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                         SMALL MICHELL (BANKI) TURBINE:
                               A CONSTRUCTION MANUAL
                                    W.R. BRESLIN
                              a VITA publication
                              ISBN 0-86619-066-X
                         1600 Wilson Boulevard, Suite 500
                          Arlington, Virginia 22209 USA
                     Tel:  703/276-1800 * Fax:   703/243-1865
                  [C] 1980 Volunteers in Technical Assistance
                        SMALL MICHELL (BANKI) TURBINE:
                            A CONSTRUCTION MANUAL
   I.   WHAT IT IS AND WHAT IT IS USED FOR                  
  II.   DECISION FACTORS                                    
       Cost Estimate                                       
       Site Selection                                      
       Alternating or Direct Current                      
   V.   CONSTRUCTION                                        
       Prepare the End Pieces                             
       Construct the Buckets                              
       Assemble the Turbine                                
       Make the Turbine Nozzle                            
       Turbine Housing                                    
  VI.   MAINTENANCE                                         
 VII.   ELECTRICAL GENERATION                               
VIII.  DICTIONARY OF TERMS                                
  IX.   FURTHER INFORMATION RESOURCES                       
   X.   CONVERSION TABLES                                   
APPENDIX I.  SITE ANALYSIS                                
                    SMALL MICHELL (BANKI) TURBINE
The Michell or Banki turbine is a relatively easy to build and
highly efficient means of harnessing a small stream to provide
enough power to generate electricity or drive different types
of mechanical devices.

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The turbine consists of two main parts--the runner, or wheel,
and the nozzle.  Curved horizontal blades are fixed between the
circular end plates of the runner (see page 17).   Water passes
from the nozzle through the runner twice in a narrow jet before
it is discharged.
Once the flow and head of the water site have been calculated,
the blades of the 30cm diameter wheel presented here can be
lengthened as necessary to obtain optimum power output from the
available water source.
The efficiency of the Michell turbine is 80 percent or greater.
This, along with its adaptability to a variety of water
sites and power needs, and its simplicity and low cost, make it
very suitable for small power development.   The turbine itself
provides power for direct current (DC); a governing device is
necessary to provide alternating current (AC).
Applications:    *  Electric generation (AC or DC)
                 *  Machinery operations, such as threshers,
                    winnower, water pumping, etc.
Advantages:      *  Very efficient and simple to build and
                 *  Virtually no maintenance.
                 *  Can operate over a range of water flow and
                    head conditions.
Considerations:  *  Requires a certain amount of skill in working
                    with metal.
                 *  Special governing device is needed for AC
                    electric generation.
                 *  Welding equipment with cutting attachments
                    are needed.
                 *  Electric grinding machine is needed.
                    Access to small machine shop is necessary.
$150 to $600 (US, 1979) including materials and labor.   (This is
for the turbine only.  Planning and construction costs of dam,
penstock, etc., must be added.)
(*) Cost estimates serve only as a guide and will vary from
country to country.
Development of small water power sites currently comprises one
of the most promising applications of alternate energy technologies.
If water power will be used to produce only mechanical
energy--for example, for powering a grain thresher--it may be
easier and less expensive to construct a waterwheel or a windmill.
However, if electrical generation is needed, the Michell
turbine, despite relatively high initial costs, may be feasible
and indeed economical under one or more of the following
*  Access to transmission lines or to reliable fossil fuel
   sources is limited or non-existent.
*  Cost of fossil and other fuels is high.
*  Available water supply is constant and reliable, with a head
   of 50-100m relatively easy to achieve.
*  Need exists for only a small dam built into a river or stream
   and for a relatively short (less than 35m) penstock (channel)
   for conducting water to the turbine.
If one or more of the above seems to be the case, it is a good
idea to look further into the potential of a Michell turbine.
The final decision will require consideration of a combination
of factors, including site potential, expense, and purpose.
When determining whether a project is worth the time, effort,
and expense involved, consider social, cultural, and environmental
factors as well as economic ones.   What is the purpose of
the effort?  Who will benefit most?  What will the consequences
be if the effort is successful?   And if it fails?
Having made an informed technology choice, it is important to
keep good records.  It is helpful from the beginning to keep
data on needs, site selection, resource availability, construction
progress, labor and materials costs, test findings, etc.
The information may prove an important reference if existing
plans and methods need to be altered.   It can be helpful in
pinpointing "what went wrong?"   And, of course, it is important
to share data with other people.
The technologies presented in this and the other manuals in the
energy series have been tested carefully and are actually used
in many parts of the world.  However, extensive and controlled
field tests have not been conducted for many of them, even some
of the most common ones.  Even though we know that these technologies
work well in some situations, it is important to
gather specific information on why they perform properly in one
place and not in another.
Well documented models of field activities provide important
information for the development worker.   It is obviously important
for a development worker in Colombia to have the technical
design for a machine built and used in Senegal.   But it is even
more important to have a full narrative about the machine that
provides details on materials, labor, design changes, and so
forth.  This model can provide a useful frame of reference.
A reliable bank of such field information is now growing.  It
exists to help spread the word about these and other technologies,
lessening the dependence of the developing world on
expensive and finite energy resources.
A practical record keeping format can be found in Appendix IV.
Both main parts of the Michell turbine are made of plate steel
and require some machining.  Ordinary steel pipe is cut to form
the blades or buckets of the runner.   Access to welding equipment
and a small machine shop is necessary.
The design of the turbine avoids the need for a complicated and
well-sealed housing.  The bearings have no contact with the
water flow, as they are located outside of the housing; they
can simply be lubricated and don't need to be sealed.
Figure 2 shows an arrangement of a turbine of this type for

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low-head use without control.   This installation will drive an
AC or DC generator with a belt drive.
This is a very important factor.   The amount of power obtained,
the expense of installation, and even, by extension, the applications
for which the power can be used may be determined by
the quality of the site.
The first site consideration is ownership.   Installation of an
electricity-generating unit--for example, one that needs a dam
and reservoir in addition to the site for the housing--can
require access to large amounts of land.
In many developing countries, large lots of land are few and it
is likely that more than one owner will have to be consulted.
If ownership is not already clearly held, the property questions
must be investigated, including any rights which may
belong to those whose property borders on the water.   Damming,
for example, can change the natural water flow and/or water
usage patterns in the area and is a step to be taken only after
careful consideration.
If ownership is clear, or not a problem, a careful analysis of
the site is necessary in order to determine:   1) the feasibility
of the site for use of any kind, and 2) the amount of power
obtainable from the site.
Site analysis consists of collecting the following basic data:
*  Minimum flow.
*  Maximum flow.
*  Available head (the height a body of water falls before hitting
   the machine).
*  Pipe line length (length of penstock required to give desired
*  Water condition (clear, muddy, sandy, acid, etc.).
*  Site sketch (with evaluations, or topographical map with site
   sketched in).
*  Soil condition (the size of the ditch and the condition of
   the soil combine to affect the speed at which the water moves
   through the channel and, therefore, the amount of power
*  Minimum tailwater (determines the turbine setting and type).
Appendix I contains more detailed information and the instructions
needed to complete the site analysis including directions
for measuring head, water flow, and head losses.   These directions
are simple enough to be carried out in field conditions
without a great deal of complex equipment.
Once such information is collected, the power potential can be
determined. Some power, expressed in terms of horsepower or
kilowatts (one horsepower equals 0.7455 kilowatts), will be
lost because of turbine and generator inefficiencies and when
it is transmitted from the generator to the place of
For a small water power installation of the type considered
here, it is safe to assume that the net power (power actually
delivered) will be only half of the potential gross power.
Gross power, or power available directly from the water, is
determined by the following formula:
Gross Power
  Gross power (English units:  horsepower) =
Minimum Water Flow (cubic feet/second) X Gross Head (feet)
  Gross power (metric horsepower) =
1,000 Flow (cubic meters/second) X Head (meters)
Net Power (available at the turbine shaft)
  Net Power (English units) =
Minimum Water Flow X Net Head(*) X Turbine Efficiency
  Net Power (metric units) =
Minimum Water Flow X Net Head(*) X Turbine Efficiency
Some sites lend themselves naturally to the production of
electrical or mechanical power.   Other sites can be used if work
is done to make them suitable.   For example, a dam can be built
to direct water into a channel intake or to get a higher head
than the stream provides naturally.   (A dam may not be required
if there is sufficient head or if there is enough water to
cover the intake of a pipe or channel leading to the penstock.)
Dams may be of earth, wood, concrete, or stone.   Appendix II
provides some information on construction of small dams.
Flowing water tends to generate automatically a picture of
"free" power in the eyes of the observer.   But there is always a
(*) Net head is obtained by deducting energy losses from the gross
head (see page 57).  A good assumption for turbine efficiency
when calculating losses is 80 percent.
cost to producing power from water sources. Before proceeding,
the cost of developing low-output water power sites should be
checked against the costs of other possible alternatives, such
*  Electric utility--In areas where transmission lines can furnish
   unlimited amounts of reasonably priced electric current,
   it is often uneconomical to develop small or medium-sized
   sites.   However, in view of the increasing cost of utility
   supplied electricity, hydroelectric power is becoming more
*  Generators--Diesel engines and internal-combustion engines
   are available in a wide variety of sizes and use a variety of
    fuels--for example, oil, gasoline, or wood.  In general, the
   capital expenditure for this type of power plant is low compared
   to a hydroelectric plant.  Operating costs, on the other
   hand, are very low for hydroelectric and high for fossil fuel
   generated power.
*  Solar--Extensive work has been done on the utilization of
   solar energy for such things as water pumping.  Equipment now
   available may be less costly than water power development in
   regions with long hours of intense sunshine.
If it seems to make sense to pursue development of the small
water power site, it is necessary to calculate in detail
whether the site will indeed yield enough power for the specific
purposes planned.
Some sites will require investing a great deal more money than
others.  Construction of dams and penstocks can be very expensive,
depending upon the size and type of dam and the length of
the channel required.  Add to these construction expenses, the
cost of the electric equipment--generators, transformers,
transmission lines--and related costs for operation and maintenance
and the cost can be substantial.
Any discussion of site or cost, however, must be done in light
of the purpose for which the power is desired.   It may be
possible to justify the expense for one purpose but not for
A turbine can produce both alternating (AC) and direct current
(DC).  Both types of current cannot always be used for the same
purposes and one requires installation of more expensive equipment
than the other.
Several factors must be considered in deciding whether to
install an alternating or direct current power unit.
The demand for power will probably vary from time to time during
the day.  With a constant flow of water into the turbine,
the power output will thus sometimes exceed the demand.
In producing AC, either the flow of water or the voltage must
be regulated because AC cannot be stored.   Either type of regulation
requires additional equipment which can add substantially
to the cost of the installation.
The flow of water to a DC-producing turbine, however, does not
have to be regulated.  Excess power can be stored in storage
batteries.  Direct current generators and storage batteries are
relatively low in cost because they are mass-produced.
Direct current is just as good as AC for producing electric
light and heat.  But electrical equipment having AC motors,
such as farm machinery and household appliances, have to be
changed to DC motors.  The cost of converting appliances must be
weighed against the cost of flow regulation needed for producing
While a 30.5cm diameter wheel has been chosen for this manual
because this size is easy to fabricate and weld, the Michell
turbine has a wide range of application for all water power
sites providing head and flow are suitable.   The amount of water
to be run through the turbine determines the width of the
nozzle and the width of the wheel. These widths may vary from
5cm to 36cm.  No other turbine is adaptable to as large a range
of water flow (see Table 1).
                             Impulse or Pelton        Michell or Banki       Centrifugal Pump
                                                                             Used as Turbine
   Head Range (feet )         50 to 1000                   3 to 650
   Flow Range (cubic)
    feet per second           0.1 to 10                  0.5 to 250
   Application                high head                   medium head           Available for any
                                                                             desired condition
   Power (horsepower)         1 to 500                    1 to 1000   
   Cost per Kilowatt            low                          low                      low
   Manufacturers              James Leffel & Co.       Omberger-Turbinenfabrik      Any reputable dealer
                             Springfield, Ohio       8832 Warenburg               or manufacturer.
                             45501 USA               Bayern, Germany 
                             Dress & Co.             Can be do-it-yourself
                             Warl. Germany           project if small weld and
                             Offices Bubler          machine shops are
                             Taverne, Switzerland    available.
                           Table 1. Small Hydraulic Turbines
The size of the turbine depends on the amount of power
required, whether electrical or mechanical.   Many factors must
be considered to determine what size turbine is necessary to do
the job.  The following
example illustrates the
decision-making process
for the use of a turbine
to drive a peanut huller
(see Figure 3).  Steps will

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be similar in electrical
power applications.
*  Power enough to replace
   the motor for a 2-1/2 hp
   1800 revolutions per
   minute (rpm) peanut
*  Gross power needed is about 5 hp (roughly twice the horsepower
   of the motor to be replaced assuming that the losses
   are about one-half of the total power available).
*  Village stream can be dammed up and the water channeled
   through a ditch 30m (100 ft) long.
*  Total difference in elevation is 7.5m (25 ft).
*  Available minimum flow rate:  2.8 cu ft/sec.
*  Soil of ditch permits a water velocity of 2.4 ft/sec (Appendix
   I, Table 2 gives n = 0.030).
*  Area of flow in ditch = 2.8/2.4 - 1.2 sq ft.
*  Bottom width = 1.2 ft.
*  Hydraulic radius = 0.31 x 1.2 = 0.37 ft (see Appendix I).
Calculate results of fall and head loss.   Shown on nomograph
(Appendix I) as a 1.7 foot loss for every 1,000 feet. Therefore
the total loss for a 30m (100 ft) ditch is:
                           10   = 0.17 feet             
Since 0.17 ft is a negligible loss, calculate head at 25 ft.
Power produced by turbine at 80% efficiency = 6.36 hp
Net power = Minimum water flow x net head x turbine efficiency
           2.8 x 25 x 0.80
                     8.8         = 6.36 horsepower
Formulas for principal Michell turbine dimensions:
  ([B.sub.1]) = width of nozzle =        210 x flow
                                  Runner outside diameter x [square root] head
                               =   210 x 2.8 = 9.8 inches
                                  12 x [square root] 25                    
  ([B.sub.2]) = width of runner between discs - ([B.sub.1]) = 1/2 to 1 inch
                                = 9.8 + 1 inch = 10.8 inches
 Rotational speed (revolutions per minute)
                                =      73.1 x [square root] head  
                                   Runner outside diameter (ft)
                                   73.1 x [square root] 25    = 365.6 rpm
 The horsepower generated is more than enough for the peanut
 huller but the rpm is not high enough.
 Many peanut threshers will operate at varying speeds with
 proportional yield of hulled peanuts. So for a huller which
 gives maximum output at 2-1/2 hp and 1800 rpm, a pulley
 arrangement will be needed for stepping up speed. In this
 example, the pulley ratio needed to step up speed is 1800
 .365 or approximately 5:1.  Therefore a 15" pulley attached to
 the turbine shaft, driving a 3" pulley on a generator shaft,
 will give [+ or -] 1800 rpm.
Although materials used in construction can be purchased new,
many of these materials can be found at junk yards.
Materials for 30.5cm diameter Michell turbine:
*  Steel plate 6.5mm X 50cm X 100cm
*  Steel plate 6.5mm thick (quantity of material depends on
   nozzle width)
*  10cm ID water pipe for turbine buckets(*)
*  Chicken wire (1.5cm X 1.5cm weave) or 25mm dia steel rods
*  4 hub flanges for attaching end pieces to steel shaft (found
   on most car axles)
*  4.5cm dia solid steel rod
*  two 4.5cm dia pillow or bush bearings for high speed use.  (It
   is possible to fabricate wooden bearings.  Because of the high
   speed, such bearings would not last and are not recommended.)
*  eight nuts and bolts, appropriate size for hub flanges
*  Welding equipment with cutting attachments
*  Metal file
*  Electric or manual grinder
*  Drill and metal bits
*  Compass and Protractor
*  T-square (template included in the back of this manual)
*  Hammer
*  C-clamps
*  Work bench
(*) Measurements for length of the pipe depend on water site
An actual size template for a 30.5cm turbine is provided at the
end of this manual.  Two of the bucket slots are shaded to show
how the buckets are installed.
Figure 4 shows the details of a Michell runner.

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*  Cut out the half circle from the template and mount it on
   cardboard or heavy paper.
*  Trace around the half circle on the steel plate as shown in
   Figure 5.

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*  Turn the template over and trace again to complete a full
   circle (see Figure 6.

42p18b.gif (353x353)

*  Draw the bucket slots on the template with a clockwise slant
   as shown in Figure 7.

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*  Cut out the bucket slots on the template so that there are 10
*  Place the template on the steel plate and trace in the
   bucket slots.
*  Repeat the tracing process as before to fill in the area for
   the shaft (see Figure 8).

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*  Drill a 2mm hole in the steel plate in the center of the
   wheel where the cross is formed.  The hole will serve as a
   guide for cutting the metal plate.

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*  Take a piece of scrap metal 20cm long x 5cm wide.  Drill a
   hole the width of the opening in the torch near one end of
   the metal strip.
*  Drill a 2mm dia hole at the other end at a point equal to the
   radius of the wheel (15.25cm).  Measure carefully.
*  Line up the 2mm hole in the scrap metal with the 2mm hole in
   the metal plate and attach with a nail as shown in Figure 10.

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*  Cut both end plates as shown (in Figure 10) using the torch.
*  Cut the bucket slots with the torch or a metal saw.
*  Cut out a 4.5cm dia circle from the center of both wheels.
   This prepares them for the axle.
Calculate the length of buckets using the following formula:
   Width of Buckets   =            210 x Flow (cu/ft/sec)                              + (1 .5in)
   Between End Plates        Outside Diameter of Turbine (in) x [square root] Head (ft)
*  Once the bucket length has been determined, cut the 10cm dia
   pipe to the required lengths.
*  When cutting pipe lengthwise with a torch, use a piece of
   angle iron to serve as a guide, as shown in Figure 11.

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   (Bucket measurements given in the template in the back of
   this manual will serve as a guide.)
*  Pipe may also be cut
   using an electric
   circular saw with a
   metal cutting blade.
*  Cut four buckets from each section of pipe.  A fifth piece of
   pipe will be left over but it will not be the correct width
   or angle for use as a bucket (see Figure 12).

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*  File each of the buckets to measure 63mm wide.  (NOTE:  Cutting
   with a torch may warp the buckets.  Use a hammer to straighten
   out any warps.)
*  Cut a shaft from 4.5cm dia steel rod.  The total length of the
   shaft should be 60cm plus the width of the turbine.
*  Place the metal hubs on the center of each end piece, matching
   the hole of the hub with the hole of the end piece.
*  Drill four 20mm holes through the hub and end piece.
*  Attach a hub to each end
   piece using 20mm dia x
   3cm long bolts and nuts.
*  Slide shaft through the
   hubs and space the end
   pieces to fit the

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*  Make certain the distance from each end piece to the end of
   the shaft is 30cm.
*  Insert a bucket and align the end pieces so that the blade
   runs perfectly parallel with the center shaft.
*  Spot weld the bucket in place from the outside of the end
   piece (see Figure 14).

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*  Turn the turbine on the shaft half a revolution and insert
   another bucket making sure it is aligned with the center
*  Spot weld the second bucket to the end pieces.  Once these
   buckets are placed, it is easier to make sure that all the
   buckets will be aligned parallel to the center shaft.
*  Weld the hubs to the shaft (check measurements).
*  Weld the remaining buckets to the end pieces (see Figure 15).

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*  Mount the turbine on its bearings.  Clamp each bearing to the
   workbench so that the whole thing can be slowly rotated as in
   a lathe.   The cutting tool is an electric or small portable
   hand grinder mounted on a rail and allowed to slide along a
   second rail, or guide (see Figure 16).  The slide rail should

42p24b.gif (353x353)

   be carefully clamped so that it is exactly parallel to the
   turbine shaft.
*  Grind away any uneven edges or joints.  Rotate the turbine
   slowly so that the high part of each blade comes into contact
   with the grinder.  Low parts will not quite touch.  This
   process takes several hours and must be done carefully.
*  Make sure the bucket blades are ground so that the edges are
   flush with the outside of the end pieces.
*  Balance the turbine so it will turn evenly (see Figure 17).

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   It may be necessary to weld a couple of small metal washers
   on the top of either end of the turbine.  The turbine is
   balanced when it can be rotated in any position without
*  Determine nozzle size by using the following formula:
                   210 X flow (cubic feet/second
            runner outside diameter (in) x [square root] head (ft)
  The nozzle should be 1.5cm to 3cm less than the inside width
  of the turbine.
Figure 18 shows a front view of a properly positioned nozzle in

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relationship to the turbine.
*  From a 6.5mm steel plate, cut side sections and flat front
   and back sections of the nozzle.  Width of front and back
   pieces will be equal to the width of the turbine wheel minus
   1.5 to 3cm.   Determine other dimensions from the full-scale
   diagram in Figure 19.

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*  Cut curved sections of the nozzle from 15cm (OD) steel pipe
   if available.   Make sure that the pipe is first cut to the
   correct width of the nozzle as calculated previously.  (Bend
   steel plate to the necessary curvature if 15cm pipe is
   unavailable.   The process will take some time and ingenuity on
   the part of the builder.  One way of bending steel plate is to
   sledge hammer the plate around a steel cylinder or hardwood
   log 15cm in diameter.  This may be the only way to construct
   the nozzle if 15cm steel pipe is unavailable.)
*  Weld all sections together.  Follow assembly instructions
   given in "Turbine Housing" on page 29.
The diagram in Figure 19 provides minimum dimensions for proper
turbine installation.
  Build the structure to house the turbine and nozzle of concrete,
  wood, or steel plate.  Figure 20 shows a side view and

42p29.gif (600x600)

  front view of a typical installation for low head use
  (1-3m).   Be sure housing allows for easy access to the turbine
  for repair and maintenance.
*  Attach the nozzle to the housing first and then orient the
   turbine to the nozzle according to the dimensions given in
   the diagram in Figure 19.  This should ensure correct turbine
   placement.   Mark the housing for the placement of the water
*  Make water seals.  In 6.5mm steel plate, drill a hole slightly
   larger than the shaft diameter (about 4.53cm).  Make one for
   each side.   Weld or bolt to the inside of the turbine housing.
   The shaft must pass through the seals without touching
   them.   Some water will still come through the housing but not
   enough to interfere with efficiency.
*  Make the foundation to which the bearings will be attached of
   hardwood pilings or concrete.
*  Move the turbine, with bearings attached, to the proper
   nozzle/turbine placement and attach the bearings to the foundation
   with bolts.   The bearings will be on the outside of the
   turbine housing (see Figure 21).  (Note:   The drive pulley is

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   omitted from the Figure for clarity.)
Figure 22 shows a possible turbine installation for high head

42p31.gif (600x600)

applications.  A water shut-off valve allows control of the flow
of water.  Never shut off the water flow suddenly as a rupture
in the penstock is certain to occur.   If maintenance on the turbine
is necessary, reduce the flow gradually until the water
The Michell (Banki) turbine is relatively maintenance-free.  The
only wearable parts are the bearings which may have to be
replaced from time to time.
An unbalanced turbine or a turbine that is not mounted exactly
will wear the bearings very quickly.
A chicken wire screen (1.5cm x 1.5cm weave) located behind the
control gate will help to keep branches and rocks from entering
the turbine housing.  It may be necessary to clean the screen
from time to time.  An alternative to chicken wire is the use of
thin steel rods spaced so that a rake can be used to remove any
leaves or sticks.
It is beyond the scope of this manual to go into electrical
generation using the Michell (Banki) turbine.   Depending on the
generator and accessories you choose, the turbine can provide
enough rpm for direct current (DC) or alternating current (AC).
For information on the type of generator to purchase, contact
manufacturers directly.  A list of companies is provided here.
The manufacturer often will be able to recommend an appropriate
generator, if supplied with enough information upon which to
make a recommendation.  Be prepared to supply the following
*  AC or DC operation (include voltage desired).
*  Long range use of electrical energy (future consumption and
   addition of electric devices).
*  Climatic condition under which generator will be used (i.e.,
   tropical, temperate, arid, etc.).
*  Power available at water site calculated at lowest flow and
   maximum flow rates.
*  Power available to the generator in watts or horsepower (conservative
   figure would be half of power at water site).
*  Revolutions per minute (rpm) of turbine without pulleys and
*  Intended or present consumption of electrical energy in watts
   if possible (include frequency of electrical use).
*  Lima Electric Co., 200 East Chapman Road, Lima, Ohio 45802
*  Kato, 3201 Third Avenue North, Mankato, Minnesota 56001 USA.
*  Onan, 1400 73rd Avenue NE, Minneapolis, Minnesota 55432 USA.
*  Winco of Dyna Technologies, 2201 East 7th Street, Sioux City,
   Iowa 51102 USA.
*  Kohler, 421 High Street, Kohlen, Wisconsin 53044 USA.
*  Howelite, Rendale and Nelson Streets, Port Chester, New York
   10573 USA.
*  McCulloch, 989 South Brooklyn Avenue, Wellsville, New York
   14895 USA.
*  Sears, Roebuck and Co., Chicago, Illinois USA.
*  Winpower, 1225 1st Avenue East, Newton, Iowa 50208 USA.
*  Ideal Electric, 615 1st Street, Mansfield, Ohio 44903 USA.
*  Empire Electric Company, 5200-02 First Avenue, Brooklyn, New
   York 11232 USA.
*  Bright Star, 602 Getty Avenue Clifton, New Jersey, 07015
*  Burgess Division of Clevite Corp., Gould PO Box 3140, St.
   Paul, Minnesota 55101 USA.
*  Delco-Remy, Division of GM, PO Box 2439, Anderson, Indiana
   46011 USA.
*  Eggle-Pichen Industries, Box 47, Joplin, Missouri 64801 USA.
*  ESB Inc., Willard Box 6949, Cleveland, Ohio 44101 USA.
*  Exide, 5 Penn Center Plaza, Philadelphia, Pennsylvania 19103
*  Ever-Ready Union Carbide Corporation, 270 Park Avenue, New
   York, New York 10017 USA.
AC (Alternating Current)--Electrical energy that reverses its
        direction at regular intervals.  These intervals are
        called cycles.
BEARING--Any part of a machine in or on which another part
        revolves, slides, etc.
DIA (Diameter)--A straight line passing completely through the
        center of a circle.
DC (Direct Current)--Electrical current that flows in one
        direction without deviation or interruption.
GROSS POWER--Power available before machine inefficiencies are
HEAD--The height of a body of water, considered as causing
ID (Inside Diameter)--The inside diameter of pipe, tubing, etc.
NET HEAD--Height of a body of water minus the energy losses
        caused by the friction of a pipe or water channel.
OD (Outside Diameter)--The outside dimension of pipe, tubing,
PENSTOCK--A conduit or pipe that carries water to a water wheel
        or turbine.
ROLLED EARTH--Soil that is pressed together tightly by rolling
        a steel or heavy wood cylinder over it.
RPM (Revolutions Per Minute)--The number of times something
        turns or revolves in one minute.
TAILRACE (Tailwater)--The discharge channel that leads away
        from a waterwheel or turbine.
TURBINE--Any of various machines that has a rotor that is
        driven by the pressure of such moving fluids as steam,
        water, hot gases, or air.  It is usually made with a
        series of curved blades on a central rotating spindle.
WEIR--A dam in a stream or river that raises the water level.
Brown, Guthrie J.  (ed.).  Hydro Electric Engineering Practice.
     New York:   Gordon & Breach, 1958; London:   Blackie and Sons,
     Ltd., 1958.   A complete treatise covering the entire field
     of hydroelectric engineering.  Three volumes.   Vol. 1:  Civil
     Engineering; Vol. 2:  Mechanical and Electrical Engineering;
     and Vol. 3:   Economics, Operation and Maintenance.
     Gordon & Breach Science Publishers, 440 Park Avenue South,
     New York, New York 10016 USA.
Creager, W.P.  and Justin, J.D.  Hydro Electric Handbook, 2nd
     ed. New York:  John Wiley & Son, 1950.   A most complete
     handbook covering the entire field.  Especially good for
     reference.   John Wiley & Son, 650 Third Avenue, New York,
     New York 10016 USA.
Davis, Calvin V.  Handbook of Applied Hydraulics, 2nd ed.  New
     York:   McGraw-Hill, 1952.   A comprehensive handbook covering
     all phases of applied hydraulics.  Several chapters are
     devoted to hydroelectric application.  McGraw-Hill, 1221
     Avenue of the Americas, New York, New York 10020 USA.
Durali, Mohammed.  Design of Small Water Turbines for Farms and
     Small Communities.  Tech.   Adaptation Program, MIT, Cambridge,
     Massachusetts 02139 USA.  A Highly technical manual
     of the designs of a Banki turbine and of axial-flow turbines.
     Also contains technical drawings of their designs
     and tables of friction losses, efficiences, etc.  This
     manual is far too technical to be understood without an
     engineering background.  Probably only useful for university
     projects and the like.
Haimerl, L.A.  "The Cross Flow Turbine," Water Power (London),
     January 1960.  Reprints available from Ossberger Turbinen-fabrik,
     8832 Weissenburg, Bayern, Germany.  This article
     describes a type of water turbine which is being used
     extensively in small power stations, especially in Germany.
     Available from VITA.
Hamm, Hans W.  Low Cost Development of Small Water Power Sites.
     VITA 1967.   Written expressly to be used in developing
     areas, this manual contains basic information on measuring
     water power potential, building small dams, different
     types of turbines and water wheels, and several necessary
     mathematical tables.  Also has some information on
     manufactured turbines available.  A very useful book.
Langhorne, Harry F.  "Hand-Made Hydro Power," Alternative
     Sources of Energy, No.  28, October 1977, pp.   7-11.
     Describes how one man built a Banki turbine from VITA
     plans to power and heat his home.  useful in that it gives
     a good account of the mathematical calculations that were
     necessary, and also of the various modifications and innovations
     he built into the system.  A good real-life account
     of building a low-cost water power system.  ASE, Route #2,
     Box 90A, Milaca, Minnesota 59101 USA.
Mockmore, C.A.  and Merryfield.  F.   The Banki Water Turbine.
     Corvallis, Oregon:  Oregon State College Engineering Experiment
     Station, Bulletin No. 25, February 1949.  A translation
     of a paper by Donat Banki.  A highly technical
     description of this turbine, originally invented by
     Michell, together with the results of tests.  Oregon State
     University, Corvallis, Oregon 97331 USA.
Paton, T.A.L.  Power From Water, London:  Leonard Hill, 1961.  A
     concise general survey of hydroelectric practice in
     abridged form.
Zerban, A.H.  and Nye, E.P.  Power Plants, 2a ed.   Scranton,
     Pennsylvania:  International Text Book Company, 1952.
     Chapter 12 gives a concise  presentation of hydraulic
     power plants.  International Text Book Company, Scranton,
     Pennsylvania 18515 USA.
  1 Mile                  = 1760 Yards                 = 5280 Feet
  1 Kilometer             = 1000 Meters                = 0.6214 Mile
  1 Mile                  = 1.607 Kilometers
  1 Foot                  = 0.3048 Meter
  1 Meter                 = 3.2808 Feet                = 39.37 Inches
  1 Inch                  = 2.54 Centimeters
  1 Centimeter            = 0.3937 Inches
  1 Square Mile           = 640 Acres                  = 2.5899 Square Kilometers
  1 Square   Kilometer    = 1,000,000 Square Meters   = 0.3861 Square Mile
  1 Acre                  = 43,560 Square Feet
  1 Square   Foot         = 144 Square Inches         = 0.0929 Square Meter
  1 Square   Inch         = 6.452 Square Centimeters
  1 Square   Meter        = 10.764 Square Feet
  1 Square   Centimeter   = 0.155 Square Inch
  1.0 Cubic Foot          = 1728 Cubic Inches          = 7.48 US Gallons
  1.0 British Imperial
       Gallon             = 1.2 US Gallons
  1.0 Cubic Meter        = 35.314 Cubic Feet          = 264.2 US Gallons
  1.0 Liter               = 1000 Cubic Centimeters     = 0.2642 US Gallons
   1.0 Metric Ton          = 1000 Kilograms             = 2204.6 Pounds
  1.0 Kilogram            = 1000 Grams                 = 2.2046 Pounds
  1.0 Short Ton           = 2000 Pounds
  1.0 Pound per square inch           = 144 Pound per square foot
  1.0 Pound per square inch           = 27.7 Inches of water*
  1.0 Pound per square inch           = 2.31 Feet of water*
  1.0 Pound per square inch           = 2.042 Inches of mercury*
  1.0 Atmosphere                       = 14.7 Pounds per square inch (PSI)
  1.0 Atmosphere                       = 33.95 Feet of water*
  1.0 Foot of water = 0.433 PSI       = 62.355 Pounds per square foot
  1.0 Kilogram per square centimeter  = 14.223 Pounds per square inch
  1.0 Pound per square inch           = 0.0703 Kilogram per square
  1.0 Horsepower (English)            = 746 Watt    = 0.746 Kilowatt (KW)
  1.0 Horsepower (English)            = 550 Foot pounds per second
  1.0 Horsepower (English)             = 33,000 Foot pounds per minute
  1.0 Kilowatt (KW)  = 1000 watt       = 1.34 Horsepower (HP) English
  1.0 Horsepower (English)            = 1.0139 Metric horsepower
  1.0 Metric horsepower                = 75 Meter X Kilogram/Second
  1.0 Metric horsepower               = 0.736 Kilowatt   = 736 Watt
(*) At 62 degrees Fahrenheit (16.6 degrees Celsius).
                           APPENDIX I
                         SITE ANALYSIS
This Appendix provides a guide to making the necessary calculations
for a detailed site analysis.
                          Data Sheet
                      Measuring Gross Head
                         Measuring Flow
                     Measuring Head Losses
                        DATA SHEET
1.  Minimum flow of water available in cubic feet
    per second (or cubic meters per second).             _____
2.  Maximum flow of water available in cubic feet        _____
    per second (or cubic meters per second).
3.  Head or fall of water in feet (or meters).           _____
4.  Length of pipe line in feet (or meters) needed         
    to get the required head.                            _____
5.  Describe water condition (clear, muddy, sandy,
    acid).                                                _____  
6.  Describe soil condition (see Table 2).               _____
7.  Minimum tailwater elevation in feet (or meters).     _____
8.  Approximate area of pond above dam in acres (or
    square kilometers).                                  _____
9.  Approximate depth of the pond in feet (or
    meters).                                              _____
10.  Distance from power plant to where electricity
     will be used in feet (or meters).                   _____
11.  Approximate distance from dam to power plant.       _____
12.  Minimum air temperature.                            _____
13.  Maximum air temperature.                            _____
14.  Estimate power to be used.                          _____
     MAP WITH SITE SKETCHED IN.                         
The following questions cover information which, although not
necessary in starting to plan a water power site, will usually
be needed later.  If it can possibly be given early in the project,
this will save time later.
 1.   Give the type, power, and speed of the machinery to be
     driven and indicate whether direct, belt, or gear drive is
     desired or acceptable.
 2.   For electric current, indicate whether direct current is
     acceptable or alternating current is required.  Give the
     desired voltage, number of phases and frequency.
 3.   Say whether manual flow regulation can be used (with DC
     and very small AC plants) or if regulation by an automatic
     governor is needed.
                    MEASURING GROSS HEAD
Method No. 1
1.  Equipment

42p51.gif (353x353)

    a.   Surveyor's leveling instrument--consists of a spirit
        level fastened parallel to a telescopic sight.
    b.   Scale--use wooden board approximately 12 ft in length.
2.  Procedure
    a.   Surveyor's level on a tripod is placed downstream from
        the power reservoir dam on which the headwater level is
    b.   After taking a reading, the level is turned 180[degrees] in a
        horizontal circle.  The scale is placed downstream from it
        at a suitable distance and a second reading is taken.
        This process is repeated until the tailwater level is

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Method No.  2
This method is fully reliable, but is more tedious than Method
No.  1 and need only be used when a surveyor's level is not
1.  Equipment

42p52.gif (393x393)

    a.   Scale
    b.   Board and wooden plug
    c.   Ordinary carpenter's level
2.  Procedure
    a.   Place board horizontally at headwater level and place
        level on top of it for accurate leveling.  At the downstream
        end of the horizontal board, the distance to a
        wooden peg set into the ground is measured with a scale.
    b.   The process is repeated step by step until the tailwater
        level is reached.

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                        MEASURING FLOW
Flow measurements should take place at the season of lowest
flow in order to guarantee full power at all times.   Investigate
the stream's flow history to determine the level of flow at
both maximum and minimum.  Often planners overlook the fact that
the flow in one stream may be reduced below the minimum level
required.  Other streams or sources of power would then offer a
better solution.
Method No. 1
For streams with a capacity of less than one cubic foot per
second, build a temporary dam in the stream, or use a "swimming
hole" created by a natural dam.   Channel the water into a pipe
and catch it in a bucket of known capacity.   Determine the
stream flow by measuring the time it takes to fill the bucket.
   Stream flow (cubic ft/sec) = Volume of bucket (cubic ft)
                                   Filling time (seconds)
Method No. 2
For streams with a capacity of more than 1 cu ft per second,
the weir method can be used.   The weir is made from boards,
logs, or scrap lumber.  Cut a rectangular opening in the
center.  Seal the seams of the boards and the sides built into
the banks with clay or sod to prevent leakage.   Saw the edges of
the opening on a slant to produce sharp edges on the upstream
side.  A small pond is formed upstream from the weir.  When there
is no leakage and all water is flowing through the weir
opening, (1) place a board across the stream and (2) place
another narrow board at right angles to the first, as shown
below.  Use a carpenter's level to be sure the second board is

42p55a.gif (437x437)

Measure the depth of the water above the bottom edge of the
weir with the help of a stick on which a scale has been
marked.  Determine the flow from Table 1 on page 56.

42p55b.gif (393x393)

                              Table I
                 FLOW VALUE (Cubic Feet/Second)
                                       Weir Width                  
Overflow Height  3 feet  4 feet   5 feet  6 feet   7 feet  8 feet  9 feet
   1.0 inch        0.24    0.32    0.40     0.48    0.56    0.64     0.72
   2.0 inches      0.67    0.89    1.06     1.34    1.56    1.80     2.00
   4.0 inches      1.90    2.50    3.20     3.80    4.50    5.00     5.70
   6.0 inches      3.50    4.70    5.90     7.00    8.20    9.40    10.50
   8.0 inches      5.40    7.30    9.00    10.90   12.40   14.60    16.20
  10.0 inches      7.60   10.00   12.70    15.20   17.70   20.00    22.80
  12.0 inches     10.00   13.30   16.70    20.00   23.30   26.60    30.00
Method No. 3
The float method is used for larger streams.   Although it is not
as accurate as the previous two methods, it is adequate for
practical purposes.  Choose a point in the stream where the bed
is smooth and the cross section is fairly uniform for a length
of at least 30 ft.  Measure water velocity by throwing pieces of
wood into the water and measuring the time of travel between
two fixed points, 30 ft or more apart.   Erect posts on each bank
at these points.  Connect the two upstream posts by a level wire
rope (use a carpenter's level).   Follow the same procedure with
the downstream posts.  Divide the stream into equal sections
along the wires and measure the water depth for each section.
In this way, the cross-sectional area of the stream is determined.
use the following formula to calculate the flow:

42p56.gif (437x437)

                     MEASURING HEAD LOSSES
"Net Power" is a function of the "Net Head."  The "Net Head" is
the "Gross Head" less the "Head Losses."  The illustration below
shows a typical small water power installation.   The head losses
are the open-channel losses plus the friction loss from flow
through the penstock.

42p57.gif (540x540)

42p58.gif (600x600)

Open Channel Head Losses
The headrace and the tailrace in the illustration above are
open channels for transporting water at low velocities.   The
walls of channels made of timber, masonry, concrete, or rock,
should be perpendicular.  Design them so that the water level
height is one-half of the width.   Earth walls should be built at
a 45 [degrees] angle.  Design them so that the water level height is
one-half of the channel width at the bottom.   At the water level
the width is twice that of the bottom.
The head loss in open channels is given in the nomograph.  The
friction effect of the material of construction is called "N."
Various values of "N" and the maximum water velocity, below
which the walls of a channel will not erode are given.
                                 TABLE II
                               Maximum Allowable
                               Water Velocity
      Material of Channel Wall  (feet/second)            Value of "n"
      Fine grained sand                0.6                   0.030
      Course sand                      1.2                   0.030
      Small stones                     2.4                   0.030
      Coarse stones                    4.0                   0.030
      Rock                             25.0     (Smooth)       0.033 (Jagged) 0.045
      Concrete with sandy water       10.0                   0.016
      Concrete with clean water       20.0                   0.016
      Sandy loam, 40% clay             1.8                   0.030
      Loamy soil,  65% clay             3.0                   0.030
      Clay loam,   85% clay              4.8                  0.030
      Soil loam,   95% clay              6.2                  0.030
      100% clay                         7.3                   0.030
      Wood                                                   0.015
      Earth bottom with rubble sides                        0.033
The hydraulic radius is equal to a quarter of the channel
width, except for earth-walled channels where it is 0.31 times
the width at the bottom.
To use the nomograph, a straight line is drawn from the value
of "n" through the flow velocity to the reference line.  The
point on the reference line is connected to the hydraulic
radius and this line is extended to the head-loss scale which
also determines the required slope of the channel.
Using a Nomograph
After carefully determining the water power site capabilities
in terms of water flow and head, the nomograph is used to
*  The width/depth of the channel needed to bring the water to
   the spot/location of the water turbine.
*  The amount of head lost in doing this.

42p59.gif (600x600)

To use the graph, draw a straight line from the value of "n"
through the flow velocity through the reference line tending to
the hydraulic radius scale.  The hydraulic radius is one-quarter
(0.25) or (0.31) the width of the channel that needs to be
built.  In the case where "n" is 0.030, for example, and water
flow is 1.5 cubic feet/second, the hydraulic radius is 0.5 feet
hr 6 inches.  If you are building a timber, concrete, masonry,
or rock channel, the total width of the channel would be 6
inches times 0.25, or 2 feet with a depth of at least 1 foot.
If the channel is made of earth, the bottom width of the channel
would be 6 times 0.31, or 19.5 inches, with a depth of at
least 9.75 inches and top width of 39 inches.
Suppose, however, that water flow is 4 cubic feet/second.  Using
the graph, the optimum hydraulic radius would be approximately
2 feet--or for a wood channel, a width of 8 feet.   Building a
wood channel of this dimension would be prohibitively

42p60.gif (600x600)

However, a smaller channel can be built by sacrificing some
water head.  For example, you could build a channel with a
hydraulic radius of 0.5 feet or 6 inches.   To determine the
amount of head that will be lost, draw a straight line from the
value of "n" through the flow velocity of 4 [feet.sup.3]/second to the
reference line.  Now draw a straight line from the hydraulic
radius scale of 0.5 feet through the point on the reference
line extending this to the head-loss scale which will determine
the slope of the channel.  In this case about 10 feet of head
will be lost per thousand feet of channel.   If the channel is
100 feet long, the loss would only be 1.0 feet--if 50 feet
long, 0.5 feet, and so forth.
Pipe Head Loss and Penstock Intake
The trashrack consists of a number of vertical bars welded to
an angle iron at the top and a bar at the bottom (see Figure
below).  The vertical bars must be spaced so that the teeth of a
rake can penetrate the rack for removing leaves, grass, and
trash which might clog up the intake.   Such a trashrack can easily
be manufactured in the field or in a small welding shop.
Downstream from the trashrack, a slot is provided in the concrete
into which a timber gate can be inserted for shutting off
the flow of water to the turbine.   (See shut-off caution on page

42p61.gif (600x600)

The penstock can be constructed   from commercial pipe.  The pipe
must be large enough to keep the head loss small.   The required
pipe size is determined from the nomograph.   A straight line
drawn through the water velocity and flow rate scales gives the
required pipe size and pipe head loss.   Head loss is given for a
100-foot pipe length.  For longer or shorter penstocks, the
actual head loss is the head loss from the chart multiplied by
the actual length divided by 100.   If commercial pipe is too
expensive, it is possible to make pipe from native material;
for example, concrete and ceramic pipe, or hollowed logs.  The
choice of pipe material and the method of making the pipe
depend on the cost and availability of labor and the availability
of material.

42p62.gif (600x600)

                          APPENDIX II
                    SMALL DAM CONSTRUCTION
                         Introduction to:
                           Earth Dams
                           Crib Dams
                   Concrete and Masonry Dams
This appendix is not designed to be exhaustive; it is meant to
provide background and perspective for thinking about and
planning dam efforts.  While dam construction projects can range
from the simple to the complex, it is always best to consult an
expert, or even several; for example, engineers for their construction
savvy and an environmentalist or concerned agriculturalist
for a view of the impact of damming.
                           EARTH DAMS
An earth dam may be desirable where concrete is expensive and
timber scarce.  It must be provided with a separate spillway of
sufficient size to carry off excess water because water can
never be allowed to flow over the crest of an earth dam.  Still
water is held satisfactorily by earth but moving water is not.
The earth will be worn away and the dam destroyed.
The spillway must be lined with boards or concrete to prevent
seepage and erosion.  The crest of the dam may be just wide
enough for a footpath or may be wide enough for a roadway, with
a bridge placed across the spillway.

42p65.gif (300x600)

The big problem in earth-dam construction is in places where
the dam rests on solid rock.   It is hard to keep the water from
seeping between the dam and the earth and finally undermining
the dam.
One way of preventing seepage is to blast and clean out a
series of ditches, or keys, in the rock, with each ditch about
a foot deep and two feet wide extending under the length of the
dam.  Each ditch should be filled with three or four inches of
wet clay compacted by stamping it.   More layers of wet clay can
then be added and the compacting process repeated each time
until the clay is several inches higher than bedrock.
The upstream half of the dam should be of clay or heavy clay
soil, which compacts well and is impervious to water.   The
downstream side should consist of lighter and more porous soil
which drains quickly and thus makes the dam more stable than if
it were made entirely of clay.

42p66.gif (600x600)

                           CRIB DAMS
The crib dam is very economical where lumber is easily
available:  it requires only rough tree trunks, cut planking,
and stones.  Four- to six-inch tree trunks are placed 2-3 feet
apart and spiked to others placed across them at right angles.
Stones fill the spaces between timbers.   The upstream side
(face) of the dam, and sometimes the downstream side, is
covered with planks.  The face is sealed with clay to prevent
leakage.  Downstream planks are used as an apron to guide the
water that overflows the dam back into the stream bed.   The dam
itself serves as a spillway in this case.   The water coming over
the apron falls rapidly.  Prevent erosion by lining the bed
below with stones.  The apron consists of a series of steps for
slowing the water gradually.

42p67.gif (600x600)

42p68.gif (600x600)

Crib dams must be embedded well into the embankments and packed
with impervious material such as clay or heavy earth and stones
in order to anchor them and to prevent leakage.   At the heel, as
well as at the toe of crib dams, longitudinal rows of planks
are driven into the stream bed.   These are priming planks which
prevent water from seeping under the dam.   They also anchor the
If the dam rests on rock, priming planks cannot and need not be
driven; but where the dam does not rest on rock they make it
more stable and watertight.  These priming planks should be
driven as deep as possible and then spiked to the timber of the
crib dam.
The lower ends of the priming planks are pointed as shown in

42p69a.gif (317x317)

the Figure on page 69 and must be placed one after the other as
shown.  Thus each successive plank is forced, by the act of
driving it, closer against the preceding plank, resulting in a
solid wall.  Any rough lumber may be used.  Chestnut and oak are
considered to be the best material.   The lumber must be free
from sap, and its size should be approximately 2" X 6".
In order to drive the priming planks, considerable force may be
required.  A simple pile driver will serve the purpose.  The
Figure below shows an excellent example of a pile driver.

42p69b.gif (353x353)

Concrete and masonry dams more than 12 feet high should not be
built without the advice of an engineer with experience in this
field.  Dams require knowledge of the soil condition and bearing
capacity as well as of the structure itself.
A stone dam can also serve as a spillway.   It can be up to 10

42p70.gif (393x393)

feet in height.  It is made of rough stones.  The layers should
be bound by concrete.  The dam must be built down to a solid and
permanent footing to prevent leakage and shifting.   The base of
the dam should have the same dimensions as its height to give
it stability.
Small concrete dams should have a base with a thickness 50
percent greater than height.   The apron is designed to turn the
flow slightly upwards to dissipate the energy of the water and
protect the downstream bed from erosion.

42p71.gif (437x437)

                         APPENDIX III
If you are using this as a guide for using the Michell (Banki)
Turbine in a development effort, collect as much information as
possible and if you need assistance with the project, write
VITA.  A report on your experiences and the uses of this Manual
will help VITA both improve the book and aid other similar
              Volunteers in Technical Assistance
               1600 Wilson Boulevard, Suite 500
                Arlington, Virginia 22209, USA
*  Describe current agricultural and domestic practices which
   rely on water.  What are the sources of water and how are
   they used?
*  What water power sources are available?  Are they small but
   fast-flowing?   Large but slow-flowing?   Other characteristics?
*  What is water used for traditionally?
*  Is water harnessed to provide power for any purpose?  If so,
   what and with what positive or negative results?
*  Are there dams already built in the area?  If so, what have
   been the effects of the damming?  Note particularly any
   evidence of sediment carried by the water--too much sediment
   can create a swamp.
*  If water resources are not now harnessed, what seem to be
   the limiting factors?  Does cost seem prohibitive?  Does the
   lack of knowledge of water power potential limit its use?
*  Based on current agricultural and domestic practices, what
   seem to be the areas of greatest need?  Is power needed to
   run simple machines such as grinders, saws, pumps?
*  Given available water power sources, which ones seem to be
   available and most useful?  For example, one stream which
   runs quickly year around and is located near the center of
   agricultural activity may be the only feasible source to tap
   for power.
*  Define water power sites in terms of their inherent potential
   for power generation.
*  Are materials for constructing water power technologies
   available locally?  Are local skills sufficient?  Some water
   power applications demand a rather high degree of construction
*  What kinds of skills are available locally to assist with
   construction and maintenance?  How much skill is necessary
   for construction and maintenance?  Do you need to train
   people?   Can you meet the following needs?
   *   Some aspects of the Michell turbine require someone with
      experience in metalworking and/or welding.
   *   Estimated labor time for full-time workers is:
   *   40 hours skilled labor
   *   40 hours unskilled labor
   *   8 hours welding
*  Do a cost estimate of the labor, parts, and materials
*  How will the project be funded?
*  What is your schedule?  Are you aware of holidays and
   planting or harvesting seasons which may affect timing?
*  How will you arrange to spread information on and promote
   use of the technology?
*  Is more than one water power technology applicable?  Remember
   to look at all the costs.  While one technology appears to be
   much more expensive in the beginning, it could work out to
   be less expensive after all costs are weighed.
*  Are there choices to be made between a waterwheel and a
   windmill, for example, to provide power for grinding grain?
   Again weigh all the costs:  economics of tools and labor,
   operation and maintenance, social and cultural dilemmas.
*  Are there local skilled resources to introduce water power
   technology?   Dam building and turbine construction should be
   considered carefully before beginning work.  Besides the
   higher degree of skill required in turbine manufacture (as
   opposed to waterwheel construction), these water power
   installations tend to be more expensive.
*  Where the need is sufficient and resources are available,
   consider a manufactured turbine and a group effort to build
   the dam and install the turbine.
*  Is there a possibility of providing a basis for small
   business enterprise?
*  How was the final decision reached to go ahead--or not go
   ahead--with this technology?  Why?
                        APPENDIX IV
Photographs of the construction process, as well as the
finished result, are helpful.   They add interest and detail that
might be overlooked in the narrative.
A report on the construction process should include much very
specific information.  This kind of detail can often be monitored
most easily in charts (such as the one below).
 Labor Account
                          Hours Worked
     Name        Job    M  T   W  T   F  S  S      Total  Rate?    Pay?
Materials Account
         Item            Cost Per Item     # Items    Total Costs
                                      Total Costs
Some other things to record include:
*  Specification of materials used in construction.
*  Adaptations or changes made in design to fit local
*  Equipment costs.
*  Time spent in construction--include volunteer time as well
   as paid labor; full- or part-time.
*  Problems--labor shortage, work stoppage, training difficulties,
   materials shortage, terrain, transport.
Keep log of operations for at least the first six weeks, then
periodically for several days every few months.   This log will
vary with the technology, but should include full requirements,
outputs, duration of operation, training of operators, etc.
Include special problems that may come up--a damper that won't
close, gear that won't catch, procedures that don't seem to
make sense to workers, etc.
Maintenance records enable keeping track of where breakdowns
occur most frequently and may suggest areas for improvement or
strengthening weakness in the design.   Furthermore, these
records will give a good idea of how well the project is
working out by accurately recording how much of the time it is
working and how often it breaks down.   Routine maintenance
records should be kept for a minimum of six months to one year
after the project goes into operation.
Labor Account
                                                          Also down time
      Name          Hours & Date            Repair Done      Rate?     Pay?
                              Totals (by week or month)
Materials Account
          Item              Cost     Reason Replaced     Date     Comments
Totals (by week or month)
This category includes damage caused by weather, natural disasters,
vandalism, etc. Pattern the records after the routine
maintenance records.  Describe for each separate incident:
*  Cause and extent of damage.
*  Labor costs of repair (like maintenance account).
*  Material costs of repair (like maintenance account).
*  Measures taken to prevent recurrence.

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