BOMAG positions the BW 138 AC-5 as the anchor of its light articulated tandem roller range - a roughly 4.2-to-4.5-ton tandem vibratory roller with two independently vibrating smooth drums spanning 1,380 mm working width, designed for asphalt patching, footpath and driveway compaction, and small-to-medium road construction where maneuverability and compaction documentation determine productivity. Powered by a 45.1-horsepower Kubota diesel engine meeting Tier 4 Final emissions compliance, the BW 138 AC-5 delivers dual vibrating frequencies and dual amplitudes - allowing the operator to select between low-frequency/high-amplitude for thick soil lifts and high-frequency/low-amplitude for thin asphalt layers and finishing passes.
The machine's defining engineering feature is the "crab-walk function" - BOMAG's steering system that allows the front drum to be offset laterally relative to the rear drum, letting the operator compact flush against walls, curbs, and structures without leaving an uncompacted edge strip. Combined with firmly bolted articulation joint geometry and a 35-degree steering angle, the BW 138 AC-5 delivers a turning radius tight enough to work in cul-de-sacs, parking garages, and pathway intersections where a rigid-frame roller cannot operate effectively.
The machine's "ECONOMIZER" compaction documentation system uses an integrated compaction meter to map compaction passes and identify optimally compacted zones in real time - allowing the operator to eliminate unnecessary passes on already-compact areas, reducing fuel consumption, machine wear, and over-compaction of finished surfaces. Combined with two spring-loaded and tiltable scrapers per drum (which keep the drum surfaces free of asphalt pickup) and a pressure sprinkler water system with interval control, the BW 138 AC-5 delivers verified compaction quality with reduced water consumption. Standard equipment includes hydrostatic travel and vibration drive, a ROPS-certified cab or optional ROPS frame, and BOMAG's standard LCD display for machine status monitoring - positioning the roller as a direct competitor to Hamm HD 14 VV, Caterpillar CB34B, and Dynapac CC1200 in the global 4-ton tandem roller segment.
