EldoradoDredge
VisitorGuide
Cock’sEldoradoDredgehasremainedinitsfinalmooringplaceatEldorado20kmeastof Wangarattasince1954.Itwastieduphereafteroperatingfor18yearsandwinning70,664
ouncesofgoldand1,383tonsoftinconcentratefromthe rich alluvial plain of Reedy Creek.
TheDredge Walk
An easy 15 minutewalk around the pond tellsyou about the dredge,its operation and the environment. Numberedposts along theway correspondwith information in this brochure.
Before startingthewalk, takea look at the internal workings.Followthegangway tothefirstfloor toviewthe Control Room (14) and the lower floors (5,7 and8).
Numbers in ( ) refer to numbers on the diagram overleaf.
Note: Access to other parts ofthe dredge is currentlynot permitted. Swimmingand diving are not permitteddue to the possibility of striking submergedobjects.
1.Movement and digging
An endless beltwith about110 steel buckets did the actualdredging. The buckets, carried ona moveable arm called thebucket ladder (1), cutinto the alluvium (gold and tinbearing earth) with an action similar toa slowmoving chainsaw.
The digging end of the bucketladderwas moved byan elaborate set of pulleysandcables visible on the fore gantry(2) across the bowof the dredge.The operator couldadjust the depth of the dig to 98 feet (30m) belowwater, or raise the ladderabove water formaintenance.Twosteel cables ran from the fore gantryto a 160 hpdouble drumwinch (3)mounted on the deckwhich raised andlowered the bucket ladder.
Cables from each corner of the dredge are attached to mooring points onland (trees or posts) andwere used to manoeuvre the dredge sideways.A fifthcable, theheadline, ran forward to another anchor point.Thiscontrolled the depth of cut into the bank.
2.Maintenance,powerandsafety
From here you can see the bucket ladder more clearly.
The small crane witha latticework of supporting struts is the jib crane (4) used to remove and replace buckets needing repair, a routine task duringweekly maintenance shut-downs on Thursdayand Sundays.
Immediately behind the jib crane is thewelder’s shopwhere repairs and minorweekly maintenancewere carried out.Alongwith mechanical and electrical repairs, the dredge needed constant greasing.
Thedredge takingshape –Photo courtesyEldorado HistoricalSociety
FormoreinformationcalltheParksVictoriaInformationCentre
on131963orvisitourwebsiteat
Further along to your right, protruding from the corrugatediron sheeting, are bracketswhich held the 6,600 volt electricity
4. Removing wasteF
w
cable that ranacross the pond on floats (44 gallon drums) and in through theopeningwherethe lowand high portions of the
roofmeet.Thecable terminated ina transformer to 440 volt 3
phase power to drive the main motors and110 volt single phasepowerfor lightsandsmallermotors.
The dredge’sonboard treatment plant consisted of a large
rotaryscreen or sieve (6), and various jigs (agitators) (7). The Pplant separated out the smallproportionof gold and tin in the c alluviumand discarded the bulk of the materialwhichwas p
ejected from chutes ora pipe at the stern.
T
Despite hazardousworking conditions, no fatal or serious injury ever occurred onthe dredge.The only fatalitywas that
ofTed Fealy who drownedwhen a steep bank at the edgeof
the dredge pond collapsed onhis boat during maintenance
Coursegravel and stoneswere caught in therotaryscreen,s passed into thelower semi-circular “stone-chute” (8) ands
discharged from the stern, fairlyclose to thedredge.
F
work on the bucket ladder.lo
a
3. Spare buckets
Originallythe bucketswere made of cast chrome steelwithL
digging lipsof manganese steel riveted onfor additionalv
toughness andwear resistance.Theycan hold around12w
cubicfeet (0.36m3) andweigh 1.6 tons.
Lipsonthe buckets requiredregular repair, largelythrough5
striking bedrock where it roseclose to the surface on theC
northern boundaryof the claim.o
a
Bucket band failures in 1939 resulted in months of delay. Thea
failure stemmed from the installation of a more powerful 320s
hp motor. Theoriginal motor was 200 hp (5).The newmotorw
placedextra stresson thebucket band.Strongerwasnot
necessarilybetter!T
C
The number 8 weldedon thebucket replaces the originalcast-on CE (Commonwealth Engineering)8,which you can see belowand to the left and nearly wornawayon some of the buckets.The lip on this bucket has been extensively repaired.
h p
Earlyvisitors tothe construction site 1936– Photocourtesy F Richardsonc
Finer gravel and sandwhich passed through the perforated walls of the rotaryscreenwas discarded in one oftwoways.
Poor grade materialwas simplyejected via the upper semi- circular chute (9). Gold and tin bearingalluvium went through primaryand secondaryjigs to separate the metals.
The waste material from the primaryjigswasdischarged asa slurry into open troughs or “launders” (10) running downeach sideof the dredgeandprotrudingfrom the stern.
Finewaste from the secondaryjigswaspumped through the long pipe suspended from thestern on a lattice frame (11), anddischarged on top of thecourse graveland stones.
Layering of fine waste on top of coursewassupposedto help vegetation regrowthafter dredging finished.You can see whether this happened or not.
5. Reedy Creek
Clean, reliable and plentifulwater was essential for dredging operations, firstlyto enable the dredge to float and move aroundand secondlyfor treatment and transportof the alluvium from the buckets intothe rotaryscreen.Other jets sprayed the material in the rotaryscreen and jigs. Most of the waterwas supplied from upstream.
Toensurea supply of clean water and to protect Reedy Creek, large settling ponds (slum dams)were constructed to hold muddywater. Once the silt had settled, cleanwaterwas pumpedback into the dredgepool. In 1936 the settling ponds covered 62 acres and therewere three pumpingplants.
The wall near youwas built inabout 1949 to form a settling pond or ‘slum’ dam.
Some of the larger settling ponds (former sluicingholes) can still be seen along the Eldorado/WoolshedRoad.
Silt or “slum” dams gradually became ‘choked’ andwereoften abandoned.A glimpse across the slum damindicated the poor rate of regeneration inthese areas–weedsandwattlespredominate.
In 1951, Reedy Creekwas diverted to its present position so that dredging could occur in the originalcreekbed.The dredge,whichwas further upstream, then followed theoriginal coursedownstream,workingover previously undredged ground.
Near the sternof the dredgeyouwill noticeasmall tin shed perched precariously on railings over the dredge pond. This “dunny” (12)was one of theveryfewstaffamenities onboard.
.
Forfurtherinformation
ParksVictoriaInformationCentre
Call131963
orvisittheParksVictoriawebsite
VisitorInformationCentreCornerToneRoadandHandleyStreetWangaratta3677
Freecall:1800801065
Caringforthe environment
Helpuslookafter yourparkbyfollowingtheseguidelines:
Pleasetakerubbishhomewithyouforrecyclingordisposal
Allnativeplants,animals,
historicalandarchaeologicalsitesandgeographicfeaturesare
protectedbylaw
Dogsarenotpermitted
intheparkFirearmsareprohibited
Lightfiresonlyinfireplacesprovided.
Nofires,includingbarbecues,maybelit
onadayof
TotalFireBanWarbyRangeStateParkisintheNorthEastFireBanDistrict
Bringyourownfirewoodforbarbecues.Gasbarbecuesarerecommended
Prospectingispermittedindesignatedareas.ProspectorsmustholdacurrentMiner'sRight.RefertotheProspecting
Guideformoreinformation.
Vehicles,includingmotorbikes,mayonlybeusedonformedopenroads.Driversmustbelicensedandvehicles
registeredandroadworthy
6.Cranes and meters
From this pointyou can look up and see the overheadtravellingcrane.
The beam (13) extending out over thewaterwas used to lift heavyequipmenton and off the dredge.
Further toward the bowat first floor level is the Control Room (14).
Anelaborate system of electricalswitchesand meters (15) controlled the various motors and other equipment.
The control roomc 1936 – Photo courtesy EldoradoHistoricalSociety
Mechanicallevers were used to start or stop the winch(16)motors.These winches in turn controlledall movement of the dredge including the bucket ladder and band.
Costs in treating gold and tin alluvium increased dramaticallyin the early1950s, forcing suspensionof dredgingon 13August 1954. The dredgewasdocked at its present site on 24 August 1954 and hasnot moved since.
7.Onshore
The jigs on thedredge produced a black sand containinggold, tin and other minerals. This was taken ashore by rowboat, andthen toa treatment plant knownas the “Tin shed”(about 1km from the dredgesite).
Goldwas separated from tin and other substances using an amalgamating barrel, then retorted andsmelted into gold ingots.The tin ore was further processedand bagged.
In addition to the “Tin shed” therewas an office in Eldoradoandamaintenance workshopwhere buckets and pumpswere repaired and other maintenance jobs carriedout.
In the latter stages of the dredge’s life, the office andworkshopwere moved to this vicinity.Soon after the dredgeceased operation, the “Tin shed” andworkshopbuildings and plantwere soldand presumably removed. Onlyafewpieces ofequipment remain, includingan amalgamating barrel,various motors, capacitor banks,winch drumetc.
The former office was used as a caretaker’s residence forabout 20 years after 1954. The site of this building was further upthe hill in amongstthetrees. Once the caretaker left, the building became derelict andwasdemolished. A few bricks mark its former location.
The caretaker’s home for 20 years – photo courtesyF Richardson
Future ofthedredge
Despiteattempts bythe companytosell the dredge it finally passed into government hands in 1984. Rusting of the pontoons caused thedredge to take water and list. The future for the largest and most intactbucket gold dredge in Australia was indoubt.
Cock’s Eldorado dredge is nowlisted on the Victorian Heritage Register and Parks Victoria is investigating various strategies for its improved longterm conservation. Thismayinclude re- floating the dredge.
A cathodicprotectionsystem, fundedbya grant from Heritage Victoria, has beeninstalled tostop rusting.
How to get there
Eldorado Dredge is located 17km east ofWangarattaon theWangaratta-EldoradoRoad.
June2007
PrintedonAustralian-made,100%recycledpaper.