Common Load Causes of Broken Plough Beams

A broken plough beam stops work completely, and it almost never happens without warning. Beams carry the bodies through every furrow, and they fail when the load exceeds what the frame can absorb. Understanding the common load causes helps operators avoid the shocks and stresses that end in a cracked beam.

Sudden obstacle impact

The most common breakage cause is meeting a buried stone, rock or steel stake at speed. The beam absorbs the full shock at its weakest point, usually near a body bracket, and cracks. Working unfamiliar ground slowly, and skimming the field before ploughing, catches many of these obstacles before the plough meets them.

Over-deep work in hard soil

Ploughing deeper than the frame was rated, in compacted or dry hard soil, loads every body far beyond design. The beam flexes with each furrow, and repeated flexing sets up fatigue cracks that grow until the beam breaks. Work to the rated depth, and break hard ground in passes rather than forcing one deep cut.

Stress concentration at brackets and welds

Beams break where a body bracket is welded on, because the bracket creates a stress point. Cracks start at the weld toe and spread under repeated load. Inspect these welds every season: a fine crack caught early can be repaired, while a fatigue crack left alone grows through the beam during work.

Corrosion weakens the section

A beam that has rusted inside, or that has been left dirty for years, loses section strength. Pitted rust and internal corrosion thin the steel until the beam can no longer carry the same load. Clean, paint and inspect beams regularly; a beam that looks rusty from the outside may be thinner than it appears.

Choose the right beam for the work

When ordering a replacement beam, match the section and rating to the plough's expected work. A heavier beam suits heavy soil and deeper work; a lighter beam is fine for easier ground. Fit the replacement to specification, re-check welds, and give the new beam the same care the old one should have had. A well-matched beam lasts the plough's working life.

References

BROWN R T, DAVIES M K. Fatigue failure of plough beams under field load[J]. Biosystems Engineering, 2020, 198: 150-159.

Brown, R. T., and M. K. Davies. "Fatigue Failure of Plough Beams under Field Load." Biosystems Engineering, vol. 198, 2020, pp. 150-159.

Brown, R. T., & Davies, M. K. (2020). Fatigue failure of plough beams under field load. Biosystems Engineering, 198, 150-159.