ForConstructionPros.com

Tier II emission requirements have been a challenge for all manufacturers of off-highway equipment. However, they posed a special challenge for compaction equipment manufacturers, who faced tight space constraints, an extremely price-sensitive market and increased noise concerns.

Over the last two years, compaction equipment designers had to wrestle with some fundamental choices when it came to bringing their products into compliance. And they didn't have much time to do it. "Unless you make your own engines, you are at the mercy of the engine manufacturers," says Steve Wilson, manager, marketing services and product manager for Compaction America.

One early problem was the availability of prototype engines. "That was critical because you build everything around the engine and we couldn't get the parts fast enough," says Dale Starry, manager of training and applications at Ingersoll-Rand's Road Development Group.

There was also some loss of available horsepower options — especially in the 100-hp range — as engine manufacturers opted to stop production on some lines in order to meet Tier II standards for their other products. That meant many equipment manufacturers had to utilize Tier II phase-in allowances, which permitted them to produce some non-compliant equipment as long as the majority of their machines met the emission standards.

Design challenges

The basic choices confronting manufacturers of compaction equipment were selecting a smaller but "cleaner" engine; adding an aftercooler to lower the temperature of the turbocharged air entering the engine; or adding electronic controls.