New Sakai SW654ND features Sakai’s unique dual drum vibe/oscillation
The new Sakai SW654ND launched at the 2017 ConExpo-Con/AGG Conference in Las Vegas March 7 through 11 offers today's paving contractors an oscillatory tandem drum roller in a 58-inch (1,480 mm) drum width for speedier, more profitable compaction. The design upgrade offers improved operating efficiency as well as ease-of-maintenance. Applications include both thin and thick asphalt lift compaction, as well as compaction of coarse graded asphalt mixes and aggregate base and subbase layers.
The SW654 tandem roller's fuel efficiency is based on a 3.3 L Kubota, EPA Tier 4 emissions compliant engine coupled with Sakai's new ECO Compaction Mode (ECM). ECM reduces fuel consumption up to 37 percent.
Side clearance is 2.5 inches (67 mm) with curb clearance of 28 inches (705 mm).
Maximum operating weight (with ROPS) is 16,250 pounds (7,370 kg). Front axle load is 7,740 pounds (3,510 kg). Rear axle weight is 8,510 pounds (3,860kg).
Additional design enhancements of the SW654ND design include improved ease of maintenance and serviceability through easier engine compartment access and centralized location for common maintenance items.
Sakai 'ND' Dual Drum Vibration
The SW654ND roller on site at ConExpo-Con/AGG features Sakai's unique “ND” configuration. ND-series asphalt rollers have independent dual drum vibration or oscillation capability from twin eccentric shafts. Amplitude and frequency for the ND version of the SW654ND are 0.021 inches (0.52 mm) at 2,940 vibrations per minute.
Josh Steele, marketing manager for Sakai America, Inc., said the versatility of a dual drum roller capable of independent vibration/oscillation is becoming increasingly valuable to paving contractors today.
“While vibration is still used on the overwhelming majority of compaction jobs to achieve density,” Steele said, “we are seeing more and more jobs spec'd as 'no-vibe' – meaning that you cannot engage your vibration.”
Sakai's unique ND configuration, he said, increases versatility by giving paving contractors a choice between up-and-down vibratory action and the gentler forward-and-back action of an oscillating roller on both drums. And the selection can be made with a flip of a switch on the operator's console for seamless transitions from the vibratory to no-vibe sections of a job on the fly.
While oscillation mode is effective in both thin and thick layer applications, it is especially beneficial when a mat is being built up with thin layers or in jobs, for instance, paving over sensitive structures, such as bridges, in which vertical impact is undesirable.
“Changing the direction of force from vertical to horizontal allows the drum, in effect, to massage the mat to density,” Steele said.
Some other manufacturers feature dual-drum rollers pairing one vibratory drum with one oscillation drum on a rig. Steele said these mixed-drum rollers do not achieve the compaction quality of Sakai ND-series machines with dual-drum vibration and oscillation system, since two oscillating drums share the compaction work on a Sakai ND-series roller.
“The result is gentler, smoother mat compaction to greater theoretical maximum density compared to single oscillating drum systems,” Steele said. “We even know of at least one contractor whose standard operating procedure required operators to use only static compaction for first passes. Otherwise, the use of their roller's oscillation on the first pass caused material displacement. Our SW654ND – like all our Sakai ND-rollers – allows contractors to use oscillation on all passes without increased risk of displacement.”