Te answer is simple. Woollen garment damage is caused by two factors. Temperature and mechanical agitation.
You'll have noticed that this machine drives the wash solution through the wool at 90rpm. This may look unconventional, but this minimal mechanical agitation is the best way to wash wool without subjecting the load to excessive mechanical wear. Once wool fibres are damaged - they're damaged for good. Despite the unusual wash speed (@40ºC), the woollen garments should come out pretty clean and undamaged.
Hotpoint Man, February 2006