Publisher’s version / Version de l'éditeur:
Engineering Journal, 42, 11, pp. 55-60, 1959-12-01
READ THESE TERMS AND CONDITIONS CAREFULLY BEFORE USING THIS WEBSITE.
https://nrc-publications.canada.ca/eng/copyright
Vous avez des questions? Nous pouvons vous aider. Pour communiquer directement avec un auteur, consultez la
première page de la revue dans laquelle son article a été publié afin de trouver ses coordonnées. Si vous n’arrivez
pas à les repérer, communiquez avec nous à PublicationsArchive-ArchivesPublications@nrc-cnrc.gc.ca.
Questions? Contact the NRC Publications Archive team at
PublicationsArchive-ArchivesPublications@nrc-cnrc.gc.ca. If you wish to email the authors directly, please see the
first page of the publication for their contact information.
NRC Publications Archive
Archives des publications du CNRC
This publication could be one of several versions: author’s original, accepted manuscript or the publisher’s version. /
La version de cette publication peut être l’une des suivantes : la version prépublication de l’auteur, la version
acceptée du manuscrit ou la version de l’éditeur.
Access and use of this website and the material on it are subject to the Terms and Conditions set forth at
Frazil ice: a review of its properties, with a selected bibliography
Williams, G. P.
https://publications-cnrc.canada.ca/fra/droits
L’accès à ce site Web et l’utilisation de son contenu sont assujettis aux conditions présentées dans le site
LISEZ CES CONDITIONS ATTENTIVEMENT AVANT D’UTILISER CE SITE WEB.
NRC Publications Record / Notice d'Archives des publications de CNRC:
https://nrc-publications.canada.ca/eng/view/object/?id=f683a087-d82c-4542-81e8-398c95993824
https://publications-cnrc.canada.ca/fra/voir/objet/?id=f683a087-d82c-4542-81e8-398c95993824
Ser
TiIl
l
N21t2
NATIONAL RESEARCH COUNCIL
CANADA
DIVISION OF BUILDING RESEARCH
l t
FRAZIL ICE
A Reuiew of its Properties with a Selected
Bibliography
by
G. P. Williams
Ati Ai--t'i;i)
REPRINTED FROM
THE ENGINEERING IOURNAL
voL. 42, NO. tt, NOVEMBER 1959, p.55-60
"':'iifioti?1'n
FEB
r 1960
TECHNICAL PAPER NO. 8T
OF THE
DIVISION OF BUILDING RESEARCH
OTTAWA
DECEMRER T959
PRICE IO CENTS
This publication
is being distributed
by the Division
of Building
Research of the National Research Council as a contribution towards better
building in Canada. It should not tre reproduced in whole or in part, without
permission of the original publisher. The Division would be glad to be of
assistance in obtaining such permission.
Publications of the Division of Building Research may be 'obtained
by mailing the appropriate remittance, (a Bank, Express, or Post Office Money
Order or a cheque made payable at par in Ottawa, to the Receiver General
of Canada, credit National Research Council) to the National Research
Council, Ottawa. Stamps are not acceptable.
A coupon system has been introduced to make pavments for
publica-tions relatively simple. Coupons are available in denominapublica-tions of 5, 25, and
50 cents, and may be obtained by making a remittance as indicated above.
These coupons may be used for the purchase of all National Research Council
publications including specifications of the Canadian Government
Specifica-tions Board.
jlililrl
FRAZIL ICE
A Reuiew
"f
its Properties.
With a Selected Bibliography
G. P. Williams
Research Officer,
Snow and Ice Section, Dioisi,on of Bui'ldi'ng Research,
National Research Council, Ottawa 2, Ont'
This report reviews the theory of frazil ice formation and the main factors which cause- formations. The methods of forecasting ftazil ice and the design and remedial considerations are also included. Although the frazil ice problem has been solved at many sites in Canada, this _review summarizes investigations which would not generally be available to Canadian engineers.
Tf-f HENEVER supercooled water
l [ /
vY rn reservolrs, lakes or rivers
comes in contact with hyd,ro-electric
plant intakes, lvater supply intakes,
ilrigation and water supply canals,
there is a danger of serious clogging
because of fuazil ice. Frazil ice
oc-curring in large rivers is a
naviga-tional hazard and can be the cause
of serious ice jams. In Canada the
work of Barnesl is the first major
effort to present detailed summaries
of available information on frazil ice
formation and occurrence. Since then
many investigations have been
car-ried out, notably in Russia and other
European countries. As no
publica-tion is available in English,
appar-ently, which summarizes these more
recent developments, this survey of
existing information on frazil ice has
been prepared, accompanied by a
number of selected references.
Theory of Formation
Ice is formed on the calm water
of small lakes and stagnant pools
when the loss of heat to the
atmos-phere by radiation, convection and
evaporation results in the
supercool-ing of the surface water. In this
static type of ice formation described
by Devik2 the crystallization begins
partly from solid matter on the beach
and from solid material suspended
or floating in the water. If the water
remains at rest and the cooling
con-tinues. a surface sheet of ice ii
rap-idly formed.
With dynamic ice formation as in
running water or on the surface of
lake water disturbed bv wind.
sur-face water exposed to the heat loss
will be interchanged with water from
lower depths so that a mass of water
down to different depths, depending
on the degree of turbulence, will be
cooled to 0"C without ice formation.
If the cooling continues the water
near the surface will be supercooled
a few hundredths of a degree
(Alt-berg3). At a certain stage in this
supercooling, frazil ice particles will
start to form.
In their early development, frazil
ice particles are thin ,circular discs.
Frequently,
the particles are of
ir-regular outline but the edges are
in-variably rounded as shown in the
ex-cellent photographs by Schaefera. As
growth proceeds, however, flat
den-drites grow out from the edge of the
flat discs, eventually producing the
needle-like fragments commonly
rec-ognized as frazil ice. Under favourable
cooling,conditions these fragments
rapidly form and group into the large
spongy masses that cause so much
trouble on underwater
installations.
Figure I illustrates the different stages
in frazil ice formation. Figure 2 shows
some micro photographs of frazil ice
in different stages of growth.
A similar type of formation occurs
in lake water when supercooling
co-inciding with stlong wave-action
re-sults in
agglomeration
(Wilson5).
Even though the general nature of
flazil ice folmation has been known
fol a long time there is still
argu-rnent and confusion in the literature
Fig. I Stages in frazil ice formation.
S U R F A C E C O O L I N G F U R T H E R C O O L I N G C O O L I N G C O N T I N U E S o O S T A G E I o o o H I G H C O N C E N T R A T I O N O F C I R C U L A R D I S C O I D S T O R M f D S T A G E 4 C O O L I N G C O N T I N U E S U S T E R S O F F R A Z l L N E E D L E . L i K E D E N D R I T E S G R O C E N E E D L E S C L U S T E R I N G T O -G E T I I E R T U R B U L E N T [ , l I X I N G I C E C O N G L O M E R A T E F L O A T I N G T O S U R f A C E A N D B I ] I I - [ ] N G ( J P O N I ] N D E R W A T E R O B J E C T S O U T F R O I I D I S C O I D S
floating changing shape Frazil ice particles growing and chang-Frazil ice particles
surface.
on water Frazil ice particles water surface.
regarding the phenomenon
(Timon-offo, LamborT).
Supercooling atTd Nucleation.
In-vestigators seem to agree that
super-cooled water often exists in streams for
long periods -
even for days under
favourable conditions8. There is
ar.-gument,
however,
regarding
the
amount of supercooling, although it
is generally assumed that it will rarely
exceed .01"C in natural streams and
lakes (Schaefera). The theory of
super'-cooUng is still a matter of some
disagreement. Dorseye indicates that
there are two theolies to explain the
freezing of water and the
phenome-non of supercooling. In one,
freez-ing is considered to be initiated by
certain aggregates of water molecules
called ice molecules. The other theorv
considers
freezing
to
begin
ut
heterogeneous singularities, i.e.,
for-eign particles in the water which
serve as nuclei. Dorsey combines
ele-ments of both theories. He
distin-guishes between an embryo comprised
of water molecules only, and a
com-plex embryo with a foreign par.ticle
as a centre to which molecules of
water adhere.
Altberg3 believes that crystals do
not form in absolutely pure liquid
but only upon dust particles
sus-pended in the liquid. He concludes
that the ability of a liquid to
crystal-lize depends upon the number of
nu-cleating centres per unit volume.
Piotrovichlo in a more recent studv.
points out that in water with only-a
few hundredths o[ a degree of
super.-cooling, all ordinary inclusions are
inactive as crystallizing agents.
Kumai and Itagakil2 in their
cin-erntrtoglaphic study of ice r:r.ystal
formation in water conclude that the
rate of growth of discoids (or frazil
ice particles) is a function of the rate
of cooling of the water and the
number of discoids. Their
photo-graphs show clearly the development
of circulal discoids into stellar
crys-tals. Their studies show that with
supercooling from 0"C to -0.3"C,
discoids and spicules are produced,
and from -0.6'C
to -0.9"C
spicules
only are produced.
Much of the work done in recent
years on the physics of supercooled
water droplets in the atmosphere is
of relevant interest to investiqators
of flazil ice (SchaeferrB).
Frazil lce Properties. The frazil ice
discoids vary in size. Schaefera
ob-serves particles with a range of
thick-ness 25 to 100 microns for particles
1000 to 5000 microns in diameter.
Hubbardla reports thickness almost
identical
to
those
reported
by
Schaefer. Altberg3 ,claims that
dis-coids up to several centimetres in
diameter could be grown artificially.
Baylis and Gersteinl5 have observed
particles that grow rapidly from Ya-in.
diameter up to 4 in. in diameter and
l/32 in. thick.
The buoyancy of frazil ice
parti-cles is of particular practical interest.
When the stream flow is not
ex-tremely turbulent, frazil particles
re-main submerged and do not appear
to collect at the surface. Barnes
at-tempts to explain this phenomenon
in terms of viscosity and Stoke's
Law8. Schaefera suggests that the
large ratio of major to minor axis
and the small difference in specific
gravity between jce and water cause
the palticles to tumble about within
Fig. 2 Micro photographs of frazil ice in different stages of growth.
ing pattern at water surface.
the stream much the same as
water-soaked leaves are carried underwater
in a turbulent stream.
Schaefera estimates that the
vol-ume concentration of frazil ice
ao-proaches 106 per cubic meter in h]is
observations of frazil ice on the
Mo-hawk river in 1950. Frazil ice
parti-cles will adhere to each other and
also build up on underwater objects
causing many problems. According
to Piotrovichlo, when water is
super-cooled there is a strong increase
in the cohesion forces between ice
crystals and in the adhesion of ice
crystals with stones, wood, metal and
other objects in the water. Schaefer
suggests that the laminar type of
build-up indicates regelation between
these ice particles.
Piotrovich also suggests that, as
ice does not adhere strongly to
cer-tain substances as plastics of purely
organic composition, these may be
used as coatings to protect against
underwater ice accumulations.
Ac-cording to Murphyl6
waterwheels
protected by wooden racks are better
able to withstand frazil attacks than
those protected by iron racks,
indi-cating a difference in the ability to
cohere between these two materials
and ice.
One point that should be stressed
is that ice will not adhere to obiects
that are slightly above 32'F. This
is why the heating of underwater gate
racks has often been successful in
reducing frazil ice accumulation.
Gale17 observes that freshly formed
frazil ice is "very sticky" and much
more difficult
to handle than frazil
rvhich has passed under surface ice
and has not been subject to such
str.ong
,.cooling. This suggests tha
even slight increases in t..""*p"."iur.
may reduce considerably th" ;jh;;;;
ability of fr.azil ice.
#",H'"#i";;:f #i"l'" or coorins
ffi*T[if**'."
fi,'"'',:un*
*o-:,
Fig' 3 Factors that affect the rate of cooling of a section
of river water.
The st. Lr
AMr oF FALLTNG
sNow oR RA'N
v' s oau(rvrt
ur nver wat(
contain
""
tl::ffi"f"i$il*tt:?t"rt":
\ \ \ \ \ \ \ \ f o r m r f i n - i n - : , , ^ * ^ r . r .
*ateR ,rou.t-.*t \L,
--ff--.|d
losses
from u *"t", r;,f;;;:"j"#
\\\\\\\.\\
ormation in rivers. I" ;;
.""i],
Q rn,
'ittJt\t,
AMouNr
oF |
\\\,.\[.,\
coNvEcrlvE cooLlNG
the rate of co-oling
ttr"t
"""
#";
. -:"''
"
I
ur\rJ\\
,/
pected from the differerrce f;;;,
aear caRRreo\ ri,ii,rtr
/
lNTo sec1oru\ ).p[
/
>- EvAPORATTvE
cooltNc
Sean
air temperature
u.td_
-eun *"t"r
DE.REE
o,',,",,.,".u
i#";r'J.r,:l:i"l'+tilltilti
:",Jfii"T;ll
Jlft,;
A M O U N T O F F L O A T I N G I C E A M O U I J T O F
river waier to cool to freezing
tern-perature, provided the mean air
tem-perature is known or can be predicted.
It must be appreciated that these
formulae are necessarily very
simpli-fied presentations of a most complex
situation. From the theory it is
diffi-cult to see how the wind velocity
terms can be ignored in any formula.
It is apparent from Fig. 3 that there
are a large number of variables not
included
in these formulae
which
might have important effects on the
rate of cooling of river water,
Baylis and Gersteinls state that,
"frazil ice formed under a wide
var-iety of wind and air temperature
conditions". Ruths2? mentions that,
"with
air temperatures as low as
-25"C
or -30"C
and no wind.
frazil ice will not always appear owing
to the presence of a heat insulating
layer of moisture saturated air on
top of the water which rvill prevent
the cold air from cooling the
sur-face water to the critical
tempera-fure".
It also should be stressed that
frazil ice is often produced a
con-siderable distance upstream from the
sections of the river under study;
these geographical factors cannot be
ignored in any study. Murphyro, ttt
1909
suggested that
very
large
amounts of frazil ice develop in Lake
Deschenes, 3 to 4 miles upstream
from the rapids near the Hull power
plants on the Ottawa river.
These complications do not mean
that a practical means of predicting
the rate of cooling, and hence of
frazil ice formation, cannot be found.
They do imply that site conditions
must be taken into consideration.
Standingzs gives some practical rules
used at a particular plant for
fore-casting frazil ice as much as 12 hours
in advance. On a longer-term basis
Wardlaw2e
calculates
the
mean
monthly heat losses from a water
surface under winter conditions and
obtains reasonable agreement with
other calculated values for heat losses
from open-water surfaces.
Forecasting Frazil Ice from Water
Temperature Measurements
In some plants it is common
prac-tice to keep a record of water
tem-perature. Whenever the water
temper-ature is near 32'F' and severe wind
or temperature conditions are
experi-enced, fi'azil ice formations may be
expected.
Granbois3o reports a method of
precise water temperature
measure-ments with
an electric resistance
thermometer and recorder. With his
apparatus he was successful in
meas-uring the rate of temperature change
of river water and relating it to frazil
ice formations. His studies indicate
that frazil occurs only when the rate
of temperature change is greater than
0.01'C/hr between temperatures of
0.1"C and 0'C.
At
temperatule
changes less than 0.01'C/hr a natural
ice sheet is formed. Granbois in his
paper gives a fairly complete
des-cription of the resistance thermometer
bulb, bridge and recorder which he
used.
Anyone
contemplating
the field
measurement of river water
temoera-ture near 32"F, however, *rrri b"
prepared for some problems. Perhaps
the main difficulty to be overcome is
that as soon as water falls below
0'C, ice begins to form on the
tem-perature indicator.. The only
tempera-ture then recorded is the freezins
point, even though there may bc
supercooling present. Glanbois
over-came this by removing the detector
bulb after each successive run and
melting the ice from the indicator in
preparation for the next run.
Devik2 measures the amount of
supercooling of the surface layer of
water
with
a "moll"
thermooile.
Special precautions were taken
re-garding radiation effects, including
the taking of measurements just
be-fore sunrise. Nybrant3l points out
some of the problems of measuring
water temperatures under field
con-ditions. He indicated that sensitive
galvanometers are difficult to use and
that it is necessary to keep a
measur-ing bridge at constant temperature
and to check its calibration freouentlv.
One must also consider the stabiliiy
of the temperature sensing elements
and
check their
calibration
fle-quently.
Although
the work of Gr.anbois
indicates that it is possible to measure
river water at temperatures around
0'C to the necessary accuracy for
frazil ice predictions at a particular
site, special precautions and
equip-ment are required which are usually
not readily available for field
installa-tions.
Design Considerations
Although it is not the purpose
of this review to go into detail
re-garding the design of canals, hydro
intakes and racks for ice conditions,
some general comments on design are
included in order to complete this
general revjew.
In 1919, Wilsonle stated that
hy-dro plants could be designed to be
practically immune from ice troubles.
Some of the standard textbooks on
hydro-electric design (Creager and
Justins2) give general consideration
to the design of hydlo plants to
mini-mize frazil ice conditions.
Loughlandza gives some general
instructions for the desisn,of sluices
and canals. including the suggestion
that covering the flume will prevent
snow from falling into the canal,
thus reducing the rate at which the
water cools. Carpenterss indicates
that by coveling a flume and
pro-viding an additional supply of
stor-age water the frazil ice problem at
the Barriere Hydro Plant in British
Columbia could be overcome.
In addition to the usual procedure
of carefully surveying existing river
conditions, ensuring proper approach
conditions and locatins the racks at
a sufficient dcpth, metebrological
fac-tors should not be neglected. For
example, care should be taken in
determining the prevailing wind
di-rection, for if it prevails towards the
intake channel large quantities of
ice will be for,ced into the channel.
Even the direction of the wind
rela-tive to the flow of the river has a
varying effect on frazil ice
produc-tion. A wind blowing upstream
pro-duces more frazil than one blowing
downstream because of increased
surface agitation (Hendry3a).
Once a rivel or canal is frozen
over the rate of cooling is greatly
redu,ced by the ice cover and the
danger of large fraziT ice formations
is usually' eliminated. For this reason
considerable study has been made
of the r,r'ater velocities at which
canals or livers will freeze. The
fac-tors affecting the formation of ice
covers on rivers or canals are
gener-ally the same as those which
-affect
the rate of cooling of a river or canal
as shown in Fig. 3.
The St. Lawrence Waterway
Pro-ject25 gives some practical
informa-tion on the relainforma-tion between water
velocities and ice formation. Because
velocity and turbulence of water are
only two factors which will affect
the formation of ice cover it is not
possible to give limiting velocities
which will apply in every case. In
its report the Joint Board of
Engi-neers came to the general conclusion
that "smooth ice covers may be
ex-pected to form in rivers with
veloci-ties up to 1.25 ft/sec in zero weather
providing there is no high wind
pre-venting such action".
A comrhittee of the Power. Division
of the A.S.C.E. investigated ice as
jt affects porvel plants and published
a special report (Shenehon35). In
ad-dition to a bibliography on the
sub-ject, they give much information of
use to design engineers. Some of the
effects of ice on stream flow are of
special interest to engineers
design-ing canals or modifydesign-ing river
chan-nels under
conditions (36' 37'
3 8 , 3 9 , 4 0 , 4 1 ) .Remedial Action
For established power plants and
hydraulic works, it is often possible
to prevent the formation of frazil
ice by electrical heating. Reida2 gives
some details of the heatinA of
rack-bars in hydro-electric planis,
includ-ing a formula for calculatinclud-ing the
power required. He emphasizes that
electric heating is of particular value
in locations where frazil ice develops
quickly and is not of Iong duration.
Ruths2? gives a table of electricai
values, including the power required,
used in heating racks at several power
houses in Norway. A report by the
subcommittee of the Hydraulic Power
Committee for the Canadian
Elec-trical Associationa3 gives some details
of the electrical
"trergy
utilized by
different companies in Canada
for-keeping sluice gates free of ice.
Var-ious other references are availabie,
indicating that formations of frazil
ice have been successfully combatteC
bY electrical heating++' l5' +0.
Steam heat has also been used for
preventing
ftazil
ice
formationa3.
DolionaT relates some of the
difficul-ties connected with preventing
ac-cumulations of frazil ice with steam
at a pump intake.
Compressed air jets or air-bubbling
systems to prevent ice formation have
been applied for many years. Air
bubbling systems depend on the fact
that warm water below the surfa,ce
can be brought to the surface by
the rising air bubbles and so used to
prevent frazil ice at specific locations.
Skerretta8 in 1923 described how
jets of compressed air were utilized
to prevent ice formation on gates of
hydro-electric plants. In 1935
Sker-rettae gave sorne details of how ice
pressure was prevented by air
bub-bling systems. Other more lecent
papers are given by Owenso,
Sim-monds51, and Granboiss2. Some fairly
complete experiments on preventing
water from freezing by means of
complessed
ail
were
done
by
Kaiterass in 1948.
In addition to heat and air
bub-bling systems other means ale being
used to combat frazil ice formation.
In Switzerland where, because of
climatological and hydrographic
con-ditions. frazil ice ploblems 1ys not
generally severe, mechanical devices
to
clean
out
intakes
are
used
(Han yia).
Murphyl6
reported
in
1909 that frazil ice can be olevented
by creating an artificial balrlier acloss
the stream to start sulface ice
forma-tion.
It has been suggested by Schaefer'{
that the seeding of ponds with dry
ice mieht
hasten ice
formation.
Granboiiso reports limited
success
by seeding river water with dry ice;
the resulting fragile ice sheet was
destroyed as fast as it was formed.
Lavrov55 considers that artificially
increasing the number of
crystalliza-tion nuclei cannot be an effective
counter-rneasule because the
in-tensity of underwater ice formation
depends on heat losses from the
stream, not on crystal number.
A dditional lnformation The SIPRE
biblioglaphy
contains many useful
refelences on frazil ice and relaterd
problems, including a series of
sian abstracts. A few selected
Rus-sian references have been chosen from
these abstracts and are listed as a
Bibliography.
I a Houille Blanche, (Numero 4,
juiilet, aoirt 1950) contains an
excel-lent review of snow and ice technical
terms in French and English. In
ad-dition, this volume contains a general
review of frazil ice problems and
related phenomena.
The Meteorological Abstracts and
Biblioglaphy of the A.M.S. for July
and August 1956, contain an
anno-tated bibliography on the
micromete-orology of snow covers. This would
be of value to anyone studying the
thermal regime at snow and ice
sur-faces.
This paper is a contribution of the
Division of Building Research of the
National Research Council of Canada.
and is published with the approval
of the Director of the Division.
References
1. Barnes, H. T. Ice Engineering; Renouf Publishing Co., Montreal, 1928. 2. Devik, Olaf. Supercooling and Ice
For-mation in Open Waters; International U n i o n o f G e o d e s y a n d G e o p h y s i c s , I n -ternational Association of Scientific Hvdrolosv, 1948. pp. 380-389. 3 A i t b e r e , - W . J . ' f w e n t y Years of Work
in the Domain of Underwater Ice For-mation (1915-1935); International Union of Geodesv and Geophvsics, Internat i o n a l A s s &lInternat; j c i a l i o n o f S c i e n Internat i f i c H y d r o -logy, 1936. pp. 373-407.
4. Schaefer, V. J. The Formation of Frazil and Anchor Ice in CoId Water; Trans. Amer. Geophys. Union, vol. 31, no. 6, December 1950.
5. Wilson. J. T. and others. A Study of l c e o n a n I n l a n d L a k e ; S I P R E R e p o r t no 5, Pt. I, April 1954. 78p.
6 Timonoff, V. E. On the Establishment of a Working Hypothesis of Ice Pheno-mena in Lakes and Rivers; Interna-t i o n a l U n i o n o t G e o d e s y a n d G e o -p h v s i c s . I n t e r n a t i o n a l A s s o c i a t i o n o t S c r e n t i f i c H y d r o l o g y , 1 9 3 6 . p p . 3 6 7 - 3 7 2 . ?. Lanbor, Julian. La-Genese -di: la Gtace
Flottante et son Apparitiou sur les Cours d'Eau de l'Europe Centrale
Appartenant au Bassin Baltique; Inter-nitional Union of Geodesy -anii Geo-p h y s i c s , I n t e r n a t i o n a l A s s o c i a t i o n o f Scientific Hydrology, 1948. pp. 367-379. 8. Ice Formation in Open Water;
Min-nesata U. Engineeriirg Exp. Slation, July 1951. pp 104-107. (In Review of the Propertres of Snolv and Ice, Edited by Homer T. Mantis. SIPRE Report 4 ) . 1 6 r e f s .
9. Dorsey, N. E. The Freezing of Super-Cooled Water; Trans. of Amer. Philos. Society, vol 38, Part 3, Nov. 1948. pp. 245-328.
10. Piotrovich, V. V. Formation of Depth-Ice; Translated from Priroda, vol-. 9. 1956, pp. 94-95, Defence Research Board, D S.I.S. Department of National Defence, Canada. T235R.
11 Arakawa, Kiyoshi. Experimental Stu-dies on Freezing of Water; Interna-tional Union of Geodesy and Geo-physics, International Association of Scientific Hydrology, 1954. pp. 474-4 7 7 .
12. Kumai, M., and K. Itagaki. Cinemato-graphic Study of Ice Crystal Forma-tion in Water; International Union of Geoclesy and Geophysics, International Association of Scienti.tic lrydrology, 1954. pp. 463-467.
13. Schaefer, V. J. The Formation of Ice Crystals in the Laboratory and in the Atmosphere; International Union of Geodesy and Geophysics, International Association of Scientific Hydrology, 1948. pp. 186-209.
14. Hubbard, Fran. When Winter Grips Yosemite; Natural History vol 63, Dec. 1954. pp. 448.-451 (illus.)
15. Baylis, J. A. and H. II. cerstein. Fighting Frazil Ice at Waterworks; Engineering News-Record, vol. 140, no. 16, April 15, 1948. pp. 80-83. 16. Murphy, John. The Ice Question
-as it Affects Canadian Water Powers - with Special References to Frazil and Anchor fce; Proc. Trans. Roy. Soc. Can., 1909, section 3, pp. 143-U7. 17. GaIe, G. Discussion of Paper by R. M. Wilson, Journal of Engineering Insti-tute, vol. II, no. 5, 19f9. p. 392. 18. Stakle, P. Frazil and Anchor-Ice in
the Rivers of Latvia: International Union oI Geodesy and Geophysics, International Association of Scientific Hydrology, 1936, pp. 351-366. 19. Wilson, R. M. Design of
Hydro-Electric Plants for Combatting Ice Troubles; J. Eng. Inst. Conn., vol. 2, 1919. pp. 283-395.
20. Hoyt, - W. G. The Effects of lce on Stream Flow; U.S. Geol. Survey, Water Supply Paper 33fi f913. 77p. 21. Geiger, R. The Climate Near the
Ground; Harvard University Press, 1950. 482p.
22. Powell, IM. M., and G. L. Clarke. The Reflection and Absorption of Daylight at the Surface of the Ocean; J. of the Optiial Soc. of America, vol. 26, March 1936.
23. Loughland, G. E. Ice Formations in the Main Sierra Canal; Military En-gineer, vol. 16, Nov. - Dec. 1924. pp. 487-490.
24. Atkins, W. R. G. and H. H. Poole. The Photo-Electric Measurement of the Penetration of Lieht of Various Wave-Lengths into thd Sea and the Physiological Bearing of the Results; Trans. Roy. Soc. London (1935). 25. St. Lawrence Waterway Project;
Re-port of Joint Board of Engineers. Ice Formation in the St. Lawrence and Other Rivers, Appendix E, (1924), D.406.
26. Wemelsfelder, P. J. An Investigation Concerning the Balance of Heat in a River During Violent Frosu Interna-tional Union of Geodesy and Geo-Dhysics, International Association of Scientiftc Hydrology, 1945, pp. 191-197. 27. Ruths, Arvid. Ice Troubles in
Nor-wegian Water Power Plants; Trans. of the First World Power Conference, vol. II, 1924, pp. 771-787.
28. standing, R. o. Ice Problems at Chats Falls and Other North Eastern Can-adian Plants; Symposium on lce Prob-lems at Hydro-Electric Plants in Northeastern United States and Can-ada - Minutes for Meeting of the Hydraulic Power Committee of the Pennsylvania Eleetric Ass'n. Feb. 9, 10, 11, 1950. pp. 38-43.
29. Wardlaw, R. L. A Study of Heat Losses from a Water Surface as Re-lated to Winter Navigation; Proceed-ings Eastern Snow Conference, vol. 2. 1953 and 1954.
30. Granbois, K. J. Combatting Frazil Ice in Hydro-Electric Stations; Power Apparatus and Systems, no. 5, April 1 9 5 3 p p . 1 1 1 - 1 1 6 .
31. Nybrant, G. Temperature Measure-ments in Lakes and Rivers Performed by the Meteorological and Hydologi-cal fnstitute of Sweden; International Union of Geodesy and Geophysics, International Association of Scientific Hydrolo8y, vol 3, 1954. pp. 62-72. 32. Creager. W. P. and J. D. Justin.
Hydro-Electric Handbook; 2nd Edition, John Wiley and Sons, New York, 1950.
I t D t D .
33. Carpenter, E. E Winter Operation of Barriere Hydro Plant; I(amloops Power System of B.C. Electric Rail-way Company Limited. Engineering Journal, vol. 19, no. 8, August 1936. 34. Hendry, M. C. Ice Troubles in
Hydro-Electric Plants; Canadian Engineer, voI. 27, Nov. 1914. pp. 693-694. 35. Shenehon. F. C. and others. Ice as
Affecting Power Plants; Final Reports of Comm:ittee of Power Division, Tians.
Amer. Soc. Civil Engineers, vol. 95, 1 9 3 1 . p p . 1 1 3 4 - 1 1 5 0 .
36. Kolupaila, Steponas. Methods for De-termining Winter Run-Off Amounts - (Text in German with English and French Summaries): Trans. World Power Conference, Barcelona, Spain, vol. 2, 7929. pp. 653-679.
37. Barrows, H. K. and R. E. Horton. Determination of Stream Flow Durine the Frozen Season: U.S. Geol. Survey-, Paper No. 187, 1907.
38 Laszloffy, M. W. R6gime des Glaces des Rividres; La Houilte Blanche, vol. 3, no. 6, Nov-Dec. 1948. pp. 469-491. 39. Wemelsfelder, P. J. The Influence of
an lce-Cover on the Discharse Con-d i t i o n s o f a R i v e r ; I n t e r n a t i o n a t U n i o n of Geodesy and Geophysics, Interna-tional Association of Scientific Hydro-logy, 1954. pp. 182-190.
40. Parsons, W. J. Ice in the Northern Streams of the Ilnited States, Trans. Amer. Geophys. Union, Part III, 1940. pp. 970-973.
41. Stevens, J. C. Winter Overflow from Ice-Gorging on Shallow Streams; Trans. Amer. Geophys. Union, Part III, 1940. pp. 9?3-9?8.
42. Reid, C. R. Electric Heating of Rack-Bars in Hydro-Electric Plants; En-gineering Journal, vol. 11, April 1928 43. Methods of Handling Ice and
Heat-i n g S l u Heat-i c e g a t e s , a n d T r a s h R a e k s Heat-i n Hydro-Electric Plants; Report by Sub-committee of the Hydraulic Power Committee, The Canadian Electrical Association, Montreal. 16p
44. Samsioe, A. F. Measures taken in Sweden Against Ice Troubles at Power Plants: Trahs. First World Power Conference, vol. 2, 1924. pp. 806-8 1 1 .
45. Goodrich, R. D. Induction Heating for Drum cates; Electrical World, vol. 114, Nov 16, 1940. pp. 1462-7465.
46. Blanke, J. H. D. Preventing Ice Troubles on Screens Before They
Statt; Water Works Engineer, vol. 81, August 1928. p. 1180.
47. Dorion. Robert. Frazil Ice Problems i n P u m p i n e S t a t i o n s ; C a n a d i a n E n -g r n e e r , i o l . 7 2 , n o . 1 9 , N 4 a y 1 1 , 1 9 3 7 . p p . U - 1 4 .
48. Skerrett, R G. Redueing Ice Pressures with Compressed Air; Canadian En-gineer, vol. 45, 1923. pp 181-185. 49. Skerrett, R. G. Thwarting lce
Pres-sure with Air Bubbles; Compressed A i r M a g a z i n e , v o ] . 4 0 , M a r c h 1 9 3 5 , pp. 4677-4680.
50. Owen. T. C. Ice Prevention bv the Air-Lift System at Grand C6ulee; Trans. Am. Soc. Mech. Eng., vol. 64, 1942. pp. 201.206.
5I. Simmonds, A. T. Prevention of fce Formations bv Air Bubblins: Proc. E a s t e r n S n o w C o n f e r e n c e , - v o l . 2 , 1953, 1954. pp 37-39
52. Granbois, K. J. Experimental Use of Air Bubbles for the Control of Sheet Ice at Safe Harbour; Proc. Eastern Snow Conference, vol. 2, 1953, 1954. 53. Kaitera, Pentti. Keeping Water from Freezing by Means of Compressed Air; fnternational Union of Geodesy and Geophysics. International Association o f S c i e n t i f i c H y d r c l o g y , 1 9 4 3 . p p . 3 9 0 -398.
54. Harry, A. Ice Action on llydro-Elec-tric Plant Installations in Running W a t e r ; R e v u e . G e n . E l e c t r i c i t 6 , v o ] . 42, Oct. 30, 1937, pp. 555-571; Nov. 6, 1937, pp. 593-604.
55. Lavrov. V. V. On the Formation of Underwater Ice; Meteorologiia i Gidro-l o r g i i a , 1 9 5 7 , n o . 5 , M a y 1 9 5 7 , p p . 4 3 - 4 5 .
Bibliography
Artsybashev, S., Measurements of sub-surface temperatures by thermocouples and some observations of the Ansara River winter temperatures. (Texf in Russian) Meteorologicheskii Vestnik, 35: 30-31, 1925. SIPRE No. U6851.
Makkaveev, V. M., Theory of mixing phenomena accompanying the turbulent motion of fluid in open streams and questions concerning the winter regime of rivers. (Text in Russian with English summary) Zapiski Cosudarstveniogo Gidrologicheskogo fnstituta, 5: 75-116 incl. tables. 1931. ? refs. SIPRE No. u5153.
Lotter, G. I(., Influence of conditions accompanying ice formation and ice thickness in the design of diversion canals. (Text in Russian with English summary) Izvestiia nauchno-issledova-tel'skogo instituta gidrotekhniki, 7: 55-81 incl. tables, 1932. SIPRE No. U1487. Bydin, F. I., The nature of anchor ice
and counter-measures. (Text in Rus-sian) Trudy Nauchno-issledovatel'skogo Instituta Gidrotekhniki. Sbornik oo L e d o t e k h n i k e , l : 9 - 5 8 i n c l . i l l u s . t a b l e s , map, diagrs. 1933. 38 refs. SIPRE No. u 6 1 1 4 .
Bydin, F. I., Winter regime of the rivers a n d t h e m e t h o d s o f s t u d y . ( T e x t i n Russian with French summary) Issledo-vaniia rek SSSR, Gosudarstvennyi
Gidro-A list of all putrlications of the Division of Building Research is
avail-able and may be obtained from the Publications Section, Division of Building
Research, National Research Council, Ottawa, Canada.
Iogicheskki Institut, 5: 5-237 incl. illus. tables, graphs, diagrs. 1933. 113 refs. SIPRE No. U5?50.
Piotrovich, V. V.. Method to determine the porosity and the quantity of ice m a s s i n r i v e r i a m s . I z v i s t i i a G o s u d a r -stvennogo Gidrblogicheskogo Instituta, No. 59.: 27-30, 1933. SIPRE No. U1371. Makkaveev, V. M., Stream flow in the
presence of ice. (Text in Russian) Vse-soiuznyi S"ezd Inzhenerno-Tekhniches-kogo Obshchestva Gidravlikov i Girdo-tekhnikov, Trudy, 1931: 15-35, 1934. 2 refs. SIPRE No. 13465.
Al'tberg, V., Anchor ice. (Text in Russian and French) Doklady Akademii Nauk SSSR, 21 168-172, April 21, 1934. 8 refs. SIPRE No. 9627.
Piotrovich, V. V., Selective ability of anchor ice formation. Meteorologia i Gidrologiia, No. 3: 106-109 incl. illus. tables, 1938. SIPRE No. U1356. Girillovich, N A., Planning of the
condi-tions for low head hydroelectric stations built in river channels. (Tdxt in Rus-sian with English summary) Izvestiia nauchno-issledovatel'skogo instituta gid-rotekhniki, 22: 128-156 incl. illus. tables, graphs, 1938. 14 refs. SIPRE No. U1529. IAgodin, N. N., Study of winter conditions
at hydraulic structures of Boz-Su reser-voir (Text in Russian with English summary) Izvestiia nauchno-issledbva-tel'skogo instituta gidrotekhniki, 222 157-18? incl. illus. graph, maps, diagrs. 1938. SIPRE No. U1635.
Zil'berman, A. N., On the process of underwater ice formation in ftowins waters. (Text in Russian with German summary) Meteorologiia i Gidrologiia, 6, No. 12: 3-18 incl. illus. 1940. 11 refs. SIPRE No. U2353.
Estifeev, A. M., The artifical freezing of rivers. (Text in Russian) Nauka i Zhizn', 18 No. 1: 4€-49 incl. illus. Jan. 1951. SIPRE No. 9537.
Fokeev, V. S., Some properties of a stable eddy current. (Text in Russian) Gidrotekhnicheskoe Stroitel'stvo, 20, No. 5: 4l-44 incl. illus. graphs, diagrs. 1951. SIPRE No. U5443.
Fradkin, B. M.. and L. S. Kuskov. Control of anchor and frazil ice on hydroelectric stations. Gidrotekhnicheskoe Stroitel'-stvo, 20, No. 4: 14-16 incl. table, diagr. 1951. SIPRE No. U4137.
Bikmamatov, Kh. D., Frost-free metallic muff coupling tor joining wooden pres-sure pipelines with the reservoir. (Text in Russian) Gidrotekhnika i Melioratsiia, 4, No. 11: 73-?6 incl. diaErs. Nov. 1952. 6 refs. SIPRE No. U5129.
Bibikov, D. N., Thermal conditions in a stream during the period of under-water-ice formation. JText in Russian) fzvestiia Nauchno-Issledovatel'skogo In-stituta Gidrotekhniki. 52. 237-234 inc]' tables, graphs, diagr. 1954. SIPRE No. 15959.
Germanishvili, V. Sh.. Sludse in caucasian rivers and methocis of lorecasting its appearance. (Text in Russian) Trudv TSentral'nogo Instituta Prognozov, 58-: 3-36 incl. tables. graphs, maps, 1957. 16 refs. SIPRE 15945.
