A 1917 Samson 6-12 Sieve Grip tractor sold for a record £67,500 at Cheffins‘ vintage auction last Saturday (24 July).

The Sieve Grip was so called because it used cast-iron open wheels with a centre ring and cross strakes arranged in herringbone fashion. The idea was to allow soft soils to flow through the gaps and to spread the weight of the tractor and break up soil clods.

It had a single, massive cylinder with a 7in bore and a 9in stroke and ran at a steady 450rpm. There was one forward and one reverse gear (so no agonising over gear choice) and power output was 6hp at the drawbar and 12hp at the belt.

The Samson Iron Works was founded in Stockton, California, in 1898 by inventor John M Kroyer. The company produced ten different models, all of a similar configuration apart from the engine and size of the transmission.

The Sieve Grip came about to cope with the soft reclaimed peat soils of Sacramento and San Joaquin river deltas in California. Those same soils also prompted the development of the tracklayer by another Stockton tractor pioneer Benjamin Holt of Caterpillar.

In February 1917, six Sieve Grips (four 6-12s and two 10-15s) were shipped to England. Just 11 6-12s remain in existence across the world, with five in New Zealand, five in North America and just one original UK import. However a 1914 Samson 10-25 sieve grip also exists in the UK as part of the Norman Vince collection.

The Samson sold on Saturday was purchased by the father of the current vendor from brothers Harold and Willie Brownrigg who farmed at Great Orton, east of Carlisle. It starred in a threshing scene in Granada Television’s Forsyte Saga.

According to Cheffins, the tractor is in good condition with little wear on the gears. It is believed to have last run in 2003.