History of the drum irrigation machine
In the following lines, the history of the irrigation machine is outlined for the interested reader, and we hope you enjoy reading it.
Since the earliest days of field irrigation in 19th century England, hose lines have been a central component of irrigation systems. In almost all phases of the evolution of irrigation technology, inventors and users have been happy to use flexible lines, as the latter enable largely continuous irrigation at constantly changing locations without interrupting the water supply. The flexible lines, which are rather inconspicuous in technological terms but extremely important in conceptual terms, were to play this key role in the era of automated field irrigation that began after the Second World War. From 1960 onwards, the conditions for profitable agricultural production changed noticeably in all major industrial nations, as energy prices gradually rose and more and more workers migrated to other, higher-paying jobs. Like agricultural technology as a whole, irrigation technology also responded to such developments with appropriately tailored innovations. One approach was to reduce or even completely eliminate the unavoidable interruptions in the water supply at the interface between the water supply line and water distribution (hydrant) when advancing the irrigation equipment. In doing so, the application-related concept of the flexible line was also remembered.
In comparison to solutions that provide a rigid connection of the water distribution system component by means of a pipe directly to the hydrant, a flexible connection to the feed line basically allows the irrigation device to be fed forward continuously. The latter makes the high workload usually associated with agricultural irrigation easier and significantly reduces it. In addition, it also has significant advantages in terms of irrigation technology, which are noticeable in a more even water distribution in the field, among other things. Above all, however, this type of water transfer from the feed line to the mobile system part defines the level of automation of the entire system - and is thus the bottleneck of any mechanization and automation in field irrigation! This is particularly true for the irrigation technology that is by far the most common in Europe - the drum irrigation machine.
A drum irrigation machine is generally a mobile device for field irrigation which, during the irrigation process, continuously and fully automatically advances a large sprinkler or double-beam sprinkler on a flexible line over a distance corresponding to the length of the line across the feed line at the edge of the field, while at the same time automatically winding the flexible line onto a drum. The automation of the sprinkler advance is not based on a direct, active drive of the water distribution device itself, but rather the mechanized work processes which automate the transfer of the large-volume flexible line into a state ready for transport are used for a passive advance of the sprinkler which is in continuous operation.
From a technological point of view, this requires a drum and a special water guide in the device itself, which ensures a permanently tight transfer of water through the moving drum axis, as well as a flexible, windable line and a drum drive integrated into the device, which usually does not require its own power engine by covering its energy requirements from the water flow supplied under high pressure. Another important feature of drum irrigation machines is the mobility of the entire technological unit, so that several areas, possibly far apart, can be irrigated one after the other.
After the Second World War, it was the chemical industry that provided the impetus to intensively deal with this mechanized handling of large flexible pipes in field irrigation, because polyethylene (PE) had been discovered - a raw material from which flexible pipes with extremely resistant, stable walls can be made, whose flow cross-section, in contrast to hose pipes, is largely retained even without water filling, internal pressure and wire reinforcement. This property ultimately led to the new technical term "windable pipes" being derived, which prompted many to now also speak of pipe reel irrigation machines in order to emphasize the most important difference to the hose reel irrigation machines already known.
One of the most interesting areas of application for PE pipes is in water supply, as the non-toxic, almost inert material is an ideal material for drinking water pipes. For this purpose, long lengths of pipe are extruded from the melted raw material granulate and wound onto drums during the production process, so that after stripping, so-called "ring bundles" with up to 1000 m of pipe are created. This type of production and assembly initially met the efforts to reduce costs and make work easier in pipeline construction, as the PE pipe could be laid quickly without time-consuming alignment and coupling. The pipes were often unrolled directly above or next to the route using simple wooden or metal reels mounted on chassis. Unique material properties and the significantly reduced installation effort immediately made the PE pipe a very attractive product for the entire water industry, and by the end of 1956 over 30,000 km had already been laid across Europe.
Agriculture also soon became the focus of the industry, as marketing was already supported by advertising material at the beginning of the 1950s, which outlined other applications for PE pipes in addition to fixed underground installations, with the initial idea being seasonal above-ground water pipes on farms, pastures and campsites. This gave rise to the idea of laying a PE pipe only temporarily so that it could be used again at any time if required. In this context, the question arose as to how a previously laid PE pipe should be retrieved. Mobile pipe reels already existed for storing, transporting and laying out the wound PE pipe, but these would have required the PE pipe to be wound up by hand - admittedly an extremely laborious undertaking. Thus, the seasonal use of PE pipes propagated by the industry probably only existed on paper at least until 1955, because it is only documented in schematic form in old brochures, but not photographically.
After the Second World War, the engineer Josef Brand from Duisburg had set up a mining supply company whose product range also included PVC and PE pipes required for mine shafts. Brand initially obtained the latter from the Dutch company Draka, so that between 1948 and 1953 he must have received brochures in which the PE pipe was not only advertised as a drinking water pipe, but also in which the above-mentioned new application examples and forms of use of the coilable PE pipe were shown. Brand had recognized early on the special importance of plastic pipes for agriculture and as early as 1953 was considering bringing the PVC and PE pipes he offered to the mining industry closer to an agricultural customer base. To do this, he acquired a shell company called "Schlehbusch" in the structurally weak Westerwald region and founded his new company under it. After the engineer Ortwien Konegen joined the company a year later, the company began to focus on field irrigation for the first time and to sell quick-coupling pipes made of domestic PVC, which became known as the "System Zimmer" and had a firm place in German field irrigation until the end of the 1950s.
In order to become more independent from suppliers, Brand founded a second company in 1956 - also in the Westerwald - called "Kunststoffwerke Höhn", which began manufacturing PE pipes in 1957. The latter were introduced to the market under the name "Brandalen", and thanks to the strong demand for drinking water pipes from the water industry, production increased steadily from year to year. Despite this great commercial success, Brand and Konegen did not slacken in their efforts to introduce PE pipes into field irrigation practice via the Schlehbusch company, and as early as 1957, German agriculture began to use PE pipes - initially only sporadically - as simple feeders in row irrigation systems. For these applications, in which temporary laying of the PE pipe was common and thus mechanized handling of the flexible pipe was desirable, Brand's company "Schlehbusch" built a simple mobile reel in 1957 (Figure 1) which - pulled by a tractor - was moved over the laid out PE pipe towards the end of the pipe and picked up the pipe automatically and without pulling according to the distance covered. If you look closely, you can clearly see the reel drive via V-belts on both sides from the front axle. In order for the PE pipe to be wound onto the reel in even layers, the tractor driver had to operate a pipe guide fork while driving, which he had to swing back and forth slowly across the entire width of the reel.
Figure 1: Simple pipe reel car from Schlehbusch around 1957 as the first precursor to the pipe reel irrigation machine (Photo: Schlehbusch)
Even if there were only a few prototypes, this inconspicuous arrangement of coilable pipe and simple pipe reel carriage represents the first precursor to the pipe drum irrigation machine, because it is the earliest evidence of an actual, targeted, location-independent use of the PE pipe, which had previously only been laid in one place, and which for the first time fully brought the concept of the "coilable pipe" to full effect! The idea for this most likely came from the Dutch company Draka and was delivered to the Schlehbusch company "free of charge" with their early brochures; but Brand and Konegen deserve credit for having successfully introduced this concept into field irrigation practice.
However, given the modest diameter of the early PE pipes, manufacturers and customers alike had legitimate doubts as to whether PE pipes could ever replace traditional steel quick-connect pipes as temporary supply pipes, as field irrigation usually involves high flow rates. This assessment did not change even when PE pipes with nominal diameters of up to 110 mm came onto the market in the late 1950s. Therefore, around 1959, German irrigation companies adopted a new concept for integrating PE pipes, which was developed in southern France in 1957 and was much more in line with the field irrigation practice of the time: PE pipes in sizes 50-84 mm were ideal as sprinkler lines for the row irrigation that was widespread at the time due to their low weight, so that quick-coupling pipes made of PE were developed, which were cut to lengths of up to 18 m and thus made both the laying and the advancement of sprinkler lines noticeably easier. Otherwise, however, their handling was no different from that of the quick-coupling pipes made of steel, so that the conversion of the sprinkler lines still took a lot of time despite the weight reduction.
Even before the extremely dry summer of 1959 caused demand for irrigation equipment to rise dramatically, the engineers at Schlehbusch had combined their early pipe reel with this new form of row irrigation in a logical continuation of the "windable pipe" concept by fitting a whole PE pipe bundle with slim, pivoting branch sleeves at regular intervals, to which small sprinklers were connected directly or via hose lines after the PE pipe had been laid out. This new type of solid sprinkler line was handled with the above-mentioned pipe reel (Figure 1) in the manner described above, because the PE pipe remained windable despite the branch sleeves. This meant that from now on there was no longer any need to manually load sprinkler lines!
In 1960, a generational change took place at Schlehbusch, with the engineers Brand Jr. and Konegen providing new impetus for field irrigation. In view of the increasingly vehement demand from practitioners for further work relief, Brand Jr. developed new sprinkler stands for Schlehbusch's mechanized row irrigation system in 1962 and equipped the old pipe reel cart with a cardan shaft drive and an automatic pipe guide so that the previously laid out PE pipe and sprinklers could be pulled out of the field (!) with the reel after the irrigation process had ended (Figure 2). The sprinklers, which had to be uncoupled during the retraction process, were stored directly on the base unit. This conversion to a direct mechanical drive made the pipe reel cart a mobile pipe reel device from then on.
Figure 2: Mobile pipe reel device from Schlehbusch with cardan shaft drive for row irrigation around 1962 as the second precursor to the pipe reel irrigation machine (Source: Schlehbusch)
Brand submitted the technological concept of the mobile pipe reel device for patenting in 1964, but was only granted limited utility model protection. With its unique transport aid for flexible sprinkler lines, however, the Schlehbusch company had shown a way that was immediately adopted by both field irrigation practitioners and competitors, which significantly increased the popularity of row irrigation at that time.
The enthusiasm for innovation in those years finally led Schlehbusch's engineers onto a path that brought them the most decisive step closer to the pipe drum irrigation machine. In 1966, several farmers in the Lüneburg Heath founded the Tetendorf Irrigation Association with the aim of irrigating the manure and wastewater that accrued on their farms in order to increase soil fertility. This had previously been an extremely unpleasant undertaking with the sprinkler pipes that had to be moved manually, because the regular changing of the position of pipes and sprinklers was less of a burden due to the weight of the material or bad weather than to the unhygienic working conditions.
Therefore, in the same year, the Schlehbusch company began to further develop its mechanized row irrigation process using the mobile pipe reel device: instead of fitting the PE pipe with sprinkler connections at regular intervals, it was now left - as it came from production - in a pipe bundle that was completely wound onto the reel. A large sprinkler on a sliding tripod was coupled to the end of the PE pipe. Equipped with a flexible nozzle, this sprinkler sprinkled up to 30 m³ of liquid manure per hour and worked in sector mode for hygiene reasons (Figure 3). Since wastewater irrigation only requires small amounts of precipitation of 3-5 mm per pass, the large sprinkler could be quickly and continuously pulled towards the base unit during the irrigation process on the PE pipe using the tried and tested universal joint drive. This combination of water application and simultaneous winding process turned the mobile pipe reel device, which until then had only supported the handling of the PE pipe in terms of transport, into a technology that also had a direct influence on the irrigation process.
Figure 3: Pipe drum irrigation device from Schlehbusch with large sprinkler and cardan shaft drive for wastewater irrigation around 1966 as the third precursor to the pipe drum irrigation machine (Photo: Schlehbusch)
The first demonstration of this pipe drum irrigation device in February 1967 in Tetendorf by engineers from Schlehbusch was also the premiere of pipe drum irrigation machine technology in field irrigation practice! Brands and Konegen's latest product largely corresponded in its basic features to what is understood today as a pipe drum irrigation machine. The following characteristic features are worth mentioning:
automatic continuous advance of a single sprinkler
simultaneous mechanized winding of a windable pipe
full mobility of the entire technological unit
Only the drum drive was not integrated into the device and was still operated by a tractor via a cardan shaft; therefore, this irrigation technology is not yet considered a self-sufficient machine in the strict sense, but forms the third, final precursor to the tube drum irrigation machine.
As the summer of 1967 approached, the Schlehbusch company closed the last gap that had existed up to that point in terms of the basic technological concept of the pipe drum irrigation machine by introducing the tractor-independent, automatic drive of the drum, which at the same time also automated the retraction of the large sprinkler. For this purpose, a small 24-volt DC motor was placed directly on the gear box, which was powered by two 12-volt batteries integrated in the basic device. This relatively simple upgrade made the mobile pipe drum device a real, self-sufficient machine from now on, both in terms of handling the PE pipe and in terms of the irrigation process - the pipe drum irrigation machine in the truest sense of the word (Figure 4).
Figure 4: First real pipe drum irrigation machine from Schlehbusch with large sprinkler and integrated electric drum drive for field irrigation around 1967 (Photo: Schlehbusch)
In view of the large amounts of precipitation that are common in field irrigation, which are 5-10 times higher than in wastewater irrigation, a redesign of the drum drive had now become absolutely necessary, since in order to apply such high amounts of water - assuming the same inflow rates - it was necessary to work with correspondingly lower retraction speeds. To do this, however, the drum did not move the large sprinkler slowly and continuously, but rather quickly and discontinuously in steps of 12.5 m towards the base unit, because the designers had left the gear reduction unchanged. In emergencies and for maintenance work, however, it was possible to wind up the PE pipe again using a cardan shaft - an important detail that can still be found on pipe drum irrigation machines today. In order to achieve greater stability when pulling out the PE pipe and during irrigation, the machine was already equipped with additional support struts. This famous model series from Schlehbusch became known under the name "Program 2000" - easily recognizable by the control box attached to the side, in which the desired rainfall level could be regulated by changing the duration of the large sprinkler, ie by varying the frequency at which the electric motor was switched on.
With this first real pipe-drum irrigation machine, the Schlehbusch company had made a partially automatic large sprinkler system available for field irrigation, which marked the end point of a very special development direction in irrigation technology. Because of the now automated and trouble-free handling of a large-dimensioned flexible pipe, the evolution of partially automatic individual sprinkler systems in agriculture reached an irrigation technology level that could not be further increased. The Schlehbusch company deserves credit for having implemented the technological concept of the pipe-drum irrigation machine, particularly as a result of the integration of the new PE pipe for field irrigation, and for having single-handedly advanced it to practical maturity! In addition to the Brand family, the chief engineer Ortwien Konegen was significantly involved in this development within the Schlehbusch company - a dazzling personality who was to continue to surprise people in irrigation technology for another 20 years.
From then on, interest in the tubular drum irrigation machine technology increased significantly in specialist circles, and even those who had not previously been involved in the development now contributed suggestions for improvements in order to perfect the new product. Despite the obvious shortcomings of the electric drum drive, such as insufficient battery capacity, motor short circuits and fires in the control box, the Schlehbusch company left its "Program 2000" model unchanged for a surprisingly long time; there were also no discernible efforts to convert the machine to a continuous large sprinkler feed, which was already common at the time. So other developers and designers gradually moved into this technological and irrigation vacuum - including the HÜDIG company.
Like the Tetendorf Irrigation Association, the Braunschweig Wastewater Association wanted to make the irrigation of treated wastewater, which had been practiced there for a long time, less labor-intensive and more user-friendly at the beginning of the 1970s. At that time, large industrial companies in the region had created many new and well-paid jobs, which also had a great appeal for the staff of the wastewater association. This made it increasingly difficult to maintain the year-in, year-out irrigation of wastewater without disruption using the labor-intensive irrigation methods that had been common up to that point. In this particular case, the rather unhygienic working conditions of the wastewater irrigation did not exactly encourage long-term employment; even wage incentives and other benefits could not change this. As has so often been the case in agricultural irrigation, the decisive impulse for innovation once again came from the field of wastewater irrigation, whose special technical but also social conditions made an improvement in work economy unavoidable.
With this in mind, the Braunschweig Wastewater Association approached four German manufacturers of irrigation systems in 1972 - including the HÜDIG company - and asked for appropriate proposals. It quickly became clear to all those involved that only a specially designed pipe drum irrigation machine would meet the high expectations. While the Schlehbusch, Wollny and Perrot companies already had a wealth of experience in pipe drum irrigation machine technology, the HÜDIG company was now breaking new ground in irrigation technology. To finance their research and development work, however, each of the four companies included in the tender received an equal amount of funding, with the help of which the individual companies were able to develop their own pipe drum irrigation machines to series production within a very short period of time. Perrot's special technological concept of the axially movable drum carriage was ultimately able to convince the client due to its solid design and therefore well suited for continuous use, so that in 1973 the Braunschweig Wastewater Association awarded Perrot the contract to supply a considerable number of pipe drum irrigation machines.
But the development work promoted as part of the tender also bore fruit for the other companies, because the generally positive economic situation in agriculture in those years led to an extraordinarily high willingness on the part of the farms to invest in view of the growing shortage of skilled workers. After the Braunschweig Wastewater Association had shown how labor-saving irrigation technology advances could be used profitably on a larger scale, the true value of tube drum irrigation machine technology was finally recognized in German field irrigation, the advantages of which have since been demonstrated at numerous demonstrations at home and abroad. Even foreign manufacturers were now pushing their way onto the German market, after the first French products had already been admired at the DLG exhibition in Hanover in 1972.
The technological development of the pipe drum irrigation machine can therefore be considered complete by 1976 at the latest. In the course of a "boom" that spread across Europe, an almost incalculable variety of different models and series emerged, but this did not lead to any significant, fundamental innovations. Instead, improvements in detail followed, which mainly affected the handling of the machine and water and energy savings. This constant optimization of the pipe drum irrigation machine continues to this day and is mainly supported by solid companies in the industry with a broad range of technologies, whose diversification in the water sector makes them relatively insensitive to the adversities of a still highly volatile market.
Author: Dr. agr. Rolf Hübener, PO Box 1229, D - 31520 Neustadt/Rbge.