When new emissions regulations are formulated, far more than engines are affected. Development and test facilities must also progress and improve. The EPA's new on-highway regulations scheduled to go into effect in 2007 and 2010, along with new rounds of off-road regulations pending in 2006 and beyond, are especially challenging in that they require accurate measurement of dramatically reduced N[O.sub.x] and particulate emissions levels. As one observer put it, to verify that their engines meet the standards, engine manufacturers have to get very good at measuring almost nothing.

As a major manufacturer of truck diesel engines, Caterpillar determined that it needed to modernize part of its engine emissions testing facilities at the Engine Technical Center in Mossville, Ill. Located at the heart of the Tech Center, Building L houses 98 test cells. It was determined that three of the 1970s-era cells needed to be upgraded to meet certification requirements through 2020.

Beyond the complexity of upgrading the cells was the challenge of doing so while not significantly affecting other critical engine development work ongoing at the facility. To help meet that challenge, Caterpillar teamed with Affiliated Construction Services (ACS), a national desigu-focused construction services firm specializing in high performance test facilities and custom test equipment.

Separately incorporated in 1994, ACS is a spin-off of Affiliated Engineers Inc. (AEI) dedicated to providing complete turnkey technical test facilities. Headquartered in Madison, Wis., the organization has regional locations in Washington D.C., North Carolina, Florida, California and Washington state.

The ACS/AEI team offers its capabilities in all phases of test facility development, including design, construction, commissioning, custom test equipment fabrication, PLC controls, etc. The company has a long and familiar list of clients, which on the heavy-duty side has included Allison Transmission, Fairbanks Morse Engines, Cummins, Consolidated Diesel, Detroit Diesel, Deem, Mahle, International Truck and Engine, Waukesha Engine and Eaton Corp.

"Finding a needle in a haystack is a difficult enough task," said Dave Sereno, engineering project manager and AEI principal. "But imagine someone decreasing the size of the needle by an order of magnitude. That is exactly what engine developers worldwide are facing as a preponderance of environmental health studies drive environmental emissions regulations to stricter levels--i.e., the needle shrinketh.

"Achieving accurate and repeatable data--there is an important statistical difference if you wish to certify saleable engines--is a difficult laboratory measurement and is particularly complex for diesel due to the presence of particulate matter. This difficult also translates into significantly more facility infrastructure: test equipment, space and utilities. Furthermore, the nature of engine development advancements is incremental breakthroughs--Eurekas! are not the norm--such that the measurable building blocks demand yet another order of magnitude reduction in measurement discernability--i.e., the needle shrinks further.

"The answer to this challenge is to reduce the size of the haystack and that in a nutshell is the impetus for this facility upgrade. The "haystack" is the variability impacting the measurements required to certify and more significantly, develop engines. Herein lies the paradigm shift from 1990s era regulations--where the environment was confined to the cylinder head--to today where literally all systems serving or in proximity to the unit under test affect data quality."

The upgrade of the three test cells began in the fall of 2003 and was completed in late 2004. "Cat was working on the preliminary design of the project when ACS and Caterpillar began discussions about how the integrated delivery approach of ACS could deliver the project at a reduced cost and accelerated schedule, while still giving Caterpillar the control over the technical aspects" said David Bartels, ACS principal and project manager. "The design-led integrated approach of ACS allows the owner to maintain control over the quality of the project, by being as involved as they wish on equipment and component selection, while relying completely on ACS to manage the design, procurement, construction and commissioning phases.

"Ultimately, Caterpillar contracted with ACS to manage the entire project, everything from the smallest construction subcontract to the purchase of the dynamometers and emissions measurement equipment."

The test cells incorporate two 750 hp and one 535 hp ac dynamometers, all of which were supplied by Foremost Industrial Technologies, East Peoria, Ill. Foremost integrated Electric Apparatus Corp. motors with custom bases to supply the custom trunnion-mounted dynos, which are run by three Siemens SIMOVERT 6SE70 850 hp ac vector drives.

The dynamometers are controlled via AVL Digalog TestMate controllers that have custom drivers that allow Caterpillar's internally developed data acquisition system to run any manner of steady-state or transient test cycle.