Whether we wanted them or not, the EPA emissions regulations, beginning with Tier 1 and now through Tier 4 and beyond, have dramatically revolutionized every aspect of the construction industry. The regulations that so profoundly cut the emissions coming from off-highway equipment will continue to inform and influence engine and equipment design for years to come. The good news is that construction equipment, just like automobiles, runs cleaner and more efficiently than it did in the past, although not all agree about the efficiency. But it took many years of hard work to get to this point and adjustments are still being made. Meanwhile, those benefits are questioned by many end users and the rental companies that provide them with the equipment.
To a considerable degree, engine makers and original equipment manufacturers were forced to reconsider almost every aspect of the machines they made in order to conform to emissions requirements. And even now, as probably less than a quarter of the machines currently on jobsites are using Tier 4 Final engines, already the process of tweaking and re-defining and perfecting is underway. And although there are no “Tier 5” regulations on the books, the possible next stage of regulations is already being looked at and will likely be similar to Europe’s incoming Stage 5, which would enable manufacturers to be more uniform in their manufacturing and not have to make as many different machines for different markets.
“It is true that EU Stage V will further tighten the particulate matter regulations and will likely require a DPF to meet them,” says Craig Timmerman, product marketing manager, engines and powertrain, John Deere Construction & Forestry.
“I anticipate that the EPA will harmonize with the EU standards at some point in the future,” predicts Todd Howe, manager global generator products for Doosan Portable Power.
For some rental companies, Tier 4 Final engines are a headache as their customers have yet to adapt to them, and they pay as much as 25 percent more for machines that don’t seem to offer obvious benefits at a time when rental rates are relatively stagnant. Sunstate Equipment senior vice president of operations Jeff Vance says that on smaller equipment such as generators and air compressors acquisition increases are closer to the 40-percent range.
Promises of enhanced fuel efficiency and extended service intervals are benefits that don’t seem obvious to many yet. While there are customers, especially on government jobs, who specifically request low-emission machines, there aren’t enough to satisfy most rental companies at this point in the adoption cycle. Still, standing back and looking at the entire picture, the development of Tier 4 engines is a remarkable achievement.
“I would applaud the engine companies,” says Brad Allen, vice president of marketing, PM and engineering at Genie. “The more we worked with our various engine partners, seeing the challenge that they faced having to re-do their engines, having to work very quickly re-doing their entire lines, we’ve been pleasantly surprised with what we’ve ended up with. That said, it feels a lot like where cars were in the late 70s and early 80s. They met the requirements, they worked, but what we’ve seen since then is the ability to perfect them. I think the challenge for the engine makers going forward will be to go back through and look at the electronic controls, the software and how it reacts to various environments and really perfect that.”
Re-thinking and re-engineering
It wasn’t just about putting on an after-treatment, or just about eliminating certain emissions. Engine manufacturers had to re-think the entire process, and OEMs had to redesign everything to fit with the engines. The Tier 4 Interim period allowed manufacturers time to adjust and make improvements.
“Basically Tier 4 has impacted every facet of the industry,” says Jennifer Stiansen, manager of marketing communications for JCB North America. “Not only did engines need to be re-engineered to meet advancing and more stringent EPA regulations, but they required manufacturers to redesign equipment to accommodate these engines to work efficiently with the new technology.”
“What we saw in the field is that with Tier 4 Final, some manufacturers strived to the simplicity of the system. They tried to lessen intervention in the equipment. They tried to eliminate the need for operators to manage regeneration, and the need to replace filters down the road and maintenance service intervals; they tried to go to technologies that would meet the emissions by actually involving the operator less -- fewer bells and whistles; fewer points of contact; fewer maintenance intervals. So with Tier 4 Final you see the delineation between two types of manufacturers, those that use the same exact components that they used at Tier 4 Interim, and just added additional components to them. On the other hand, Case and a few others looked at that solution again and said ‘How can we change this to manage Tier 4 Final emissions by actually taking what we learned and impacting the customer less.’ ”
Hence manufacturers like Case, Deere and JCB have managed to eliminate the need for diesel particulate filters. Some say that may not be possible in European Stage 5 regulations and possible future Tier 5 regulations in the United States.
Revving up research
Engine manufacturers have spent hundreds of millions or even billions of dollars in research and development to progress through the various stages to get to Tier 4. “As regards the Tier 4 Final products introduced in 2014, essentially all the calibration and fuel efficiency fine tuning was finalized during our extensive field test program and our experience so far is that there has been no significant requirement for calibration changes driven by in-service use,” says Kevan Browne, off-highway communications at Cummins Engines. “Our Tier 4 Final field test program was based on over 150,000 hours of use by operators working on commercial service with over 70 machines.”
Still Cummins does not take for granted that the machines cannot be improved upon.
“For each Tier 4 product entering the market, Cummins institutes an ‘infant care’ program for around the first 12 months of introduction, with a team specifically tasked to look for any instances to improve operational or service aspects, while the population is still at a relatively low volume,” Browne says.
Genie’s Allen says the problems caused by Tier 4 Final engines in aerial work platforms for the user, rental companies and manufacturers appear to be far fewer than anticipated. “After the initial period where everything was new, we are not seeing problems with the Tier 4 Final engines beyond what was expected of typical engines,” he says. “The issues we experienced with Genie aerials were around simple components, mostly mountings like brackets and plugs, and with support. The engine manufacturers took longer than anyone thought to get their field support up and running but we seem to be past that now. We have also seen that the issues in the field are driven by after-treatment. Those engines with the simplest systems that require the least interaction are the most reliable.”
“AMS-Merlo took the Tier 4 Interim requirements as an opportunity to renew and redesign our telehandlers,” said Fabio Garino of AMS-Merlo, Rock Hills, S.C. “We used the new engines to introduce our modular philosophy in the telehandler market. Thanks to the new modular re-design, we gave our customers many new innovations in our machines including Eco Power Drive technology to reduce fuel consumption, a new cab design to increase comfort and efficiency, easier accessibility to the engine components to reduce maintenance time, and new CAN-bus solution to manage the entire machine performance in a smarter way.”
Manufacturers such as Volvo, which has also made engines for cars and trucks, have benefited by that experience.
“Volvo Construction Equipment has clearly benefited from the proven engine technology developed earlier by the Volvo Trucks organization for its heavy-duty highway engines,” says Tim Hudspeth, technical support specialist manager. “The introduction of Tier 4 Final engines has been very smooth, confirmed by tens of thousands of cumulative hours on Volvo construction equipment operating in the field. For example, we have one articulated hauler customer running a fleet of 46 trucks 12 hours a day, six days a week, and he is extremely satisfied with the performance and the relative simplicity of the Tier 4 Final engine.
“That simplicity is a major differentiator between Tier 4 Interim and Tier 4 Final. The new engine technology incorporates fewer components in the emissions system, so there is less potential for service issues to occur and if they should, it is easier for a service technician to diagnose and repair.”
There are other challenges for manufacturers. “Tier 4 products represent still a small portion of the total global market for compressors and generators, yet they share very few components with lesser regulated products,” says Doosan’s Howe. “As a result it is difficult to achieve commonality between our U.S. product lines and our global product lines which do not yet need to meet Tier 4 standards. This results in increased complexity in our assembly operations and that challenges our lean manufacturing goals. As a result, our emphasis in the coming years will be to work on product designs that can meet the various emission regulations around the world while modernizing our packages with feature sets that meet the needs of the global market.”
Howe says Tier 4 technology has been challenging across the generator industry. “Typical generator applications often do not provide a consistent high load on the engine, and as a result, the after-treatment systems used on Tier 4 engines would operate at lower temperatures than they were designed for,” he says. “This initially leads to issues with DPF plugging which caused considerable downtime. However, as an industry we have worked with engine suppliers to improve engine performance in these applications, and we are providing customers with better guidance on how to correctly size generators to their applications to achieve better performance.”
Rental reaction
While some rental companies appreciate Tier 4 technology, others have found the going more difficult.
“The major issues are mostly maintenance-related when regeneration cycles or DEF levels are ignored,” says Bob Kendall, president of Star Rentals, Seattle. “The problem is getting customers up to speed on taking some ownership in these processes.”
Some rental companies aren’t seeing the improved performance manufacturers speak of. “I have not identified any improvements in performance,” says Bill Thompson of Thompson Pumps, which rents equipment as well as manufactures it. “Fuel consumption may be improved but only by a very small amount, if at all. That improvement is offset by the cost of the diesel exhaust fluid that is required by the selective catalyst reduction on some of the mid-range and larger engines. Maintaining the diesel particulate filters and the SCR devices have created new checklists and procedures that the field mechanics and machine operators have to follow. There is a learning curve associated with this.”
Thompson says he is optimistic that engine manufacturers will continue to develop and fine-tune their engines to meet the EPA’s requirements without “the burdensome, bulky and costly after-treatment devices that are currently employed.”
“It has caused more service calls for us,” says Mike O’Neal of Rental One, based in Colleyville, Texas. “There are still a lot of things to work out. Most Tier 4 engines are not as reliable as Tier 3. Any fuel consumption savings has been overshadowed by the high cost and poor performance.” O’Neal says with the current oversupply of equipment in the field creating more rate pressure, it’s even more difficult for rental companies to keep up with the increased costs of Tier 4 equipment.
“I have experience with just about every major construction equipment engine type and I have experience with all their previous tiers,” says Mitch Garfinkel, director of sales, Able Equipment Rental, Deer Park, N.Y. “Tier 4 equipment does not yet run hot enough, combustion is not yet thorough enough, idling has to be handled in a completely different way and DEF injection units and their associated tanks introduce many new challenges. Will over-burned and less efficient engines and a new national chemical distribution of DEF offset the Tier 4 benefits to our environment? We’re constantly adjusting engine speeds depending on the environment the equipment is running in, we have to do more frequent parts and maintenance, DEF units and their tanks need to be kept surgically clean and DPF filters need more frequent blowouts and baking. [That means] extensive time and money.”
Vance says Sunstate is just beginning to hear of increased fuel consumption from a few customers and is currently investigating.
Although rental companies have not seen obvious dramatic differences in fuel efficiency, there have been other benefits, say manufacturers. “The systems run at a much higher efficiency level, you have cleaner operations, you have higher regulations for the type of fuel that goes into the machine, so they run cleaner and less maintenance is required over time,” says Stemper. “You’re improving performance by extending certain maintenance intervals on the machine, not having to do maintenance as often because everything coming into it is that much cleaner. You have the opportunity, depending on the system, to manage the power input and the power output better. A lot of equipment has incorporated work modes to allow customers to adjust the machines’ operational performance to what their application is. So one customer runs in Eco Mode because they don’t need raw power as often and another customer relies on that raw power and they turn it up to high workload or the high output mode depending on the machine they’re running.”
“Clearly one cannot argue the fact reduced emissions from diesel exhaust has a benefit to improving our environment,” adds Doosan’s Howe. “The advanced technology that makes the engine clean has also increased its efficiency, so we are seeing power density and improved fuel efficiency. As an example, as recently as 15 years ago, a 185-cfm air compressor was typically powered by a 4.5L engine. Today, Doosan’s 185-cfm model is powered by a 2.4L engine, almost half the displacement with no tradeoff in performance, durability or economy.”
And since rental companies and their customers are still struggling with a learning curve, rental companies will need to make greater efforts to educate their customers. “Customers need to ensure they use the right quality diesel exhaust fluid and fuel and that the dispensing method aligns with the manufacturers’ recommendations,” says Stiansen.
New directions
Now that emissions levels have been reached, engine manufacturers will have the opportunity to take technologies in new directions as well as continue to refine technologies developed to meet Tier 4.
“Having put in place the suite of technologies needed to achieve these near-zero levels of emissions, the industry can now provide an even greater focus on enhanced customer value as the technologies mature and experience is gained,” says Mike Reinhart, marketing manager for Perkins Engines, Peterborough, U.K.
“Hybridization, more efficient after-treatment technologies, improved combustion designs and drivetrain integration all represent areas where future improvements could occur,” says Darrin Treptow, John Deere Power Systems’ manager of worldwide marketing.
“I am extremely optimistic about engine technology development,” says Allen. “Looking at how research has driven automotive engine improvements, we should expect similar improvements from our engines over the coming years. Who would have expected to see sub-four liter engines powering full-size pickup trucks with fuel efficiencies over 20 miles per gallon? We are already seeing multiple injections per stroke and optimization of combustion chamber design from our engine suppliers. Tier 4 Final weeded out the engine suppliers who couldn’t master technology and opened the door for some new ones.”
One of the by-products of emissions legislation is the deeper levels of cooperation and research that has come about as a result. “Tier 4 Final has driven a couple of key trends in the industry,” Allen adds. “First, the discussion on whether or not aerials should have electronics is essentially dead. Over 25 horsepower they just do. Second, the change has driven more cooperation between manufacturers and engine suppliers and highlighted those suppliers with the widest support and most knowledgeable people in the field. This trend will need to continue as we drive field support of the engines in our products as a primary specification for engines in Genie aerials.”
“We’re currently investigating highly efficient and compact after-treatment systems, thermal efficiency improvement, friction and parasitic reduction, optimization of thermal management, model-based control and diagnostic systems,” says John Romanick, manager, market planning, at John Deere Power Systems.
“In the coming years, we expect to see a continuous downsizing on engine dimensions, reducing the engine displacement, and, at the same time, we expect to see an increased interest in lower power engines,” says AMS-Merlo’s Garino.
“Following the automotive and on-highway vehicle manufacturers, alternative energies and hybrid vehicles have already made their entrance to materials handling equipment, and we expect to see this trend continue,” says Herman Klaus of the Hyster Co. “Alternative power solutions such as hydrogen fuel cells and lithium-ion technology will likely enter the high capacity product range in the relatively short term, as these technologies can be applied to high power demands with the potential to offer some payback to customers. The focus of this development should remain on providing more energy efficient equipment and further reducing the overall cost of operations.”
Telematics will prove to be an important tool in engine development in the coming years, with remote diagnostic capability and remote monitoring helping rental companies to track problems in the field and easing the transition to Tier 4.
Engine manufacturers, OEMs, rental companies and their customers all have a continuing transition period as Tier 4’s penetration deepens into the field. Meanwhile, exploration into new fuels and new realms of knowledge will continue the evolution of the engines.
