r 6 0 0 ~~l~ :T~¥~ N ...JL TUNNELS ANO SHAFTS Snowy-Murray Development Some idea of the broad scope of the Snowy Mountains Hydro scheme can be gained from this diagram which shows every dam and power station and pumping station involved. Many tunnels and shafts are also involved, to transfer water to and from reservoirs. In 1949, The Commonwealth Government established the Snowy Mountains Hydroelectric Authority (the SMA). It was given responsibility to investigate, design and build the scheme. All earlier proposals were considered, some proposing as much as 800km of open channel aqueducts. Previous schemes proposed 16 power stations generating a total of 2.6 gigawatts. When one takes a 3-dimensional view of the Snowy Mountains, it is difficult to comprehend the complexity of the final plan, let alone the finished construction. The Authority's final design envisaged 144km of tunnels, 80km of aqueducts, 16 large dams, 7 power stations generating 3.74GW, and many smaller projects. Included under the heading of "smaller projects" were: (1). Shifting a whole town, including the removal and rebuilding of the historic stone church at Adaminaby; (2). Establishment of seven regional towns and 100 camps; (3). Building over 1600km of roads, access tracks and rail lines; (4). Construction of hundreds of kilometres of high voltage power lines (10 at 330kV and four at 132kV); (5). The transport of bulky, heavy power station equipment from seaport to site; and (6). Supervising the many subcontractors and caring for the 100,000 people who worked on the scheme at various stages. The first blasting shot was fired in 1949, and the whole scheme was completed on time, on budget, by 1974. The cost was $820 million. The highest number of on-site employees was reached during 1959, when 7300 people toiled on the project. Cash loans from the Commonwealth paid for the work. Thes e loans are being repaid over 70 years from sales of electricity. No charge is made for water used by the states for irrigation purposes. Large scale engineering The Snowy Mountains Scheme still ranks as the greatest and most complex water management/electri city generation undertaking in the world. The project was built over 3200 square kilometres of immensely difficult mountain terrain and is truly the greatest engineering feat yet accomplished in Australia. One dam alone holds nine times the volume of Sydney Harbour. The water management aspect involves a complex system of dams , tunnels , gates, valves and pumped storage. The geography naturally divides the scheme into two sections: (1). The northern Snowy-Tumut development; and (2). The southern Snowy-Murray proj ect. This follo ws from the three-cornered layout nature originally created. The Snowy River runs roughly from Mt Kosciusko to the south east. The Ge ehi flows south w est from the mountain to pour into the Murray. The Tumut River (originally called Doomut) crashes down its precipitous gorges in a north westerly direction to join the Murrumbidgee near Gundagai. Central to both sections of the scheme is the Eucumbene Dam. This , by far the largest storage in the system, holds 4. 798 billion cubic metres of water. Completed in 1958 , its rockcapped earthfill wall rises 116 metres above th e bed of the Eucumbene River. As is usual with earth/ rock dams, the ]ULY 1991 95 ~~ ~; _ &/ 1 . "#'., l!lfl\ T 01 ,✓ • "); ;- ·- ~~ ~ ,:~~~ ~ ';{e]IIIU'ilHIH=Wi❖UIUst·liMii·WK•maot--.--~--, :/ .~ r , ""· ~ I • • -:, •. • .- fr\\ l-......,·/ . '• \ ~ -. Cl. .\ ::J 'I!. > .,.,~ Q , '<c, ~ ~~ l11 ~, z • . ®. 19 ,o 99 100. ~ '- · <♦• ~ UJ G a:: ,)..._...,. 1 Q ( • ,. I- (/) 19 .... ~ ., _ - 1). {l BNC . SOLDERLESS TWIST ON PLUG Q a:; < ~ :E > cc ~ ~ UJ 3: CANNON TYPE 3 PIN CHASSIS MALE to. 100 , 1.g P10ll62 $3.50 $295 $250 J l:•w r CA~ TYPt ·i.· 1-9 10. -' 3 _jj j ~ LI.. ~ M ,... 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BF199 ........... $0.60 BF245A ... $1.95 8F469 ........... $1.20 8F470 .. ..... $1 .20 8FY50 ...... ..... $1 .50 8FY90 ........... $3.00 8U208A ...... .. $4 .90 8U326A ..... ... $4.95 8UX80 .......... $5 .95 8 U806 ........... $7 .95 MFE 131 ........ $2.90 MFE3001 ...... $9.90 MJ1 0012 ....... $5.95 MJ 802 .. . ..... $7.60 MJ1 5003 ....... $9.50 MJ 15004 .. ..... $9. 70 MJ 15024 ....... $9.60 MJ2Q55 . ....... $2.95 MJ4502 ........ $8 .50 MJ E'.l-10 .... ... $2 .00 MJ E350 ........ $2 .50 MJ E2955 .. .. ..$4 .90 MJ E3055 ...... $3 .90 MJ E13007 .... $4 .95 MJ E13009 .... $9 .95 MPF131 . .....$2 .90 MPSA06 ... .... $1 .00 MPSA13 .......$0 .50 MPSA42 .. ..... $0.60 MF'SA43 ... .... $0 .50 MPSA93 ....... $0.50 MPF10 2 .... .... $0.90 MPF10 9 ... .... $0.90 M PSU5 6 ....., .$1.75 PN 100 .......... $0.25 PN200 .. .... . $0.25 TIP318 .. ...... $1.00 TIP31C ......... $1.20 TI P32 8 .. ...... $1.00 TIF32C .. ....... $1 .20 TIP41A .... ... ..$1 .90 TIP41C .. ..... .. $2 .00 TIP42A .. ..... .. $1 .90 TIP42C . .... ... $2.00 TIP49 .. ......... $1 .90 TIP50 . ·· ········ $2·20 TIP53 .. .... ... $2.50 TI P 112 ..... ..... $2 .50 TI P1 16 ... .. .... $2 .50 TI P1 17 ······· ···$2 .50 TIP 120 .. . .. .$2 .90 TI P122. ... ..... $1.95 TI P1 25 ..... ..... $2.90 TIP127 ..... .... .$1.95 TIP147 .. .... $4 .95 TIP2955 ... ..... $2 .,5 TIP 3055 ....... $1.95 ~~i -,.!fim•n1 .. ,r BC107 .......... $0 .80 8C108 .......... $0 .80 8C109. .........$0.80 BC2 12 .......... $0.3 0 8C31 8 ..... ..... $0.30 8 C327 .... $0.30 8C 328 ... .. ..... $0.30 8C337 ... ...... .$ 0.40 BC338 .......... $0.40 BC 548 .. ........ $0.30 BCl547 ... $0.15 8C548 .......... $0.15 lfll N 6! 11V.. $0.25 12V..$0.25 13V..$0.25 15V.. $0.25 16V .$0.25 18V .$0.25 20V .$0.25 22V .$0.25 24V .$0.25 27V .$0.25 30V .$0.25 33V .$0.25 36V $0.25 -Description ........ $ 1N4n8 3V3 .$0.35 1N4n9 3V6 .$0.35 1N4730 3V9 .. $0.35 1N4731 4V3 ..$0.35 1N4732 4V7 ..$0.35 1N4733 5V1 ..$0.35 1N4734 5V6 ..$0 .35 1N4735 6V2 ..$0.35 1N4736 6V8 ..$ 0.35 1N4737 7V5 ..$0.35 1N4738 8V2 ..$0 .35 1 N4739 9V1 .. $0.35 1N4740 1 OV .. $0 .35 1N474 1 11 V .$0.35 1N4742 12V. $0.35 1N4733 13V .$0 .35 1N4744 15V .. $0.35 1N4745A 16V$0.35 1N4746 18V .. $0 .35 1N4747 20V .. $0 .35 1N4748 22V .$0 .35 1N4749 24V .$0 .35 1N4750 27V .$0 .35 1N4751 30V .$0 .35 1N4752 33V .. $0 .35 1N4753 36V ..$0 .35 1N4761 75V .. $0 .80 ■11;11 SW ZENER DIODE Ooscrlpt lon ......... $ 1N53398 5V6$ 1.50 1N53428 6V8$1.50 1N53498 12V$1.50 1N5358 15V$1 .50 1N5361 27V $1.50 1N5359 24V $1 .50 1N5363 30V $1 .50 1N5372 62V $1 .50 l!li~~ll·]~~ 8scnpb on....!. 1MHz ............ $6 .00 1.8432MHz ... .$7.50 2MHz ... .. ...... $3 .00 2.4576 MHz ... $2.00 3MHz ............. $4 .90 3.57954MHz .. $3 .00 4.00 MHz ... ... $3.00 4.19430MHz .. $3 .00 4.433618MHz$2.00 4.44 MHz ....... $2 .00 4.9562 MHz ... $3 .00 SMHz .... ....... $2 .00 6 MHz .. ··· ·····$2 .00 6. 144 MHz .... $3 .00 8.00 MHz .. ... .$3 .00 8.86723MHz .. $3 .00 10 MHz ... ... .$2 .00 11 MHz ..... .... $3 .00 12 .00 MHz ... .$3 .00 14.318 MHz .. $2 .00 15 MHz ..... ... $2.00 16.00 MHz .... $3 .00 20 .00 MHz ....$2 .00 2A MHz ...... .. $3 .00 48MHz . ......... $2 .00 32 .768KH• .. ., 00 ~(D=!H~ e sc npt,on 74HC00 .........$0 .75 74 HC02 ......... $0 .75 74H C04 ........$0 .75 74HC08 ........ $0.75 74HC10 .. .... ..$0 .75 74HC11 . ..... .. $0 .75 74HC14 ........ $1 .60 7>1HC30 .... .... $0 .60 74HC32 ........$0 .80 74HC42 . ....... $0 .90 74HC74 ........$ 1.10 74HC85 ........$ 1AO 74HC86 ..$ 1.10 74HC123 .. ....$1AO 74HC132 ...... $1 .25 74HC138 .... ..,1.40 74H CU7 .... .. $1 .25 74HC181 ...... $2.25 74HC184 .... ..$2.25 74 HC244 ...... $2.00 74HC 245 ...... $2.50 74HC273 ....... $2.75 74HC367 ....... $1.85 74HC373 ....... $1.80 74HC393 .... ... $2.75 74HC4040 .... $1.65 74HC4060 .... $3.95 74 HC4066 ..... $1.70 ~-%1!t1\'I'~• ! scnpbon .... ... . 4000 ..............$0.75 4001 ... ........... $0.4') 4002 .............. $0.55 4006 .............. $1.55 4007 ... $0.45 4008 ..... ······$1.70 4009 ............. $0.90. 4010 ... $0.90 4011. ..... $0.45 40.12 .. .......... $0 .45 4013 .. . ... ... $0.70 4014 ........ ..... $1 .00 4015.. ... $0 .90 4016 ......... $0.70 4017 .... .........$1.35 4018 .............l0.50 40 19... ..$0.80 4020 ...... .... ... $1.40 4021 .............. $1.50 4022 ... . ... ...$1.45 4023 .............$0.45 4024 .. ....... $1.60 4025 ............. $0.45 4026 ............. $1.10 4027 .. . .. ..... $0.85 4028 .. ....$1.15 4029 ............. $1.50 4030 ...... $0 .50 4033 .. ........ $2.75 4038 ..... ... .....$2 .25 4040 .. . ...... $1.20 4042 .. . ..... $1.50 4043 .... ........ $1 .20 4044.. ..... $1 .25 4045 ............. $4 .90 4046 ............. $1.00 4047 .. ..... $1.90 4049 ............ $0.60 40 50 ........... .. $0.60 4051 .. ... $1. 20 4052 ·•· ......... $1.20 4053 ... . ..... $1.20 4060 ·············$2.50 4066 ..... ..... ... $0 .80 4068 .. . ... $0 .50 4069 .. ... ..... $0 .50 4070.. . .... $0 .50 4071 .. ... ..... $0 .50 4073 ·········'°·50 4075 ............. $0 .50 4076 .... $1.90 40n ............. $0 .50 4076. .. . . ... $0 .50 4081 .. ···· ···$0 .50 4082 ............ $0.50 4093 .. ........... $0.80 4098 ..... ........ $1.90 45 104 .......... $7.25 4503 . ........... $1.:30 45 10 ..... ........ $1.40 4511 ......... ..... $1.45 4512 ..... ... .... $1.40 4514 ............. $2 .60 4515 .. ..... $1.90 4516 ............ $1.60 4518 ..... ..... ... $1 .50 4520 .. . .. .... $1.00 4522 ............. $1 .90 4526 4528 4532 4536 ............. $1.00 ............. $1.95 ..... ........ $2 .65 ..... ..... ... $6.50 4538 .... ... ... ... $1 .20 4543 .......... ... $2 .50 4556 ............. $1.25 4584 .. . ...... $1.00 40014 ........... $1.50 40175 ........... $2.00 74COO ..... ..... $1.00 74C04 ........... $1 .00 74C08 ......... $1 .00 74C14 ........... $1.75 74C74 ........... $1 .00 74C86 ........ ... $1 .50 74C90 .. ...... .. $2.50 74C192 ...... ..$3.50 74C22 1 . .... .. $3 .85 74C244 .. ..... $3.95 74 C373 .. . ... $8.95 74C906 .. ...... $2.90 74C922 ...... $14.95 74C926 ...... $13.95 74C946 ...... $24.50 lit!wjjt.1 74S04 ......... .. .$1 .20 74S08 ......... ...$1 .50 74S30........ ....$1 .00 74S32 ............ $1 .00 74S132 .... ...... $3.50 74S133 .......... $ 1.20 74S138 ...... .... $2.50 74S 139 .... ...... $3.30 74S 174 ..... .... $3.50 Ulldwt1 :i., t.4fi1; 1 ?.'. 7400 .......... .... $0 .80 7402 ...... $1.00 7403 ..... ......... $1 .00 7404 .............. $0.30 7406 ............. $0.40 7407 .. . ... $0 .50 7408 ............. $1.00 7409 ... $1,00 74 10 ............. $1.20 7414 .. ....... $1.50 7416 ............ $0.50 7430 ............. $ 1.00 7432 ............ .$1.00 7438 .............$0.80 7442 .............$1.50 7445 ........... .$1.00 7446 ...... ... ....$1.20 7447 ....... .. .. $1.75 7473 .. .. .........$1 .20 7474 .. ...........$0 .40 7475 .............$1 .20 7478 ............. $1.50 7483. . .. ....$1.10 7490.. ..$1 .20 7493 ......... .... $ 1.25 fZ!l-;.l-•1jj11:S."1 t!.ln),on?f 74 LSOO ... ... ... $0.:30 74LS01 ..... .... $0 .60 74LS02 ......... $0.60 74LS03 .. ..... $0.60 74LS04 ......... $0.75 74LS05 ..... .... $0.75 74 LS08 ... ... ...$0.60 74LS 10 ......... $0.:30 74 LS11 ......... $0.75 74 LS13 ... $0.90 74LS14 ... $0.75 74LS15 . ....... $0 .80 74LS20 ......... $0.90 74 LS21 ....• ... $0.90 74LS27 ........ $0.90 74LS30 ... $0.30 74 LS32 ... $0.60 74 LS379 ... $0. 70 74LS38 .. ...... $0.80 74LS42 74L S629. 74LS640 8Scnpbon ... 74F00 ............ $0.25 74F04 ............ $0.25 74F32 ..... $0 .25 74F74 ..... .$0.25 74F109 .......... $0.50 74F138 .... ...... $1 .00 74F151 ......... $1 .20 74F153 .......... $1.20 74F157 .......... $1 .20 74F194 ...... ....$2.41 74F244 ..........$3.·'2 7412 1 .......... .$1 .55 74123 .......... $0.50 74125 .. ...... $ 1.00 74126 .......... $ 1.00 74150 .. ... ...... $ 1.90 74154 ..........$2 .50 74157 . .......... $1.30 74161 ...... ...... $1.20 74164 .......... $1.20 74177 .. ... ...... $1.95 74193 ........... $1.50 74195 ........... $1.00 74197 ........... $ 1.20 74283 . ...... ... .$2 .45 74290 ... $0 .90 11 tP'Kf-,.p Description .. .... ... . ...$1.20 $ LM394CH ... ... $7 .95 LM39ST.... ...... $9.95 !. M395K ......... $7 .95 LM396K ....... $16 .50 LM399H ..... $7 .so LM711 ......... .$1 .20 LM725 ... .. .... $7 .50 LM733 .......... $ 1.50 LM741 .. .. ..... $0.60 LM747 ........... $1 .50 LM748 ........... $1.1 0 LM759 ....... .... $3.90 LM833 .. ........ $2.1 0 LM1830 ....... $4.90 LM1871 N....... $7 .50 LM1872N .. ... $8.60 LM1886 ...... .... $9 .10 LM2907·14 .... $3 .50 LM2907-8 ...... $5 .10 LM2917-14 ... . $2 .50 LM2917·8 .... .. $4 .80 LM3900 .... .... $0 .80 . LM3909 ......... $2 .50 LM39t1 ....... .. $3.95 LM3914 .. $2 .90 LM3915... .. $2 .90 LM3999Z ..... . $5 .95 LM 4250 .... .. .. .$2 .45. LM11CN .. ... .. . .$4 .95 LM 13600 ........ $2 .70 LMC555 .......... $ 1.25 MA X23211CC232 HMC232 .......$11 95 OM350 .......... $21 .00 MC1408L8 ...... $7 .50 MC 1458 ........ . $1 .20 MC1488 ...... . $0 .60 MC1489 ......... $0 .60 MC1496 ......... $2 .50 MC3334P.... ... $6 .95 MC34018P.. ... $8 .95 MOC302 1 .. .... . $1 .95 NE555.. .. $0 .50 NE556 . $0 .95 NE558 ...... ..... $6 .50 NE564 .. .. ...... $7 .00 NE566 ............ $2 .90 NE557 ........... $2 .00 NE570.. . ... $8.95 NE571 ......... $6.95 NEsn .......... s 11 .20 INS82SON .. .. $ 18. 10 TA 7205P..... ... $2 .95 TDA 1024 ... .... $ 3.90 TEA1002 ....... $17 .50 TL064 ....... ...... $2 .10 TL0711 LF351 . $1 .20 TL072/ LF353 . $1 .60 74LS47 .. ... $1 .80 OACOBOO ........ $4.95 74 LS48 ... $1 .80 0 ACOB08 ........ $4.90 74LS74 ...... ... $0.40 AOC0800CN .. $29.95 74LS75 $1 .20 AOC0803 ...... $13 .50 74 LS76 ... $1.00 AOCOB04 ......... $7.95 74LS85 .... ..... $0 .85 ADC0808 ....... $13.00 74LS86 .. ...... $0.60 AOC0820LCN.$27 .95 74LS90 ... $1 .20 OAC0832 .... ..... $7 .95 74LS92 .$1 .20 OAC1020 ....... $16.28 74LS 93 ... $1 .50 11C90 .......... $16 .50 TL074/ LF347 . $1 .40 74LS95 .. $1 .20 0AC 1220 . . .... $22 .95 TL081 ... $1 .90 74LS107 ... ... $0.90 OAC1408 ... ..... $1.00 TL082 ............. $2 .20 74LS109 ... ... $0.90 A D590J ........ $12 .95 TL084 ......... .... $1 .50 74LS112 . .$0. 70 UA710CN ....... $1.00 74LS123 ...... $1 .30 UA739 ............. $2 .75 74 LS125 ... $1 .00 UP08288 .... $16 .50 74 LS126 ....... $1 .00 XR2206 .......... $9 .95 74LS132 ... . ..$1.00 XR2209 .......... . $6.90 74LS138 ...... $0.80 .AY-3 -101 s ..... $11.95 . XR221 1 ........ .. $7.95 74 LS139 ....... $0.80 .AY-3· 8910 ..... $19.95 XR2216 ..... ...... $5.90 74LS145 ....... $1.50 .AY-5-8 11 6 ..... $14.50 XR2240 ... ....... $ 6.95 74 LS147 ....... $2.50 CA3028... . .. $3.95 XR2243 .......... $5.95 74L S151 ......$1.20 CA3086 ... ..... $1.20 26LS30 ... ..... . $2.00 . 74LS153 ....... $1 .00 CA3130E ....... $2.90 26LS31 ... ...... . $2.00 74LS155 ....... $0.50 CA3130T... ..... $3.95 26LS32 .......... $2 .00 74 LS156 ....... $1 .50 CA3140E .... .... $1 .30 5534AN .......... $3 .95 74 LS157 ...... $1 .20 CA3140T... .. .. $2 .95 74LS158 ....... $1.00 CTS256A .... . $45 .60 . 8155 ... ··········· $8 .95 OM2502 ...... $13 .60 8156 .............. .$8 .50 74LS160 ....... $1 .50 LF347 ............ $1 .40 81LS95 .......... $1.00 74LS161 .. ..... $1.00 81LS96 .. ......$2 .75 74LS162 .......$0 .50 LF351N ......... . $1 .20 8216 .............. $3 .00 74LS 163 ...... $1 . 10 LF353 ............ $1 .60 8237 . ....... ..... $14 .50 LF356N ......... $1 .50 74LS 164 ...... $1.40 LF357 ... ...... $2 .95 8255 ............... $6 .90 74LS165 ...... $1.20 LF398.. . . . $5 .90 8279 .............. $8 .50 74LS 166 .. .... $1.25 ..... $6 .95 LM301H ...... .. $1.50 8830 74LS168 ....... $2.10 LM301N ... ...... $0.50 9SH90 .. ....... .$10 .50 74 LS174 ....... $1 .20 LM302H ..... . . $6.50 9667 ............ .. $0.90 74LS175 .. ... .. $0.70 LM305H.. ..... $1.50 9668 . .... ... $2 .95 74LS181 ... .. . $4.00 LM307CN ...... $1.50 74LS191 ....... $1 .20 LM308 ..... .. .. .. $0.50 74LS193 .. ..... $1 .20 LM309K ... .. ... $2.85 74LS195 ..... $0.50 LM310N ...... ... $4 .95 74LS196 .. ..... $1 .20 LM311 ..... ...... $1.00 74LS22 1 .. ..... $2.00 LM324 ... . ...... $1.20 S240 ....... $1 .40 LM331 ..... .......$6 .00 t . ..... $0.95 LM339 ... ... ..... . $0.60 ., ,,,J ...$ 1.10 LM348 .. . ....... $1.00 74 LS 244 .... $2 .20 LMl49 ........ ... $2 .95 74LS245 ... ... .$2.95 LM358 ............ $1 .40 74LS257 ....... $1 .20 LM3F1 .. .. ...... .. $4 .95 74LS258 ....... $1 .20 LM380N·14 ... . $1.95 74LS259 ..... .$2.25 LM380N·8 ... .. $1 .50 74 LS266 ...$0.70 LM36 1 ............$4 .95 74LS273 .... ... $ 1.00 LM382 .... ........ $3.50 74LS323 .. .. ... $6.50 tl11lfl1·li._ 74LS352 74LS365 .. 74LS368 74 LS387 74LS373 11!1liil'li~·~ LM317T. ......... $2 .50 LM317KC .... ... $5.50 LM320K12 ..... $1.40 LM320 K-05 .... $3 .00 LM320T-5 ...... $1.40 LM323K ········ $9 .50 LM326 ........... $5 .50 LM3290Z ...... $0 .90 LM334Z . ...... .. $1.70 LM335Z .... ..... $2 .50 LM336Z-2.SV. $2 .95 LM350K. .. - 1M·08 .. ........ $14 .95 _]J_ ~\ \ ~· ---\ • $11 50 ~ r 78 L12... $0 .75 78L15 ... .$0 .75 79L05 .. .......... $1 .20 1M X 9-80 .. $125.00 1M X g.7Q .. $129 .00 79Ll2 ........ . ... $1 .20 79L15 .. ... ....... $1 .20 •:~11~,, LM396K ....... $16 .50 Wil:W+W Description ... .. $ 9-80 .. $49 .00 Desc ription. $ 76489 ...... ..... $12 .50 ICL7660 ..... ... . $6 .90 VN88A F. .........$5.95 MM5369 ......... $4.95 1M X 9-80 .... $125.00 1M x Q-70 .... $12Q.00 1n·r1a•i13;1 ! ,pt on 5502A ........... $16.96 6522A ....... .... $15.95 6802. .. $7.00 6809 ......... ..... $ 17.00 6821 ............ .... $5.50 6845 ....... ... .... $9 .95 6850 .............. $3 .50 7910.... $29 .95 8035N-6 ......... $6.90 8039 ............... $9 .90 8080 ............... $8 .00 8085A ...... $16 .50 8088 .. ··· ·•····· $12 .50 ICL7106 ..... .. $15 .95 ICM7216B .... $59 .50 LF13741 ........ $0.80 NS 16450 ..... $26 .95 S3530 .... ... $24.95 S P0256 .... ... $21.95 TR1863 .......... $8 .90 V20A ....... .... $35.95 V20 ... ..... . ... $29.95 W0 2123 ..... .. $29 .85 XR80 38 .......... $7 .50 Z80A CTC ..... $8 .50 Z80 8 CPU ... $13 .50 Z80A CPU ... ... $5.75 Z80A PIO ..... .. $4 .50 Z80A S IO .... $14 .50 Description .......... $ 3 mm L EOS Rod ................. $0 .20 Groe n ....... ..... $0 .30 Yellow ............ $0 .30 Orange ........... $0 .30 5mm LEDS Rod .......... ... .. $0 .20 Gree n ... ........ $0 .30 Yello w .... ........ $0.30 Orahge .......... $0 .30 1Clmm JU MBO LE ADS Rod .... ............ $1 .50 Gree n ............ $1.50 Orange ........... $1.SO S UP ER BR IGHT LEO S Rod . ........... ... . $1.00 GrHn .......... .. $1.00 Yel low ....... ..... $1 .00 Smm FLASHING LE OS Rod ................ . $1 .25 RECTANGLE LEOS Rod ..... .... ...... . $0 .25 GrHn ........... $0 .30 Yello w .. .. .. .. ... $0 .30 Orange . $0 .30 5mm RED/GREEN DUAL LEO .... $1.05 8087-2 ... $279.00 8087-1 ...... $379.00 80287•6 .... $249.00 802 87-8 .... $379.00 80287-10 ... $459.00 80387-16 .... $695.50 80387-20 . .. . $795 .00 80387·25 ... $8Q6.00 80387-39 ... .$995 .00 i Prices a re 1-9. I I I I I I I I 10-99 less 10%. 100+ less 20%. I I I I I I I I p I ~ ~ ~ LM386-1 ...... ...$1.40 LM390 .... ...... . $2.9b LM392 . ... .... .. .. S1.50 . ~ -~,. ~,/ / " - " J / ' --~ A_ 7 L----------.J 7•LS375 ...... $1.00 l . ,. 7BP05GC ..... $14 .50 7805 ... $0 .75 Descn t.i11on $ 256 X 9-80 . ... $49 .00 008 335757 TOLL FREE MAIL ORDER HOTLINE FOR CREDIT CARD ORDERS! I /.' :t LM378 .. $6 .95 TL494 ... $4.90 LM723CH .. $1 .50 LMn3CN ... .. $0.95 78HGK ........... $9.50 1M• 10 ........... $13 95 LM367 ........ .... $2.75 7'LS374 .. ... ..$2.00 - r- LM337KC .... $12 .50 LM338K ........ $9 .45 LM340T-5 .. $0 .90 LM340KC·S ....$2 .95 LM340T-5 ..... $0.90 LM340KC·5 . .. $2 .95 LM340T•12 .... $0 .90 Lf.4 l40T-1 8 ... $2 .00 LM340T-15 .. .. $0 .90 LM340KC-12 $4 .95 LM350T.... $8 .40 8264 LP ·10 .. $19 95 62256L P-10 . $39 95 X ~ ~ L M 33625 .0V. . $2 .95 L M337 T. ........ $2.90 44256-08 .. ... $14 .95 44256-07 ... ... $15 .95 6116 . $5 .50 256K t.I l[iliS · J-lit-Z ! scnptJo n ...... $ i cnp o n ; 2114 ............ .... $5.20 2716 ..... $12 .50 2732-200 .... .... $8 .25 2764-250 ....... . $8.95 27128 ........ .. .. $8 .00 27256-250 .. .... . $9 .50 275 12-250 . ... $14.95 27-1MEG ....... $29.50 27C64-200NS. $8 .95 27C1 28 ......... $12.50 27C2561 250NS .. ...... .. $15.50 27 C512 ........ $22.50 27C 1M EG ... $34.50 41 16 16K ....... $ 3.95 4164- 10 ... $4.95 4464- 10 ....... . $5.50 4464·08 .. ........ $5 .90 41256 · 10 ........ $4 .95 41256-08 ... ..... $5 .50 44256-10 ... ... $13 .95 LM383 .. ... ... .... $4 .95 LM384 ............ $3.50 ... $2.20 ... .$1.00 ...$1.00 ... $1.00 ... $2.00 " ___......- JA . . 1 N747A 3V6 .$0.25 1 N748A 3V9 .$0.25 1N749A 4V3 .$0 .25 1 N750A 4V7 .$0.25 1 N75 1A SV 1 .$0.25 1 N752A 5V8 .$0.25 1 N753A 6V2 .$0.25 1 N754A 6V8 .$0.29 1 N755A 7V5 .$0.25 1N758A 8V2 .$0.25 1N787A 9V1 .$0.25 1N758A 10V .$0.25 1N962A 1N759A 1N964A 1N9658 1N9668 1N9678 1N9688 1N9698 1 N9708 1 N9718 1N9728 1 N9738 1N9748 r-1 ·1>-/-F> I Snowy River and the Island BendEucumbene tunnel. This reverse flow mode is only used in times of heavy precipitation on the Mt Kosciusko areas and then only provided the Geehi River and reservoir alone can provide enough water for the Murray 1 and Murray 2 power stations. Finally, (5) water can pass by reverse flow in the Tumut Pond-Lake Eucumbene underground tunnel. This mode is only used when snowmelt/ rainfall in the upperTooma and Tumut rivers catchment exceeds the water requirements of the Tumut 1, 2 and 3 and Blowering power stations. Tumut Pond is also fed by another tunnel from Tooma Reservoir plus four vertical intakes from smaller streams under which the tunnel runs. Eucumbene outflow ;:, ,I,{,. The first dam to be built on the Snowy scheme was Guthega, shown here in the early construction stages during 1954. The associated Guthega power station was also built during these early years. wall is enormously thick, tapering ·in section from 686 metres at the base to just a roadway's width at the crest. Complex design Some idea of the complexity of the Snowy scheme can be gained when we consider the 4-way water flow pattern into and out of Lake Eucumbene. The overall design purpose is to: (1). Always provide sufficient water flow down the Murray & Tumut rivers for downstream towns and the Murray and Murrumbidgee Irrigation Areas. To meet these requirements, the whole scheme provides an annual equivalent of 2,350,000 megalitres of water. (2). Store enough water to generate 98 SILICON CHIP sufficient electricity for the ACT and to assist NSW, Victoria and South Australia with their peak load requirements. (3). As far as possible , prevent downstream floods and wastage of excess rainfall and snowmelt by storing all surplus precipitation in Lake Eucumbene for later use. Water can flow into Lake Eucumbene from five different sources: (1) from the Eucumbene River and its tributaries; (2) from rainfall/snowmelt on the mountains surrounding the lake; (3) via an underground tunnel from Tantangara Reservoir on the headwaters of the Murrumbidgee River; (4) from Guthega Pondage via Guthega power station , the upper In dry times , the Tumut and Upper Tooma rivers cannot provide enough water for the Tumut-Blowering power stations and downstream Murrumbidgee irrigation areas. Also, during droughts, the Geehi river is insufficient for the needs of the Murray 1 and 2 power stations and the Murray irrigation system. In such conditions, the vast storage of Lake Eucumbene is the saviour of the whole system. Water then flows by tunnel from Eucumbene via Happy Jack to Tumut Pond, thence through the three Tumut power stations to Blowering and on downstream. Also, to supply the Murray system, water flows by tunnel from Lake Eucumbene to Island Bend and then by tunnel to Geehi and on through the Murray 1 and 2 power stations. Jindabyne storage Precipitation falling in the catchments of the Crackenback River, the Snowy River below Island Bend and the lower Eucumbene River is stored in Lake Jindabyne. This lake is third in storage size in the scheme and holds 689,790 megalitres of water. Riparian rights (ie, irrigation and fishing rights) in the Snowy River below the dam is provided by a 914mm diameter siphon. To cope with floods , twin balanced radial gates can open a spillway capable of passing approximately 3000 cubic metres of water per second. The operation of these huge gates is fully automatic and is controlled by the height of the water in the dam. SECTION THROUGH GUTHEGA POWER STATION RL4422 120 TON OVERHEAD TRAVELLING CRANE --ttH---t::r::i:'lE:r:::I SCALE OF FEET This cross-section diagram of Guthega power station shows how water drives the turbine and the 30 megawatt generator. Water enters at the side and leaves the turbine from the bottom. The challenge to the engineers of the Snowy scheme: harness the vast catchment of these rugged mountains so that the water can be used for electricity generation and agriculture. They succeeded admirably. The function of Lake Jindabyne is to store Snowy River water for subsequent passage westward in tunnels under the mountain to Geehi Reservoir via Island Bend. But as the transmountain tunnel is 231 metres higher than Jindabyne, the water is pumped up to this height using cheap electricity in the middle of the night. Because of cavitation effects, lift pumps are unsatisfactory (and impossible above about 10 metres oflift). As the main Jindabyne pumps are located 20 metres above the water stor- age, booster pumps are installed below minimum dam water level. These booster pumps at the foot of the pumpwell are driven, via long vertical steel shafts, by 7.46MW (10,000 horsepower) induction motors mounted up in the pumphouse. The 40MW (53,600 hp) main pumps are horizontal shaft double suction single stage centrifugal types, capable of pumping 13 cubic metres of water per second against a 232 metre head. These are driven by llkV synchronous motors. The starting procedure for these motors is interesting, particularly when one considers that the water pressure due to the 232-metre head is always present at the foot of the Jindabyne-Island Bend tunnel, whether the pumps are running or not. To avoid any power surges when the pump motors are started, an auxiliary pelton water turbine, driven by this 231-metre water head, is used to get the main motors up to speed. The supply transformers for these 1 lkV motors are oil filled but they are cooled by heat exchangers in the pumped water stream. During times of excessively high flow in the Geehi river, water from this western source can be diverted backwards via the trans-mountain tunnel for storage at Jindabyne. Rivers like the Geehi, flowing in precipitous mountain gorges, have tributaries falling from great heights. Many of these enter the Geehi below the dam yet the bulk of their length is at greater elevation. Therefore, high up the rocky cliffs, aqueducts, tunnels and buried pipelines catch much of this water and shunt it back for storage in the dam. Construction of the Jindabyne pump system began in March 1966 and was completed in the summer of 1969. Of the seven power stations in the final design, Tumut 1 and Tumut 2 are underground, deep within the granite and granitic gneiss mountain formations. The remaining five stations Tumut 3, Blowering, Guthega and Murray 1 & 2 - are above ground. Individual station power ratings range from 60MW (Guthega) up to 1.5GW (Tumut 3). The first steps The first step was the essential detailed survey. Accurate measurements were taken of rain, snowfall and snow JULY 1991 99 SECTION THROUGH JINDABYNE PUMPING STATION 75-TON OVERHEAD TRAVELLING CRANE FSL LAKE JINDABYNE RL2990 FOUNDATION EXCAVATION LINE LAKE JINDABYNE 20 0 20 40 60 SCALE OF FEET depth. Above 1400 metres, the precipitation falls as snow in winter and is up to three or four metres deep on the highest areas. On-site measurements supplemented by local knowledge gave information on snowmelt runoff periods. The dominant runoff cycle begins each year in August, peaking in September and October. Peak monthly stream flow varies from 400 million cubic metres in a dry year to 1.5 ,billion cubic metres in wetter times. Because of the height of the Snowy Mountains, their stream flow varies less in wet-year/dry-year ratio than other Australian rivers. This fact enhances the reliability of the hydroelectric installations. While surveyors established detailed ground levels, geologists measured the deep rock structure. A thorough knowledge of the type, age and condition of subsurface strata and the location of faults was essential before the precise locations of power stations and dams could be decided. Also, the geological foundation vastly influenced the type of dam chosen for each site. 100 SILICON CHIP A fluid mechanics laboratory set up at Cooma test-proved the proposed designs for dams and spillways. Construction begins The geology near Mt Kosciusko is a mix of basalt lava flows, older clays and gravels overlaying ancient bluegrey granite up to 500 million years old. In places, glacial moraines show the only evidence on the mainland of past ice ages that occurred some two million years ago. It was in this type of area, 13km from the highest point in Australia, that the first dam and power station of the Snowy Mountains system was built. The Guthega Dam foundations were dug in the bed of the upper Snowy River at the beginning of December 1951. As with most of the Snowy sites, conditions were very difficult. The straight concrete gravity dam , rising a mere 33.5 metres above its granite foundation, holds back 1548 megalitres of water, at 1582 metres above sea level. The Guthega power station is supplied from the dam by a 5.87-metre wide horseshoe shaped underground Pumped water storage for later use during peak electricity demand periods is a key element in the function of the Snowy Mountains scheme. The two pump stages in the Jindabyne Pumping Station are used to lift water some 230 metres up to Island Bend pondage. pressure tunnel ending in two penstock pipes, in all totalling 5.5km in length. The penstocks reduce in diameter from 2.13 metres at the top to 1.52 metres at the bottom as the water velocity increases. To withstand the pressure of the 247-metre head of water, the pipes at the lower end of the penstocks are constructed from 24mm steel plate. Within the power station, two 3 lMW Francis vertical shaft water turbines together use about 40 cubic metres water per second to drive the alternators. Rotating quietly at 428 rpm, the two alternators together contribute 60MW to the system grid. The generated 1 lkV is stepped up to 132kV for tran.:;mission to Khancoban, Jindabyne and Cooma. That's all for now. We'll resume our story of the Snowy Mountains Schernfl next month. Acknowledgement Special thanks and acknowledgements to Libby Langford and the Snowy Mountains Hydroelectric Authority for data, photos and permission to publish. SC