June – July
A different tact for the revolution this time around, rather than focus on the technical side of things we are going to take a look at some of the challenges facing the machine control revolution from a more market driven perspective. To do this we are going to focus on the excavator market, a market which surely represents the biggest opportunity for both users and suppliers of machine control.
Are excavators the forgotten machine?
The prevalence of machine control is increasing of that there is no question, the market is growing and genuine interest in the technology is broadening, tenders are even calling for the use of the technology more frequently which is all good news for those of us with an interest in the technology. This being said no matter how many dozers, graders and scrapers use the technology only a fraction of the total potential market can ever be realised, the reason for this – the largest group of machines that can benefit from machine control could be excluded, that group is the humble excavator, the work horse of the construction site.
The excavator is without doubt the staple of the job site their sheers numbers dwarf all other machine types combined and whilst it is not uncommon to see sites without dozers and graders working it is almost inconceivable that the excavator will be absent. Beyond their sheer numbers there are other factors to consider when it comes to machine control; variety and size of machine for example, excavators range in size from less than a ton to many hundreds of tons, within that size range there are machines with multiple articulations, offset booms, zero tail swing, wheeled and tracked, machines specially adapted to work on rails and any other number of other variants. The capability of the excavator is further enhanced by the huge numbers of attachments that are available, ditching buckets, rippers, grabs, tilting buckets, rotating tilt buckets, hammers, even blades and the list goes on. The permutations are endless and with all this available is there any machine on any site that can perform as many tasks as the excavator, lifting, digging, grading, armour rock placement? All are well within its capabilities, in short the excavator can do a whole lot more than just excavate.
Given all these factors surely excavators represent the natural choice for machine control and indeed in some geographical markets machine control installations on excavators have become commonplace. Scandinavia is the main case in point where machine control system sales per machine far exceed what is achieved in other markets, accepted the Scandinavia construction industry has certain nuances that make it a fertile ground for developing sales of these type of systems, in particular the owner operator culture and the way in which jobs are bid, but outside of this region and other than in specialist applications such as dredging most people consider the implementation of machine control as a costly unnecessary exercise. All this said there have been some encouraging signs that all this is about to change, manufacturers of the technology are focussing more resources on both the development and marketing of their products and a recent survey in an industry publication indicated there may be a greater will on the part of the customer base to look more seriously at the benefits of the technology on excavators.
The challenges ahead
Despite the positive signs the path to the ready acceptance of machine control on excavators will not be an easy one, and it is some of the machines very strengths that will act against it. In reality the excavator cannot compete with a finely tuned grader when it comes to accuracy nor is it the bulk earthmoving machine of similar size dozers and scrapers, the jack of all trades and master of none is a phrase that is wholly appropriate for the excavator. Suppliers of machine control systems are asking customers to invest significant sums of money in a piece of equipment they would normally spend on enhancing one of their thoroughbreds, only now we’re asking them to spend that money on a pack horse. A closer look at the challenges facing the development of the excavator machine market reveals some answers that already exist and other challenges that require the industry to perhaps look at some alternative tactics.
Versatility and number of machines– We have already established that excavators do far more than “what it says on the tin” which is fantastic in terms of overall machine utilisation however if the machine is being used for things other than grading or excavating it means that machine control is not being used, why spend money on something you don’t use? Now combine this perceived under utilisation with the fact the most contractors will have far more excavators than any other type of equipment and that with most excavator systems currently available today we are talking about a one system per machine investment, the economics are not attractive. The answer to this particular problem may not be far away with the arrival of truly “portable” (wireless) systems such as our very own DigPilot which mean that one system can cover a number of machines with little fuss. The arrival of this new technology will certainly help the cause.
Now that we have solution for one of the headline problems let’s take a look at some more practical specifics related to the excavators versatility. OK so the manufacturers’ of machine control systems have all realised that a contractor is going to want to use more than one bucket on his machine and ticked that box, but what about when he wants to add an extra articulation to the machine or use a different dipper – is it easy to upgrade the system and install a new sensor or move the existing installation to the new dipper do you need an engineer to do what should be a relatively simple task? Or what if he wants to use a hammer or ripper on the same machine – will the system still work after exposure to those kinds of rigours. All these things are well within the capability of his machine, but are they all things that are within the capability of his machine control system, or are they even things that parts of that system will survive. The truth of the matter is that the answer to all of the above is potentially yes, the extra articulation or equipment change is easily solved again by the wireless approach, likewise if the sensor is easy to remove you can solve the hammer/ripper issue The problem is whilst there are many readers that will know there are solutions to these minor issues but do contractors know this? Or more importantly do they know the shortcomings when they sign on the dotted line and ultimately to they just end up getting frustrated when one of the issues described up inevitably arises. A frustrated customer who thinks he may have been miss sold is not very far from a customer lost for good and not just to the company he perceives has done the miss selling but to the industry as a whole.
Another less than desirable practice is over specification, let us look at a 3D application using GPS on a dozer and a similar install on an excavator; more specifically let’s look at the GPS refresh rates. I have seen dozers with full hydraulic control in the field fitted where only a 5Hz GPS data refresh rate is being used, with such installation producing more of a sin wave than a straight line grade, 20Hz on such applications is a must, a similar installation on an excavator will work fine at 5Hz. The reality is that in the case of machine control and especially excavators the GPS is another sensor, and this is not to decry its importance but just to say that in this case it is less important than things like usability
The biggest challenge?
One of the other major problems with machine control on excavators is that contractors do not necessarily see the benefits when it come to general earthmoving applications, OK there are plenty of examples where a contractor can be digging along a harbour wall or placing armour rock and without machine control he would have to put a diver in the water at £800 per day to achieve the right result but on trenching or batters, possibly not. Yet those benefits are there to be had, I can illustrate this with a real (albeit extreme) example on a pipeline project in the UK, The total length of pipe to be laid was just over 185 miles and consisted of 48” welded steel pipe to be buried underground, the nominal cover to pipe required was specified to be 48 inches.
Because the contractors had no real means on managing the excavation depth accurately, in order to guarantee the nominal minimum cover they deliberately over excavated the trench to bury the pipe to greater depth than the specification called for.
A 475yard stretch was examined, at random, and only 45 yard of pipe was laid to the specified 48 inches depth. The other 430 yard was all buried too deep, on average by over 20 inches. It was calculated that an extra 395 cubic yards of material was removed from that 475 yard stretch alone, based only on the vertical slice directly above the pipe, and making no allowance for the extra material removed from the sides of the trench where the sides were battered back. This will equate to around 500 tons of material, plus the battered sides, over this single 475 yard stretch – a ton per meter of pipe length unnecessarily moved.
Of course costs don’t end there though; the pipe had to be laid in the trench on a bed of crushed limestone, and then backfilled with crushed limestone to a depth of 12inches above the pipe. The amount of additional crushed limestone required to fill the void space beneath the pipe where the trench was uneven will have been fairly substantial ( £18 -£24/ton).
Once the pipe was laid and backfilled with the limestone dust, the removed trench waste was crushed, put back into the trench and compacted. Any additional trench waste was removed from site and disposed of.
Looking briefly at a number of other records over open ground, around 65 – 70% of the pipe was buried to a greater depth than specified. The contractor doing the ground work in this example would not have lost out because of the way the market works on this funny old island but the client certainly would have, but what happens when on the next job the contractor bids against a competitor who has the technology to makes sure the same costly errors are not incurred. That is where we need to take this industry – when having machine control on the excavator is a competitive edge that the contractor can use as leverage. Only then will we see uptake rise significantly.
Conclusion
If machine control is too reach its true potential for both users and suppliers installations on excavators need to play a significant part, a wide variety of systems to meet the diverse uses of the excavator itself need to be available, contractors should be told the limitations of not just the system but the technology as well. Sell only what the contractor actually needs (trust me it works in the long term). I believe that things are slightly back to front, manufacturers currently slugging it out to get a big share of a small market, by following a sensible approach a huge market can be created from which a smaller share of that market becomes very attractive, this benefits the suppliers and more importantly the customer!