Emission objective

Regulations on engine emissions in mobile machines were first implemented by the European Commission (EC) in 1999, in order to reduce the number of premature deaths caused by air pollution.

The rulings covered a wide range of vehicles and machines, including non-road mobile machinery (NRMM). Within this bracket is mobile cranes- including all terrain cranes, despite their ability to travel on public roads. Since the initial 'Stage I'

regulations were introduced, the crane industry has come a long way- reducing the limit values on nitrous oxide and particle emissions by 96% with today's Stage IV standards.

Despite this dramatic progress, the mobile crane industry is now preparing for the introduction of Stage V, set to demand even lower emission levels. The EC published a proposal for the new regulation of directive 97/68/ EC last September, basing limit values on the mass of the particles and also limiting the particle number. This came after further research into the health impact of particles suggested that even the existing Stage IV limits do not provide adequate protection.

The move would make European legislation more stringent compared with the current limits set by the US EPA's Tier 4 regulations, used both in the USA and other markets. The two sets of rulings are closely aligned, albeit with some differences.

However, the terms of the Stage V regulations are not yet set in stone, as the process of fi nalising the laws is gradual-the EC currently hopes to have the fi nal terms set by 2017.

The mobile crane industry is therefore now in the process of lobbying the EC to make amendments to the proposal. These include extending the length of the transition period between Stage IV and Stage V to enable crane and engine manufacturers to have solutions ready for market, and the ability to replace older, existing engines in cranes with like-for-like components for longer than the current suggestion of ten years- without which, existing cranes more than ten years old that break down would have to be scrapped or rebuilt to house the new engines, potentially creating huge cost for owners and limiting residual values.

Transition revamp

For manufacturers of mobile cranes, fi tting a new engine can be a lengthy and challenging process. Additional components such as a diesel particulate fi lter (DPF) and exhaust gas after-treatment systems alter the size and shape of engines, requiring the housing within the crane to be changed. For mobile cranes, this has to take place within road regulations concerning size, weight and axle load- and may require two engines, for travel and crane operation, to be updated.

Despite this, the proposed transition period for converting to engines which comply with the Stage 5 is 12 months. Many in the industry feel this is insuffi cient-particularly given the number of different crane types which require new engines and past experience of the time required to change to new engines-and are pressing for an extension.

The FEM represents four types of equipment directly affected by the regulations, covering industrial trucks, mobile elevating work platforms and telehandlers along with mobile cranes. Secretary general Olivier Janin says:

"Materials handling manufacturers are in a very specifi c position compared with other machine manufacturers in that none of them produces engines. This makes them completely dependent on engine manufacturers to start the redesign of their machines. "Experience with changes from one stage to the other has shown that OEMs tend to receive prototype engines rather late. This impacts on the time they have to do the redesign of their machines. So far these delays have been covered by using the fl exibility scheme. The Commission is now proposing a more simple transition scheme, the structure of which is supported.

The proposed duration is however insuffi cient, not only because of the generally late availability of engines but also because Stage V will apply at the same date for both categories 19-37kW and 37-56kW, which had different application dates in the previous stages. "Concretely, this means doubling the R&D for many product families, notably industrial trucks, the vast majority of which are in the 19-56kW range. For all these reasons, FEM feels the transition period should be increased to 24 months, with six months for sell-off.

"As far as mobile cranes are concerned, their unique situation and specifi c constraints call for an even longer transition period of 36 months with six-month sell-off. With only 2,000 units placed on the EU market every year, coming in 170 models (all in the same power category) that need to be adapted with diesel particulate fi lters to comply with Stage V and this with the additional constraints represented by road regulations. A study, available on the FEM website, showed that a minimum of three years is needed for all the models to be redesigned as engines are supplied late because of the low volumes."

The importance of applying specifi c standards to the different equipment groups covered by Stage 5 was also raised by Euromot's general manager Dr Peter Scherm, in the organisation's initial response to the EC's proposals:

"With such a diverse range of machines included in the scope, one technical solution does not work for all applications. The Commission has generally succeeded in proposing a regulation that recognises this diversity, setting limit values that challenge manufacturers to further reduce the impact on the environment, while setting different limit values according to the size and function of the engine category, taking into consideration the cost effectivity of the chosen limit. We believe it is essential that Council and Parliament also recognise this diversity during their deliberations."

The replacements

Janin continues: "Another issue is the need to (re)introduce a replacement engine provision. This is very important to ensure that users of machines, the engine of which has failed, can continue to use it and thereby get a return on investment."

This issue was also raised by Euromot, the association for European engine manufacturers, in a position paper released in collaboration with CECE and CEMA in April. Euromot, which represents crane engine manufacturers including Cummins, Volvo Penta, Daimler, Doosan, and Isuzo Motors Europe, said that while it welcomed the introduction of provisions for a replacement engine in the new regulations, the proposed time limit of ten years should be increased to at least 25 years.

The organisation argues in the paper that cranes are "high-value, long-life capital investments, not consumer goods that may only last up to ten years" and that "limiting machine life by restricting availability of replacement engines to a certain time period is contrary to principles of circular economy and contrary to principles used for other sectors". It also cites the equivalent US legislation, which permits like-for-like replacement engines to be produced for machines up to 40 years old.

Further recommendations raised in the paper include enabling engines to be supplied without any parts of the emission control system not requiring replacement, a straightforward reporting system, and the addressing of concerns over the mandatory retrieval of replaced engines.

Anja Schneider, press offi cer at the Committee for European Construction Equipment (CECE), emphasises the importance of this issue, although says there are positives to be taken from the ongoing negotiations in the European Parliament and EC:

"A number of positive points can be noted a few months into the legislative process. First, the EU institutions are striving to stick to an ambitious adoption schedule, aiming to conclude the fi le by the end of the year. This is important to secure suffi cient lead-time between the adoption of the legal text and the entry into force of the new requirements in 2019/20.

"Second, Parliament and Council seem to have taken on board that parts of the non-road machinery industry need some additional transition time (CECE has asked for an extension by six months) to enable compliance throughout the width and breadth of the industry and the multitude of product applications. "However, discussions have not reached the fi nal stages yet and a third important point, concerning replacement engines, is still under heavy scrutiny. To be precise, negotiations here focus on the modalities under which a provision can be re-included in the regulation to allow for the replacement of irreparable engines with a like-for-like emissions stage engine.

"CECE believes that these modalities should refl ect current practice. A time limitation should be avoided, in particular for large, high-value machines that have a long operational life. Retrieved engines, furthermore, should be allowed to be re-manufactured and made available on the EU market. Limiting the options for replacement clearly goes against the circular economy principles.

"CECE is particularly worried about the potential inclusion of a limitation in time, prohibiting the like-for-like replacement of engines after a number of years following the end of an emissions stage. Suggestions for a limitation of ten years fi rst emerged in documents from the EU Council working group that is treating the fi le. CECE along with the European associations representing engine manufacturers, agricultural equipment and material handling (Euromot, CEMA and FEM, respectively) are opposing this small, and in fact arbitrary, number of years."

New model army

For the mobile crane sector, updating the full range of models in the market is a lengthy and costly process. The FEM commissioned a team from the Institute for Materials Handling, Material Flow and Logistics from the Technical University of Munich to conduct an impact study examining how the proposed regulations would affect the mobile crane industry.

Converting from Stage IIIb to Stage IV, introduced in 2014, cost the industry around €57m, and the next step to Stage V will cost an estimated €66m. The study also stated that, based on previously conversions, around four-and-a-half years are required to update the 170 models affected.

A key concern raised by the study is that due to the very short proposed transition scheme, the total PM emissions from mobile cranes will actually be higher over the five-year period after Stage V is introduced, compared to a scenario where Stage V is either not introduced at all, or introduced with a longer transition period. This is because, as new Stage IV cranes would not be available to buy after Stage V is introduced, crane operators would be forced to run older equipment with higher levels of emissions. Manufacturers will only be able to convert one-third of the mobile crane portfolio under the current time limits, the study estimates, due to the scale of the redesign required.

"With the modifications of the engine the complete periphery had to be remodeled," says Dr Ulrich Hamme, managing director at Liebherr Ehingen, of the conversion to Stage IV. "Further components were affected by the adaption. In particular the increase in volume and the new shape of the Stage IV engines and the related exhaust gas after-treatment units led to extensive alterations of the steel construction of the carrier frame and the slewing structure, as the engine collided with the bearing frame. The function of the frame as a supporting structure for the crane had to be reconfirmed by means of static calculations.

"Each of these measures requires time-consuming test series, which confirm the functionality of the new drive lines and the safety and reliability of the machines."

Specific steps included redesigning various assembly units in the slewing structure and carrier, to incorporate the additional components. Space for installation and the arrangement of the components was very limited says Hamme, as installation of the new exhaust gas after-treatment had to strictly follow the specifications of the engine manufacturers.

"These narrow boundary conditions can lead to tremendous redesign efforts. The complexity of the necessary redesign of already existing crane models varies from model to model."

For example, crawler cranes are more straightforward to redesign than all terrain cranes, says Hamme: "The redesign of crawler cranes is much easier. You do not have to regard so many restrictions from on-road regulations concerning dead weight, axle loads and dimensions of the entire machine. But nevertheless, installation space is limited and the work requires diligence and manpower.

"For all terrain cranes especially the increase in weight leads to modifications of further components for compensating the additional weight, or to balance the new centre of gravity of the entire crane. So, for example, load capacity reductions at the counterweight had to be performed. What appear to be small modifications at first view entail modifications of one component or assembly group after another, and lead finally to tremendous efforts.

"On some crane models no possibility existed to keep to the permissible total weight and the maximum allowed axle loads. Different measures were necessary to solve these problems. On some crane models, to reduce weight the power unit in the superstructure with the separate diesel engine was eliminated. For the required single engine concept an extensive and time-consuming development activity was necessary. This resulted in a complete new design of the carrier frame and finally of the entire machine."

Tadano Faun experienced a similar challenge, says Martin Lottes in project planning and development: "The step from Stage 3B to 4 was huge, partly because the engines types changed from V-type to Inline-type, the exhaust and AdBlue system is more complicated, and so are the cooling and air systems. We also had to fight against adding more weight. And don't forget the much higher price, with only a small benefit for the end customers."

Emiko Ishikawa at the sales administration section of Kobelco Cranes in Japan says that smaller emissions means larger engines: "To accommodate Tier 4 regulations, we redesigned the main machine's layout and control system to install the SCR system. As emission regulations became stricter, the size of an engine and the equipment that comes with it became bigger. Redesigning the layout and system matching (for the engine control system and crane operation system) are the key for us to catch up with these changes. The SCR system requires an aqueous urea storage tank and other specialist equipment besides the engine, and so we need to change layout and control system of each machine."

Locatelli sells rough terrains around the world, often including in markets like Africa and the Middle East that refer to older US EPA Tier standards. Michele Mortarino, sales manager, describes how his company changed engines to Tier 4: "We recently switched to Tier 4 engines, which involved redesigning the chassis and frame of the crane. We had to address exhaust issues, and the engine manufacturers set very strict requirements on the positioning of the engine on the chassis-if we did not follow these we would not have the acceptance of the engine manufacturers-and this limited the redesign of the crane.

"We were one of the first manufacturers in our field to switch to Tier 4-our main competitors preferred to move to Tier 3b. This was not our target, however, as we wanted a direct passage to Tier 4 to give our customers a better performance.

"Manufacturers will be able to use Tier 3b engines until the end of 2016, but if they renew any of their models they will have to use Tier 4 engines.

"This revolution is definitely expensive-engine manufacturers practically doubled the price of Tier 4 engines compared to Tier 3 engines. The costs have to be managed by crane manufacturers. Because we produce relatively small volumes of cranes, the costs that need to be redistributed are higher."

A further issue is that Stage IV engines require low-sulphur diesel to operate-conventional diesel causes issues, says Gerhard Kaupert, director of technical projects for EMEA in engineering at Manitowoc Cranes: "The technologically-complex exhaust gas aftertreatment with the SCR-system for maintaining the emission limit values is sensitive to sulphur contained in diesel fuel. With more than 50ppm of sulphur in diesel fuel, disturbances in the exhaust gas aftertreatment system occur. Therefore we already now sell cranes with the old emission stages to countries where the fuel necessary for the newer stages is not available, and so mobile crane manufacturers have to keep more models in production."

"It is a very big problem that there is still a large proportion of the world market where diesel fuel with low sulphur is not available," says Lottes. "The consequence is that we are forced to build cranes with 'old' engines in parallel for these markets." One method of countering this is employed by Locatelli, whose GRIL8700T 65t rough terrain crane is designed to allow it to be fitted with either a Tier 3 or Tier 4 engine at the last minute, depending on where the crane will be sold: "It is fitted in the same space," says Mortarino, "with the additional exhaust system mounted on the side at the back."

Generation V

The next step is to prepare for the conversion to Stage V, and to complete that process, crane manufacturers will need engine manufacturers to have the new engines ready-which are currently still in development.

"The basic technology may be ready for (certified) laboratory prototype engines, but final solutions to be installed as series standard in a crane are not available today and in the near future," says Hamme at Liebherr.

"An exact delivery date for series engines and exhaust gas aftertreatment units for Stage V in all power classes for mobile cranes cannot be expressed at this time, as the planning of the engine manufacturers is still not concluded. The actual planning envisages the start of the series production for the middle of 2018, but only then can funded engineering and application work be continued or started.

"This is one of the reasons to extend the transition period for the manufacturing of Stage IV and V cranes simultaneously from 12 months, which is the proposal of the EC, up to a minimum of 36 months for mobile cranes, as is the requirement of the mobile crane industry. A postponement of the effective date, 1 January 2019, is not expedient.

"The extension of the transition is a must, for the environment because of long-term reduction of the air pollution and for the crane manufacturers to overcome this exceptional challenge." During the move to Stage IV delays from the engine manufacturers hampered developments, says Lottes at Tadano Faun-but they are anticipating a smoother process this time.

"A big problem when we developed cranes for Stage IV was that the engines arrived too late from the engine manufacturers to be ready for implementation. After we had the engines we then had to redesign the complete steel structure from the carrier and the superstructure.

"The engine manufacturers have promised that the changes from Euromot 4 to 5 are not so tremendous, and they will be ready with design much earlier. "Still, we have only a few months to change the complete fleet, we have no flexi-solution this time and nearly no pre-buy-engines to work with. Our fear is that we can't change all engines in such a short time, and a lot of customers will not be willing to pay once more a lot of money only for cleaner air. It may be that they shift the purchase from new cranes."

Manitowoc's Kaupert, a representative of FEM, says: "We as FEM and especially the Technical University of Munich have communicated with all engine manufacturers and they will not be ready earlier than around half a year before the beginning of 2019 with their final engines. Experiences with earlier stages showed us that even today they have still problems with engines of Stage IV. Why should this change from Stage IV to V?

"Through previous engine regulations we have learnt that every change on the crane takes a lot of time to get through the design, prototype, test and pre-production phases. Our cranes are optimised regarding sizes, weight and loads, so there is nearly no space for changes without the need for a redesign.

"In particular the increase in volume and the new shape of the Stage IV engines led to extensive alterations of the carrier frame, as the engine collided with the frame. From Stage IV to V the engine will not change, but the SCR catalyst will be extended by a particle filter which increases the weight and dimension of the after-treatment system once more."

For rough terrain crane manufacturers, however, there may be longer to work on the next engine upgrade, says Mortarino at Locatelli: "Rough terrain cranes are too small to be affected by Tier 5, so we should be able to use Tier 4 engines for longer than other crane types. At the moment we have had discussions with engine manufacturers but they currently have no solutions for Tier 5 engines for rough terrain cranes."

There are advantages of the newgeneration engines that go beyond simply meeting regulations, and can be passed on to customers. At a presentation at the recent Intermat show, engine manufacturer Cummins highlighted that following its Stage IIIa engines, its Stage IIIb engines launched in 2011 improved fuel economy by 5%, and the Stage IV engines the company introduced in 2014 improved fuel economy by 8-10%. This was achieved with no loss of reliability or durability, tests showed.

The next step, Stage V, will use existing diesel particulate filter (DPF) and selective catalytic reduction (SCR) technology which has been proved in Stage IV engines-but will also provide an opportunity to further improve the engine in other ways, said Cummins. This includes combining the three modules of the after-treatment system-the DPF, SCR and AdBlue doser - into one module, making it smaller, lighter, and more efficient