Australian Sugar Tramways in 1980
By I. R. Crellin
Adapted and updated from "Australian Sugar Tramways - The Challenge of the 1980s" by I.R. Crellin, published in Light Railways No.66, October 1979. [email@example.com]
- From the past
- New developments in cane handling
- Motive power technology
- Tramway operations
- Permanent way & track maintenance
- The computer age
One of the greatest joys for the person with an interest in railways in Australia, must surely be the vast network of narrow-gauge lines inthe north of the country which serve the farms and mills of the sugar industry. Each year in the winter season, millions of tons of sugar-cane are harvested and loaded onto light railways for the journey to the mill, where it iscrushed and processed into raw sugar. Some of this raw sugar is then transported to port for shipment by light railway on its way to the food industriesof the world.
Much of the wetter coastal strip of east Australia, from Harwood near Grafton, New South Wales, in the south; to Mossman near Cairns, Queensland, in the north - owes much to the growing of sugar for its livelihood and prosperity. Some 2000 miles of tramway, most of 610 mm gauge, can be found serving the mills on this strip of tropical and sub-tropical coastline.
The industry rose from humble beginnings in the last century to its present situation where it is an advanced high-technology undertaking handling volumes of product undreamed of even in recent times. Along with the expansion, modernisation of facilities including the tramways which serve the industry, also proceeded. Today computer-assisted milling processes are found, even extending to the operation of the tramways. Scheduling is computerised at many mills and advanced technology features such as radio-controlled brakevans and locotrol-style slave locomotive operations may be found in daily operations. On the heaviest of the tramways engineering standards approach those of conventional railways. The changes in the industry have indeed been of the most profound nature.
Until 1960, the sugar tramways of Australia operated much as they had since the end of the last century. While early lines often were horse powered or sometimes manpowered, the simple locomotives of Decauville, Fowler, Krauss and other companies soon made their mark in the canefields. They hauled open wagons with stake ends, sometimes holding as little as one ton of cane each. These trains were braked only by the engine brake, and operations over the light tracks must have been a somewhat hazardous procedure. Although some plantations installed well equipped systems, bringing the tracks into the fields, many independent farmers had to cart their cane to the nearest siding with a transhipment derrick, or alternatively, run temporary lines from the permanent line across road and field to the place where cutting of the cane was occuring. Of course, this line was too light for locomotives to run on, so after the cutters had loaded the wagon by hand man or horse would push or pull it back to the siding. In later years, the tractor took over this role.
Motive power was provided by the steam locomotive. A variety of light engines, typically 0-4-0T, 0-4-2T, 0-6-0T and 0-6-2T patterns, were popular. A number of 4-6-0T locomotives from war disposals were obtained after World War I. Tender engines were not widely used, with the exception of the very successful 0-6-0 Hudswell Clarke tender design, built from 1915 to the early 1950s. CSR (Colonial Sugar Refining Co.) ordered many of these locomotives and they lasted until the last days of regular steam operations in the industry. Wood and coal were the early fuels. Mossman Mill still used wood until recent years. Experiments with oil firing, notably at Macknade Mill also occurred.
One of the delightful aspects of operations in the steam days was the local character that the locos of certain mills would acquire. Modification and rebuilding occurred. Consider one of CSR's Hudswell Clarke locos built in 1925, becoming Hambledon No. 6. It was later transferred to the Macknade Mill becoming No. 4. Here it was reboilered with an ill-fitting spare boiler off an 0-6-2T Fowler loco and ended her days converted to oil-firing and wearing a falsepiece fitted to join the replacement boiler to the smokebox. It is events like this that make tracing the history of locos on the canefields so difficult, yet so interesting.
Locos would bring the full wagons to the mill where they, or a yardshunter would push the wagons across a weighbridge to a tipper where the stalks would be tipped for crushing. A few small petrol or diesel locos were used in yards or for works trains from pre-war days and a number of larger Fowler petrol-mechanical locos were obtained in the 1930s. But it was not until the 1950s that the diesel took over in force. With the need for higher throughput rates and reliability, the older steam locos could not do the job at the price required and faded away.
Today we see the canefields worked by fast chopper harvesters, with tractors or trucks carrying bulk bins darting behind them collecting the shower of cut cane which tumbles from the machine. Thirty years ago, the same canefields would have seen gangs of sweating men cutting and trimming the cane with long knives. Loading the stalks onto the wagons was also done by the men. Labour costs and shortages turned inventive minds to mechanisation. First, loading machines were made to lift the cut cane onto wagons. Hydraulic grab types and front end loader types were both widely used. The dirty and heavy manual task of cane cutting still was left to man.
Early in the century, experimental cutting machines were made but failed to gain acceptance. Large plantations like Fairymead persevered and developed large mechanical cutters. These users had engineering facilities and financial strength. The small farmer often had neither, nor did he have the large areas of cane to warrant such a machine. In the 1950s, small whole stick harvesters became available and these were adopted by a modest number of farmers. The bigger chopper harvesters did not become widely used until the 1960s, and then often only by contractors or a shared machine between a group of farmers. While the whole stick harvester represented a mechanisation of a manual function in an existing system, the introduction of chopper machines required radical changes to the whole system, from farm to mill. It was accepted because it offered the best chance of development into a highly efficient mechanised bulk material-handling system. It was the step that lifted the industry from the old simple days to the new high-technology situation.
Wholestick cane could be gathered in bundles and transferred to tram wagons from carts or from simple stacks on the ground. Chopped cane however, was a less tractable substance and it was found that the easiest way to handle it was in large mesh-lined bulk bins. Initially these were built up on the frames of old wholestick wagons. They were taken into the fields on trailers and towed behind the harvester, being filled from a conveyor belt on the harvester. When filled, they would be taken to the tramway and run off the trailer onto the rails for haulage to the mill. Chopped cane proved susceptible to spoilage by bacteria. Juice from contaminated cane failed to crystallise satisfactorily in processing, to the despair of the millers. By better co-ordination of harvesting and transportation, and speedier service, this problem is minimised, but cane cannot be left safely in trucks through a mill breakdown without spoilage.
In wet weather, it was found that trailers with bulk bins were bogging, stopping harvesting. Side tipping trailers were developed, running on fat tyres. These were driven to the siding and the cane tipped into the railbins. Experiments were made with direct transport by road trucks from the field to the mill. Problems of bogging and getting good utilisation of the units can occur. Container systems of up to 20 ton capacity are in use in the NSW mill areas, but they are not taken into the field for filling directly from the harvester.
An impressive system based on the container principle, has been developed by Freighter Industries. 'Canetainers' of approximately 10 ton capacity are built so that they can be fitted to road vehicles or to bogie underframes of 610 mm gauge. The canetainers can be hydraulically transferred between these modes and onto stands at sidings or at the roadside. Empty ones are delivered to a site near the farm and either transferred onto stands, or filled directly from side tipping trailers. As harvesting progresses, trailers or trucks collect empty ones, take them infield to be filled then return them to the stands, full, to await transport to the mill. Road or rail may be used and any canetainer may be delivered by one mode and collected by another. Thus mill management has great flexibility in scheduling its collections for optimum operations. Early models had side or end flaps for tipping at the mill. Later practice has been to invert the whole canetainer and empty it through the open top. Mossman Mill has adopted their use and the system has been shown overseas. The system can be used with road transport alone but tipping problems and queuing inefficiencies may arise. The solution in this case is to have a circuit of 610 mm gauge track at the mill and to transfer canetainers onto bogie underframes for the short trip to the tipper. When first introduced at Mossman, a solution was found to problems of bogging the heavy containers in wet fields. The usual 3 ton bins were filled and brought to the canetainer, where it was lifted and inverted by a modified forklift truck.
The basic bulk bin has changed little since its introduction. Capacity has increased to 4 tons and Racecourse Mill has built 5.6 ton models with low friction bearings. Stability problems and permanent way standards limit the size of bins.
Until the 1950s, steam reigned supreme on the tramways of the sugarfields.Early diesel introductions had mainly been of the rail-tractor type although CSR introduced several Fowler petrol mechanical 0-6-0 types at Huxley Mill in 1930. In the early '50s, CSR again led the way with a number of Baguley-Drewry0-6-0 diesel mechanical locomotives. These proved successful and were the forerunners of large fleets of diesel locomotives now operating on the sugar tramways.
Several manufacturers soon were in hot competition for the market. A number of early locos were fitted with mechanical transmissions, in deed many still operate in the 1970s although some have been converted to hydraulic transmission. The pattern was soon set however and the typical cane loco emerged as a diesel-hydraulic 0-6-0 of 15-20 tons. Clyde and Commonwealth Engineering emerged as major early suppliers and at a later stage E.M. Baldwin also entered the market. One failure was the venture by Bundaberg Foundry to build Austrian designed Jenbach locos. Although a number were built, their mechanical transmissions were unable to perform like the hydraulic ones then coming into service, and further locos were not built. The advantagesof these early diesels were soon recognised by the mills; greater economy, lower maintenance, less staff and greater availability. Victoria Mill's experience was that one of the early units could haul one and a half times the load of a steam engine of equivalent weight.
The size of the first generation of diesels was limited by several factors.The major limit was how to control a train of unbraked, loose-coupled cane wagons on light and often irregular track. When one considers the wagon construction, it is obvious that they too were not designed for high powered locos. In the early 1970s, experiments with brakevans were carried out, promising to give crews a better way of controlling the trains. Early ones were merely towed behind the loco and provided the driver with extra braking power at the head-end. The problem of getting braking power at the tail-end of the train was solved by radio-controlled brakevans. Now the driver can apply the brakes by remote control and have greater control of his train.Heavier loads can now be safely worked because of this additional development. Wagon construction standards have also been upgraded. Steel wagon frames are now in use, where older trucks were of wooden frame construction. Standards are not uniform for all mills, causing problems when gear is transferred or sold.
Stock from Condong Mill transferred to Victoria Mill in the mid-70s, had to have old ring-style couplings replaced by modern Willison autocouplers before being able to be used at that mill. Advances have been made in axle bearings also, but not without problems as the unbraked wagons then become more free-running in shunting. Shunting impacts then become more violent, causing more wagon damage. Double-heading is an obvious way of increasing loads. Coupling-pull limits and bridge limits make the operation of double-headers impractical. If the second loco is near the rear of the train, then it is possible, but as this requires a second crew, savings in cost are then not as great as they could be.
In the 1970s, the Sugar Research Institute worked on a 'Locotrol'-type device whereby a second loco could be worked by remote control, by the driver of the front loco. They opted for a small computer to control the 'slave' loco, rather than a hard-wired logic system. Mounted in a small wagon adjacent to the slave, it monitors the engine and transmission as well as receiving instructions by radio. Sanding, throttle, clutch and brakes are controlled. Trials in the Bundaberg district provide it practical and it is in use on the Gin Gin line. This line has some deep cuttings and it is said that some spills occurred in trials when the radio signals to the second loco were screened by the rock walls, causing the safety over-rides to apply the brakes of the second locomotive.
While double-heading can increase loads, so can introducing bigger locos. In the late 1970s BB diesel hydraulic bogie locos of around 25 tons, built by EMB and Comeng were introduced. Modern wagons and better track has enabled these giants to be utilised.
Tramway operations are now big business and all phases must be more precise and controlled than in the past. Once running could be relaxed, stopping here and there to drop empty wagons or to collect full ones at many sidings. Safe working often consisted of watching up the line for the smoke of any other loco in the vicinity. In recent years, pressures on the tramway to keep the mills supplied with cane to meet the increased crushing rates and to avoid the spoilage problems with chopped cane, haveput an end to that style of operations from the past. Today the loco crew are not out on their own, but are linked by two-way radio to the controller. Problems are solved instantly and cane rescheduled to ensure optimum flow of cane to the mill. The modern tramway controller has the services ofthe computer to assist him in planning the best course of action to take. This technique known as scheduling, is discussed later. In general, it results in coordinated harvesting by geographic groupings of farmers, enabling the tramway to operate fast direct services to and from a compact supply area. This type of operation is much more efficient than the pick-up type. As a result of this change in operations, track systems are also changing. Small sidings are disappearing.
In some cases, small branches are closing and others being truncated to consolidate on a number of larger central collection points. The taskof assembling the bins of cane is better left to motor transport with its inherent flexibility, leaving the bulk, block-loads to the tramway. It is interesting to see how this process is paralleling the changes on the state railway system's goods handling policies.
The millyard is a very important place. The orderly flow of full wagons in one end, tipping of the cane from the wagons and the dispatch of empty wagons to the farms at the other end of the yard is a great asset when compared to yards where both ends of the yard receive full wagons and dispatch empties. Redesigning of yards to achieve this flow is of benefit to efficient operations. The pattern of lines at many mills was dictated by settlement history and a line usually started from the closest side of the mill yard. Much extra shunting and counter-current movement resulted from these old layouts.
The tipper is the part of the system which sets the amount of cane being delivered to the crushers. To increase milling rates, one must tip more cane. The switch to larger wagons has enabled more cane per tip, but modern rotary tippers also enable more tips per hour to be made. The old mills often had an old loco or rail tractor pushing rakes of wagons over the weighbridge and on to the tipper. Modern wagon placing systems today do the job with greater accuracy and timeliness. With automatic weighbridges and tippers, these systems, sometimes computer-controlled, handle the tipping of large throughputs with greater reliability and precision than a shunting loco could ever achieve. Many mills have installed such a system in thepast decade. Many too, took the opportunity to redesign their yards and approaches for maximum efficiency when they made the change. A further development occurred in 1975 when North Eton Mill installed the first doubletipper. This device holds and tips two wagons simultaneously, thus increasing the flow of cane to the crushers.
With the emphasis on speedy movement of bulk cane, attention has focused on speeding up the trains themselves. The use of radio-controlled brakevans on the rear of trains has assisted in speeding up services. Consideration has also been given to re-gearing locos for faster running. Farleigh Mill has looked at this option for improving operations on its long line north from the mill towards Calen.
As can be imagined, the increased pressures on the tramways as they are being asked to carry more, at higher levels of punctuality and efficiency is pressuring the system towards its limits. In the early 1970s, derailments were a major problem for many systems. New wagon designs were blamed in some cases, and bearings modified. Wet weather brought home the lesson that higher speeds and axle-loads needed heavier track and better ballast. Breaking axles and wagon frames also caused problems. Farleigh Mill instigated the testing of axles and bin frames using ultrasonic methods in 1972, following a spate of incidents where the failure of these items contributed to delay or damage. As the level of utilisation of the tramway increases, so too does the level of complexity of its operations and the seriousness of the consequences of any accident, delay or failure.
The theme which has been developing through this article has been howthe sugar tramways have met each new demand of them by new technology, better operational procedures or intensification of services. By doing so, the volume of cane handled and the efficiency have progressively increased over recent years. This excellent performance could not have been achieved without developments in the field of permanent way standards and track maintinance, complementing the developments in the other fields.
Modern tramway operations require heavier track and better structures than in the past. The cost of a derailment in terms of delay to the total milling system makes it imperative that this be so. Victoria Mill is often quoted as a model of an advanced 610 mm gauge tramway system, with high tonnages, dense traffic and long haul distances. The locomotives includea number of modern bogie diesel-hydraulic models of high weight and capable of high speeds. The track provided for such operations is 62 Ib/yard weight. This is heavier than some branch line and siding track on Government railways.While most tramways use 30-40 lb/yard weight track, lighter track is not unknown. Many mills have been rerailing their lines with heavier rail in recent years. The market for second hand rail from Queensland Railways lines is one source of replacements. Suitable rail has not always been readily available and one recalls that in the early 1940s, reclaimed rail from the closed Rockhampton street tramways was used by Mourilyan Mill.
Along with heavier track, better sleepers have been introduced. Bothtreated-wood and prestressed concrete products have been marketed and are in service at a number of mills. Getting the best from improved track materials also means that proper ballast must be provided to support the track. Some earlier attempts to operate with higher axle loads and speeds produced a large number of derailments. The high rainfall and unstable soils in some areas have made ballasting an essential part of the upgrading program at many mills. Past practice has varied, but few mills used crushed stone ballast, as gravel and rubble was sufficient in those less demanding times.
Ballast has provided a new set of problems for the track maintenance engineers. In the past, gangs of fettlers did the required maintenance manually and in later years, with the assistance of powered tools. This approach has been found to be inadequate in the face of the increased demands on the tramway systems. Like the Government systems, the mills have sought mechanical track maintenance equipment to provide economical and speedy track maintenance. While the larger systems have purchased this type of gear, the smaller mills have been able to improve the speed and productivity of their maintenance effort by smaller-scale improvements, such as introducing pneumatic hand-held track tools. A number of firms have supplied new types of equipment, not previously seen on the canefields. Ballast tampers have been put in service at many mills. Tamper (Aust) P/L and Plasser make 610 mm gauge tampers. The Plasser model KMX06, can level and tamp 400 sleepers per hour, greatly improving on the results achieved by manual gangs. As with many aspects of tramway improvement, the CSR mills at Ingham were pacesetters in its development and introduction.
New hopper wagons for carrying crushed rock ballast have been introduced. These dwarf the old 4-wheel ones, often no more than old wholestick canewagons with wooden sides added. High capacity bogie hoppers are now being used on the tramways. These new wagons are a vast improvement on the ones they replace.
When the lines and branches were originally laid, some nearly a century ago, many imperfect features were incorporated. They were designed as light railways, and in the best light railway tradition incorporated such features as steep grades, tight curves, roadside location, light bridge standards, flood-prone locations and level crossings of roads, railways and other tramlines. While these features and the associated operating style adopted to cope with them gladden the heart of the railway enthusiast, they dismay the engineer and the economist. In the overall process of improving the tramway system, the general raising of engineering standards of track and associated structures has been necessary. Faster speeds, higher axle loads and heavier trailing loads demand it, and if it is not done, breakages and derailments will follow. Programs of bridge and culvert strengthening have been undertaken. Low-level wooden bridges have been replaced by higher, steel bridges and wooden openings replaced by concrete pipe. High capacity transport systems require high engineering standards to operate in an economical manner.
A small improvement in a limiting section of the tramway may lift thewhole tramway's performance significantly. Over 30 years ago, Isis Mill built a cut-off line which saved many miles of difficult working over the course of the years. Marian Mill has a difficult section over the Messmate Range where grade improvements in recent years have meant improvements in capacity and cost savings. Such projects need not be large. The elimination of level crossings over mainline railways is one area where significant delays can be eliminated. Farleigh Mill installed an underpass under the QR North Coast Line near the mill, around 1975. This has eased delays where previously cane trains had only been able to enter the yard from that particular line when cleared to cross the QR track. Prosperine Mill is also undertaking a similar replacement project at the present time. The elimination of level crossings over roads can also make operating conditions more satisfactory. Some older branches are located such that crossings are not readily visible to oncoming cars. Speed restrictions and collision risk make road crossing removal worthwhile in some cases. Prosperine Mill realigned some of its track in the tourist area near Shute Harbour to eliminate a number of level crossings . In this busy area, many drivers were tourists, not used to looking for tram crossings!
Great improvements to the tramway systems are possible where the engineering standards permit new loco and rolling stock technology to be employed.
While recent developments have taken sugar tramway technology and operations to a highly developed state, milling and administration have not been far behind. In all of these phases in the process of getting the stick of cane on the farm to the sugar crystal on your table, one common feature of recent years has been the use of computers to increase the efficiency of the process.Tramways have been no exception to this and have used them in exciting ways. The future however holds more in store. The old style steam driveror tramway manager will not recognise some features of operations in the future.
Computers were introduced at a number of mills from the late 1960s. Early uses tended to be for accounting and record keeping, but it was soon seen that the computer could make an important contribution to the control of the milling and transport processes. Fairymead Mill used its IBM System7 wagon recording at the weighbridge and tipper. Mossman and Mourilyan Mills also were early users of computers. The data entered is used for preparing accounts and statistics on the cane, and with other information entered into the computer, e.g. juice strength, trash rates etc., can be linked to further stages of milling ensuring better technical control over the process because of the additional information.
Other uses of the computer touch more directly on the operation of the tramway. Daily scheduling of the tasks of the transport system can be done with an appropriate computer program. The day's operations must be done in such a way that sufficient empty wagons are available for harvesters, sufficient full wagons are available at the mill at all times for the crushing schedule to be met and the minimum amount of deterioration of the cane is permitted. The latter is important as the farmer gets paid on the sugar content of his cane when crushed. All this must be done in the knowledge of loco maintenance needs, staff shifts permitted and feasible loco runs. The question of minimum-cost transport and greatest efficiency is at the core of this technique. Tully Mill adopted this technique in 1968 to minimise the cane spoilage problem. Strict control of harvesting time and coordinated transport have significantly improved the position.
The use of day-to-day planning techniques like loco scheduling can be regarded as tactical planning. There also exists scope to use computers for what can be regarded as strategic planning. The Sugar Research Institute is one body which uses the technique of transport system modelling to investigate long term planning problems of mill transport systems. The sort of question which is looked at here may be; 'Should my mill introduce more powerful locos?', 'Should we reduce the maximum grade on our lines?', 'Should we abandon any branches and replace with road haul?' or 'What is the optimum number of locos and bins for our mill's needs?'. This is done by running a mathematical model describing the structure and operations of the system, for a large number of situations and assessing the results. The interpretation of the results is a skilled and complex task. Such things as balancing the interests of the miller and the farmers, or choosing between options where one has lower costs but higher risk of failure against another with higher costs but lower risk of failure, call for the wisdom of Solomon! While such a procedure has its drawbacks, these computer simulation techniques are useful tools for comparing alternatives open to a mill to overcome a problem related to its transport system.
New applications for the computer are being developed. New instruments and techniques enable better monitoring and control of the sugar making processes. For the tramway, two possibilities stand out. The first is automatic truck recognition. Here the serial number of the truck is read as it passes to the tipper, by a sensor. Electric-eye types are used in other industries and the SRI has experimented with eddy current effect sensors. These read a coded number set in a sequence of metal tags on the underside of the wagon. For containers, they are set into the top. This eliminates the chance of error when a human operator enters the numbers manually. The second is the development of 'train describer' systems which enable the computer to monitor the status and location of all trains on the system at all times. Mill management will receive automatic prediction of arrivals, shortfalls and bottlenecks. It can also be programmed to perform safeworking functions and even extended to automatic remote point setting and colour-light signalling.
The computer will bring a revolution to the canefields, both in the mill and on the tracks, as surely as did the diesel loco and the chopper harvester in the 1960s.