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By Dermot M. Ross-Brown

The objectives of this generic study were to use numerical modeling techniques to determine under what conditions seismic waves generated by an earthquake might cause instability to an underground opening, or cause fracturing and joint movement that would lead to an increase in the permeability of the rock mass. In general, the study showed that moderate earthquakes (up to 0.41 g) did not cause instability of the tunnel or major fracturing of the rock mass. An artificial rock-burst tremor with high accelerations, however, was found to be amplified around the tunnel, and fracturing occurred as a result of the seismic loading in salt and granite. In shale, even moderate seismic loading resulted in tunnel collapse.

Jan 1, 1981

By Peter Cammack

Where raw coal from a mine is treated in dense medium separators ash in the washed product is generally very consistent, provided control of the medium suspension is maintained at a given specific gravity. When, however, the washing process is a Baum jig or other similar apparatus, making a separation at rather arbitrary gravities, the control of the product ash is less accurate, particularly in those cases where the design capacity of the washbox is exceeded by the load of high ash fines. In either of these cases an instantaneous measurement of ash while not essential would be desirable, to check the quality of the washed product and provide operator or management with instantaneous warning of changes in ash. Nearly 60% of all British coal mined goes for electricity generation, to burn at 17% ash, and since the overall average ash content of raw coal as mined is about 30% and varies within a range of 18 ? 40%, incombustible material has to be removed. The ash specification could be met either by total washing, or by washing part and blending the clean coal produced with the remaining untreated coal. Some plants use a straight tonnage split, but generally speaking in Britain it has been found more economical to screen and wash the oversize only. In either case for effective quality control in blending an instantaneous determination of the ash content of the product as it is made has been found essential, since standard ash determination by pyrolysis methods is lengthy and provides information too late to be used in the control of plants blending at the rate of 1000 ton/h.

Jan 1, 1976

By Irina Melekestseva, Beltenev. Victor, Victor Ivanov

"One of the major problems discussed over the last years is a possibility of mining of seafloor massive sulfide deposits. In spite of the pessimistic points of view on their commercial development, they are still of great interest and continue to be studied (Hannington et al., 2011). Recently, Barriga (2012) paid special attention to the underestimated amount of massive sulfide hydrothermal fields and pointed to the importance of the buried fields and subseafloor mineralization.This study examines the geochemistry of seafloor and subseafloor precipitates collected at the Peterburgskoe (19°52´ N) and Irinovskoe (13°20´ N) hydrothermal fields (MAR) during the 34th cruise of the R/V Professor Logatchev in 2011. These fields were discovered by the Polar Marine Geosurvey Expedition in 2010 and 2011, respectively (Shilov et al., 2011; Beltenev et al., 2012). The Peterburgskoe field, associated with basalts, is located 16 km west of the main rift valley at the depth of 2800-3100 m at the junction of a large non-transform discontinuity with the second rift ridge parallel to the rift valley. The Irinovskoe field occurs at depths of 2700-2850 m and has a northwestern satellite sulfide site, both confined to an oceanic core complex (MacLeod et al., 2009), which includes mafic and ultramafic rocks. The details of geological structure of the fields may be found in the relevant papers.Diverse samples were collected from the hydrothermal fields: seafloor massive sulfides, Fe-hydroxide crusts, SiO2-rich sulfide-bearing precipitates, and subseafloor mineralized rocks (Melekestseva et al., 2014a). Massive sulfides may be subdivided on the Fe-rich and Cu-rich types. The marcasite-pyrite, pyrite, hydroxide-marcasite, and chalcopyrite-pyrite (Fe-rich) mineral types are dominant in the Peterburgskoe field at lesser amounts of sphalerite-hydroxide-chalcopyrite and pyrite-covellite-chalcopyrite (Cu-rich) massive sulfides. The mineralized sulfide-talc-carbonate-chlorite, chlorite-sulfide-quartz, and hematite-sulfide-quartz rocks host stringer-disseminated sulfides including chalcopyrite, covellite, and pyrite."

Sep 1, 2014

An AFM has been applied to study in situ the adsorption of oleic acid on fluorite in aqueous solutions. The AFM images show that fluorite surface becomes smoother with the adsorption of 7 × 10-5 M oleic acid solution at pH 9. Force measurement shows that fluorite is strongly positively charged in water at pH 6, suggesting a neglectable surface carbonation of fluorite. The adsorption of oleic acid at pH 9 renders fluorite more and more negatively charged. The surface morphology change of fluorite as shown by the AFM images suggests that oleic acid chemisorbs on fluorite at pH 9. Increasing temperature can help increase the adsorption of oleic acid on fluorite. It may also improve the lateral polymerization of unsaturated oleic acid on fluorite as suggested by the smoother mineral surface in oleic acid solutions at an elevated temperature.

Feb 23, 2014

By N. C. Miller

In situ stope leaching is an innovative mining system that reduces the surface impacts of conventional underground mining. As in any leaching operation, stope leaching requires hydrologic site characterization and control of leaching solutions. Several tracer tests, using sodium chloride (NaCl) in various concentrations, were conducted by the U. S. Bureau of Mines (USBM) in an underground experimental stope to simulate a leaching environment. The tests were conducted in fractured crystalline rock that was partially saturated. As tests progressed, the surrounding fractures became more saturated. A predominant flow direction away from the stope was found during testing. Testing procedures, preliminary results, and remediation ideas based on field observations are presented in this paper.

Jan 1, 1995

By Walter E. Dean

Deep-sea manganese nodules are considered to be potential ores of manganese, nickel, cobalt, and copper. Considerable time, effort, and funds have been applied to the study of Se distribution of nodules on the sea floor and the location of economically important areas, but little effort has been spent in understanding the origin of nodules. Most theories that have been proposed to explain the origin of manganese nodules have been based on inorganic physicochemical processes. It is not by coincidence, however, that the area considered to be most economically feasible is in the zone of high biological productivity in the eastern equatorial Pacific Ocean and underlain by siliceous biogenic sediment. The genesis of manganese nodules and the concentration of many trace elements are intimately associated with biological processes.

Jan 1, 1982

By Avula Rajashekar Yadav, Sreenivasa Rao Islavath

Barrier pillars and gateroads play a vital role for the safe exploitation of coal from the panel in the longwall workings. The barrier pillars and gateroads are subjected to the front abutment and side abutment loads during the retreat of the panel. These structures may fail if the developed load on them is higher than their strength. The stability of the longwall structures such as barrier, gateroads and face is paramount in extracting the coal from the panel safely. For this, a deep longwall mine in India is chosen for the study using a 3D numerical modelling technique. In this paper, three critical conditions such as scenario 1 (no side goaved-out panel), scenario 2 (with side goaved-out panel) and scenario 3 (with two side goaved-out panels) are taken. For each scenario, five retreat distances such as 100, 125, 150, 175 and 200 m are considered for detailed investigation. The development of vertical displacement in gateroads, vertical stresses on barriers, vertical stress concentration factor, abutment zone and yield zone for longwall face are extracted and analyzed. Also, the safety factor of the barrier and longwall face is estimated considering the Hoek–Brown rock mass failure criterion. From the study, it is observed that the maximum vertical displacement of 121 mm in TG3 at scenario 3 for a retreat distance of 200 m and a minimum vertical displacement of 33 mm in TG2 for a retreat distance of 100 m at scenario 2. The development of vertical stress on the barrier is found to be between 8.78 and 13.40 MPa, and the safety factor of the barrier lies in between 1.56 and 1.80. The study also revealed that the yield zone at the longwall face lies within 2 to 3 m.

Dec 29, 2023

By Drummond Earley III

The hydrology of in situ leach mining operations is being studied by the U.S. Bureau of Mines using a variety of techniques, and the Bureau has made significant advances in tracking and modeling the flow of leach solutions in rock formations. However, the influence that leach solution composition has on the hydrology of these systems is poorly understood, and geochemically-controlled changes in the hydrologic characteristic of ore deposits during in situ leach mining of porphyry-hosted, copper oxide ores have not been previously studied. The Cyprus Casa Grande in situ leach mining operation mines fracture-hosted and disseminated copper oxides (predominantly chrysocolla) hosted by granodiorite porphyry using a pattern of underground wells. The injection solution consists of sulfuric acid raffinate from a solvent extraction-electrowinning plant. Chemical analysis of representative injection and recovery solutions reveals that gangue cation concentrations in these solutions are high, and geochemical modeling shows that the solutions are saturated or nearly saturated with respect to gypsum, jarosite, and various amorphous oxides. Precipitation of these solids is evoked by calcium-exchange reactions, rising pH, and perhaps locally rising redox potential, as the leach solution reacts with the ore minerals, host rocks, and the atmosphere. Mass and volume balance calculations show that approximately 25 cm of precipitates are formed per gram of copper recovered at Cyprus Casa Grande. The results of geochemical modeling agree with petrologic examination of pre-and post-leach core samples from the leached horizon. Moreover, hydrochemical modeling and hydrologic field data suggests that chemical precipitation causes significant decreases in porosity and permeability during in situ leach mining of porphyry-hosted, copper oxide ore.

Jan 1, 1992

By J. Marsden

Lift height, overall heap height and climate all play an important role in determining precious metals leaching rates, recoveries, operating costs and capital cost requirements for heap leaching operations. The effects of these factors are not easy to predict from testwork, and this can result in unexpected delays in metal production, lower recoveries than expected and higher capital and operating costs than necessary. This paper investigates the economic impact of lift height, overall heap height and climate on heap leaching and provides criteria to assist in the design and operation of leaching facilities. Descriptions of three heap leach operations in the western USA are provided to support the discussions and conclusions.

Jan 1, 1995

By F. A. Edwards

The Macassa Division of Lac Minerals Ltd. is a high grade gold mine that has been operating in Kirkland Lake, Ontario for the past 51 years. It produces approximately 120,000 tonnes of ore per year, averaging approximately 18.7 grams per tonne (0.45 ounces per ton) of gold. Over the years, the ore body has been developed to a point where mining takes place below the 1,220 m (4,000 feet) elevation and 1,830 m elevation (6,000 feet) west of the original shaft. The mine is currently serviced by two surface and two winze shafts. (Figure 1). The ore body extends below the 1,930 m (6,400 feet) Level which is the bottom of the existing mining operation. An ambitious underground exploration program has substantially increased these reserves. Concurrent with the discovery of greater reserves, has been rapidly escalating mining costs, particularly labour which constituted 66% of the total cost in 1981. These costs continued to escalate as the major proportion of mining was carried out to the west, far away from the existing hoisting systems. This required a three lift hoisting system for men, materials and ore. In addition to the increased travel time and ore handling expense, increased humidity, temperature, ventilation and compressed air losses have added to the inefficiency of the operation. As a result, studies were initiated in 1980 to assess the future of the Macassa operation. The results of the studies indicated that a new deep shaft with a potential to hoist from 2,135 m (7,000 feet) or below was the most attractive option. Detailed design of the shaft and associated surface plant commenced in January, 1982 and the following milestone dates were achieved: 1980 - initial study of hoisting and haulage facilities; January, 1981 - ore reserves in excess of 1 million tonnes of ore at 18.7 g/tonne (0.45 oz/ton) confirmed; March, 1982 - preliminary study of Macassa No. 3 Shaft completed; April, 1982 - permanent hoisting plant purchased; June, 1982 - site clearing commenced; September, 1982 - shaft collared; May 1, 1983 - shaft sinking commenced; February 11, 1985 - shaft reached 1,600 m (1mile); December 1, 1985 - shaft scheduled for completion.

Jan 1, 1985

By Yoichi Shimada, Katsuyuki Nishida, Shinichi Takahashi, Yasushi Okada, Yohei Nakamichi, Kazunori Oshiro, Taichi Terui, Sigehiko Sugie

"Temporary retaining walls are ordinarily used for tunnel construction work conducted using the opencut construction method. Retaining walls in such instances are typically installed vertically. However, shoring (such as struts and king posts) is required to ensure the stability of retaining walls in cases of excavation work to depths that exceed approximately 4 m. A new design and construction method that focuses on the effectiveness of retaining walls that are installed on an incline was studied with the aim of improving construction workability by omitting shoring. The inclined braceless excavation support (IBES) method, which was developed for use with the inclined buttress method, requires no shoring, even for deep-open-cut construction work and can be applied to deep excavation work on ground with a high groundwater level. This method has been applied at six work sites in Japan in recent years. This paper introduces the IBES design and construction method and presents verification results based on the design method, a model experiment, finite element analysis, and measurements obtained during construction work.INTRODUCTIONBackgroundIn the past, temporary retaining walls used in open-cut construction work have been installed vertically, and shoring (such as struts and king posts) has typically been used to ensure the stability of these retaining walls when the excavation depth reached 3–4 m. However, shoring interferes with structures built within excavations and requires box-outs and penetration sections in the structures, as well as concrete joints that raise concerns about their impact on the watertightness and long-term durability of structures (Figure 1).Shoring also narrows the space available for conducting construction work and reduces construction work efficiency, and the installation and removal of shoring increases the construction duration and cost. As a result, there has been a demand for ways to reduce or eliminate shoring to improve the quality of structures and construction work efficiency."

Jan 1, 2016

By G. J. Karabin

The Boundary Element Method of Numerical Modeling has become an increasingly popular rock mechanics -mine design tool. It has been used by the Roof Control Division, Pittsburgh Safety and Health Technology Center, MSHA, to aid in the resolution of complex ground control problems since 1985. This paper will present an overview of an evolving simulation process and details of methods utilized to generate necessary coal, rock and gob input properties. Also included is a description of a Deterioration Index System that is used to link model output to observed mine conditions and two case studies to illustrate that process.

Jan 1, 1995

By Ralf Winterberg, Axel G. Nitschke

"Macro synthetic fiber reinforced concrete or shotcrete is seen by many design engineers as offering a viable alternative to steel reinforcement in tunnel linings. The technology is now commonplace for primary and permanent ground support in both mining and civil tunnel applications. It has for instance become the standard form of reinforcement in the Australian mining industry, and has been used for a majority of permanent tunnel linings in recent tunnel construction in Norway. Similarly, macro synthetic fibers are becoming a standard solution for the initial lining in the USA.The use of macro synthetic fiber offers innovative solutions, yielding robust and sustainable tunnel lining designs. Citing recent research and actual projects, this paper presents state-of-the-art design considerations for fiber reinforced tunnel linings relating to structural and long-term performance. Topics include seismic resistance, crack width control, corrosion and durability, as well as sustainment of performance with age.INTRODUCTIONMacro synthetic fiber reinforced concrete (MSFRC) and shotcrete (MSFRS) has reached maturity as an engineered material and is widely used in all forms of tunnel linings, for temporary as well as permanent ground support in both, mining and civil tunnel applications. In the Australian underground mining industry, it became the standard form of reinforcement, where 2014 literally marked the end of steel fiber use in shotcrete [1], and has been used for over 80 percent of permanent tunnel linings in recent tunnel construction in Norway. Similarly, macro synthetic fibers are becoming a standard solution for tunnel initial linings in the USA. Recent examples in civil tunneling are the Devil’s Slide Tunnel and Caldecott Fourth Bore Tunnel in California or the Anacostia River Tunnel Intershaft Connector Tunnel in Washington D.C. In addition, an increasing number of tunnels are adopting shotcrete permanent linings using macro synthetic fibers. Examples include the A3 Hindhead tunnel near Guildford in the UK and the North Strathfield Rail Underpass in Sydney, Australia [2, 3]."

Jan 1, 2016

By Gilbert A. Bonforte, Hugh P. Caspe, Tracy K. Lundin

The Narragansett Bay Commission (NBC) Combined Sewer Overflow Abatement Program is a major effort to address and mitigate discharges from combined sewer overflows in the Providence, Rhode Island area. The proposed system consists of three deep rock tunnel segments totaling 17.8 km (11.1 miles) in length that will provide 860,000 cu m (227 million gal) of storage at depths up to 99m (325 ft). This paper discusses 13.5 km (8.4 miles) of 6.64m (21.8 ft) finished diameter tunnel, four construction shafts, 19 dropshafts and one large diameter pump station shaft tapered from 1 5.2m (50 ft) at the surface to 27.4m (90 ft) at depth. All facilities are in preliminary design.

Jan 1, 1995

By W. R. Reed, D. E. Pollock, T. W. Beck, J. A. Organiscak, J. D. Potts

"In underground continuous mining operations, ventilation, water sprays, and machine-mounted flooded bed scrubbers are the primary means of controlling respirable dust exposures at the working face. Changes in mining arrangements, such as, face ventilation configuration, orientation of crosscuts mined in relation to the section ventilation, and equipment operator positioning, can impact the ability of dust controls to reduce occupational respirable dust exposures. This study reports and analyzes dust concentrations measured by the Office of Mine Safety and Health Research for both remote-controlled continuous mining machine operators and haulage operators at ten U.S. underground mines. Results of these respirable dust surveys show that continuous miner exposures varied little based on depth of cut, but are significantly affected by ventilation configuration. Haulage operators experienced elevated concentrations in blowing face ventilation. The type of cut influenced exposures, with elevated exposures observed for both continuous miner operators and haulage operators when working in crosscuts driven into, or counter to, the section airflow. Individual cuts are highlighted to demonstrate instances of minimal and excessive dust exposure attributable to particular mining configurations. These findings form the basis of recommendations for lowering face worker respirable dust exposures when performing a variety of continuous mining cuts.INTRODUCTION Underground continuous coal mining operations may encounter a wide range of conditions and arrangements during production and development activities. These activities typically produce respirable coal mine dust, putting operators of continuous mining machines and coal haulers at risk for elevated exposures. In order to comply with federal regulations limiting respirable dust exposures for the duration of a working shift, mine operators typically implement ventilation, water sprays, and machine-mounted flooded-bed dust collectors (scrubbers) to dilute and control mine dusts during coal cutting. Nevertheless, changes in operational conditions can limit the ability of these controls to effectively reduce dust exposures. Some examples of conditions that can change during the course of mining include face ventilation configuration, orientation of crosscuts mined in relation to the section ventilation, and operator positioning. Because these arrangements are largely under the control of mine operators, any insight into associated exposures may inform future plans and behaviors, reducing occupational exposures to respirable dust. The objective of this OMSHR study is to evaluate respirable dust exposures associated with a range of continuous mining arrangements by comparing occupational dust concentrations measured during a series of field surveys. These comparisons consider face ventilation configurations, depths of cut, and crosscut mining practices."

Jan 1, 2015

By F. H. Mertens

The costs of an open-pit operation can be classified according to the following hierarchy : -overall cost of production (per ton of ore) -costs of basic operations and functions -costs of auxiliary operations -costs of machines and equipment -maintenance costs. Production cost is a measure of the open-pit mine performance and should be the final target of the management control. It is also a measure of the share of the mine in the processing stages.

Jan 1, 1990

By J. Andrew McGlenn, Brian McInnes, Bruce Downing, Murray Gant

The Second Narrows Water Supply Tunnel crossing beneath Burrard Inlet is an important component of the Greater Vancouver Water District’s plans to increase seismic resilience and meet increasing water demands. The project included the 110-meterdeep (350 ft) South TBM Receival Shaft, one of the deepest shafts to date in the sedimentary rock unit underlying much of Metro Vancouver. The shaft encountered varied sedimentary rock types, including fractured rock, with accompanying high groundwater inflows. This paper discusses the design and construction challenges associated with this shaft and the necessary means to complete the shaft in time for TBM arrival.

Jun 13, 2023

By Z. Scopa, E. Tarshizi, R. Setterlind, L. Frost, R. Livernois

"THE MINES OF THE FUTURE The mines of the future present a host of challenges, which may appear exciting or daunting depending on one’s perspective. Whether some sectors of the public recognize it or not, the demand for raw resources is not going away any time soon. In fact, it is rising as global population grows, urbanizes and attempts to steadily increase quality of life. Yes, at the same time that much of the highly developed world is calling for greener goods, reduced consumption, and cleaner production, in other areas there are cries for clean water and sanitation, consistent energy supply, access to health care and education, personal security, and support for basic human rights. The balancing act for sustainable development of our global society is indeed precarious, and the mining community is necessarily a key player. Fortunately, many industry members have accepted this role and the responsibility to provide leadership and a solid foundation for progress. Looking ahead, we need new generations of leaders, many of whom will be mine engineers, which are ready to tackle all sorts of complex problems. There are tremendous needs just for technological innovations. Increasingly tough deposits will require that we continue to expand scale toward “super” pits and “deep” underground mining fully develop unconventional recovery techniques like in-situ leaching and gasification or deep-sea extraction, and seriously consider off-earth endeavors. Such work will take entirely autonomous equipment; novel separations, processing and recycling methods; and systems that can withstand extreme physical conditions – just to name a few. It will also take a level of systems integration never-before seen in our field, complete with big data issues, sophisticated analytics and modeling efforts, and cyber-security challenges. Moreover, increasingly complex environmental problems will require creative solutions. Addressing issues like pollution control across multiple media, emerging contaminants, optimal management of wastes, selective mining, and shared use of resources between mine operations and surrounding communities and ecosystems are among top priorities. Really, a complete paradigm shift must occur, such that our focus is on overall improvement of environmental conditions, rather than minimization of impacts. A similar shift will be required in the social realm. How can we make miners safer and healthier on-site and off? How can we contribute to communities such that they are better off, now and long-term, for having a mine next door? How can we help transform artisanal mining practices to also contribute to sustainable development? How can our work be a factor in increasing economic and political stability? How can we improve the public understanding of raw resources and the need for mining enterprises?"

Jan 1, 2017

By C. D. Elifrits

The required reclamation of land disturbed by surface coal mining often results in the creation of some over steepened slopes which are prone to rapid erosion and sediment production. This natural activity on such slopes is not desirable nor allowed under current regulations. Experience has indicated that novel approaches must be devised to address the problem. Research conducted on field sites in Missouri has indicated that construction, during the reclamation and grading processes, of a man-made drainage system will control the erosion. The drainage system must replicate or exceed the natural system in terms of drainage density and channel frequency. Basic design considerations will be summarized in this paper and field results shown.

Jan 1, 1986

By Earle Faig

Earle Faig Along with other transportation modes, the barge industry will be greatly affected by trends in domestic coal production. Traditionally, coal has been one of the major commodities moved by barge. Now, because of events in the international energy market, coal is finally getting the recognition it deserves as a major component of the country's energy program. Perhaps even more significantly, a series of events has caused other countries to turn to the United States as a source of coal. Although the outlook for coal demand is optimistic, it will be greatly influenced by the ability of the transportation sector to handle the additional traffic. Because of its long experience in moving large quantities of coal, the barging industry is in an excellent position to capitalize on coal's increased popularity. A brief description of the barging industry should facilitate the discussion of coal as it relates to that industry. Barge companies operate on a river system that is over 40 Mm (25,000 miles) long. It includes the East and West Coasts and the Mississippi River System comprised by the Allegheny, Monongahela, Kanawha, Ohio, Illinois, Missouri, Tennessee, Cumberland, Arkansas, Warrior-Tombigbee, and Mobile Rivers, and some smaller tributaries. The Gulf Intracoastal Waterway stretching along the Gulf Coast from Brownsville, TX, to Apalachicola, FL, also is considered part of the inland waterway system. Approximately 1,800 companies operate on the inland river system and have a combined fleet of about 4,400 towboats and 28,000 barges. The fleet of towboats represents 4.8 GW (6.4 million hp) of power. The towboats comprising this fleet vary in size from a small harbor boat to a large line haul boat with 7.5 MW (10,000 hp) of power. The choice of size and power of the boat depends on a number of factors, including the size of the river and operational constraints, such as lock size, river-current rate, and water level. The choice also depends on the tow size. A single tow on a river capable of locking through 15 barges at a time handles up to almost 20 kt (22,000 st), whereas a tow on the lower Mississippi, which has no locks, can accommodate up to 41 kt (45,000 st) of cargo. Because the quality of coal is not typically damaged by exposure to the elements, it is usually moved in open hopper barges, although covered barges are used occasionally. The most frequently used size is the jumbo barge that measures 59 m (195 ft) long by 11 m (35 ft) wide by 4 m (12 ft) deep and can handle up to 1.4 kt (1,500 st) of coal. Advantages of Barge Transportation Barging offers several inherent advantages in transportation of bulk commodities like coal. First, barges can carry large quantities of product. A single jumbo hopper barge can handle 1.4 kt (1,500 st) of cargo while it takes 15 91-t (100-st) capacity rail cars or 57 trucks hauling 24 t (26 st) each to move an equivalent amount of cargo. Thus, barges can move more tonnage with less equipment than competing forms of transportation. Second, barging offers the most fuel efficient means of transportation. Less energy is required to push a load over water than to pull a similar load over land. The amount of pollution attributable to barge traffic is minimal because barges consume less fuel. Third, barging is an inexpensive form of transportation. The inland waterway industry transports about 12% of the nation's freight for about 2% of the total freight bill. This can be attributed to competition between the large number of companies on the river system and competition with other transportation modes. Fourth, barging is an environmentally safe method of transportation. Inland river routes expose fewer urban areas to hazardous substances than rail or truck. And barge spills occur less frequently than rail or truck spills. The industry does pose some disadvantages. The waterway system is constrained by the natural river network, so barges cannot travel on the most direct straight-line route. This means that barging is usually an incomplete form of transportation requiring interface with truck or rail. The industry's market is limited to those geographical areas that are located on or near the rivers. In addition, it is a time-consuming transportation mode, making it impractical for many types of commodities.

Jan 10, 1982