Sluice Gate Presentation1

7/30/2019 Sluice Gate Presentation1

1/44

Cowlitz Fallsowlitz FallsHydroelectricydroelectricProjectroject

The Continuing Saga of thehe Continuing Saga of theCowlitz Falls Sluice Gatesowlitz Falls Sluice Gates2003 Repairs003 Repairs

By Steve Grega & J im ByrdBy Steve Grega & J im Byrd

NW Hydro Conference J une 9, 2005NW Hydro Conference J une 9, 2005


2/44

Overview ofOverview of

Cowlitz Falls ProjectCowlitz Falls Project


3/44

Where isWhere is

Cowlitz Falls Dam?Cowlitz Falls Dam?

Cowlitz Falls Dam

I-5SR-12

Chehalis

Randle


4/44

Cowlitz Falls Project HistoryCowlitz Falls Project History

Started Studies in

1977 License

Application in April

1981 NEPA EIS April

1983

Licensed in J une1986

Permitting until1991


5/44

Construction Started J une 1991Construction Started J une 1991

Blasting

Digging


6/44

Construction Continued ThrougConstruction Continued Throug

19931993

Concrete

Equipment


7/44

Commercial Operation J uneCommercial Operation J une

19941994

Dam


8/44

Cowlitz Falls StatisticsCowlitz Falls Statistics

145 feet off ofBedrock

700 feet Long

2 Kaplan-TypeTurbines

2 35MWGenerators

265,000MWHr

Annually


9/44

Dam Unique FeaturesDam Unique Features

Floating Debris

Barrier (Queen Mary)

Powerhouse SpillwayPowerhouse SpillwayOverflow DesignOverflow Design


10/44

Operation of Cowlitz FallsOperation of Cowlitz Falls

ProjectProject Run of River Operation

SCADA holds Lake at nearly Constant Level Up to Two Foot Daily Reservoir Variation

If Flows are between 1000cfs and 1800cfs,Generate only Part of Day

Inflow below 1000cfs and Riffe Lake below

Elevation 750, Pass Inflow Drawdown if flows are great than 15,000 cfs

in Randle. 10 to 20 dependant on Inflow


11/44

Staffing OperationStaffing Operation

Staff of 7 Full-TimeEmployees

Man the Plant 7days / week, 365days/ year

8 Hours / day

On-Call 16 hours /

day Manned Full Time

when Conditions

warrant


12/44

Flood OperationsFlood Operations

December 1995 FloodDecember 1995 Flood --70.000 cfs70.000 cfs

February 1996 Flood ofFebruary 1996 Flood ofRecord 100,000 cfsRecord 100,000 cfs


13/44

Flood OperationsFlood Operations

Gates 2 & 3 Full OpenGates 2 & 3 Full Open

Gates 1 & 4 Full OpenGates 1 & 4 Full Open


14/44

The Sluice GatesThe Sluice Gates

Two gated low-

level outlet tunnelsunder Spillway #4

Tunnel is equippedwith 12 wide by16 high wheeled

gatesThird diversion

tunnel blocked off


15/44

Purpose of Sluice GatesPurpose of Sluice Gates

Assist in passing siltin front of dam

Assist in passing flowsin access of turbineflow >10,500cfs

Passing low flowsduring time inflowsbelow turbineminimums

Dewatering Reservoir

below spillway ogee

l i


16/44

Sluice GateSluice Gate

DesignDesign Regulating Wheel Gate

74,000 poundsw/ballast

Design Head 92 feet

12 Stainless steelwheels 19.7diameter

Hydraulic Raised,Gravity Closed

3.5diameter rod @

1000psi raises gate


17/44

Sluiceway DewateringSluiceway Dewatering

MaintenanceBulkhead Gate

Closes only underbalanced headconditions

Guides do notcome to surface

Requires diversand 50-ton craneto install andretrieve

O i i l GO i i l G t


18/44

Original GateOriginal Gate

DesignDesignTop & Bottom flanged

wheels to restrainlateral movement

Top & Bottom springTop & Bottom spring

rollers to restrainrollers to restrainupstream movementupstream movement


19/44

First ProblemsFirst Problems May 1994May 1994

Start-up testing ofSluice Gates

Both Gates Noisy

Both Gates

jammed Would not move

up or down

Drained Reservoir Found gates off

track


20/44

Modifications #1Modifications #1 Dec 1994Dec 1994

Experts UnsteadyPressures exist that

cause gate to jump Add Heavier spring

assemblies

Add side rails &bumpers

Modify top Lintel

Chamber ceiling

Repair Wheels, etc.

Some improvement but still loud banging

M difi ti #2M difi ti #2 AA


21/44

Modification #2Modification #2 AugAug

19961996 Installed pressing

system To holdgate downstream

Control software

modifications opengate to 112% toremove from

waterway

Still too

much gatemovement


22/44

Modification #3Modification #3 Nov 1997Nov 1997

Installed 4 zeroInstalled 4 zero--clearanceclearance

side guide shoesside guide shoes

Installed stainless

steel side guide rails

Testing & Acceptance of theTesting & Acceptance of the


23/44

Testing & Acceptance of theTesting & Acceptance of the

GatesGates Full operation testing

conducted in Mar 98

Gates smooth to 80%

90% to 112% roughoperation

112% open andspillway gate 4 open

3, sounds reduced SG#4 to 10open,sound reduced

Manufacture &Engineer left us


24/44

Gate operation ProblemsGate operation Problems

19991999 20032003 Apr 99 Notice a bottom

Bumper was missing

Sep 99 Inspection found 3of the 4 bottom bumpergone

Bolts failed in tension Lower section of side rail

missing

Reduced max opening to63% or 10

Continued to Operate Gates

Top Side Bumper


25/44

Failed ComponentsFailed Components

Box holdingbumper pads

Bolts securing bottom

bracket failed in tension


26/44

Feb 2003 Operational FailureFeb 2003 Operational Failure

Plant mannedduring moderate

flood heavysediment load,drawn downreservoir 14 feet(elev. 848)

Spilling fromSpillways 1 & 4

SCADA system

opened sluice gates1 & 2 to 5

2003 Operation Failure2003 Operation Failure


27/44

2003 Operation Failure2003 Operation Failure

Corrective ActionsCorrective Actions Operator closed Spill

Gate 4 followed by theclosing of sluice gates

Sluices closed to foot

Re-opened spill gate 4to pass flood

Other attempts were

made to close sluices Both gates stuck at 9

open

Stuck sluice gate fromD/S side

Drain the Reservoir?Drain the Reservoir?


28/44

Drain the Reservoir?Drain the Reservoir?

Yep!Yep! After analyzing situation

balance closure withsluice bulkhead required

Must obtain permits

Clean out moorage site Move Debris Barrier

Construct a 2nd bulkhead

Drain Reservoir Install bulkhead gates


29/44

Drawn Down ReservoirDrawn Down Reservoir

Silt?

lkh d l


30/44

Bulkhead ClosureBulkhead Closure

After some coaxingbulkheads finally

seated & stoppedthe flow


31/44

Removal of Sluice Gate #1Removal of Sluice Gate #1 Difficult &

expensive tofind crane tohandle load

1st remove

hatch cover Removecylinder & rod

Remove topplatform

Remove top

bumpers


32/44

Removal of Sluice Gate #1Removal of Sluice Gate #1

Requires a 300-ton crane

Experienced Ironworkers

InspectionInspection


33/44


& Findings& Findings Wheel Friction, 6 of

12 wheels could notbe turned by hand

IIWheel thrust washersWheel thrust washers

in poor conditionin poor condition



34/44

InspectionInspection Wheel & Rails indicated

scoring on surfaces(from wheels not turning)

IISide spring rollersSide spring rollersindicated heavy impactindicated heavy impact


35/44


ConcreteConcrete slotsloterosionerosion

Indications of

Lateralmovement(rail scoring)

C l i


36/44

ConclusionsConclusions Gates Stuck do to

increased wheel bushingfriction

Wheel Damage causedby large impact forces

Bushing Damage caused

by dirt and possiblebushing material swelling no clearance

Gravity closure safetymargin too small

Lower bumpers subject

to high velocity flows &debris impact

G i & difi iG t R i & M difi ti


37/44

Gate Repairs & ModificationsGate Repairs & Modifications Replaced wheel

bushings - Lubritemang-brnz with G-10lubricant

Add seals to reduce

contamination

IIReplaced thrust washersReplaced thrust washers

(Manganese(Manganese--Bronze)Bronze)

IIFace cut wheelsFace cut wheels

Gate Repairs & ModificationsGate Repairs & Modifications


38/44


Rebuilt side rollerspring assemblies

Combined lower

roller spring & zero-clearance guides

OrkotSliding Pad withRubber Pad behind



39/44


Repaired Guides andConcrete

Used Emaco S88, fiber-reinforcedstructural repair mortar



40/44


Rebuilt hydrauliccylinder

Rebuilt electronicposition device(temposonic)



41/44


Repaired pressingsystem roller rails

Repaired Gate Seals

Final CheckFinal Check


42/44

Final CheckFinal Check

and Installationand Installation Rehabilitation

Complete

Where do we go from here?Where do we go from here?


43/44

Where do we go from here?Where do we go from here?

Tested gates to 10

Evaluate adding

additional ballastto gates

Evaluated addingupper snubbersystem to reducemovement in fullopen position

Extend gantrycrane rail acrossbay 4

Cowlitz Falls HydroelectricCowlitz Falls Hydroelectric


44/44

yy

ProjectProject

Questions?

Documents

Sluice Gate Presentation1