In parts of the West Indies where sugar-cane has been a major crop for almost 300 years, plantation units of to-day have de- veloped by progressive amalgamation from very small estates, each with its sugar works and distillery, to organizations with modern central factories and cane areas which might easily be measured in square miles. Thus in Jamaica in the closing years of the eighteenth century there were more than 1,000 independent self- contained small estates with a total output of less than one-third of the near 300,000 tons of sugar from the 22 mills now in opera- tion. Old landmarks such as drains, canals and aqueducts, sites of works, and locations of great houses are distinguishable to-day, and still have the imprint of the careful work carried out by their owners of long ago. Matters like wayleave for road traffic, water for the " works " and drain discharge were troublesome and con- tentious. Each estate had its access to the sea and its barquadier or loading place for ships, often no more than an open beach.
Without these its produce could not be shipped, and incoming supplies could not be landed. Main drains of adjoining estates sometimes ran within a few feet of one another on each side of the common boundary. Fields were small and irregular in shape.
The works, slave quarters, cattle pens, and farm buildings were in
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a close and compact group, dominated by the great house nearby, the residence of the owner or his attorney. Judged by our stan-
dards, waste and inefficiency characterized the industry, but labour was cheap and the value of sugar and rum high, so profits were made and apparent contentment prevailed.
Successive waves of economic pressure on the one hand, and improvements in field and factory practice on the other, brought about the establishment of the so-called " centrals " of the late nineteenth and early twentieth century, forming larger groups of sugar-cane farms from those amalgamated in earlier times. The significance of the term " central" soon underwent a change in the direction of bigger groupings, some of which came into bemg in St. Kitts, Antigua, Jamaica and Trinidad during that period to be followed more recently by further similar developments in Jamaica and Trinidad. All these movements entailed some re- planning, but little change seems to have occurred in field lay- out until mechanical methods began to replace the use of animals in cultivation and estate haulage work. The phase of field mechani- zation which first became evident when steam ploughs were introduced has rapidly transformed the layout and operational patterns of cane plantations during the past 25 years, since the diesel-powered track laying tractor became available for agricul- tural work. Large irrigation and drainage projects in various places also contributed to the development of modern sugar-cane plantation layout, with rectangular fields and internal road and rail systems of regular design. In Jamaica the replacement of the banana, which reached the zenith of its production in 1937, by sugar-cane has necessarily been accompanied by some re-planning of several large plantations. Expansion of the sugar industry in many countries has brought large areas of new land under sugar- cane, involving careful attention to this matter.
T h e main principles of planning are similar for both phases of the subject, but the extent to which they can be put into practice is limited in the case of a plantation already in existence. On the other hand the experience of earlier years, and the knowledge gained of the productivity of the land, the problems of drainage, and of numerous other matters which affect the success of farm- ing operations enable redesigning to be carried out .with certainty of success.
Land Survey
The first essential to any planning project is an accurate and detailed survey, with levels at vertical intervals which are deter- mined by the configuration of the land, ranging from 1 ft. in flat land to 5 ft. or more in sloping and hillside land. The survey should show all natural features, as well as roads, tracks, drains, and buildings.
A e r i a l S u r v e y s
Aerial surveys are being used to an increasing extent. They give a photographic representation of the land surface as seen from above to convenient scales, and record every marked feature visible from the air (Figs. 15 and 16). They are carried out quickly, accurately and comparatively cheaply. The photographs prepared from them are used for the preparation of survey plans similar to those which result from surface surveys (Fig. 17).
Supplementary work is required on the ground. The location relative to other areas and the scale are determined by using a few prominent fixed points which show clearly in the photographs, of which the positions and accurate distances apart are known.
Contours at intervals of 5 ft. can be shown on plan from the photographic survey, but in the case of flat areas, especially where irrigation and drainage works are to be constructed, more accurate levelling must be done by instruments on the ground.
An outstanding advantage of this type of survey work is the photographic recording of certain useful features which are barely if at all distinguishable from surface observation. Among those of help in the planning of sugar-cane estates are old water-courses and drains, sites of former dwellings and works, evidences of previous cultivations, traces of roads and tracks, and differences in vegetative growth caused by soil and moisture variations.
Observations on t h e Ground
Ground reconnaissance is used to provide information regarding the nature, variety and extent of vegetation, to observe differences in types of soil, and to select areas for priority of development.
At the same time visual soil observations are made at depths down to about 2 ft., using a soil auger or other convenient tool. On the results of these, points are selected for soil pits, and for samples
to be taken to be examined in a laboratory. Obviously this work should be carried out by a soil scientist. These surface observa- tions, supplemented by the results of soil examinations are now considered in relation to the survey previously completed, and the first stage of actual planning proceeds.
The Focal Point
In the course of this preliminary work, what may be termed the focal point of the plantation is determined. For an entirely new project this will be the site of the sugar factory if one is to be erected, or already exists to receive and process the sugar-cane.
Should the project be a cane farm for supplying to a factory some distance away, the focal point will be the outlet from the farm to a public or other road, or to a railway siding as the case may be.
In some cases it might be a loading point on a water-way. The whole outward movement of cane from the fields and the inward movement of machines, implements, materials and field personnel should now be considered in relation to this focal point.
General Requirements
At the same time, main drains and canals, if irrigation is to be practised, should be planned. The result of this will be the com- pletion of the second stage, with main roads and tramway traces, main drains, and irrigation canals. If water for irrigation is to be conveyed by pipes, the pipe lines will take the place of canals but will not necessarily be similarly located. The land contours need careful study in connection with this part of planning, more particularly with main drains and canals, which must be related to the actual field requirements in both cases, the former for the unrestricted movement of surplus water into the drains and the latter to enable water to be applied in controlled quantities when needed. The positions of rail and tramway sidings, hoists and weighing stations, farm buildings of various descriptions, staff residences and labour quarters should be selected and demarcated.
In some instances it may be possible to select sites on ground not suitable for sugar-cane, without interfering with a practical lay- out, but the primary consideration should be the efficient operation of the plantation from the view point of sugar-cane growing.
When bush and woodland areas exist, it is desirable that the
plans should provide for the retention of some portions of them, particularly if they occur in poorer types of soil and in sections where there are commons useful for grazing. Such reserved areas need not interfere with the layout of roads, railway, drains, or irrigation works.
The possibilities of impeded drainage caused by roads, canals, the railway permanent way, sidings and other places where consolidated earthworks are to be constructed, should as far as possible be foreseen, provision being made by culverts and other relief measures for the free movement of drainage water. The location of main drains, canals and tramways is determined very largely by the configuration of the land and particularly the contours. Greater freedom of selection is possible for the main internal roads, though these should be so laid out that the subse- quent field subdivisions fall into a regular design of rectangles of uniform size except where other features prevent this. Subsidiary surface drainage should fit into the same pattern.
Thus the subsidiary drains follow gentle slopes from the fields to the mains, the fields being so laid out that they drain naturally into the subsidiaries. In level and flat land—using the terms in the sense of level land having practically no slope and flat land a very gentle slope, being in fact a slightly inclined plane—fields can be easily laid out in rectangles of strictly uniform size. Steeper land, ranging through varying degrees of slope to hillsides, is more difficult to plan and does not lend itself to regularity or uniformity of design. With such terrain the protection of the soil from erosion is a major consideration. Careful levelling by instrument to plot contours is an essential preliminary to laying out roads and drains, which must run at a small angle only to the contour, with protective works at hillside turns. Tramways in such land also closely follow the contours and their traces are planned in accord- ance with the principles of railway engineering.
Cane Fields
The size of fields is determined by the extent to which mechani- zation of agricultural operations is practised, the rainfall, and whether surface irrigation is conducted, as well as by the general configuration of the land. Fire risks and control should exercise some influence. In the Florida Everglades, where there is no
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surface irrigation, the fields are 40 acres in extent, and they fit into a rectangular pattern of mile square sections (Fig. 2). Estates in Jamaica in the dry area, using surface irrigation, have fields rang- ing from 8 to 15 acres. In the wet districts, the size rarely exceeds
10 acres (Fig. 17); and in some areas is even smaller because of the necessity for closer drains. Small fields are also characteristic of districts where manual cultivation methods and animal drawn implements are largely used. No rule can be laid down for opti- mum field area, and so long as the conditions for economical and successful production are met, considerable variation is possible.
Roadways, Tramways and Field Intervals
Easy access to fields, with facilities for free movement of personnel, equipment, supplies and reaped cane are provided by intervals or traces between the fields and subsidiary roads which lead into the estate main road system. When tramways, with portable temporary feeders laid as required, are used, they largely replace the roads, but the field intervals are still necessary, as they provide for the rail tracks, as well as for the movement of tractors and implements. Drains and irrigation ditches will in general run at the side of these traces and subsidiary roads. The width of the intervals or traces, which thus separate fields from each other, will vary in accordance with the purposes to be served. An important consideration is fire control, which is assisted by wide intervals.
On the other hand, the planter desires to put his land to pro- ductive use, and subject to the convenient conduct of field opera- tions, is inclined to reduce the area taken up by roads and intervals to the minimum. The smallest interval width should provide space for a shallow drain on each side, and allow for the passage of a motor vehicle, such as a small four-wheel drive light truck, when the cane is fully grown. It will be seen that the choice of interval width is governed by working requirements and personal judgment, and that the general pattern will be narrow traces
between individual fields running into wider ones serving groups of fields which in turn connect with the subsidiary and main road system, with a similar design of tramways are used.
The broad outline of planning now includes all but the internal layout of the individual fields, which is discussed in Chapter 5, but there remain some details to be considered. It is clear that
freedom of movement is not only needed for men and materials, but for water, whether it is to be used for irrigation or removed from the land by the drainage system. Impedance of drainage has been mentioned in relation to consolidated earth work, but the permanent drainage and irrigation plans must provide for water crossings at numerous places in the system of roads, railway and intervals. These should be provided by bridges, culverts, pipes and siphons, in accordance with the special needs of each case. The design and construction of these works should be such that they will withstand the movement of tractors and other heavy loads, and are not liable to become choked with floating debris or silt.
An important point in the layout of flat and level lands is to arrange groups of fields in line with unobstructed intervals be- tween them, so that major preparation and planting operations can be continued on long runs from field to field through the intervening traces, which are restored when the crop is established.
This reduces lost time and heavy wear on machines and imple- ments at headland turns.
Methods of cane delivery vary considerably, ranging from a road system with animal or tractor drawn carts, to a standard gauge railway, so that the planning of the transport facilities depends upon the particular practice in use. An essential for all of them is provision for accurate weighing of all loads whether of cane or miscellaneous materials. Some of them require means of quickly transferring loads from one vehicle to another. All need places where vehicles can pass each other in safety, and where numbers of them can be left standing without interfering with traffic. The question of space occupied by other things than growing cane again arises, but though economy in the layout of transport works is desirable like any other aspect of the job, it must not be exercised at the risk of congestion and restriction of free movement of traffic.
Road-Rail Transport
Plantations which have railway systems need road systems capable of conveying traffic to the railway loading points, and suitable arrangements at the latter for dealing with it. At carefully selected points, railway sidings are put in, with ancillary equip- ment comprising a weigher and a transfer crane or hoist. The
siding itself should be of adequate length to take a complete train of cars and should be of the " passing " rather t h a n the " stop- end " type. The weigher and hoist should be sited to operate at the siding leaving the main line clear. They should be surrounded by a yard with well-ballasted foundation and h a r d surface, of sufficient size to accommodate the maximum road traffic, inward, outward, and resting, likely to be experienced, a n d to allow it to move in and out without obstruction. If a platform scale is to be used, it should be located at a point where incoming traffic enters, with space between it and the transfer hoist to allow loaded vehicles room to wait when necessary until they can proceed under the hoist for discharge. The siting of the hoist requires care, and it must be in proper relative position to the railway siding, being so erected that loads can be accurately placed in each rail car as it comes beneath. Some types of hoist have swinging booms, and others a travelling overhead carriage. Both should have space for placing loads on the ground so that cane may be stored if rail cars are not immediately available, and road vehicles released quickly.
The weigher may be incorporated with the hoist, in which case no separate scale house and platform machine is required. Good lights for night working are necessary.
Tramways and Railways
A common type of light railway is of 24-in. gauge, and portable track is used to convey cane from the fields to the permanent line.
The latter requires passing sidings at carefully chosen points, but transfer of loads is not necessary. Yards with hoists or other equipment are therefore not required. Provision f o r weighing is desirable, and can be made by a scale in the rail t r a c k at a con- venient point over which all traffic can pass, with a passing siding to avoid locomotives having to move over the weigher.
Survey Plans or Maps
The various essential works and field subdivisions having been decided, a scale plan or map should be prepared f o r the whole, with supplementary detailed drawings for bridges, the larger culverts, road and rail crossings, building sites, railway sidings, and all major requirements. Before any permanent construction is begun, the sites of all major jobs should be located on ground,
using instruments in accordance with survey practice. These matters require the attention of an experienced person. Correc- tions of some observations made in the original survey may be necessary as a result of the re-checking which should be done at this time. It should not, however, be necessary to delay all field work connected with land preparation and planting, which can proceed concurrently with other operations in the areas selected for first development. These will usually be sections where drain- age and irrigation can most easily be provided, and which fit into a scheme of plant-ratoons crop cycle.
The completed estate plan will be kept for general reference and guidance in the progressive development of the whole, being altered and added to as the work proceeds. Separate plans should be drawn for particular works, such as main and subsidiary irrigation canals, or piping system ; roads ; railway ; and main drainage, so that minor works related to each can be designed and constructed in relation to the whole. Staff who need to use the plans or portions of them should be provided with prints, the master plans being retained in the office and used only by an authorised person, who should be the estate civil engineer or surveyor. The information recorded on the plans should enable the exact location, nature and extent of all works to be known.
Field areas are among the important data used in computing acreage yield and costs, and must therefore be accurately deter- mined. If underground water is to be used for irrigation, well sinking will proceed at selected points during the preliminary stages of survey and planning, as the position of successful wells will be a factor in determining the layout of the water supply system and of the fields. These matters are discussed in greater detail in Chapter 13.
Planning for Non-Irrigated Areas
The planning of non-irrigated plantations, and of extensions to existing ones is conducted on similar lines. In high rainfall dis- tricts closer attention to the drainage of roads, railways, loading sidings, and farm buildings, is necessary, sites above average land level being chosen wherever possible. Expansion projects asso- ciated with established plantations often offer opportunities for improved lay-out as compared with the existing one, though