Municipal rotary mowing - A missed opportunity?

James Whittonin Machinery & Mechanics

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James Whitton has been in the groundcare industry for nearly forty years and has kindly offered to share his machinery experience with a series of articles. In this first one, he will explore the reasons why, unlike most other countries in the world, the UK has still not adopted rotary mowing as the predominant method of amenity grass cutting.


To provide a full picture on this subject, it's worth taking a look back to when rotary municipal mowing was first attempted in the UK municipal market and consider the issues and challenges encountered at the time. It's interesting to see how attitudes back then affected the widespread use of the rotary mower, and how thirty odd years on, the same challenges and issues still exist, preventing users from getting the very best from their rotary machines.

I have been in the groundcare machinery business since the late 1970s, and worked for a number of companies including dealers, UK distributors and manufacturers. I started out as a demonstrator for a well-known American brand and was focused entirely on developing sales of out-front rotary machines in the UK municipal market.

The UK has always been almost unique in municipal mowing world because the preferred mowing method has always been, and to a large extent still is, cylinder mowing. Maybe this is because the cylinder mower was born here, it's quite likely I would suggest. Back at the start of my career, large amenity areas and sports pitches were mown by tractor drawn, ground driven gang mowers carried on basic transport frames. Even Landrovers were used by some councils to pull the gang sets, taking advantage of the higher road speeds that a Landrover could offer compared with a typical tractor of the day. 40 or 50 kph tractor transmissions were not common then, so the use of a Landrover reduced transport times between sites significantly.

Roadside verges and housing estate areas were mostly mown by teams of operatives using 30" pedestrian cylinder mowers, or the earliest examples of the now well know "triple mower". The latter, incidentally more than 30 years later, is still one of the most cost effective ways to mow grass, if used correctly and in the right mowing application. Rotary mowing tended to be limited to the venerable Hayterette and the "old Smokey" Victa two stroke pedestrian rotary mowers, although some manufacturers of the larger 30" cylinder machines had alternative rotary heads available. It's probably also relevant that, in those days, councils were not under the same financial pressure that they are now and it was common for parks departments to have several spare triple mowers to cover for the inevitable break downs that occurred. Also, spare parts supply was not as urgent as it is now due to the availability of these spare machines.

So, set against the UK industry standard of cylinder mowing, American mower manufacturers were trying hard to establish and grow sales of their rotary machines. Bear in mind that, at the time, the American cylinders mowers were designed predominantly for golf course use and their out front rotary machines were already well developed for municipal mowing. The main selling points of the rotary machines were:

  • Lower maintenance costs
  • Easier to set up
  • More versatile and able to mow longer grass than a cylinder
  • Less prone to debris damage

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Naturally, the prospect of reducing mowing costs was a major attraction to many users, and there was a "Buzz" in the industry at the time that rotary mowing was going to take over as the predominant municipal mowing method. The UK cylinder mower manufacturers must have also been worried about this possibility because they took steps to make sure they also had a municipal out-front mower offering should the market swing to rotary as anticipated. To save the time and expense of developing a rotary machine range from scratch, they set about acquiring an American rotary mower manufacturer and offering them in the UK as a branded product.

So why did the widely expected "rotary revolution" not materialise?

Well, although a fair number of rotary machines were sold and some local authorities did change to a rotary mowing regime, it was not the landslide that was predicted. Some notable local councils that changed to rotary in the early 1980's still use a very successful rotary mowing regime today. The reason they were able to realise the advantages offered by the rotary machines, when many others failed, is that they were prepared to adapt their whole mowing regime to suit the rotary product.

Many traditional parks managers had grown up with cylinder mowing, and it was seen by them as the way to mow grass. Given that funds at the time weren't an issue and, labour was relatively cheap, grass could be cut every 5 -7 days, an ideal application for a cylinder mower. I recall on many rotary demonstrations at the time that the standard question from council officials was, "how low will it cut" or comments like, "it won't cut the heads off the daisies"! Faced with this mind-set, it was clear that these users were never going to successfully replace cylinder mowers with rotaries. And the old phrase "flogging a dead horse" sprang to mind.

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There were however, some genuine issues and concerns associated with the use of rotary machines in municipal applications. The most common of which was safety, and in particular the issue of thrown objects. Using rotary mowers on roadside verges and in public areas was seen by many council officials as far too dangerous. However, to put this into context, many American rotary machines imported into the UK at the time were still a "side discharge" configuration and inherently more dangerous than the later rear discharge designs with regard to thrown objects. There is no doubt that from a pure cutting performance and clipping dispersal perspective, the side discharge deck is far more efficient, but the thrown object risk was too much for some users to consider and they ruled out the purchase of such machines right there. It's difficult for me to argue this point because, during a demonstration of a rather large (90hp) multi-deck rotary machine in the early 90s, and with all the councils senior officials looking on, I carried out what I thought was a rather impressive sweep past them, only to find out at the end of the demo that a stone fired out from one of the wing decks had taken the rear window out of one of the attending operator's tractor cab. They didn't buy the machine, but on the upside a contractor who was also present at the demonstration did. Lesson learned though about staying a safe distance from bystanders!

The thrown object issue was a major problem but when this feedback, (now known as "voice of the Customer", VOC) it was met with considerable resistance from the U.S manufacturers, who could not understand the issue. Some eventually realised that if they were to sell their machines in the UK, they would have to offer rear discharge deck options. Other manufacturers refused to modify their decks for what was then seen as a small UK market, and the burden was then left to the importer or dealer to carry out the conversion of standard side discharge decks to rear discharge. The switch to rear discharge had its own design problems, the main one being that this type of deck required more power to drive it effectively. Some power units available at the time could only just manage the side discharge deck, and the switch to the rear discharge deck led to a need to increase engine size in the tractor unit.

So what you may ask is the relevance of all this? Well, fast forward if you will to 2009. Yes, the time of the dreaded financial crash. Now it became clear, at an early stage in this period of devastating local authority cutbacks, that cutting grass was not at the top of most council priority lists and I can say without fear of contradiction that this was one of the most difficult times in my career. Councils were in complete disarray; In my area, seven district councils were amalgamated into a new single authority. Quite understandably, long standing procurement contacts at these authorities, who didn't know if they would have a job at all, were suddenly less interested in talking about machine replacement. It would be a full two years in some cases before the situation had settled down.

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It is during this period that a full scale swing to rotary mowing could have been successful, but this is where the opportunity was missed. Never before, and probably never again, would the general public and taxpayers be as receptive to the lowering of amenity mowing standards, and it has to be said that even the very latest state of the art rotary mowers don't have the quality of cut that a well set up cylinder mower has. It was the ideal time to change.

They say that 'a little knowledge is dangerous' and, in the context of this mowing subject, I would say that 'a little knowledge is EXPENSIVE'. Council management took a severe hit during this difficult time and, in many cases, council departments were amalgamated in an effort to save money. Whether it even actually did is a whole different subject.

The classic combination seemed to be joining refuse collection with grounds maintenance. In many cases, managers of these new combined departments found themselves in charge of operations in which, through no fault of their own, they had insufficient knowledge or experience. This did cause some major problems and contributed to why the rotary revolution yet again had a false start.

I can relate to a real example of this very issue, but obviously with no names or locations. A council found itself with a new manager in charge of grounds maintenance. The manager was originally from the environmental department. The council's fleet of almost 20 triple mowers was past due for replacement, having been in service now for 7 years. Funds were obviously tight, so every effort to cut costs was being explored. The new manager had "heard" that rotary mowers were cheaper to buy and run. Because of the vast difference in cost of a standard 1.5m out-front rotary mower versus a 2.1m triple mower, the tender was duly issued and the deal done on the cheapest out-front mower. Initially, this seemed a good deal from the council's perspective, saving a six figure sum on the procurement of the machines. This however, is a classic illustration of what I am trying to explain. Right from the off, and compounded by one of the most vigorous growth seasons I have ever experienced, it all went "pear shaped" for the council.

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Mistake 1:

The council replaced the existing triple mowers, one for one, with the new 1.5m rotary machines. Even in the best case scenario, this was never going to work. A simple calculation of mowing speed x width of cut would have shown a dramatic shortfall in potential productivity. This mistake was to have severe financial consequences for the council later in this episode, which probably cancelled out the original saving on the purchase of the equipment. To cut a long story short, the mowing fell further and further behind and quickly spiralled out of control. The after cut appearance of areas was appalling and was more like a windrowed hay field than an amenity grass area. Huge amounts of clippings were left, which only compounded the problem when the areas were mown on the next cycle. It didn't end there either. The machines were taking a beating and downtime was considerable as a result. This reduced the productivity even further. Eventually, in desperation, more machines had to be hired in to get back on top of the mowing. In the meantime, this was a massive issue, with many public complaints, which also caught the attention of local press and television. It should also be noted that, because of the beating endured by these machines, they were on their knees by the end of their second year in service.

Mistake 2:

Now I believe that this mistake is the core reason why the rotary revolution stalled. The council failed to adapt their basic mowing regime to match the rotary mower, and by this I mean, in its simplest terms, setting the contract specification for height of cut (HOC) higher than had been the norm for cylinder mowing and sticking to it. This mistake is widespread and is still being made today.

Municipal rotary mowing in most other countries in the world works successfully mainly because the minimum HOC specification adopted is around 60-75mm. Yes, the conditions may be drier and the grass type easier to cut, but selecting the appropriate HOC is still key to why the rotaries are the predominant mowing method for amenity grass areas around the world. The UK insistence, to mow as low as possible, has to change if users are truly going to realise the benefits of rotary mowing. This fixation with scalping the grass is not just about rotary mowing though. For my entire career, too many users have insisted on setting cylinder mower HOC as low as possible. Don't get me wrong, from a suppliers point of view it's great for spare parts business due to unnecessary wear of bedknives and cylinders, but from a customer's standpoint, it's wasting huge amounts of money. This is squarely a management problem, and I entirely agree with my good friend and esteemed ex colleague, Nigel Church, when in his recent Pitchcare article he points out that managers need training as well as operators. There is no point setting HOC specifications if this is not robustly managed by the supervisory staff.

So why, given the importance of selecting the correct HOC, don't manufacturers design the machines so that the HOC can't be set too low? It's a very good question and one that has been raised numerous times. The straight answer is a commercial one. The professional mower industry is no different to most other industries. It's hugely competitive. Manufacturers are always seeking to get the jump on the competition in an effort to increase market share. Competitor machine specifications are monitored closely to ensure products at least match or surpass them. The majority of municipal machine purchases are procured by a tender process. If your machine does not meet the tender specification, it is excluded from the process. It's a simple as that. One classic specification found on many tenders is the machine's HOC range. I found out the importance of this the hard way, when a tender for 20 triples was lost on a difference in HOC range of just 0.7mm! Yes, I agree, a completely irrelevant dimension with regard to municipal mowing, but nevertheless it was specified in the tender, so we were out.

So what can we learn from all this and how can users realise the best performance from a rotary mowing regime. Here are some pointers:

Management

  • You need to be prepared to change some fundamental basics in your overall mowing regime. This is absolutely the key to success. If this is not possible, don't go down the rotary route. Remember, raising the contract height of cut is the most important change to make. If you are unsure about this, experiment on some areas and monitor the results. It is most important to manage the operators robustly to ensure that the new, higher HOC is maintained. If this proves to be a problem, fix the machines minimum HOC so that operators can't change it.
  • Look at the areas to be cut and look for the most appropriate machine for the job. There is no point having a 1.5m rotary machine spending all day mowing a large amenity park area. Equally, it's not cost effective to have a large multi-deck rotary mowing verge areas where only one deck can be used.
  • Take a close look at the comparative productivity rates of the cylinder and rotary machines. Be aware that productivity rates listed in manufacturer's specification sheets are mostly theoretical and although they mostly allow for overlap and turning they assume ideal conditions. Use a properly planned demonstration with clear objectives to test the machines suitability for your application.
  • Be aware that if you are replacing triple cylinder mowers with 1.5m out-front rotary machines, and you intend to mow the same area of grass, you are going to need more rotary machines than triples. This needs to be part of the budgetary calculation regarding mowing cost per/sqm.
  • Don't forget to factor in the higher fuel consumption of the rotary mower in projected operating costs. There is no point asking manufacturers for fuel consumption data, because there is no industry benchmark for the testing procedure, so the numbers can't really be compared from one manufacturer to another. This needs to be tested as part of the demonstration plan.
  • If you decide to take the plunge into rotary usage, but are not totally convinced, try one or two machines first and evaluate their performance over a complete season against carefully planned objectives.

Maintenance and operation

  • Don't assume that the lower maintenance requirement of the rotary mower means no maintenance at all. Blades on rotary machines rely on their cutting edge to mow and the speed at which this cutting edge is moving. The practical advice would be to have complete spare blade sets for each machine which can be swapped in a few minutes whilst the original blades are sharpened and balanced in the workshop. As a guide, this needs to be done weekly or every two weeks depending on blade wear. The higher productivity rate, lower fuel consumption and quality of cut will offset the lost time spent changing the blades.
  • Setting the cutting deck correctly is vital if the transition from cylinder to rotary is to be successful. If you only had to remember one paragraph from the article, this would be the one! The importance of using a higher HOC setting than cylinder has already been covered. However, it's not just the overall HOC setting that is vital. The cutting deck "attitude" or angle to the grounds has a huge effect on the machines performance. In simple terms, the cutting deck must be angled down at the front, approximately 3 degrees from horizontal. The importance of this can't be emphasised enough. Luckily, manufacturers build in this attitude angle to the design so that the operator just sets the deck HOC adjustment to the decal on the machine or to the diagram in the operator's manual and the angle is automatically set. Most rotary decks will have four HOC adjuster positions to ensure that both the HOC and the deck attitude angle are correct. To illustrate the importance of this setting, I was asked to visit a customer who had ventured into rotary mowing for the first time and was very disappointed with the multi-deck machines productivity and performance. The machine was reported to be constantly overheating and the operator reported that the machine would not operate a full day on a tank of fuel and that the deck kept stalling and blocking. These machines were on the verge of being rejected. The root cause of the issue was trying to cut too low and, more importantly, the cutting deck attitude was set incorrectly, and in fact was set tail down. These two basic settings were adjusted correctly and the machine issues solved. So, this is down to correct operator training and, indeed, supervisor training as well.

Summary

In summary then, modern rotary mowers do offer a real cost effective alternative to the traditional cylinder municipal mowing. They can be most effective when mowing cycles have to be extended for cost saving reasons. However, to realise the benefits of rotary mowing, it's not just as simple as changing the machine, because to do just that in isolation is almost always going to fail. The washed out cost to mow each square metre of grass, taking into account purchase price, depreciation, fuel, operator costs and maintenance, will be higher using a rotary mower unless the mowing regime is adapted to suit the machine as well.

I hope the article has offered some useful tips and advice on how to realise the advantages that rotary mowing can undoubtedly offer!

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About the author

James Whitton (probably best known in the trade as Jim), originally started out as a time served agricultural engineer. He completed an apprenticeship with a local agricultural machinery dealer in the north east of England, Farmway Limited, in the early 1970s servicing and repairing a number of well-known brands including David Brown and Same tractors as well as a wide range of agricultural equipment from manufacturers such as Claas,

Vicon, Bamfords, Grimme and BM Volvo to name just a few. This was the best apprenticeship anyone could hope to have and it was very enjoyable. During this time, Jim studied at Askham Bryan Agricultural College and achieved a number of City & Guilds qualifications in Agricultural Engineering.

In 1979, he joined the first full scale importer of Toro grounds maintenance machinery in the UK, Autoturfcare Limited, based in Darlington. His first job with Autoturfcare was Consumer Technical Officer, which involved processing warranty claims from UK Toro garden product dealers as well as dealer service training. He then moved to a role of Field Technician after a few months where his prime role was to carry out sales demonstrations to local authorities and golf courses all over the UK and Ireland.

He has been in the groundcare industry ever since in various roles for some of the major brands. During a spell of self-employment in the early 90s, he worked freelance as a mobile groundcare machinery technician and, during this time, also worked as a contract trainer for Askham Bryan College, East Durham and Houghall College and was also an ATB registered instructor.

With this wide range of knowledge and experience in the trade, and currently between jobs, we are delighted he has chosen to share his wisdom and technical knowledge with readers.