WEED CUTTING LAUNCHES

Extensive use has been made overseas of power-driven
launches, equipped with cutting blades, for clearing weeds from ir-
rigation, drainage and water supply channels. Following the recent
inspection of land drainage projects in Britain and the Continent by
Mr. L. R. East, chairman, State Rivers and Water Supply Commis-
sion, Victoria, when weed cutting launches were seen in operation,
two launches were purchased by the Commission and their construc-
tion and operation described in an article appearing in Commonwealth
Engineer, March 1, 1954. A condensation of the original article is
presented herein.

Results achieved through the use of the weed cutting launches
so far are quite satisfactory. The final cut is much cleaner than is ob-
tained when using hooks or saws, and as it is made at silt level, it is
considered that occasional cuts would then effectively kill the cumbungi.
Fresh cumbungi shoots can be cut easily. Cat-tail and ribbon-weed
offer only the slightest resistance. Actual operation costs have not yet

(IIB8~1)

13


Several types of lining were considered, including the use of
heavy compacted earth constructed of materials found along the canal
alinement. It was finally decided that a heavy compacted, impervious
earth lining could be constructed by blending available gravelly soils
with selected fines. For this scheme, carefully selected, fine-grained
soils are to be obtained from borrow pits some distance away and hauled
to the site. They will then be mixed with the in-place gravel in a suffi-
cient quantity, but kept to a minimum for economy, to result in an im-
pervious lining. It was necessary to test various proposed mixtures in
the laboratory to determine the proper proportions of gravel and fine-
grained soils.

Typical subgrade gravels from three locations and the proposed
fine soil were received in the laboratory for testing. From the initial
examinations and index tests, it appeared that probably a mixture of 50
percent fines and 50 percent gravel would provide the necessary imper-
meability. However, as testing progressed, it became obvious that the
percentage of fines could be reduced. Tests were continued at progres-
sively 'leaner'' mixtures until it was found that a 20-80 mixture would
satisfy requirements. It was finally recommended that a 30-70 mixture
be used to allow some leeway for variations in material and mixing in
the field.

In commenting on this procedure, which is well adapted to fine
sand and silt materials, gravel, necessarily placed on the slopes to pro-
tect them from erosion and to increase stability, is blended into the ma-
terial and compacted as the lining is placed and a gravel protective
blanket is not needed. The gravel also provides a greater density and
increases the stability of the banks. Costs of $1.45 per square yard
are reported on rather scattered work.

Laboratories can be of help in indicating the desirable mix-
tures, controls, and suggesting control during construction.

mR OK

HEAVY COMPACTED EARTH LININGS

In his resume on accomplishments of the Lower-Cost Canal
Lining Program during Fiscal Year 1954, Mr. I. E. Hosig, Chairman
of Committee, states recent experience indicates that, if suitable mate-
rials are available, heavy, compacted earth linings are the most satis~
factory. In large canals with suitable materials, heavy, compacted
earth lining is the lowest in first cost and probably in annual cost over
a long time period. For small canals and laterals, costs are high
because of the proportionately large volume of earthwork per square
foot of water area.


SODIUM-FILLED VALVES ARE HAZARDOUS

The Bureau of Yards and Docks, Department of the Navy,
issues a warning against efforts to reclaim as salvage sodium-filled
engine exhaust valves once they are removed from diesels or other
types of combustion engines.

Although precautions have already been cited by manufac-
turers, widely circulated in trade journals, both BuDocks Safety Engi-
neer and YDSO at Port Hueneme believe it necessary to repeat the
warning with advice on proper methods for disposing of the valves once
they are removed from an engine.

All service personnel and mechanics likely to encounter
sodium-filled valves should be told proper methods of disposal. For
instance, it should be explained that a sodium-filled valve MUST NOT
BE CUT, BROKEN OPEN OR THROWN ON A SCRAP PILE. Sodium
burns spontaneously at very high temperature upon contact with water
or moisture-laden air, therefore, there is immediate danger of explo-
sion or severe body burns if a valve is cut or broken. There are two
recommended ways to dispose of them:

1. Toss them into deep water where they cannot be recovered, or

2. Bury them deep in the earth (at least 30 inches) in an author-
ized area not likely to be excavated.

One manufacturer, the Caterpillar Tractor Co, » has advised
the Bureauof Yards and Docks that sodium-filled exhaust valves are now
used in all D337 diesel engines and in allDW20 andDW21 tractor engines
now leaving the factory. Some earlier Caterpillar engines have had
3H4872 and 3H5554 sodium-filled valves installed in the field. These
valves may be identified by the Part Number 3H4872 or 3H5554 and/or
the letters ''SOD" stamped on the valve head or near the top of the stem.

This article reprinted from BUDOCKS TECHNICAL DIGEST
No. 41, issue of January 1954, page 9.

HOR KK

WEED CONTROL EQUIPMENT

The articles on the following pages are prepared for removal
from this issue of the Bulletin and incorporation with similar articles
in Release No. 3 which was devoted exclusively to weed control equip-
ment.


BUMPER BRACKET HOLDS FLOOD LIGHT

When lights are needed duringemergencies, there is notimeto
improvise holders for lights. By welding a bracket on a vehicle bumper
for use in mounting a portable floodlight, Mr. James A. McDonald of
the Fresno Office, Central Valley Project, has made available an effi-
cient means of lighting at any lo ion. Mounting in such a manner
eliminates the necessity for carrying tripods and other types of stand-
ards for mounting of floodlights. His idea has proven its usefulness in
the case of a drowning in the Friant-Kern Canal, and he has received
an award under the Incentive Awards Program for his idea.

Construction Details:

Details of construction may be obtained from the Regional
Director, Bureau of Reclamation, Sacramento, California

KK

6


During the past year, a method of lining small canals and
laterals was developed on the Riverton Project by Government forces.
At a cost of 57 cents per square yard of the wetted perimeter of a
small canal, a section was lined with compacted earth. Construction
consisted of overexcavating the canal to a V-shape with 4:1 side slopes
and to a depth of 12 inches below the regular section at the critical
points (the toes of the inside slopes). The slopes after excavation were
then leveled and compacted. Two 6-inch layers of soil were then placed
and compacted. The 6-inch layer of compacted, natural earth and the
lower 6-inch layer of placed material form the impermeable layer.
This work was done with motor patrols and sheep-foot rollers travel-
ling parallel to the canal center line.

After compaction was completed, the normal canal section was
constructed with ordinary equipment and without compaction. The result
is not only a compacted earth lining of small total yardage produced by
quality production procedures, but also an ordinary earth canal section
which can cut or fill within reason and be maintained with ordinary equip-
ment without appreciable danger of injury to the buried lining.

OK OK Ok

RODENT CONTROL

Zinc phosphide is used on carrots as bait in the control of
rodents by the Yuma County Water Users! Association, Arizona. The
carrots must be at least an inch in diameter, peeled and cut in sections
about two inches long. The zinc phosphide is sprinkled over the carrots
in a bucket and then mixed thoroughly so that the carrots get a full cov-
ering of the poison. The cubes of carrots are placed in gopher runways
and not in laterals made by workings of the gopher. By placing the car-
rots in runways, a gopher must remove the carrot to pass through. A
very small amount of poison is required to kill these rodents, and in
biting into the carrot to remove it, the gopher is poisoned.

After an area has been treated in this manner, it is necessary
to go over it each year to pick up the few gophers that are left, as well
as those that migrate from an unpoisoned area. The estimated kill has
been about 90 percent. The 10 percent left increase rapidly, therefore
it is advisable to either trap or repoison each year.

The work described is under the supervision of the United
States Department of Agriculture, Fish and Wildlife Service, Phoenix,
Arizona.

eK KK


The sprinkler device, as shown being towed by a small tractor,
uses a small pump mounted on a trailer to pull water from the canal and
spray the roadway. The use of this device, coupled with regular patrol
grading, maintains the service roads in very good condition. Further
details of construction may be obtained from the Regional Director,
Bureau of Reclamation, Boulder City, Nevada.



Department of the Interior

Bureau of Reclamation

OPERATION AND MAINTENANCE

EQUIPMENT AND PROCEDURES

RELEASE NO. 9
July, August, and September 1954

y ae CER aan batt

Se sr RS ee

CONTENTS

Protection of Concrete Against Weathering
A Blended Earth Canal Lining
~ Heavy Compacted Earth Linings
» Rodent Control
Bumper Bracket Holds Flood Light
Danger -Stay Alive by Staying Out
Sprinkler Device for Service Roads
Sodium-Filled Valves are Hazardous
~ Weed Burner
Moss Screens
Weed Cutting Launches


introduced into the other chamber. The oil and air upon leaving the
chambers are mixed, creating an extremely combustible mixture.
Additional information regarding this weed burner may be obtained
directly from John C. Smith, Jr., Yuma County Water Users' Asso-
ciation, Yuma, Arizona, or the Regional Director, Bureau of Rec-
lamation, Boulder City, Nevada.

2K OK OK

(IA 13-2)
rel


ieee. LO-918

WEED BURNER

In November, 1953, an experiment was started with a new
type burner by the Yuma County Water Users! Association, Arizona,
The old type burner used oil excessively and a large percent went up
in smoke (see picture on next page), due to improper combustion.

The new type burner, using about 100 gallons of burner oil compared
to 300 gallons per hour for the old burner, has a hotter blaze and very
little smoke. The new burner, photograph above, uses a mixture of
oil and air; the air being furnished by a compressor with a capacity of
105 cubic feet per minute and mounted on the truck.

Construction Details:

The new burner head is disc shaped, consisting of three plates,
each separated by a .001 inch "'U"' shaped shim at the end attached to
the boom. The purpose of the shim is to form two open end chambers
within the single burner head. Oil is introduced into one chamber at
six to eight pounds pressure, and air, at sixty pounds pressure, is

(IA13-1)

10


DANGER - STAY ALIVE BY STAYING OUT

People were using the wooden signs placed along the Contra-
Costa Canal of the Central Valley Project in Region 2 as targets or
otherwise destroying them, Replacements were expensive. Mr. Harry
F. Yoder, an employee of the Tracy Operations Office, solved the prob-
lem by making a stencil and painting the warning signs along the sides of
the canal. Mr. Yoder was given an award under the Incentive Awards
Program for his suggested solution.

KK Ok

SPRINKLER DEVICE FOR SERVICE ROADS

Dust control and maintenance of project roads along the canal
banks have always been serious problems. During the past few years
maintenance personnel of the Yuma Project, Arizona, have developed a
very simple but effective method of taking care of both problems, The
benefits, resulting from the use of this device, accrue not only to the
project maintenance forces but to many of the water users who are
required to use portions of the maintenance roads.

7


If there are open cracks in the surface being repaired, a
more effective waterproofing may be obtained by filling the cracks
prior to applying the second coat of hot oil. A standard mineral
paste wood filler, thinned as necessary to secure the desired pene-
tration, may be used for this purpose

After the second waterproofing coat is thoroughly dry, the
entire treated surface should be given two coats of any standard out-
side white lead and oil paint. Without the protection of this pigmented
paint, the oil treatment is subject to rapid deterioration, and its po-
tential value will be seriously impaired. A color resembling concrete
can be obtained, if desired, in the paint coats, by addition of lamp-
black and raw sienna ground in oil The Oregon standard white paint
formula is as follows:

Paint composition: Percent
Pigment, notlessthan. .......... 70
Vehicle, not more than. .......... 30

Pigment composition:

White lead carbonate... ..... 2... . 40-45
Titanium barium pigment. ........ . 35-40
Zine OXIdes. 6 wy x sow, er ew wm eo ew 6BBSBO
Tinting pigment, if required ........ 0-5

The first coat should be thinned by the addition of 2 quarts of turpentine
and 2 quarts of boiled linseed oil to the gallon of the above formula.
The second coat should be thinned with about 1 quart of boiled linseed
oil to the gallon of paint so that it will not produce a heavy pigment Coat
susceptible to scaling but will be heavy enough to brush out uniformly
and evenly.

OK OK

A BLENDED EARTH CANAL LINING

In his Monthly Progress Report for May, 1954, the Assistant
Commissioner and Chief Engineer for the Bureau of Reclamation dis-
cusses this subject in which permeable materials encountered during
canal excavation have been blended with a minimum of impermeable
soil in providing a heavy compacted earth canal lining.

During excavation of the Eltopia Branch Canal, Washington,
considerable reaches of coarse, clean, gravelly soils were encountered
in the subgrade. These soils would obviously result in excessive seep-
age in an unlined canal, thus lining was deemed necessary.


been worked out in detail, but it is expected that cost of weed cutting
will be much less by means of this type of launch than is the case with
other cutting methods. The type of weed cutting launch in use in the
Kerang district is considered the most efficient mechanical means for
maintaining long stretches of reasonably large waterways. In time, it
is expected that launches of similar type will supersede hand clearing
entirely, except for very small patches or channels with many struc-
tures close together.

Construction Details:

The small launch, type W. D., is constructed for narrow water-
ways; it consists of a shallow draught flat-bottomed hull with an over-all
length of 17 feet, a hull width of 3 feet 6 inches and a net weight of 14 cwt.
It is powered by a 4-1/2-horsepower J.A.P. engine and propelled by
paddle wheels. Cutting speed is up to3 m.p.h., according to conditions.
Cutting blades consist of a number of small tempered steel sections riv-
eted on to spring steel backs, mounted in the form of a "V"' on the end of
a hinged arm. The arm is controlled for depth of cut, and angle of the

(IIB8-2)

14


3. Drive to the paddle wheels is through a spring loaded clutch,
which will slip if the paddles strike an obstruction.

Operation and Maintenance:

Operation of the launch depends upon the nature of the weed
and the condition of the channel. Submerged water weeds such as cat-
tail and ribbon-weed offer no impediment to the launch's progress. At
the other extreme, dry old cumbungi offers considerable resistance.

In the former case, the launch can be driven without pause along the
channel with blades trailing on the bed behind, making an 8-foot wide
cut each sweep. In the latter case, a cut is first made along the edge
of the cumbungi with blades trailing. This removes the fringe growth.
The tall thick cumbungi is then attacked with the blades leading and
lowered about one foot below water level. If the growth is in deep wa-
ter and not too dense, it may be possible to force the launch through,
making an 8-foot wide cut--otherwise it is possible only to make re-
peated cuts along the edge of the growth. This permits the launch to
pass over the cumbungi to allow the final cut to be made with the blades
trailing on the channel bed. This severs the stalks at silt level. A
method of removing the cut cumbungi from the face of the cumbungi
beds when the current is not strong enough to do so has been developed.
The launch, after making its first cut, raises the cut weed on the blades
and reverses out to dump in midstream. To deal with the large accum-
ulation of cut weed inevitable with such rapid cutting, trials of a weed
trap used in the United States of America to collect the cut weed and a
hay-stacking grap to remove the weed, are being made.

At present two men operate the launch. The operator in charge
has an assistant to control the cutting mechanism. Once the thick old
growths of cumbungi have been removed from the channel, maintenance
could probably be performed by one man, but two men would always be
necessary in natural waterways where snags are prevalent or in chan-
nels with a thick growth of cumbungi.

(IIB8-4)
GPO 843-417

16


PROTECTION OF CONCRETE AGAINST WEATHERING

Experience has shown that there are certain portions of exposed
concrete structures which are more vulnerable than others to deteriora-
tion from weathering in freezing climates. These are the exposed sur-
faces of the top 2 feet of walls, piers, posts, handrails, and parapets;
all of curbs, sills, ledges, copings, cornices and corners; and surfaces
which will be in contact with water or spray at frequently changing levels
during freezing weather. The durability of such concrete features can
be considerably improved and their serviceability greatly prolonged by
preventive maintenance in the form of the weatherproofing treatment
discussed in the Concrete Manual published by the Bureau of Reclama-
tion and hereinafter described. This treatment has been adapted from
that used by the Oregon State Highway Department.

Except for hand-placed mortar restorations of deteriorated
concrete, this weatherproofing treatment is ordinarily not applied on
new concrete construction. It is most advantageously used on older
surfaces when the earliest visible evidence of susceptibility to weather-
ing appears. That is, before deterioration advances to a stage where
it cannot be arrested by the treatment. Such early evidence consists
primarily of fine surface cracking close and parallel to edges and cor-
ners. Sometimes the need for protection is indicated by pattern crack-
ing. By treatment of these vulnerable surfaces in the early stage of
weathering, later repairs may be avoided, or at least postponed for a
long time.

Preparation of surfaces: After completion of the curing period,
a repair should be allowed I or 2 weeks to dry before the waterproofing
treatment is applied. New mortar and concrete patches should be given
a neutralizing wash to prevent saponification of the linseed oil used in
the waterproofing treatment. A solution of 0.25 of a pound of phosphoric
acid and 0.17 of a pound of zinc chloride to a gallon of water is brushed
over the surface and allowed to dry 48 hours. This application is not
necessary on old concrete. Rinsing or brushing after the neutralizing
wash has dried is unnecessary. Before applying the waterproofing, the
repair must be clean and dry. Dust and loose material should be brushed
off. Efflorescence may be removed by scrubbing with a 10-percent solu-
tion of hydrochloric acid.

Treatment of surfaces: After the surface is clean and dry, two
coats of linseed oil are applied. The first coat consists of a mixture of
50 percent raw linseed oil and 50 percent turpentine, heated to a temper-
ature of 175° F. and applied with an ordinary paint brush. Better results
are obtained if the atmospheric temperature is above 65° F. For this
reason the work should be done during warm weather. After the first
coat has set 24 hours, spots will be evident where the concrete is more
porous than the remaining surface. Such areas should be spot-treated
with the hot mixture and allowed to set 24 hours before the second coat
is applied. The second coat consists of undiluted raw linseed oil heated
to 175° F. and applied in the same manner as the first.


INTRODUCTION

Like a radio commentator, we often wonder who may be
getting some benefit from our efforts. Consequently, it was most
gratifying to receive a letter stating:

"We have intended for some time to report to you upon the
ready acceptance and usefulness of this publication. When
operating problems are under discussion, it is a rather
common occurrence to overhear a remark, 'l remember
seeing a picture of a gadget they use at..... in the O&M
book.' The publication has gradually acquired a kind of
‘Popular Mechanics! standing with Operation and Mainte-
nance personnel."

The remarks are appreciated and it is hoped we can continue to publish
material of interest to all concerned. Credit, however, for the success
of the Bulletin is yours. We are publishing material submitted by O&M
people for O&M people.

A really worthwhile suggestion has been made and we are
sorry we haven't followed such a plan in the past. Name credit will
be given for articles released in the Bulletin to stimulate the contri-
bution of ideas of benefit to the Bureau and other Water Users. Many
of the ideas submitted have previously been recognized under the In-
centive Awards Program which parallels our purpose of pooling Bureau
ideas for common use to reduce Government costs. In the future, name
credit will be given and the added suggestion, that the contributor be
given a copy of the Bulletin, will be followed.

It should be noted that the last three articles in this issue have
particular reference to Weed Control. These articles have been paged
and identified so that they may be incorporated with Release No. 3.

The O&M Equipment and Procedures Bulletin is circulated for
the benefit of irrigation project operation and maintenance people. Its
principal purpose is to serve as a medium of exchange of operating and
maintenance information. Reference to a trade name does not constitute
an endorsement of a particular product and omission of any commer-
cially available item does not imply discrimination against any manu-
facturer. It is hoped that labor saving devices or less costly equipment
developed by the resourceful water users will be a step toward commer-
cial development of equipment for use on irrigation projects in continued
effort to reduce costs and increase operating efficiency

xR OK OK


MOSS SCREENS

In June, 1951, moss in-
festation in the Coachella
Canal, All-American Canal
System, became so bad that
almost the entire system was
plugged. Some method had to
be developed for the removal
of the moss, and, through con-
sultation and planning between
Bureau personnel and a rep-
resentative of the Coachella
Valley Water District, arrange-
ment was made for the con-
struction of a movable type
screen by an equipment
company.

The first screens were
placed in operation in 1952 and
well demonstrated the ability
to remove moss during chain-
ing operations. Use of a finer
mesh screen was investigated
to remove the tule skins but
this experiment increased the
head loss to an unsatisfactory degree. Some mechanical modification of
the first screens was incorporated in the next two screens constructed.

The lack of electric power at the site of operations made the
use of air-cooled gasoline engines necessary. This method of motiva-
tion was a constant source of operating difficulty throughout the period
of use. It was also observed that the side of the conveyor screen was
being chewed-up along the edges by the angle iron guide rail.

Further mechanical refinements have since been made and the
District forces have installed additional units on which the conveyor
screens have a width of 4 feet. The narrower conveyor has proven
more satisfactory since the screen has less tendency to creep or to
run crooked on the rolls, and they are now serving effectively in pre-
venting debris from entering the underground system.

Construction Details:
Information for construction of the moss screens may be

obtained from the Regional Director, Boulder City, Nevada or the
Construction Engineer, Coachella, California.

(IIB7-1)

12


blade is adjustable to suit operating needs. The cutter arm is lowered
by means of a small hand winch and the cutters automatically follow the
contour of the bed, the arm being hinged at its inner end. In operation
the clutch driving the cutting mechanism is engaged; this causes the
arm with cutting blades attached to oscillate rapidly, thus producing a
positive cutting action. The launch is controlled by one man, the oper-
ating cost compares more than favorably with the cost of other weed-
cutting methods now in use.

A larger launch now in use has an over-all length, including
paddle gear, of 21 feet 3 inches, a hull length of 17 feet 3 inches, width
4 feet, and depth 1 foot 11 inches. It has a draught of approximately
11-1/2 inches and net weight of approximately 1-1/4 tons, Width of
cut is 8 feet and depth 7 feet. Cutting speed is up to 3 m.p.h., accord-
ing to conditions, There are two operating speeds--first gear for cut-
ting and second gear for travelling without cutting. The engine is a
water-cooled 10-horsepower motor which drives both the propulsion
gear and the cutting mechanism. Water enters a water tank through
screened holes in the side of the hull; it then passes through a cock into
another tank, where it is filtered and pumped to the engine. Bothscreen
and filter can be removed for cleaning. Propulsion gear is of the paddle
wheel type, fitted at the stern of the launch, The whole gear is hinged
radially, enabling it to act as a rudder, thus enabling reasonably good
control of the launch. There are two double, fluted edged cutting blades,
each 7 feet 3 inches long, similar to those of the smaller launch, Cut-
ting edges consist of a number of small tempered steel segments riveted
to a 7-foot 3-inch by 2-inch by 1/4-inch plate of spring steel, in the an-
nealed condition, reinforced with a shorter plate at the butt end. These
blades are mounted in the form of a '''V'' either in the forward or reverse
direction on the end of an arm hinged at its inner end. The cutting unit
is controlled for depth of cut and is given a rapid oscillating motion
which effectively cuts all weeds in its path. Angle of the blades is ad-
justable to suit the average depth at which they are operating, and they
are at all times rigidly supported so that they can be maintained ina
horizontal position at any depth. While they can be lowered right on
to the bed of the waterway, their weight can be sustained so that they
do not sink too deeply into loose silt and therefore give too greata
resistance.

Several devices are incorporated in the design of the machinery
to safeguard the machinery. They are:

1. Blades are made of annealed spring steel which will bend if an
obstruction is fouled.

2. Drive to the blades is through a cone clutch which is engaged

sufficiently only to cut the weed growth. The clutch slips if the
blades strike a solid obstruction.

(IIB8-3)

15