The Welsh-built Central Rly. of Chubut
Report on an extension from Gaiman to Paso de los Indios
Central Railway of Chubut
Report of a survey undertaken to Paso de los Indios
In accordance with the instructions received from the Company Representative, Mr. R. Inglis Runciman, the undersigned accompanied by Mr. J.P. Waag, and a party of nine persons, left on 2 April 19on a preliminary survey in a westerly direction, with the object of determining the most economic and direct route for the construction of a railway from Trelew to Paso de los Indios on the Río Chubut.
Lacking a suitable plan of this region, it was necessary to make a survey of the land, not only to demonstrate the feasibility of the line proposed, but also for the selection of the definitive route. With such a proposition, we started to make a detailed survey of the whole road followed, with its associated levels, locating the position of the most prominent peaks and details of importance in relation to the centre-line of the route.
The data collected are shown on the attached plan, whose description now follows.
The length of 15 kilometres between Trelew and Gaimán had been studied previously, and this study has been approved by the Government, so ours starts at Gaimán, even though the mileages indicated on the plan are taken as starting at the existing rail-head at Trelew.
The stretch between Trelew and Gaimán needs to be described only briefly. In the lands owned by the Port Madryn Company, it should be located nearer the boundary, thus the need to compensate the farmers would be avoided, and the line would be lifted to a level above that reached by the usual floods.
The earth works required are generally light, except in a throat at the entrance to Gaimán, where it will be necessary to form cuttings in rocky ground.
Within the town, the Municipality has reserved land for the construction of the station and for a wayleave 35 metres wide between the private plots next to those of the station, passing which the line will cross lands owned by various proprietors, amongst whom is the Chubut Mercantile Company.
Passing Gaimán is found another throat, where it will be necessary to form cuttings in rock. For a distance of 35 kilometres the route would pass along the foot of the hills with form the northern boundary of the Chubut Valley. This part of the route is essentially straight, with little change in level, passing through fiscal and private lands.
At Km. 25 and Km. 35 there are high lands very suitable for intermediate stations, being sufficiently extensive to satisfy the larger part of the Chubut colonies.
We left the valley and climbed a wide ravine which leads to the table-land, encountering a very narrow throat located 20 kilometres farther west. The ravine may be traversed with easy curves and the gradient would be 1 in 150.
Then the route would follow gently undulating land, situated some 90 metres above sea level. This is covered with sparse undergrowth and very little pasture.
As we needed to provide ourselves with a supply of water, we saw ourselves obliged to follow the road shown on the map, although it is evident that farther to the north a more acceptable route may be found which is shown in red on the map.
Between Km 75 and 80 we found a pass which leads to Cañadón de la Iglesia, through high chains of fells, and we continued through a ravine, which leaves the canyon, and leads to the high table-land located some 213 metres above sea level. In this way we avoided having to cross at right angles the Cañadón de la Iglesia as does the cart road, which goes up and down with gradients of 1 in 10. This way the route is shortened by 10 kilometres.
To the south of the red line are located places with a source of water such as Campamento Villegas, Campamento Nuevo and also the road from Los Pozos to Las Plumas which is 14 leagues long. The route crosses at right angles some undulations, whose heights vary between 50 and 100 metres, its being necessary to continue in a zig-zag to avoid a gradient steeper than 1 in 100, but staying away from the River where the undulations are lower. With gradients no steeper than 1 in 100, the route follows in an almost straight line until Km. 74 (as shown with red lines), at which point the descent to the valley starts anew.
This part of the route has a length of 174 kilometres and it is made up almost entirely of sandy and pebbly land which will provide excellent materials for extraction.
The earth works would be reduced, and the various engineering works to be executed, would be some culverts to deal with the drainage of rain water on the sides of the fells between Trelew and the upper part of the ravine at Km. 40.
From the point of view of the construction of and the working of the route has the inconvenience of not having any permanent water courses in the length of 150 kilometres between Km. 35 and 185.
After rainfall numerous lagoons form on the plain, and it would be of great use to store the water to feed these fields, since the Traversía Blanca is very remunerative for cattle and horses, due to the rich and abundant pasture. The only way to get water is by means of bore-holes, thus resolving the above problem.
The high northern plain of Cañadón de la Iglesia has better pasture than the lower plain of the slope.
The stretch between Km. 174 and 178 is [not easy] as the land is very irregular and needing a detailed study of the terrain [to determine] the construction. The lines shown on the plan would have gradients of 1 in 100 with curves of 200 to 300 metres radius.
In this part there would be heavy earth works, a few in rock, and it will be necessary to build some some small bridges of 20 m. span and numerous small culverts to allow the drainage of rain water.
Crossing the River at Las Plumas, at the Ferry Boat, the gradient would be very steep and the line would be longer than that indicated (see photographs 1, 2 and 3 of Las Plumas).
The Government has decreed the foundation of a town at Las Plumas, which would not be seen as a serious obstacle to founding another in Valle de los Mártires, 10 kilometres upstream, a town which would satisfy much more the necessities of the railway than the former. At this point the products of the fields of the Río Chico converge, some of which are currently embarked in the ports of Camarones and Comodoro Rivadavia.
The Valle de los Mártires is highly recommended for plantations of lucerne, and in time will be a centre of importance.
In stead of crossing the River at Las Plumas, it would be preferable to do this at Carro Roto, or farther upstream, which would avoid crossing the narrows at Jack Lewis, Western or Carro Roto, this last one being almost impossible to cross.
The external alternative from Jack Lewis would have avoided crossing all the narrows of the River resulting from crossing it at Las Plumas, but the increase in length of the route, and the steep gradients which it has, make it un-adoptable since the route along the Valley offers greater advantages.
Something, which must be kept in mind, in the routes proposed is the crossing of the Río Chubut, since not only the width of its crossing is 50 metres, which must be maintained, but also the whole wayleave is affected by the over-topping by the River and the most appropriate site for the crossing, will be some narrows of the River, such as that at Carro Roto, where the total length of the bridge to be built would not exceed 200 metres (see photographs 4, 5, 6 and 7 in which this spot may be seen).
After crossing the River, it will be necessary to follow the Cañadón del Carbón, avoiding thus a very tight bend and the dangers of the River. This canyon has been given its name as there is a narrow house made of blackish igneous rocks similar in colour to a coal stratum.
The River doubles to the west, passing a narrow neck 15 kilometres long, and a narrows varying in width between 200 and 500 metres, a throat which has been called the Cabeza de Buey, distant some 250 kilometres from Trelew. In this site the River brushes the mountains and we may say that it divides it into three parts, but in general there are no great difficulties here.
It would be necessary to make some cuttings in rock and remove some obstacles at the foot of the fells.
At Km. 250 the valley reaches a width of from two to three kilometres, continuing thus for a distance of 25 kilometres. In its middle part and for a distance of 4 kilometres, the river runs next to the fells on the south, forming the narrows called Rocky Trip, and although the River touches the fells at five distinct points, the remaining 21 kilometres would still be of very easy construction (see photographs 8 and 9).
At Km. 275 there is a further serious constriction in the narrows called Angosturas del Ojo Negro, which in general are not very difficult to get past. The first of these is called Media Luna, due to the shape of the moon in its fourth quarter (see photographs 10 and 11). It is the one which offers the greatest obstacle, since it needs the construction of the only tunnel along the whole route, which would have a length of 200 metres, and be through very hard basaltic rock. The next in importance is that of the upper elbow of the River called appropriately Ojo Negro (photographs 12 and 13 give an idea of the place; river, cart road and mountain peak).
As the pass is too narrow to accommodate the cart road and railway together, it would be convenient to displace the first and take advantage of the pass for the railway. Once this is built there will be almost no traffic on the road.
The road widens again 11 kilometres beyond Ojo Negro to reach a width of 1 kilometre, and there are no further obstacles until a further narrows at Km. 290. (Photographs 14 and 15 give an idea of the passes and 16 in one near the fell, at the foot of which the road passes).
Possibly it will offer fewer difficulties in making a cutting behind the upper pass than cutting into the side of the fell.
At this point the valley of Paso de los Indios, which heads towards the west for a distance of 30 kilometres, starts. It is land very suitable for the construction of a line of railway; the only obstacle is a narrow pass between Km. 316 and 317. Photographs 17 and 18 give an idea of the valley and of the narrows which is 930 metres long. This will be the most expensive part of the construction at the side of the River excepting done of the part of Media Luna and Ojo Negro.
The station at Paso de los Indios will be some 318 kilometres from Trelew, as is shown, being at an altitude of 300 metres above sea level; the slope of the land about 1 in 1000.
In this site there is land owned by Señor Franklin Rawson, within which may be established a village, given the excellent location (see indication on the map). Nevertheless it would be more economical to make the terminal station at Km. 312, within fiscal land.
The difference in level between Paso de los Indios, and the upper table land where the line ends, is 200 metres and, as the length of the route is 13 kilometres, it should be lengthened by 7 kilometres so as to not steepen the gradient beyond 1 in 100.
In the area of the valley are various boundary markers, which were placed by a Government Commission to mark areas of the land for colonization. Supposing that in the Lands and Colonies Directorate there would be records and plans for this survey, I returned right away to Buenos Aires, where I presented myself to the new director of that department, Engineer Carzón, an old acquaintance of mine who had the kindness to put at my disposal detailed plans of the area which gave reports and opinions of greater value than could be formed from a small scale plan to the Directorate. From the point of view of construction, these plans could give an idea of the practicality of the route in the area of the River, and from the point of view of commerce, will help form an appreciation of the probable production and [illegible] of the valley.
Having completed the description of the study of the route along the length of the valley, we open a small parenthesis to consider the north and south alternatives, which have been shown with dashed lines in the plan. As we didn't have time to traverse the routes, I have made use of data acquired in journeys made previously.
The north alternative extends across a very high land some 20 kilometres from the existing one, and follows a westerly direction towards Los Pocitos, which is 100 kilometres distant, and bearing slightly towards the south, descending along a distance of 40 kilometres to the Río Perdido or Mirasol depression. It then continues 120 kilometres in a south-westerly direction and, leaving the Río Perdido, heads for 50 kilometres to the south towards the valley of the Chubut, which it reaches by a ravine which leads to the end of the valley of the Paso de los Indios. The length of the alternative is 315 kilometres, while the route via the valley is 20 kilometres less, or 295 kilometres long.
Apart from its greater length, it may be argued against that the north alternative traverses districts whose products have their outlet through Port Madryn, and moreover does not favour the development of the valleys along the length of the Chubut, except that of the Paso de Indios.
The south alternative is more advantageous than the north one. It covers more territories than the other ones noted, approaching more the district of Río Chico and part of the Colonia Sarmiento (lakes Colhuapi and Musters). It would traverse fields better irrigated, and only once touches the deep depression of the Río Chubut but presents the following disadvantages, it is 30 kilometres longer than the route through the valley; it must cross the Río Chico; has steep gradients (except at Las Plumas), and in addition to its distance, its height with respect to the valley would make impossible the haulage of the agricultural products, such as grains, while the livestock products, such as skins and wools, would be sent down profitably towards the valley to be transported by railway.
The essential necessities which allow a route to be selected are: shortening the distance; economy in construction; source of commerce and colonization, and it is considered that these requirements are better fulfilled by the valley route than by the north and south alternatives, and must be considered first as it has more advantages when carrying out the definitive survey and design for construction.
The cost of a railway depends essentially on the gauge selected, weight of rail, materials and earthworks, the last being what must be considered in my report.
The incline of the line in its first 175 kilometres will be slight, and embankments or cuttings will not exceed one metre. For a gauge of one metre 6000 m3 of earth per kilometre needs to be moved, which at the current cost of 30 centavos per cubic metre represents $ 1,800 national money per kilometre, or else $ 315,00 for the 175 kilometres.
For the following 15 kilometres, as has been said, it will be necessary to carry out heavy works, but as the soil is composed principally of soft and friable tosca, its removal would cost $ 5,000 per kilometre, or $ 75,000 in total.
Once in the valley, the earthworks are again of little significance, and will cost more or less $ 1,800 per kilometre, as in the first section. Thus the cost of the 118 kilometres will be $ 212,400.
Still to be added is the cost of the 10 kilometres through the narrows. If we estimate the cost per kilometre as $ 5,000, there will be a total of $ 50,000. Additionally a 200 metre long tunnel has to be built, whose cost will be about $ 30,000.
The total cost, without including that of the necessary culverts, would be $ 682,400 national money – in round figures £ 1,000 per league or £ 333 per mile.
The acquisition of land should not be a problem provided the necessary negotiations are conducted with the Government to acquire the lands before they are disposed of for the colonization of the valley.
The construction of the line to Paso de los Indios would affect a number of urban plots in Gaimán, as also twenty farms between Trelew and Km 35 and Señor Nicanor Dias y Vivar's field. For greater economy, the first section could be stopped in fiscal land which bounds that of Señor Franklin Rawson.
In conclusion I have still to add that the communications between the coast and the interior are rapidly expanding; a great number of heads of cattle have been taken in to the interior and they grow in number year by year also the Superior Government decide to sell the land in small plots with easy payment facilities, there would be a great influx of buyers in the Río Chubut and throughout the whole territory.
Buenos Aires, 30 July 19.
(Signed) E.J. Williams