Below are the first 10 and last 10 pages of uncorrected machine-read text (when available) of this chapter, followed by the top 30 algorithmically extracted key phrases from the chapter as a whole.
Intended to provide our own search engines and external engines with highly rich, chapter-representative searchable text on the opening pages of each chapter.
Because it is UNCORRECTED material, please consider the following text as a useful but insufficient proxy for the authoritative book pages.
Do not use for reproduction, copying, pasting, or reading; exclusively for search engines.
OCR for page 115
APPENDIX A
ABSTRACTS OF PERTINENT ARTICLES AND REPORTS
Listing
Anonymous (1971), "Squat," Comm~ndant's International Technical Series,
Vol. I, Report No. USCG-CITS-71-1-1 (Washington, D.C.: U.S.
Coast Guard).
Anonymous (1979), "Automatic Survey Techniques on the Waterways and
Approaches to Rotterd~m" (Netherlands: Rijkswaterstaat, Direktie
Benedenrivieren, Meetdienst).
Anonymous (1981), "A Report on Bed Density Measurements and Echo
Sounding at Humber Ports," Report No. R. 286 (United Kingdom:
British Transport Docks Board, Research Station).
Anonymous (N.D.), "Density Measurements In Situ," (Netherlands:
Public Works Department, Lower Reaches Directorate, Surveying
Division, Research Section ~ .
Anonymous (1981), "New Non-Linear Sub-Bottom Profiler System, n
International Dredging & Port Construction, April 1981, pp. 29-30.
Berriman, J. W. and J. B. Herbich (1977), "Major Port Improvement
Alternatives for the Texas Coast," COE Report No. 197,
TAMU-SG-77-205 (College Station, Tex.: Texas Ash University).
Bijker, E. W. (1978), "Science and Design of Navigation Trenches and
Offshore Trenches, " Proc. 8th World Dredging Conf ., pp. 69-76.
Bijker, E. W. (1980 I, "Sedimentation in Channels and Trenches, " Proc.
17th Coastal Ena. Conf ., ilol . II, OD . 1708 - 1718.
— . ~ .
Blaauw, H. G., J. W. Koeman,and J. Strating (1981), "Nautical
Contributions to an Integration Port Design," Publication No. 251
(Netherlands: Delft Hydraulics Laboratory).
Bos, H. (1979), "Marketing Research and Business Economics," Land and
Water International, pp. 20-22
Eden, E. W. (1971), "Vessel Controllability in Restricted Waters,"
J. Waterways, Harbors and Coastal Eng., Proc. ASCE, 97(WW3~:
475~-490.
A-1
OCR for page 116
A-2
Gates, E. T., and J. B. Herbich (1977a), "Mathematical Models for the
Design, Operation and Economic Analysis of Deep-Draft Navigation
Channels," Proc. 24th International Nav. Cong., PIANC, Leningrad,
U.S.S.R., pp. 175-181.
Gates, E. T., and J. B. Herbich (1977b), "Mathematical Model to Predict
the Behavior of Deep-Draft Vessels in Restricted Waterways," COE
Report No. 200 (College Station, Tex.: Texas A&M University).
Gates, E. T., and J. B. Herbich (1978), "A Mathematical Model for the
Review or Design of Deep-Draft Navigation Channels with Respect
to Vessel Drift and Rudder Angles," Proc. Symp. on Aspects of
Navigability, Delft, Netherlands, April.
Hellema, J. A. (1979), "Density Measurements In Situ" (Netherlands:
Public Works Department, Lower Reaches Directorate, Measuring
Division, Research Section).
Herbich, J. B., W. R. Murden, and C. C. Cable (1981), "Factors in the
Determination of a Cost-Effective Dredging Cycle," Proc. XXV Int.
Nav. Cong., Inland and Maritime Waterways and Ports, PIANC,
Section II, Vol. 2, Edinburgh, Scotland, May 10-16.
Huval, C. J. (1978), "Mathematical Models for Navigation Cnannel
Design," 26th Proc., Annual ASCE Hydraulic Civ. Spec. Conf.,
Verification of Math. and Phys. Models in Hydraulic Eng.,
University of Maryland, August 9-11, pp. 273-279.
Iijima, Y., and K. Honda (1973), 'iChannel Width of Harbor Entrance, ·
J. Naut. Soc e Japan, _: 91-10 3 e
International Association of Ports and Harbors (1981), "Special Care
Measures for Safe Disposal of Polluted Dredged Material in the
Marine Environment,'' Submitted to the Ad Hoc Scientific Group on
Dumping--Sth Meeting, Halifax, Canada, May 4-8.
Kirby, R., W. R. Parker, and W. H. A. van oostrum (1980), "Definition
of the Seabed in Navigation Routes through Mud Areas,"
International Hydrographics Rev., Monaco, LVII(11: 107-117, (Also
First International Hydrographic Technical Conference, Ottawa,
My I'9~)''.''
Kondstaal, R., and J. van der Weide (1981), "Systems Approach in
Integrated Harbor Planning," Publication No. 250 (Netherlands:
Delft Hydraulics Laboratory), Presented at the Seatech III
Conference in Asian Ports Development and Dredging, Singapore,
March.
Kray, C. J. (1973), "Design of Ship Channels and Maneuvering Areas,"
J. Waterways, Harbors and Coastal Eng., Proc. ASCE, 99(WW1~:
89-~.
OCR for page 117
A-3
McDonald, R. M. (1977), "Development of the Ship Channel between
Montreal and Deep Sea," Marine Tech., 14: L92-197.
,
Mikkelsen, L., P. Mortensen, and T. Sorensen (1980), "Sedimentation
in Dredged Navigation Channels," Proc. 17th Coastal Eng. Conf.,
Vol. II, pp. 1719-1734.
Minorsky, V. U. ~ 1977 ), "Grounding Probability Studies, " final Report
on Task IV, Feb. 76 - Jan. 77, prepared for U.S. Maritime
Administration by George C. Sharp, Inc., New York.
Muir , William C., G . D . Pence , and J . R. Pomponio ~ 1981 ), "Deepening
the Hampton Roads--The EIS Process, " Proc . 14th Annual Dredging
Seminar College Station, Tex. : Texas A&M University).
Nederlof, L. (1979), '"Sailing Through Water Rich in Silt: A Vessel
Behaves Differently but Remains Manageable," Rotterdam Europoort
Delta, pp. 19-22.
Nederlof, L., and G. van Bochove (1981), "Maneuvering Behavior of Ships
in Muddy Canals and Harbors," The Dock and Harbor Authority,
Netherlands, Vol. LXII, No. 726 (May), pp. 2-6.
Ottevanger, G. (1979), "Dredging Operations in the Approaches to
Rotterdam," Land and Water International, pp. 27-32.
.
Trawle, M. J. (1981a), "Prediction of Shoaling Rates for Deepened
Estuarine Navigation Channels," Proc . 14th Annual Dredging
Seminar ~ College Station , Tex .: Texas A&M University ~ .
Trawle , M . J . ~ 1981b ), Ef f ects of Depth on Dredging Frequency : Methods
of Estuarine Shoaling Analysis, Technical Report H-78-S
~ Vicksburg, Miss .: U. S . Army Engineer Waterways Experiment
Station ~ .
Trawle, M. J . and J . B. Herbich ( 1980 ), "Prediction of Shoaling Rates
in Offshore Navigation Channels," Center for Dredging Studies,
Department of Civil Engineering, Report No. 232 (College Station,
Tex.: Texas A&M Uniters ity ~ .
Troesch, A. W., and S. Cohen ~ 1980 ), "Relationship of Underkeel
Clearance and Vessel Speed to Grounding, " Report No. 017999, Ship
Hydrodynamics Lab, University of Michigan.
Turner, H. D. ~ 1978 ), "Physical Model Study for Improved Navigation
Channel Design, " 26th Proc ., Annual ASCE Hydraulic Div. Spec.
Conf.: Verification of Math. and Phys. Models in Hydraulic Eng.,
University of Maryland, August 9-11, pp. 265-272 .
van de Ridder ~ 1979 ), "=tterdam and the Harbor Silt, " Land and Water
International, pp . 23-26 .
OCR for page 118
A-4
van Donselaar, H., et al . ~ 1981 ), "The Maritime Impact of Liquid Energy
Gases--the Planning and Operational Aspects' " Maritime Ports and
Seaways, Vol. I, Permanent International Association of
Navigation Congresses, XXV, Sec. II.
van Oostn~m, W. H. A. ~ 1979a ), "Maintenance Dredging in Soft-Bedded
Navigation, " Control Dredging Association (CDEA) Conf .,
Netherlands .
van Oostrum, W. H. A. (1979b),
International, pp . 17-19 .
"MKO Project," Land and Water
van Oostrum, W. H. A. ( 1979c ), "Operations Research in Dredging, "
Terra et Agua, 18: 2-15.
van Oostrum, W. H. A., W. R. Parker, and R. Kirby { 1980 ), "Maintenance
Dredging in Fluid Ad Areas, " Third Int. Symp. Dredging Tech.,
Bordeaux, France, pp . 177-190 .
van Oostrum, W. H. A., et al . ~ 1981 ), "Dutch Ef forts for Optimization
of Marine Dredging, " Proc. XXV Int. Nav. Cong., Inland and
Maritime Waterways and Ports, PIANC, Section II, Vol . 2,
Edinburgh, Scotland, May 10-16 e
Wang, S . ( 1980 ), "Full-Scale Measurements and Statistical Analyses
of Ship Motions in a Navigational Channel, n Marine Tech., 17:
351-370 .
Waugh, Richard G., Jr. ( 1971 ), "Water Depths Required f or Ship
Navigation, " J. Waterways, Harbors and Coastal Eng., Proc. ASCE,
97(WW3~: 455-473.
Wicker, C. F. (1971), "Economic Channels and Maneuvering Areas
for Ships," J. Waterways, Harbors and Coastal Eng., Proc. ASCE,
. .
97(WW3): 443-454.
Young, R. W. ~ 1978 ), "Or the Interactions cuff Slender Ships in
Shallow Water, " J. Fluid Mech., 85 : 143-lS9 .
-
Zahn, A. S. (1977), "Grounding Characteristics and Effects," Final
Report on Task 5, Oct . 76 - Jan. 77, Prepared for U.S. Maritime
Administration by George C. Sharp, Inc ., New York .
OCR for page 119
A-5
Anonymous (1971), "Squat, " Commandant's International Technical Series,
Sol . I , Report No. USCG-CITS-71-1-1 ( Washington, D.C .: U. S.
Coast Guard ~ .
Author's Abstract
-
The report contains four papers on squat in shallow water as follows:
from the Federal Republic of Germany, a paper on the results of model
tests of a 700,000 DWT tanker; from France, a paper on the results of
model tests of a 500,000 DWT twin-screw tanker; from Poland, a paper
on the results of model tests of two ships with large block
coefficients, one with bulbous bowl and from the United Kingdom, a
paper on the results of model tests of two ships, one in the naked
hull condition, and the other equipped with self -propulsion gear, twin
screws, twin rudders, and bulbous bow.
Anonymous (1979), "Automatic Survey Techniques on the Waterways and
Approaches to Rotterdam" (Netherlands: Rijkswaterstaat, Direkt~e
Benedenrivieren, Meetdienst ~ .
Abstract
Automation in survey and maintenance dredging activities was
introduced at the end of 1974 to supply depth information on the
waterways and approaches to Rotterdam. This report gives a brief
description of the 'tWaterweg" system which has been installed on
trailing dredgers and survey vessels. The shore-based processing
system is described, as well as the incorporation of radioactive
density meters into the system.
Anonymous (1981), "A Report on Bed Density Measurements and Echo
Sounding at Hummer Ports," Report No. R. 286 (United Kingdom:
British Transport Docks Board, Research Station).
Author's Abstract
Following the introduction of echo sounders to assist with the
production of hydrographic sounding charts, depths--particularly in
soft bed areas--have become more variable and generally less deep.
This report describes a series of field measurements which were
best -¢ determine:Lhe variatio~-=f~dens~ty worth depths alto.
establish the density horizon that echo sounders record as "the bed."
Throughout the period of study, developments have been made both
with the instrumentation (particularly that used to measure the
density of the bed) and with operational techniques. AS a consequence
greater attention has been given to the more recent observations.
In soft bed areas the echo sounder records the bed at varying
density horizons. Tome, location, density and acoustic gradients
within the bed are some of the factors which affect the measured depth.
OCR for page 120
A-6
The study concludes that in soft bed areas the depth recorded by
echo sounders does not correspond to any specific horizon. It can be
signif icantly above or below the water column/bed interface .
Consequently, it is recommended that in these areas conventional echo
sounding is supplemented by routine densimeter observations.
Anonymous (N.D.), "Dei~si.ty Measurements In S'tu," (Netherlands:
Public Works Department, Lower Reaches Directorate, Surveying
Division, Research Section ~ .
See also: Hellema, J. A. (1981), "Silt Density Measurement," fine
Dock and Harbour Authority, January 1981, pp . 282-284 .
Abstract
.
Excessive siltation takes place In Europoort, and the very thin silt
is inefficient to dredge. After extensive tests, the nautical bottom
was defined as the depth at which a density of 1200 kg/m3 was
measured. Since a normal echo sounder cannot detect this nautical
depth, because of the loss of signal in the silt, a radioactive
density probe has been developed for this purpose. The probe is
lowered into the s, it, and the amount of radiation reflected by the
silt def ines the measured density. This report describes the
practical tests of radioactive density measurements since the end of
1973, together with the findings during the ensuing operational period.
As these point-measurements are time-consun~ng' a special
subbottom profiler with parametric transmitter has been developed to
provide continuously available subbottom information. This system is
believed to be the f irst of its kind in Western Europe.
Anonymous ( 1981 ), "New Non-Linear Sub-Bottom Profiler System, "
International Dredge ng & Port Construction, April 1981, pp. 2tt-30 .
Author's Abstract
This brief article presents the technical details of a non-linear
sub-bottom profiler to be developed by Ulvertech Ltd. of UIverston,
Cumbria, for deployment in and around both Europoort and Rotterd~m.
The profiler will be housed in a gyro-stabilized platform so that
will not be affected by the roll and pitch motion of the survey
craft. The system will provide a very acurate coercer -the seabed
and show the dif f Brent dens ity layers to a depth of about 2 0 m below
the seabed. Details of a dual mechanical scanning sonar system and
sonar video system developed by Ulvertech are a' so presented in the
article .
it
Berriman, J . W., and J. B . Herbich ~ 1977 ), "Major Port Improvement
Alternatives for the Texas Coast, " COE Report No. 197,
TAlIIJ-SG-77-205 (College Station, Tex.: Texas A&61 University).
a
OCR for page 121
A-7
Abstract
With the advent in recent years of very large crude carriers ( VLCC )
and ultralarge crude carriers (UICC), the United States has fallen
behind many other maritime countries in providing suitable docking
facilities. The shortfall in port facilities capable of handling the
deep~draft vessels, coupled with rapidly growing volume of imports and
exports of bulk commodities, has resulted in a critical need for
improved port facilities in this country.
The lack of port facilities capable of handling VLCCs and ULCCs,
coupled with a rapidly growing volume of imports and exports of bulk
commodities, and projected growth in oil importation and refining
petrels, make it imperative that port facilities be further improved
along the Texas coast. The onshore deepwater port has the advantage
of being able to accommodate the larger carriers of bulk commodities
as well as large tankers which transport petroleum products. The port
improvements for the Texas coast are deemed to be necessary to provide
modern and efficient port facilities to shippers and ensure continued
economic well-being for the regions served by these ports.
Ship channel design criteria are discussed in terms of mi nimbi
width and depth requirements for various size vessels. A portion of
the design work contained ~ n this paper was checked using a
mathematical model developed by Mr. Edward T. Gates of the U.S. Army
Corps of Engineers and a graduate student at Texas A&M University. It
is recommended that this mathematical model be utilized extensively in
any future work dealing with channel design.
The following channel design criteria are necessary to provide
for the safe navigation of VLCCs and ULCCs:
1. Channel Width
Maneuvering Lane (A) = 2 . 0 x Beam + L sin 10°, where
L sin 10° applies
to channels with
strong yawing forces.
Bank Clearance Tane (B) = 1.5 x Beam
Ship Clearance Lane (C) = 1.0 x Beam
One-Way Traffic Width = A +2B
Two-Way Traffic Width = 2A + 2B + C
cquann~I D~l,j.
Channel Depth in Inner Channel = f (loaded draft, squat, and minim
keel clearance ~
Channel Depth in Outer Channel = f (loaded draft, effect of pitch
and roll,
and minimum Keel
clearance), where effect of roll
and pitch = L/2 sin 1°.
OCR for page 122
A-8
Imprc~ed channel designs are presented for the ports of Port
Arthur, Galveston, Freeport, and Corpus Christi.
Bi jker, E. W. (1978), "Science and Design of Navigation Trenches and
Offshore Trenches, " Proc. 8th World Dredging Conf ., pp. 69-76.
Author' s Abstract
The general requirements of shipping lanes are that they guarantee a
safe passage of the ships with regard to navigation in general, and
width and depth in particular. The impact of science as discussed in
this paper means that under more or less normal conditions, empirical
knowledge may be suf f icient; for extraordinary new situations,
however, a basic knowledge of the physical phenomena determining the
situation will be required. This implies that theories should be
available or developed to elaborate wave and current data in order to
predict the behavior of the channel and of the ships in the channel.
Bijker, E. W. (1980) r "Sedimentation in Channels and Trenches,"
Proc. 17th Coastal Eng. Conf., Vol. II, pp. 1708-1718.
-
Abstract
In this paper, the siltation in approach channels and trenches due to
crosscurrents and waves in discussed. When the current crosses the
channel obliquely rather than at a right angle, a greater distance
over which the water f lows over ache greater depth is introduced .
Deviations in the flow pattern due to the channel are neglected.
However, when the flow pattern is known, either from measurements in
nature or in the model, this effect can easily be introduced. The
influence of the waves is introduced through an increased bed shear
and subsequently higher diffusion coefficient. Although computer
programs are available to calculate the siltation under the above
described circumstances, the paper presents a relatively simple method
which permits a quick estimate of the siltation to be expected without
the use of a big computer. This method could be useful for a first
appraisal for the various solutions, by the engineer in the field.
Blaauw, H. G., J. W. Koeman, and J. Strating ~1981 ) , "Nautical
Contributions to an Integration Port Design, " Publication No. 251
(Netherlands: Delft Hydraulics Laboratory ~ .
Abstract
This paper presents a harbor design strategy in which the nautical
aspects are treated as an integral part. A harbor is designed to
ensure the safe and efficient transport of goods, and these goals are,
to a large extent, determined by the behavior of ships. The paper
shows that different nautical research tools should be used at the
various design phases. In the initial phase, several design
OCR for page 123
~ - 9
alternatives are produced using rules of thumb, engineering
experience, or mathematical models. An initial master plan is
selected, and in the final stage, advanced hydraulic models and
maneuvering simulators may be used to optimize the initial master
plan. The nautical research tools are described in detail, and the
setup is illustrated with the results of research programs and recent
case studies.
Bos, H. (1979), "Marketing Research and Business Economics," Land and
Water International, pp. 20-22.
-
Abstract
The Dutch dredging market is divided into three sectors: (1) the sand
sector (mining of sand, clay, gravel, etc.), (2) the maintenance
sector, and (3) the capital sector (new works). The price development
for trailing-suction dredging work in the Netherlands indicates that
the average level of prices is continually rising, while the mutual
differences between the observed market prices have increased. The
effect of recent changes in the dredging market on the relationship
between contractors and principals in various sectors of the market is
discussed. Methods for minimizing the cost of maintenance dredging
for the principal by reducing the quantity to be dredged and the price
per unit of spoil are suggested.
Eden, E. W. ( 1971 ), "Vessel Controllability in Restricted Waters, "
J . waterways ~ Harbors and Coastal Ens ., Proc . ASCE , ~ 7 ( WW3 ):
475-490.
Abstract
.
A discussion of vessel controllability in restricted waters is
presented, and the factors inf luencina controllability are considered
. . . ~ . . _
in retail . Tne ma Coon or a vessel generates pressures, currents, and
waves which, after impingement upon restricting boundaries, will
create secondary reactions. Those forces vary with the clearance
between the vessel and fixed boundaries and the speed of and distance
to other vessels, if any. The controllability of the vessel depends
upon the rudder power, the reaction of the pilot, and the speed with
which changes in vessel speed. and. heading can be madly The
hydrodynamic characteristics of vessel motion through the water and
the effects of rigid boundaries and passing ships are explained. The
action of a single propeller or twin propellers is another factor
which affects the shape and magnitude of pressure and velocity f gelds.
Methods of evaluating the controllability of a vessel are
described. Standard maneuvers such as the zig zag, spiral, or sine
test are used to determine the reaction of the vessel in full-scale,
deepwater trials or in hydraulic model tests in the laboratory.
Another index used by naval architects to define controllability is
the tu~ning.circle at full ahead speed with a 35° starboard rudde '..
OCR for page 124
A—10
The stopping distance is also an important element of
controllability. Experimental data index cate that at least four
factors important in the controllability of any vessel vary with the
re lative channel dimens ions .
These factors are (1) s~nkage or squat, (2) lateral forces and
turning moments, (3) directional stability, and (4) resistance, or
drag.
The research needs are briefly reviewed and a program to reduce
uncertainties and improve theoretical appraisals of vessel
controllability under given conditions is described.
Gates, E. T., and J. B. Herb~ch (1977a), "Mathematical Models for the
Design ~ Operation and Economic Analysis of Deep-Draf t Navigation
Channels, " Proc. 24th International Nav. Cong., PIANC, Leningrad,
U. S. S . R., pp 17S-181 .
Abstract
Engineers generally determine the dimensions of a navigation channel
by design policy and by use of standard ratios of proportions of the
selected design vessel. Because of the great changes in relative
dimensions of the world's marine fleets, these techniques should no
longer be universally applied. This criterion--ratio approach to
design--also does not take into consideration the individual
characteristics (prevailing winds and currents) of each separate
channel location. A channel design model and a channel operations
model (under development ~ are described in this paper. These models
are modular in structure and include theory limitation indicators.
The channel design model determines the design vessel's reaction
to the effects of squat, changes in water salinity, boundary layers
due to vessel motion, current, wind, changes in neutral s leering line
due to asymmetry in the channel cross -section, bank suction, and other
phenomena. The squat modu ~ ~ computes the increase in vessel draft due
to brackish water, then computes the squat for the primary ( design )
vessel alone and when ~ n a massing or overtaking condition with a
_ _
_ . ~ . . . ~ _. .
secondary vessel for each speed in a designated range. The bank
suction module computes the lateral forces and turning moments due to
the bank suction phenomenon. The neutral steering line module
computes the distance between the neutral steering line and the
channel centerline for a given cross-section and then adds this
distance algebraically to the given ship off-centerline distance.
This new distance is used by the bank suction module in computing
lateral forces and turning moments. The vessel attitude module
determines the magnitude of the drift angle and rudder angle required
to neutralize the lateral forces and turning moments caused by the
effects of bank suction, crosswinds, and lateral current components.
The ship-generated waves module calculates the magnitude of the
ship-generated wave at the vessel and at each cusp point as the wave
propagates out from the vessel sailing line. The stopping distance
module computes the astern thrust per ton displacement ratio required
to stop a vessel in a given required distance.
OCR for page 125
A-11
The channel operations model mathematically simulates the
movement of vessels and barge trains in and out of a specified port.
This model accumulates and reports operational, safety, and cost data
for delays due to passing traffic including barges, one-way traffic,
passing fixed objects such as bridge piers, accidents, insufficient
draft due to wind and tides, bad weather, unavailable dock facilities,
and traffic saturation.
The channel design model is being used by the Galveston District;
U.S. Army Corps of Engineers; the Galveston, Texas, City Port Safety
Advisory Council; and the U.S. Coast Guard, and the results to date
have been good. The channel operations model is expected to be
operational in the near future.
Gates, E. T., and J. B. Herbich (1977b), "Mathematical Model to
the Behavior of Deep-Draft Vessels in Restricted Waterwa~rs
Report No. 200 College Station, Tex.: Texas A&M University .
Predict
." COE
Author' s Abstract
Presently deep-draft navigation channel analysis, design and review is
based on empirically derived ratios of the design ~ressel's
dimensions. Because of radical changes in vessel operation purposes
and characteristics, these ratios can no longer be safely or
economically applied.
The mathematical model and related theory described in this
document provide the engineer with a comprehensive tool in the design
and review of deep-draft navigation channels. Through its use he will
be able to predict values of squat, bank suction forces and moments,
equilibrium drif t and rudder angles, and heights of ship~generated
wares for varied channel configurations, ship positions and ship
velocities. Through the determination of channel section
confi guration sensitivity, an optimal des' gn both operationally and
economically can be achieved.
Gates, E. T., and J. B. Herbich (1978), "A Mathematical Model for the
Review or Design of Deep-Draft Navigation Channels with Respect
to Vessel Drift and Rudder Angles," Proc. Sump. on Aspects of
Navigability, Delft, Netherlands, April.
Author's Abstract
A comprehensive mathematical model has been developed for the design
and review of deep-draft navigation channels. Input to the model
consists of the channel configuration, the design vessel dimensions
and environmental considerations such as winds and currents. The
output consists of squat values, neutral steering line variations,
bank suction forces and turning moments, drift and rudder angles
required to overcome the various forces and turning moments ,
ship-generated wave heights and stopping distances , all for varying
speeds and varying distances from the centerline of the channel.
OCR for page 134
A-20
silt which may be regarded as more
clearly defined surface, but the composition of muddy beds is quite
different. In that case there is no question of any clear profile.
The vessel meets a body of water with floating particles of silt,
which become more dense toward the bed. Finally there is a body of
or less consolidated.
The composition of such muddy beds had been hard to measure in
the past, but recent new measuring techniques are making it possible
to probe the structures of muddy beds thoroughly. New insights
resulted which were related to the maneuvering possibilities of {very
large and deep-drawing ~ vessels .
The study was part of a joint research project entitled
"Minimization of the Cost of Maintenance Dredging" and has given birth
to different ideas about the required depths of ports and rivers .
This is of interest to nautical experts because it has extended
the "available water depth" notion which from now on should be judged
somewhat differently insofar as muddy beds are concerned. For port
managers the information is important from the viewpoint of fixing the
time f or new dredging .
Nederlof, L., and G. van Bocho~re t 1981 ), "Maneuvering Behavior of Ships
in Muddy Canals and Harbors," The Dock and Harbor Authority,
Netherlands, Vol. LXII, No. 726 (May), pp. 2-6.
Abstract
-
Maneuverability of mammoth tankers (VLCCs ~ in silty waters has been
shown to create many problems in certain harbors throughout the
world. A group of researchers and scientists at the Netherlands Ship
Model Basin have conducted a series of tests which are broken up into
three categories or parts. The tests involve the investigation of the
composition of the bed in the approach channel, the investigation of
the maneuvering pattern of deep-draught tankers when passing over
silt, and the investigation of the maneuvering pattern of deep-draught
tankers above silt in the model tank.
Tests were run to determine the composition of the bed using a
radioactive density indicator, and the results showed that deposition
of silt was particularly heavy in the period toward the end of the
year.
Test results of a deep-draft tanker when passing over silt showed
that the passing vessel sets up a stern wave at the interface of water
and silt, the density of the silt does not change during the passage,
and when the ship is passing, a layer of silt is brought into
suspension.
The model results showed that the resistance is much greater in
silt and requires higher propeller revolutions, the stopping distance
is reduced, the squat and trim are less, the effectiveness of the
rudder increases sharply, and the effectiveness of the propellers is
not constant.
OCR for page 135
A-21
Ottevanger, G. (1979), "Dredging Operations in the Approaches to
Rotterdam," Land and Water International, pp. 27-32.
Abstract
The advantages of the trailing-=uction hopper dredger over dredging
equipment used prior to 1957 in the Nieuwe Maa" and the Rotterdam
Waterway are discussed in detail. A description of the electronic
position-fixing equipment used on these dredgers is presented.
Details are given of the execution of the dredging and disposal
operations, as well as of the supervision of the maintenance
dredging. New developments f or trailing-suction hopper dredgers
include the recording of positional and loading data on magnetic tape
for computer analysis, and a probe which continuously monitors the
loading pattern of the dredger. Survey echo sounders and systems for
position-fixing of the draghead are now being developed.
Trawle, M. J. (1981a), "Prediction of Shoaling Rates for Deepened
Estuarine Navigation Channels, " Proc. 14th Annual Dredging
Seminar (College Station, Tex.: Texas A&M University).
Abstract
~ .
This paper presents an empirical method of shoaling analysis based on
historical dredging and shoaling records that results in reliable
predictions of future shoaling for deepened channel conditions
occurring either from an increase in authorized channel depth or from
The method presented was designed to be general
enough that it can be applied to most navigation projects without
difficulty. - ~ ~ ~ ' ' ~
,
advance maintenance.
TO demonstrate how the method would be applied to real
navigation projects, the Texas City Channel in Galveston Bay, Texas,
was evaluated and results were discussed.
Trawle, M. J. (1981b), "Effects of Depth on Dredging Frequency: Methods
of Estuarine Shoaling Analysis, Technical Report H-78-5
(Vicksburg' Miss e Ue S e Army Engineer Waterways Experiment
Station) e
Author's Abstract
Whenever deepening,,of a dredged channel is under investigation, a
prediction must be made as to the effect of the deepening on the
existing dredging requirements. If the deepening is related to
advance maintenance dredging rather than to an increase in authorized
depth, the prediction becomes even more difficult because the project
is allowed to shoal over a wide range of depth. Currently, a variety
of arbitrary, rule-of-thumh procedures are used for predicting the
effect of increasing depth on dredging requirements.
The overall objective of this investigation was to evaluate the
effectiveness of advance maintenance dredging in reducing dredging
frequency and/or costs An the maintenance of coasted channels and.
OCR for page 136
A-22
harbors and to establish necessary guidelines for governing the
practice. This report, the second of a series, presents an empirical
method of shoaling analysis based on historical dredging and shoaling
records that results in reliable predictions of future shoaling for
deepened channel conditions resulting either from an increase in
authorized channel depth or from advance maintenance. The method
presented was designed to be general enough that it can be applied to
most navigation projects without difficulty. The procedure was
described step-by-step using an example (fictitious) project. To
demonstrate how the method would be applied to real navigation
projects and to point out problems that occur when evaluating real
projects, selected Galveston Bay, Texas, navigation projects were
evaluated and the results discussed.
Trawle, M. J., and J. B. Herbich ~ 1980 I, "Prediction of Shoaling Rates
in Offshore Navigation Channels, " Center for Dredging Studies,
Department of Civil Engineering Report No. 232 ~ College Station,
Tex.: Texas A&M University).
Abstract
This report discusses several techniques in use for prediction of
future dredging requirements whenever enlargement of estuarine/coastal
entrance channels is considered. The dredging requirements of six
selected entrance channels for both the existing dimensions and the
immediately previous dimensions were determined to evaluate the
"volume of cut" prediction technique. The six projects, selected on
the basis of availability of historical dredging data, were the
Wilmington Harbor entrance channel in North Carolina, the Pascagoula
Harbor entrance channel in Mississippi, the Calcasieu River entrance
channel in Louisiana, the Sabine-Neches entrance channel and the
Galveston Harbor entrance channel in Texas, and the Yaquina Bay and
Harbor channel in Oregon. The adequacy of the "volume of cut "
technique is i nvestigated by predicting the dredging requirements f or
the existing project from the previous project dredging requirements.
The results, although based only on a limited number of proj eats,
suggest that the "volume of cut" technique can be a valuable tool
during the preliminary analysis of a proposed entrance channel
enlargement.
While the "volume of cut" procedure for predicting future
dredging requirements for enlarged entrance channels, as described by
the limited investigation conducted for this paper, is a rather
simplistic approach to a very complex problem, analysis of the data
does indicate a significant correlation between "volume of cut" and
dredging requirements. A more detailed examination of the reliability
of this method of prediction would necessitate the inclusion of other
factors, not considered here, which can affect shoaling in an
estuarine/coastal environment. Such factors include the effects of
tidal action, channel alignment, littoral drift, storms, and wave
action. The results of this report indicate that even a basic
OCR for page 137
A-23
analysis using the "volume of cut" procedure, without considering any
of the above-mentioned factors, would aid significantly for prediction
purposes in the preliminary stages of project design.
Troesch, A. W., and S. Cohen (1980), "Relationship of Underkeel
Clearance and Vessel Speed to Grounding," Report No. 017999, Ship
Hydrodynamics Lab, University of Michigan.
Abstract
The linkage, trim and underkeel clearance of the lead barges in a 3 x
3 barge train were measured. The barges represented typical
Mississippi River barges. The tests were conducted in response to a
USCG request to investigate groundings due to channel depth
decreases. The water depth varied from 2.6 to 1.05 times the barges'
draft. There were two bottom contours: one with constant depth and
one with an underwater obstacle in the form of a step. The speed of
the barge train was varied from 2 kn to 8 kn, full scale.
Turner, H. D. (1978), "Physical Model Study for Improved Navigation
Channel Design," 26th Proc., Annual ASCE Hydraulic Div. Spec.
Conf.: Verification of Math. and Phys. Models in Hydraulic Eng.,
University of Maryland, August 9-11, pp. 265-272.
Abstract
The U.S. Army Engineer Waterways Experiment Station (WES) is
conducting a study to determine the minimum dimensions of deep-draft
navigation channels for safe and efficient navigation. The model
study is focused on the improvement of navigation channel design
methods and uses free-running, remote-controlled scale models of
prototype ships as a means of evaluating the channels being tested.
Present navigation channel design criteria in the United States
were formulated in 1965 and are based on the 1948 tests during the
Panama Canal sea level project. The width allowance is from 2.8 to
5.O times the design ship's beam for one-way traffic and 5.2 to 8.0
times the beam for two-way traffic. The width criterion depends on
judgment factors relative to design ship controllability, strength of
yawing forces, quality of navigation aids, type of channel, and bank
orientation. The depth allowance is the stem of ship draft, salinity
effects, wave action, squat, and underkeel clearance. The design of
navigation channels is influenced by many factors, such as ship
dimensions, ship power to weight ratio, ship rudder and propeller
assemblies , type of traffic (i.e., one-way, two-way, overtaking, ship
speed, pilot ability, and environmental conditions (i.e., wind, waves,
fog) .
In the model testing program, changes In ship draft, ship speed,
channel width, and channel depth will be evaluated. The testing
facility consists of two straight channel reaches connected with a
typical bed ~ the mid arid a tang basin at each ends T"awr
OCR for page 138
A-24
the study, wind generators and a wave generator will be placed in the
turning basin to simulate wind and wave effects on navigation at
entrance channels. During a typical test run, time-based data such as
ship speed, rudder angle and ship heading will be collected and
analyzed to determine the safety of the channel. A test channel will
be declared unsafe if an excessive amount of rudder is required to
successfully navigate the cannel or if the model ship comes too clone
to either the aide or the bottom of the channel. The test results
will be compiled and used to construct design curves which define both
channel and ship parameters. Similar design curves will be developed
for various types of traffic, ships, navigation aids, pilot skill, and
environmental conditions.
van de Ridder (1979), "Rotterdam and the Harbor Silt," Land and Water
International, pp. 23-26.
Abstract
Maintenance dredging in the Rotterdam harbor basins is carried out by
two methods: (1) bucket dredger operations and storage of spoil
ashore and (2) trailing-suction dredger operations and damping at
sea. This paper describes the technical aspects of both of these
methods.
The advantages of bucket dredgers are discussed, and the
increased production obtained after introduction of density
measurement instruments for determining nautical depth is outlined.
The transportation of the spoil to the discharge area by barges and
pipelines is also discussed.
Trailing-suction dredging operations are described for the period
from 1963 to 1977 in the Europoort and Botlek areas. The problems
involved in utilizing the full hopper capacity in both the winter and
the Sumner months and in disposing of silt contaminated by pollutants
are also discussed.
van Don~elaar, H., et al. (1981), "The Maritime Impact of Liquid Energy
Gases--the Planning and Operational Aspects," Maritime Ports and
Seaways, Vol. I, Permanent International Association of
Navigational Congresses, XXV, Sec. II.
Abstract
This report treats a certain number of aspects concerning the
large-scale importation of liquefied gas into the Netherlands. The
world's energy situation is briefly described, and arguments are
presented for the Importation of energy gases by the Netherlands. The
risk" involved in the transport of liquefied gases by seagoing vessels
are discussed, and the factors governing the Dimensions of channels
and harbors are outlined. Information is given on the relationship
between the "hip behavior and the Dimensions of the navigation
OCR for page 139
A-25
channel. Operational aspects, such as the regulation of traffic and
ship-related safety measures and procedures are also considered. The
results of traffic simulations of ships transporting liquefied gas are
presented. Various implementation aspects are discussed with
reference to existing harbors, a new shore-based harbor and an
offshore harbor. The report conclude" with some comments on dredging
aspects of the activities involved with the adaptation of existing
harbors or the construction of new ones.
van Oostrum, W. H. A. (1979a), "Maintenance Dredging in Soft-Bedded
Navigation," Control Dredging Association (CDEA) Conf.,
Netherlands.
Abstract
This paper describes the problems and solutions in the process of
maintenance dredging. The discussion includes the siltation process
and the concept of nautical depth in a soft-bedded channel. A
comparison of the advantages and disadvantages of density measuring
probes and echo sounders is presented. The automation of data
collection, data handling, and data presentation is discussed for the
dredging and surveying operations. The dredging program and dredging
decision are considered in terms of a programmed decision making
model. The final item considered is the marketing policy, especially
the ways in which to acquire the necessary capacity for dredging.
van Oostr~m, W. H. A. (1979b), "MKO Project," Land and Water
International, pp. 17-19.
Abstract
The aim of the MKO project is to study scientific, technical and
economic possibilities for reducing the costs of maintenance dredging
operations. The research project has been divided into three main
parts: (1) studies of the morphological--and other--aspects of
sedimentation, (2) research into dredging techniques, and (3) research
into marketing and business economics. This paper considers part 1 in
detail and briefly discusses part 2.
The sediment transport balance in the waterway area is analyzed,
and several means of reducing the amount of sediment to be dredged are
suggested-. The effects of a silt trap placed at the mouth of
Europoort are described, and the methods of measuring the density of
silt deposits are outlined. The paper indicates possible solutions to
the problem of recirculation of silt from the damping ground at sea to
the harbor entrance. A brief discussion of the programming dredging
method and continuous hopper measurement system is included.
OCR for page 140
A-26
van Oostrum, W. H. A. (1979c), "Operations Research in Dredging," Terra
et Aqua, _: 2-15.
Author's Abstract
Modern dredging equipment constitutes a large capital outlay and is
expensive to run. Therefore attempts are being made continuously to
boost and to raise efficiency. In particular, attention has been
given to improving the mechanical and technical components of the
dredging system. During the last decade more and more electronics
have entered dredging technology. Parallel to this, extensive
developments have taken place in the f ield of hydrographical
surveying. More recently attempts have been made to raise output in
paid m3 by improvement of the management of dredging operations.
Computerized data-handling systems form the unavoidable basis for a
further integration of the basic activities of dredging work.
The large capital and maintenance dredging works in the
Rotterdam-Europoort area form an ideal test field to develop more
efficient dredging methods. Operations research techniques are
playing an increasingly important role and several pro j eats in this
f ield have already led to practical results such as programmed
dredging, flight recorders, survey and positioning automation routing
programs and navigation programing. AS a binding element,
computerized data-flow connects all these applications.
Although most applications are related to dredging works executed
by self-propelled suction hopper dredgers, the methods are suitable
f or stationary dredging as well.
van Oostrum, W. H. A., W. R. Parker, and R. Kirby ~ 1980 ), " - intenance
Dredging in Fluid Mud Areas, " Third Int. Symp. Dredging Tech.,
Bordeaux, France, pp. 177-190.
Author' s Abstract
Recent work has shown that most mud dredging problems arise from the
penetration of harbor basins and channels by dense mobile near-bed
layers . When these layers stagnate , rapid deposition occurs, f orming
f luid mud layers which exhibit characteristics transitional between
true seawater and the seabed. These deposits present particular
dredging problems and cannot be dredged efficiently at the present
tome.
Is a result of-~he ine-ff~c~ency of con vend; maintenance --
dredging other alternatives may be adopted to decrease the dredging
requirement. Examples discussed are the location of port facilities
in zones of low sedimentation or prevention of silt penetration using
locks, bubble curtains or removable barriers. Where siltation cannot
be avoided it may be handled more efficiently, depending on local
circumstances, by other concentration into traps or spreading. In
many areas of very high sedimentation the only way to cope with the
large sediment flux is by agitation dredging.
OCR for page 141
A-27
In fluid areas still dredged by conventional trailer-suction
dredgers, increases in efficiency and production must be sought in
improvements in surveying methods and in the design of dredging
plant. In this connection density measurements are replacing
conventional echo sounding surveys. The value of density surveys is
that they provide repeatable information on seabed characteristics
which are directly applicable to dredging requirement" and to the
navigation of ships. Complementary developments of dredging systems
directed both to trailer-suction dredgers themselves and also to the
development of novel concepts such as stationary dredgers with the
complete removal of spoil from the local water circulation, point the
way to major increases in efficiency.
van Oostrum, W. H. A., et al. (1981), "Dutch Efforts for Opt ~ cation
of Marine Dredging," Proc. XXV Int. Nav. Cong., Inland and
Maritime Waterways and Ports, PIANC, Section II, Vol . 2,
Edinburgh, Scotland, May 10-16.
Abstract
A review of the present state-of-the-art in various fields of the
dredging industry is presented. The discussion includes surveying
methods, the nautical depth concept, overdredging, positioning system,
sampling technique-, dredging automation, and cost estimates.
Wang, S. (1980), "Full-Scale Measurements and Statistical Analyses of
Ship Motions in a Navigational Channel," Marine Tech., 17:
351-370.
Author' s Abstract
Due to the trend of large dry and liquid bulk carrier construction in
recent years, safe navigation in ports and channels has been a great
concern to both the governmental regulatory agencies and the merit Me
industries. This paper presents the results of a study on motions of
deep-draft vessels in a navigation channel. The objective of this
study was through measurement and analysis of the vessel motions to
validate the design assumptions for a specific channel as well as to
establish the general design information on channel width and depth
requirements, with respect to the ship characteristics and channel
environments.
Full-scale measurements of motion characteristics for 29 vessel
transits through the Columbia River Entrance Channel have been
conducted. The measurements include pitch , heave and roll motions,
vessel heading angles and position tracks. Analyses of the measured
data have been conducted with the objective to derive both the
short-term and long-term statistics. For short-term correlations, all
the motion variations have been assumed stationary, and comparisons of
the histograms of motion amplitudes with the theoretical Rayleigh
OCR for page 142
A-28
distribution have been conducted and found satisfactory. AS to the
long-term statistics, it is found that the measured data can be very
well represented by the log-normal distribution.
Waugh, Richard G., Jr . ~ 1971 ), "Water Depthe Required for Ship
Navigati on, " J . Waterways , Harbors and Coastal E:ng., Proc . ASCE,
_(WW3~: 455-473. ~
Abstract
The state-of-the-art in the selection of channel depth is briefly
reviewed to emphasize the fact that channel depth design in the United
States has been more a matter of judgment than one of rigorous
engineering analysis. The factors influencing the choice of channel
depth are discussed in detail. The recent increase in ship sizes is
outlined and a tabulation of channel depths in world ports is
presented in the Appendix. While the largest man-made federal
navigation channel in the United States to accommodate bulk commerce
has an effective depth of 45 ft. excluding additional clearances over
the ocean bar, several dredged channels in foreign ports have depths
exceeding 60 ft.
Changes in water salinity and temperature influence the density
of water and vessel draft. The trim of the vessel as loaded must also
be considered in channel depth design. For many vessels, trims of 1
ft to 2 ft at rest are not uncommon. Normally, a 1 ft allowance is
provided in selecting the channel depth.
Vessel squat is a function of the vessel speed, water depth,
wetted cross section of the vessel, and the width and section of the
waterway. It can be shown that squat is also affected by the location
of the vessel in the waterway, the trimness of the vessel's lines , and
the presence of other vessels in the same cross-section. Although
vessel squat can be computed accurately in well-defined, regular
sections, little is known of vessel squat in deep and wide waterways.
Changes in trim while under way may cause the stern of the vessel
to slam the bottom as its speed increases. AS the vessel approaches
the channel banks, its squat will tend to increase. The presence of
passing vessels will also increase the squat due to the reduction of
water area. The influence of waves on the ship motion and draft must
be taken into consideration, particularly in the ocean entrance
channels.
After-~llowan~es have DO~D - made;fa=~ncreases za ~ vessel's draft
due to squat, trim, freshwater density,and wave motion, an additional
allowance is added by the Corps of Engineers. The general practice
has been to provide 2 ft of clearance between the vessel's keel and
the channel bottom in soft material and from 3 ft to 4 ft where rock
is encountered. Although primarily for safety, this clearance
increases vessel operating efficiency because under shallow water
conditions, the speed decreases, the resistance increases, and the
rudder response becomes more sluggish.
OCR for page 143
A-29
The information available i" inadequate to determine the safe
navigation depth required for vessels moving in restricted channels.
It is believed that the most critical single factor in channel depth
design is Pretzel squat. While some data have been accumulated for
vessel. in canals, little i. known of the Pretzel phenomena that take
place in irregular-shaped channels Ad estuaries.
Wicker, C. F. (19711, "Economic Channels and Maneuvering Areas for
Ships , ~ J . Waterway. , Harbors and Coastal Eng ., Proc . ASCE ,
_
97 (WvI3 I: 443-4~4.
Abstract
Me state-of-the-art involved in the design of a ship channel is
briefly reviewed to stress the lack of knowledge concerning the
channel depths, widths, and all ~ ents necessary for safe navigation.
The --election of the channel depth depends on factor" such as squat,
change. in draft, due to differences in water density, ship response
to waves, and underkeel clearances required for large vessels to
maintain a given speed in shallow depths. However, little is known
about squat in narrow, deep channels in estuaries, or the effects of
passing vessels, channel banks, and poor tram on squat. Ship response
to waves and power requirements for large vessels in shallow waters
are also not well defined. The design width of a channel depend" on
the handling characteristics of the vessels using the waterway and the
effect" of winds, waves, and currents on vessel heading. However,
reliable information on the effects of passing vessels, channel banks
and varying conditions of operation and loading is not provided to
channel designers. The width of the channel at the turns is
considerably wider than the straight reaches. Although the vessel
length, speed of travel, rudder response, and proximity of the banks
should be considered in dete ~ ning the Amount of turn, there are no
data on the coefficients to be applied in the relationship. As a
result, channels are generally planned in accordance with the best
depths in a natural waterway, or to minimize excavation, with little
attention to the needs of navigation.
A comparison of costs for a hypothetical excavation using 2 ft
overdepth with maintenance dredging is made for an overly Conservative
channel design and an adequate, safe channel to illustrate the
excessive cost of making the channel wider and deeper than necessary.
Another cost comparison i" made between an unsafe channel and an
adequately safe channel, to demonstrate that the apparent savings
involved in a minims channel are likely to be exceeded by the
potential loaves due to accidents, loss of life, loss of vessels,
costs of removal of wrecks, vessel delays, and cleanup of pollution.
A discussion of the factors involved in the design of navigation
channels includes environmental considerations such as the tidal
range, currents, waves, water densities, ice conditions,
meteorological conditions, geometry of the waterway, bottom materials,
.
OCR for page 144
A-30
considerations such as length, beam,
are also
and shoaling potential. Vessel
static draft, trim, cruising speed, and controllability are also
discussed. Factors to be considered for vessel operation in channels
include speed and spacing regulations, density and frequency of
transits, overtaking or meeting ves=61s, and mix of vesee1e in the
traffic pattern. The human factor of pilot decisions must also be
included. Human failures can involve a lack of knowledge of the
channel inadequacies or the vessel peculiarities, a lack of skill, a
tendency to risk-taking, or a lack of complete attention.
With increasing vessel size and cost, navigation channels must be
deepened and widened, and the designer must be provided with the
necessary knowledge to design safe and economic channels.
Yeung, R. W. (1978), "On the Interactions of Slender Ships in Shallow
Water," J. Fluid Mech., 8S: 143-159.
Author's Abstract
The unsteady hydrodynamic interaction of two bodies moving in a
shallow fluid is exams ned by applying slender-body theory. The bodies
are assumed to be in each other's far field and the free surface is
assumed to be rigid. By matched asymptotics, the inner and outer
problems are formulated and a pair of coupled integro-different' al
equations for determining the unknown cross-f lows is derived. The
degree of coupling is shown to be related to a bottom-clearance
parameter. Expressions are given for the unsteady sinkage force,
trimming moment, sway force and yaw moment. Numerical calculations
for two weakly-coupled cases are presented. One corresponds to the
interaction of a stationary body with a passing one, the other to the
interaction of two bodies moving in a steady configuration.
Theoretical results are compared with existing experimental data.
Zahn, A. S. (1977), "Grounding Characteristics and Effects," Final
Report on Task 5, Oct. 76 - Jan. 77, prepared for U.S. Maritime
Administration by George C. Sharp, Inc., New York.
Author's Abstract
Data on the details of 52 groundings were collected f ram the f iles of
IMCO and U~CO from L944. to 1975. Cases are identified by number or
name, flag, type , tonnage and characteristics. Information lists
repair costs, location of casualty, weather, cause of grounding, speed
of impact, information on double bottom condition; Damage location,
description, length, width and depth ; also type of sea bottom.
The data have not been analyzed.
Representative terms from entire chapter:
channel depth
