Bomag BW278AD4

The letter D denotes rollers for compacting non-cohesive soils and hydraulically bound base layers — classic heavy earthworks and road sub-base work. Alongside it, Bomag offers PD variants for cohesive, high-moisture soils and H variants with greater gradeability and drive torque for difficult terrain; it is the soil type, not sheer machine size, that decides which letter fits a given site.

The number itself — 213 in BW 213 — positions the model within Bomag's line-up: smaller numbers, from BW 80 to BW 138, cover lighter, more precise compaction work, while larger ones, from BW 154 to BW 216, are for heavy earthmoving and asphalt sub-base. For asphalt compaction proper, Bomag runs a separate tandem-roller programme carrying the AD or ADO suffix, which should not be confused with the D/PD/H single-drum earthmoving line.

For a used machine, the first thing to check is the hour meter, usually fitted on Bomag rollers and showing actual use regardless of build year. Next comes a visual check of the drum for scoring and uneven wear, a function test of the vibration system with the engine running, and an inspection of the frame and articulation joint for cracks — on machines with several thousand hours, the vibration bearing is a known wear point that can only be judged reliably through a test run and a workshop check.

In short, BW 213 D-5 reads as: Bomag roller, size class 213, for non-cohesive soils, current generation. When assessing a specific used unit, check hours, drum condition and the vibration bearing yourself rather than relying on the model code alone. The full code is usually printed on a separate sticker on the frame in addition to the data plate, and it is worth a second look before any purchase.