Development of River Navigation in Bolivia
By Rear Admiral Orlando Roca Castedo, Bolivian Navy, (Retired), former Chief of Naval Operations
River navigation in Bolivia goes back to primitive times; Manco Kapac and Mama Ocllo were mariners who sailed from Isla del Sol (Department of La Paz, Bolivia) to found the Inca civilization. There is also mention of the river navigation of Maita Kapac, the Inca who with a naval fleet of 1,000 craft navigated and explored the basins of Bolivia’s present Beni and Mamoré Rivers.
River navigation today is conducted over the hydrographic system of the Amazon and Plata basins which, with 15,000 kilometers of navigable rivers, link these basins with the Atlantic and Pacific Oceans. The rivers and the Bolivian navigation resulting therefrom are therefore the South American “strategic junction” from which the various Programs of Regional or Latin American Integration and Development radiate and converge.
Bolivian river navigation consists of two cycles—a basic one which relates to the main traffic, route, and characteristics of the river, normally coinciding with the main hydrographic axis of the respective basin, and a second—a subsidiary or seasonal one—involving the affluents and connecting small towns and having less traffic.
The rivers of Bolivia are, on the basis of rather complete technical studies: the Iténez, the Mamoré, Beni, the Abuná, Acre, Orthon, Madre de Dios, Yacuma, Chipiriri, Chapare, Ichilo, Grande, Ibare, Itonamas, Machupo, and Blanco. Also included, among the rivers under study and others to be studied, are the Paraguay and Madera Rivers.
In these studies, consideration has been given to the route followed by the rivers, currents, depths, nature of the soil, and gauging stations. Among the obstacles to river navigation in Bolivia, the following are of special importance: poles and “palisades” [fallen trees driven into the river bed], the sandbanks or panduras, and rapids or cachuelas.
This discussion offers a description of the characteristics of the waterways for the purpose of identifying the specific improvements which must be made in order to provide, in a little-developed part of the country, navigable waterways through which international connections are planned.
The Republic of Bolivia, has 1,098,582 square kilometers of inland territory, which can be divided into three large geographical zones—plateau, valleys, and eastern plain, representing approximate percentages of 14, 27, and 39% respectively. The first two zones are the best known and logically the best developed in the exploitation of natural resources (minerals) as exportable products. In the face of the fluctuating prices paid for minerals, it has been necessary to effect the economic integration of the third zone, which has great potential resources, in significant areas of the hydrographic basins where the rivers are permanently navigable.
Amazon Basin System—Investigation of 4,500 kilometers of the main stream system in Bolivia indicate that navigable waterways can easily be increased with improvements on the rivers Mamoré, Beni, Iténez or Guaporé, Yacuma, Ibare, Chipiriri, Ichilo, Abuná, and Acre.
(a) Mamoré River—This river and its tributaries drain an area of 349,557 square kilometers of Bolivian territory. The 1,075 kilometers of navigable rivers in the sub-basin of the Mamoré are interrupted by the rapids of the Madera, the Madera being generally assumed to be the most important tributary of the Amazon.
(b) Beni River—Its tributaries are the Madre de Dios and Orthon Rivers. The Beni rises in the glaciers near the city of La Paz, and is navigable from Puerto Salinas for craft of 100 tons. This subbasin covers a drainage area of 150,000 square kilometers in Bolivian territory. The 1,876 navigable kilometers of the Beni River in its sub-basin are interrupted by rapids at Cachuela Esperanza and on the Madera.
(c) The Iténez (Guapore) River forms about 1,000 kilometers of frontier with the Republic of Brazil, being characterized by being clear of floating material and considered a possible route for connecting the Amazon and Plata basins. In 1967, a distance of 631 kilometers, navigable for craft up to 80 tons, from Piso Firme to its confluence with the Mamoré, was measured.
(d) The Yacuma River is a navigable tributary of the Mamoré system, 43 kilometers long, which can handle craft of 40 tons as far as Santa Ana.
(e) The lbare River, with its headwaters on the Llanura Beniana [Beni Plain], is navigable for 47 kilometers from its mouth for boat traffic of the Mamoré system.
(f) The Chipiriri River is now the most important tributary of the Mamoré, because of its port of Puerto San Francisco.
(g) The Ichilo River is the most stable, hydrographically speaking, being about 200 meters wide and having an average depth of 3.50 meters in the low water period, and it is an important route because it is connected with highways to the producing and consuming centers.
(h) The Rio Grande [Grand River] is one of the longest tributaries of the Mamoré, but it is not considered navigable over most of its length because it is meandering, with a heavy transport of solid material, which forms innumerable sandbanks.
(i) The Chapare River as a consequence of the accumulation of alluvial material, diverted its waters to the Chipiriri, and since then has been a tributary of no importance.
(j) The Acre River, the natural boundary with the Republic of Brazil, is a possible outlet for the area of Cobija, capital of Pando Department, and is considered navigable from that point for one-third of the year.
(k) The Abuná, frontier river in northern Bolivia, discharges its waters over a series of rapids into the Madera, and its navigation is limited to coasting service on that section.
A serious problem concerning the tributaries of the Mamoré is that they transport quantities of alluvial material and are still seeking stable courses, and it is possible that the problem of the obstacles and restrictions will become more acute as the alluvium moves downstream.
The Plata Basin System—Bolivia has access to the Paraguay River, and therefore to the Atlantic Ocean, over the natural route formed by the Paraguay, Paraná, and Plata Rivers. The Bolivian shore of this river is 48 kilometers long and, in accordance with the accepted principles of international law, this allows Bolivia unrestricted navigation over the entire Plata system. The Paraná and Paraguay Rivers form a natural channel for navigation, offering exceptional conditions. The waters flow through this 2,550-kilometer-long section at moderate speed even in the flood season, and there are no rapids to hinder navigation; the most pronounced shallow passages accommodate boats drawing five feet.
Bolivia’s Lake Basin System—This system is formed by Lakes Titicaca and Poopó, connected by the Desaguadero River. Lake Titicaca, important as a water transport route, has approximately 8,330 square kilometers and recorded depths of as much as 272 meters. Its waters wash the Republic of Peru and Bolivia, and the “Peruvian Corporation” handles a significant volume of Bolivian import and export cargo, operating a fleet of five vessels, with a railway line to a port on the Pacific Ocean.
In Bolivia, as in many parts of the world, the word “port” is used to designate any place where vessels can load and unload frequently and without facilities of any kind, and so only the most important ports will be mentioned. Generally speaking, all cargo-handling is done by hand.
(a) Puerto Guayaramerín has a population of 16,000 and serves the Mamoré for domestic and international traffic.
(b) Puerto Siles is situated 740 kilometers above Guayaramerín, and is connected by road to the towns of San Joaquin and Magdalena.
(c) Puerto Barrientos, situated at the confluence of the Ichilo and Chapare, is used for trans-shipping to smaller capacity craft which ply the Ichilo.
(d) Puerto San Francisco, the main loading point on the upper Chipiriri-Mamoré, is connected to the city of Cochabamba by highway.
(e) Puerto Loma Suarez is situated on the Ibare River, and is connected to the city of Trinidad by a 10-kilometer highway.
(f) Puerto Yacuma is used principally for the loading of livestock.
(g) Puerto Grether has a highway connection with the city of Santa Cruz.
(h) Puerto Villarroel is the site of a small oil refinery.
(i) Puerto Villazón (Remanso) serves as the head of navigation for the boat traffic of the Iténez-Mamoré system.
(j) Puerto Horquilla is a military port on the Machupo River, a tributary of the Iténez.
(k) Puerto Cobija, a port on the Acre River, has approximately 10,000 inhabitants and is adequate for domestic service and the exporting of rubber and almonds.
(l) Puerto Riberalta, a city of 25,000 inhabitants, is the busiest port of the Beni system, and when construction of the highway to Guayaramerín is completed, its port activity will be further increased.
(m) Puerto Cachuela Esperanza is the port between Riberalta and Villa Bella, on the lower Beni.
(n) Puerto Rico serves as the head of navigation of the Orton River, one of the main tributaries of the Beni.
(o) Puerto Heath is a frontier port on the Madre de Dios River with Peru.
Navigation on upstream headings is generally the safest, at speeds of three to five kilometers per hour, because of the danger of sandbanks and poles driven into the river bed. Night sailing is done only on the lower Mamoré and the lower Beni.
The rivers undermine the land at the gorges, causing the trees to fall, driving their tops into the riverbed, with the roots up. This phenomenon occurs during the flood season, and tends to change the course of the rivers. The number of fallen trees is naturally greater in the channel (concave bank) than on the convex bank. The tree trunks tilt downstream at an angle of approximately 45 degrees to horizontal, and due to their large numbers and the cost of removal, it is a project which requires heavy financing.
Sandbanks may appear anywhere on the navigable watercourse, especially at the confluences of the rivers, but more frequently in the upper portions, and in time of low water they are problems to navigation.
Rapids occur at various places on the main stream. The worst ones combine cascades with swift current and occur downstream from Guayaramerín. On the others which have a navigable channel, local pilots are frequently employed to negotiate the rapids. This involves a delay and an increase in costs. The poles and the sandbanks are apparently of great concern to the shipowners and, as heavier traffic justifies the use of larger craft, improvements will be needed in the entire river system.
Navigation charts have been prepared by the Headquarters of the Bolivian Naval Force, through its Department of Naval Hydrography. These charts have all the technical data necessary and also other items that may assist in interpreting the special characteristics of various rivers. For navigation on those rivers, the services of a pilots organization are not employed, nor do they exist for those specific purposes. Masters and crewmembers are their own pilots when sailing on Bolivian rivers because of their long years of work and experience.
A study is being made of the marking of the main rivers of Bolivia, particularly in the sections where the riverbed changes, and it is recalled that some companies, had previously performed experimental rudimentary marking using the “blind buoys” system based on tree trunks painted with showy colors. This confined navigation in certain sections to visual navigation only.
Obviously, to fulfill this basic need of river navigation on the rivers of Bolivia, it is necessary to have the technical and material support of more highly-developed navies, for Bolivia lacks radio stations and other services essential for safety on the rivers. Moreover, at present, neither boats suitable for rescue work nor rescue equipment are available.
River navigation in Bolivia, as far as the ships used in it are concerned, has undergone a complete, natural cycle of development, with considerable delays evident in technical progress. All or most of these river ships were assembled, built or reconditioned with national materials and personnel, except for the engines or machinery, which were always imported. Because of this lack of development, the Bolivian Naval Force looks hopefully to the importing and construction of ships and their equipment.
The Bolivian Naval Force has conducted studies and is continuing to work on the elimination of obstacles to navigation by cleaning the rivers under two basic programs:
Cleaning by dredging—This is done for the purpose of destroying the sandbanks which periodically are formed by the accumulation of silt transported from the headwaters.
Cleaning by destroying the poles and “palisades”—The Naval Force eliminates those obstacles by blowing up the trunks with explosive charges. For this reason, the Naval Force is urgently in need of modern dredges and pole-pullers.
For river navigation, Bolivia had, in some ports, a few shipyards that were really complete and modern. For various reasons, however, including natural wear and tear, they have fallen into a state of disrepair. The Bolivian Naval Force, after completing the study, will request cooperation and financing from international organizations for establishing and operating them.
The river craft (ships) used in Bolivia are of small capacity, used basically in the transport of personnel, livestock, and cargo.
Due to the comparatively light tonnage of the ships and the small weight and volume of the cargo, the ports have no cranes, single-whip tackle, or other usual port facilities at their disposal.
In its river navigation tasks, the Bolivian Naval Force employs its personnel and equipment in several civic action programs serving the needy peoples and classes, with particular emphasis on environmental sanitation, medical care and first aid to the riverside inhabitants, support in the construction of the road system, assistance in the installation of drinking water service to the people in the river basins, and the teaching of reading and writing and civic duties instruction among the rural classes.
As has been seen, navigation in Bolivia, which is as old as America itself, involves brotherhood and true bonds of friendship. And just as her rivers, like real arms, join the basins of the Plata and the Amazon with the Pacific and Atlantic systems in a single embrace, so does Bolivia seek to make her position one of continental liaison and balance. The Bolivian Naval Force, through its worthy representatives, seeks also to demonstrate to our sister nations our devotion to democracy, that the solving of our problems set forth here may be based on constructive friendship and cooperation.
It's All Relative
By Commander William R. Harris, U. S. Navy, Former Assistant Operations Officer, Fleet Training Group, San Diego
We have modernized everything in the Navy except the way that we evaluate its performance. We cling to the “absolute” scale of grading without considering the insight that a relative or statistical grading system would give. While we strive to reach absolute perfection our grading system innocuously disguises both our achievements and imperfections.
In order to evaluate properly our present grading system, it is necessary to compare the raw scores of ships grouped homogeneously as well as heterogeneously. Let us begin by analyzing the grades of 169 ships evaluated by Fleet Training Group, San Diego over a two-year period, while this writer was on the staff. Table I is a histogram of the heterogeneous grouping of the ships representing every type command, except the Naval Air Force, U. S. Pacific Fleet.
As shown by Table I [sic], the mean of the group is 77.5. This places the average score in the “good” (75 to 87.9) category as rated by the absolute scoring system. The distribution of scores is leptokurtic with 78.7% of the scores falling within plus or minus one standard deviation of the mean. Three ships fell within the 85-to-86 interval, but none attained the grade of excellent (88 to 94.9) or outstanding (95 to 100). The top three ships of 169 units were unrecognized since their “good” was the same rating that 81% of the ships going through training received.
On the bottom of the grade spectrum, only one ship received “unsatisfactory” (less than 62.5). The raw score of this ship was 60, indicating that the ship was very near a satisfactory rating on the absolute scale. By converting the top and bottom raw scores to standard scores, the degree of achievement or failure becomes vivid.
When a standard score (T-score) is used, 50 becomes the center of the distribution curve. The raw scores are converted to Z-scores and then T-scores as follows:
Z = Raw Score - Mean / Standard Deviation = 85.5 - 77.5 / 4.32 = 1.85
The top Z-score equals 1.85. Converting this to a T-score by means of the following formula we have:
T = 10z + 50 = 18.5 + 50 = 68.5
Using the same procedure the lowest score becomes:
Z = 60 - 77.5/ 4.32= 4.02
T = 40.2 + 50 = 9.8
The meaning of the high and low scores now becomes significant. Where the raw scores were spread 60 to 85.5, the T-scores are spread by an impressive 9.8 to 78.5. By means of the T-score, the vast difference between the scores, and therefore the performance, of the two ships can be seen. The ship that barely failed on the absolute scoring system is drastically below standards on the relative scoring system. This relationship is summarized as follows:
| Raw Score | T-score |
High Ship | 85.5 | 68.5 [sic] |
Low Ship | 60 | 9.8 |
Thus far the scores of ships grouped heterogeneously have been evaluated. Interestingly enough, the ships obtaining the highest and lowest scores came from the destroyer group.
When the raw scores of the destroyers are placed in a homogeneous group then mean increases slightly to 77.68. Two of these ships falling within the 65-to-66 raw score interval were rated “satisfactory” on the absolute scale, but only received a T-score of 25.1. These ships exceed a minus two standard deviations from the mean and, relatively speaking, are unsatisfactory. The scores of these units placed them in the bottom 10% of all the destroyers. The absolute grading system overlooked the extremely low performance of these ships by giving them a satisfactory.
[Table 1: bar graph depicting distribution of Raw Scores vs. Number of Heterogeneous Ships]
[Table 2: bar graph depicting distribution of Raw Scores vs. Number of Auxiliary Ships
Table II [sic] shows the wide range of raw scores obtained by auxiliary ships. This group of ships has the highest mean (78.55) of all groups and includes amphibious cargo and amphibious transport ships, as well as Service Force, Pacific ships. Unlike the newer destroyer types, the newer ships in this group tended to score high. It is to be noted that an auxiliary ship earning a raw score of 70 is more than minus two standard deviations from the mean when grouped homogeneously. When this ship is grouped heterogeneously, the raw score of 70 is within two standard deviations from the mean. It is therefore possible for this ship to be substandard while being unobtrusive under the present system of heterogeneous grouping.
The following tabulation will enable the reader to determine how his ship performed relative to others going through the Fleet Training Group, San Diego. Raw scores falling within plus or minus one standard deviation from the mean are average:
Group | N | M | S.D. |
Heterogeneous | 169 | 77.5 | 4.32 |
Destroyers | 68 | 77.68 | 4.83 |
Amphibious | 36 | 76.25 | 3.69 |
Auxiliary | 36 | 78.55 | 3.92 |
Minesweepers | 29 | 77.07 | 4.25 |
Although more samples (N) are required to finalize the statistics, we can see that under the present grading system it is possible for a ship to turn in a high performance and remain unnoticed. Further, it is quite possible for a ship to be unsatisfactory and also remain unnoticed. This was true for the low scoring ship of every group. The present system of raw scores tends to be innocuous, with 81% of all ships receiving a “good.” This uninjurious grading policy tends to protect the substandard performer while not recognizing the top performers. The argument for using the absolute grading system is that it keeps standards high. Paradoxically, the scores promote mediocrity by seeking a status quo around “good,” thus protecting the low performers and not recognizing the high performers.
Let us use our computers to accumulate data so that meaningful standards can be applied to evaluating ships. This statistical approach could be extended to specific areas such as damage control, engineering, and navigation. A department head would know precisely how his department compared with others in his type of ship. Commanding officers would have a basis for spot-lighting potentially serious problems before tragic and expensive mishaps occur. These Fleet standards would also be useful in correlating personnel and material problems with the performance of the ship. These correlations would offer another means of documenting the need for additional funds. A squadron commander would know how each of his ships compared with a Fleet standard rather than how they compare with each other. This knowledge would enable him to evaluate the performance of new ships entering his squadron and easily identify other ships requiring help.
We should grade our ships as follows:
► Superior—exceeds 1 S.D. above mean
► Average—plus or minus 1 S.D.
► Below Average—minus 1 to 2 S.D.
► Unsatisfactory—below minus 2 S.D. from mean
This system is not based on a vague and unattainable ideal standard, but instead offers every ship a meaningful goal.
The statistical grading system could be extended to other types of inspections that use the absolute system of grading. We should retain the absolute grading system only if we must, but let us superimpose a statistical system on it. As the old physics professor said, “It’s all relative.[”]