551 SMOOTH SEA
Ripples, no foam. Wind*: light air, 1-4 knots. Beaufort 1. Not felt on face.
552 SLIGHT SEA
Small wavelets, no foam. Wind*: light to gentle breeze, 4-10 knots. Beaufort 2-3. Felt on face, light flags wave.
553 MODERATE SEA
Large wavelets, crests begin to break. Wind*: gentie to moderate breeze, 7-15 knots. Beaufort 3-4. Light flags extended.
554 ROUGH SEA
Moderate waves, many white caps, some spray. Wind*: moderate to strong breeze, 14 - 27 knots. Beaufort 4-6. Wind whisdes in rigging.
555 VERY ROUGH
Sea heaps up, with spindrift and foam streaks. Wind*: Moderate to fresh gale, 27 - 40 knots. Beaufort 6-8. Walking resistance high.
556 HIGH SEA
Sea begins to roll, dense streaks of foam and much spray. Wind*: Strong gale, 40 - 48 knots. Beaufort 9. Loose gear and light canvas may part.
Very high waves with overhanging crests. Sea appears white as foam scuds in very dense streaks. Visibility reduced. Wind*: Whole gale, 48 - 55 knotts. Beaufort 10.
558 MOUNTAINOUS SEA
Very, very high rolling breaking waves. Sea covered with foam. Very poor visibility. Wind*: Storm, 55 - 65 knots. Beaufort 11.
♦Correlation between sea state and wind description is highly variable and dependent on fetch and wind duration. For seas not fully arisen wind speeds may be much higher than indicated.
Appendix C USEFUL INFORMATION FOR SITE SURVEYS
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General Site Investigation Checklist for Overseas Projects
Names, address, phone, fax, telex nos. Interpreters
General Project Information
Design drawings Material take-offs
Design basis (environmental design criteria, facility design requirements, system data, etc.)
General Site Information
Pocket local language(s) and tourist guides
Nautical charts (NOAA, Defense Mapping Agency, local hydrographie/topographie agencies, satellite/aerial photographs from NOAA, Defense Intelligence Agency or civilian contractors)
Sailing directions (en route & planning guide), coastal pilot, tide and current tables, wind directions and magnitude, etc. Road maps
Yellow pages/contractor/business directories/related newspaper and magazine articles (National Geographic, general ocean and construction industry publications, etc.)
U.S. and local government military bases
Military intelligence brief on local political and security conditions
Local population and labor force; social and religious practices
Weather and Climate Data
Wind, wave, current, temperature, humidity, fog, rain, snow Summary of seasonal climatology Optimum construction season
Import duties, fees, custom bonds, local taxes for imported material and temporary equipment
Port duties, storage and handling fees Sales and use tax Currency and exchange rates
Right of way acquisition: application procedures, fees, payments Local construction permit requirements POCs at consulates and government agencies Other agencies with site jurisdiction
Site Logistics for Personnel and Materials
Transportation services (marine, rail, air, auto-truck: capacities, schedules and rates) Military air service capacities, schedules and locations \
Commercial airline passenger schedules, freight capacities, airport locations Passport, Visa, Health, Immigration, and Customs agency requirements Local ports of import: photographs, location, maximum draft, dockage and anchorage availability
Port facilities: services, pilot, tug, fuel, water; fuel cargo handling capacities, storage areas, port and cargo charges
Local agents for clearing materials through customs at ports of entry Rail service: location, length, distance, loads and clearance limits for nearest rail siding
Inland freight haulers: capacities, rates, etc. Site storage area for materials
Site materials handling equipment: capacities, rates, etc. Local vendors/marine equipment suppliers
Local service facilities: machine shops, marine repair yards, steel fabricators, casting yards, etc.
Site accommodations, messing, laundry, and transportation for jobsite personnel
Local water supply quality
Medical, health precautions for site personnel
Local communications: phone/fax/radio locations and communications procedures Security/personnel clearance requirements
Location, staffing, and transportation arrangements for local recompression chambers
Local road conditions to site (clearance and load limits, new road construction requirements
Other work in general site vicinity
General Site Conditions Site plan and photographs
General description of soil conditions, boring and core locations, bearing capacity, etc.
General description of shore crossing and nearshore areas Drainage patterns and water table depth Existing structures and obstructions Existing availability and ownership
Construction Material Supply (Availability, Price, Delivery)
Fuel suppliers (gasoline, vehicular diesel, marine diesel, aviation fuel) Utility supply (air, water, electric power, sewage) Location of borrow, fill, or spoil areas
Aggregate/sand/cement/concrete/ready mix/concrete block/form lumber Steel: structural, reinforcing, sheeting
Construction Material Supply (Availability, Price, Delivery) (continued)
Explosives: availability, transportation, security, and storage requirements Project specific suppliers (i.e., diving equipment suppliers, pipeline, cable, etc.)
Local Military Equipment and Marine Contractors Marine equipment: deck plans and specs Diving equipment and contractors Marine and land survey equipment and contractors Dredging equipment and contractors Pipeline equipment and contractors ] Local military construction units
Local civilian union/labor practices for offshore work (labor categories, rates, working hours, overtime pay, holiday and health benefits, transportation, meal and travel time practices)
Horizontal and Vertical Control
Detailed topographic and bathymetric maps Local grid description
Locations and datum for local survey control points Extent of GPS coverage for project site
Installation Environmental Conditions (1 year return interval) Maximum, minimum water depth Maximum surface current Maximum bottom current (3 feet off bottom) Maximum wave height Maximum significant wave height Maximum significant wave period Maximum wind speed Tidal data: Type Datum
Extreme high water Mean high water Mean tide level Mean low water Extreme low water Monthly means of air temperature and precipitation Monthly means of seawater temperature Monthly means and maximum of windspeed and directions Monthly means and maximum wave height
Bottom conditions (soil types, vertical profiles, boring data, soils reports, etc.)
Site Investigation Pipeline Project Information
Physical properties: density, kinematic, viscosity, absolute viscosity, maximum and minimum operating temperature
How is product currently supplied/delivered at proposed site? Required flowrate (possibility of future increase?) Tie-in locations, length, and size of connecting lines Operating pressure
Storage tank or tank farm locations, elevations, and capacities
Pump locations, capacity curves
Product quality specifications
Pipeline maintenance and inspection requirements
Shore Crossing Descriptions
Location of existing pipeline or other utilities Stable or migratory sediment cover Ownership/rent/ROW acquisition Onshore or offshore obstructions Blasting, clearing, and grading requirements Debris disposal requirements Restoration requirements
Access roads, walkway, utility, drainage, lighting, fencing, and security requirements
Site Data Sources (Contact local data sources for pipeline hazard identification) Local Navy base Local port authority Local pipeline operators International oil companies Local pilots and commercial fishermen Local cable and pipeline operators Local marine contractors
Suggestions for Bathymétrie Surveys
The following suggestions for performing bathymetric survey work are from UCT experience gained in various worldwide work sites. The survey team must consider the following suggestions and decide how to apply this information to die particular job. A recommended reference for surveying is the Hydrographic Manual, Publication 20-2, U.S. Coast and Geodetic Survey, Department of Commerce, 1980.
The survey plan should be laid out so that track lines cross bottom contours at a 90-degree angle whenever possible. For steeply sloping bottoms the track lines should cross bottom contours at about a 45-degree angle.
In general, the line system layout is governed by the type of control used and the configuration of the area. A system of widely spaced cross or tie lines parallel to the coast should also be included in the survey plan to verify the accuracy of the soundings taken along the track lines. If any suspected shoal areas are discovered while running the survey, they should be fully defined by running additional short, closely spaced lines over the area. When surveying navigation channels the survey plan is normally arranged so that the limits of the channel are first defined by a series of cross lines perpendicular to or diagonally across the channel axis. Later, the channel is fully defined by a system of closely spaced lines parallel to the axis of the channel. To align successive boat runs, an EDM or a second transit should be used, assuming steerage by transit or range mark ers. Landmarks such as towers, piers, build ings, etc. can serve as aids in aligning adjacent survey boat runs.
The rough and smooth survey plots should be completed before leaving the detachment site. This will help in identifying any obvious errors in the information. The final prints must be reviewed with the facility customer before departure to ensure that the results are suited to the needs of the particular facility.
A blueprint number should be obtained from the local facility Public Works representative. The callout "UCT-1" or "UCT-2," as applicable, must be included in the tide block to clarify who performed the survey. List the surveyor's name, rate, and rank with the "DV" designation in the "drawn by," "checked by," and "approved" blocks. Recording of work into the facility drawing system is essential to ensure that anyone needing the information in the future can find it.
Survey drawings should be reviewed and approved by one of the UCT's Registered Professional Engineers if the facility is to use the survey results as a basis for project budgeting or specifying a contract. The UCT Commanding Officer and Executive Officer are usually registered and can review and approve. Inaccurate bathymetric surveys can result in high material and labor cost overruns. If the facility is reviewing a working copy before the drawings are signed, the drawings should be marked "Preliminary."
There are several "datums" or zero elevation levels depending on the use of the information. The POIC should personally review local datum information with the lead surveyor and the facility customer. The survey should be referenced to the particular datum the facility requires. The datum must be clearly described in a general note on each sheet of the survey drawings. The Navy generally uses Mean Lower Low Water (MLLW) in areas with large inequalities in the height of successive high or low tides (such as the Pacific Coast) and Mean Low Water (MLW) where the successive high or low tides are nearly equal (such as the Atlantic Coast). This pattern may be different when the worksite is overseas. Many elevation benchmarks are referenced to Mean Sea Level (MSL). The datum to be used should be discussed and agreed to prior to the job to ensure that both the tide and depth readings will be proper. The datums should be checked when the survey results are compared with previous soundings.
Existing USGS, NOAA (USC&GS), U.S. Army Corps of Engineers, State, or Navy benchmarks must be used or tied into even if only remotely available. If not available, a clear and detailed written description must be prepared for each benchmark installed, including how to reach the mark from a prominent location, the type of mark, the type of foundation, the information stamped on the benchmark, and the distance and direction to the mark from at least three permanent objects and any previous marks. A sketch should also be prepared showing the tide gage, all benchmarks used in the survey, and the objects used in the benchmark description. Photographs of the benchmarks and surrounding areas are valuable if accompanied by a description of where each shot was taken and which direction the camera was aimed.
The transit positions must be set up to give reasonable crossing angles, such as approximately between 45 and 135 degrees. Intercept errors are unacceptably large when lines of bearing approach are nearly parallel. If necessary, the transit positions must be relocated to give good intercept angles for the nearshore and offshore portions of the survey.
OIC Checks of the Surveyor's Work
Survey errors may invalidate the entire project. Survey work requires a double check by someone other than the surveyor and his assistants. The OIC or Detachment Officer may perform this check even if not an experienced surveyor. The lead surveyor (E A, BU, or other) should walk the checker through the computation steps, looking for obvious ommissions, reversed direction, or other errors. The survey drawings should be checked to see if the shapes, directions, distances, and position of landmarks make sense. This step may help point out incorrect numbers that have been improperly added or subtracted. The mathematics must be checked for calculation errors, especially those that form the basis of elevations, tide levels, and lane angles. Math errors in any of these will cause all data to be incorrecdy plotted.
Recording Details of the Survey
All UCT land and bathymetric surveys must be reproducible. Future surveyors must be able to read the UCT survey drawings and determine the following:
(1) The location of benchmarks
(2) How to reconstruct baselines
(3) How to reconstruct all angles, distances, and elevations
All numbers and descriptions necessary to reproduce the survey should be included on the final drawing, without relying on the field book notes. Supporting information or background explanations contained in the field book notes should be shown on the drawings. Any reference in the drawing notes to the field book should be by date, number, etc.
All measurements with their units of measure and any conversions between inches and tenths of feet must be clearly recorded. Readable measurements are mandatory for correct calculation and survey recheck. Errors due to incorrect units may require rework of all or part of the entire survey.
Suggestions for Fathometer Operation
Refer to the manufacturer's instructions. Testing Precautions
1. Follow the troubleshooting guide in the O&M manual.
2. Never energize the transmitter without the transducer plugged in.
3. Never energize a transducer unless it is submerged in water to prevent heat buildup.
4. The zero mark will be seen for the transducer draft and speed of sound even if the recorder or transducer is not properly transmitting or receiving.
5. A strong print of the transmitter pulse may exist even though the transducer is not working.
6. A power cutoff case switch automatically deenergizes the fathometer when the top case is opened. Check the switch if the unit is inoperable.
Read the Manual. Review the setup, test, and operating instructions, ollow the proper sequence since adjustments may affect each other. The UCT Raytheon DE-719s and CHESDIV OCEI DE-719Bs are adjusted identically although the manuals are different. The adjustment of other makes of fathometers will vary.
Zero Adjust Scale and Range. The X-
1 Range is normally used. X-2 doubles the depth readings.
Sensitivity. Normally the sensitivity (signal strength) control is not pegged. If the control is pegged, or if the signal trace fades for no apparent reason, the gain control circuitry is suspect. Follow the troubleshooting sequence in the O&M manual. Turn off the entire unit whenever disconnecting power or reconfiguring the unit.
Tide and Draft. This control represents two critical variables:
a. Draft. The depth of the transducer below the water level can be determined by direct measurement or by marking the rod supporting the transducer with depth marks. The initiation pulse is adjusted to this depth using the tide and draft control. The measured depth is noted alongside the strip chart trace. This becomes the basis for comparison of all runs that follow in that sounding session. An additional draft correction due to setdement and squat while the boat is underway must be made if the depth of the transducer below the water surface changes significantly while running at the surveying speed. The amount of this correction can be easily checked by deploying a marker buoy with a short scope and comparing fathometer readings taken while at rest beside the buoy and running it at surveying speed. All personnel and equipment expected to be onboard during the actual survey should be onboard during this test.
b. Tide. Applying a tide correction to the measured reading is essential. Corrections may be obtained from official tide tables for general route surveys, anchor placements, or "rough" depth surveys where precision is not essential. Assume that the tide tables are good to the nearest foot as long as the proper reference station and local correction factor are used, and the worksite is not a bay or inlet that may experience a tidal bore or time delay effects. When conducting a record survey such as predredging or post-dredging, or when confirming available water depth along piers, wharves, or approach channels, etc., it is most correct to use a tide gauge.
Many harbors have existing tide gauges which may be read directly. A simple tide gauge may be installed if none is convenient. A wooden staff or board of adequate length to cover the maximum range of expected tide can be marked off in feet and inches or feet and tenths. If a benchmark of known elevation is in the area, the tide gauge should be set to the local zero datum. If there is no vertical control benchmark, the tide gauge may be set to the depth and time of the locally predicted high or low tide. A series of tide readings can later be compared with the predicted tide profile to determine differences in range and time. The tide gauge is read and recorded every IS or 20 minutes when taking soundings. The readings are expanded to cover several high and low cycles when not working from a known elevation.
All tide readings should be retained as a part of the survey data and turned over to the facility in the final survey package. Tide corrections for rough surveys may be drafted into the sounding by adding the value of the tide correction to the draft adjustment. Both should be listed on the strip chart header. In this manner, depth may be read directly. If the tide correction is known in advance and with confidence, the above approach is suitable. The chart must be well labeled with all information. A plus (+) tide height must be subtracted from observed water depth. A minus tide results in an addition to the water level. This approach allows direct reading of the depth with respect to the datum. However, the tide level must be checked at the end of each line and the correction adjusted accordingly.
When performing precise surveys, the preferred approach is to apply the tide correction after completing the sounding run. The correction is added to, or subtracted from, the recorded depth. This approach minimizes the opportunity for field adjustment errors. Recording the depth uncorrected for tide does require an additional mathematical step but is the method recommended by the Army Corps of Engineers to preclude future survey confusion and possible legal claims.
Speed of Sound. The speed of sound in water is affected by temperature and salinity. Bar checks are the standard method used to compensate fathometer readings for variations in the speed of sound with depth and from one area to another. The bar may be any reflecting surface such as a length of 2- or 3-inch-diameter pipe, a wide metal bar, or a weighted board which can be lowered to a known depth below the transducer. The overall length of the bar should be at least several feet and carefully marked lines should be attached to each end for lowering and holding the bar below the transducer. Bar checks should be made at the beginning and end of each day's survey work. An additional check should be made during the middle of the day when performing record surveys, particularly in harbor and estuarine areas where the speed of sound can change significantly over a tidal cycle.
Bar checks should be made in a protected area with minimal currents so that the target can be held directly beneath the transducer. Readings should be taken at several evenly spaced intervals over the range of depths expected in the survey area. Ensure that the boat is balanced on an even keel while taking the readings. Adjust the speed of sound knob until the target appears at the exact premeasured depth. The bar check records should be saved and given to the facility customer as part of the project data.
Data Entries. All information needed to identify and correct the run must be recorded on the strip chart paper. There is no set format for a legend or tide block. The OIC or crew leader should have a tide block convention for the duration of the project. A proper title block is also essen tial on the bar check strip chart and record. The following information should appear:
Sounding Trace - Time, Date, Run Identification Number or Letter, Depth Range, Scale (X-l or X-2), Chart Speed, Boat Speed or rpm, Time of Calibration Bar Check, Draft Correction, and Tidal Height (if adjusted into the reading; if no tide correction, so state).
Bar Check - Time, Date, "BAR CHECK" at Depth," Depth Range, Scale (X-l or X-2), Fathometer Model and Number, and location where the check was conducted. A tide correction is not applied to a bar check.
A sample title block for the sounding trace and bar check follows.
Scale Setting X-l X-2
Boat Speed or RPM
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