Samenvatting
The rapidly expending use of tractors in Sweden has causeda great number of accidents,mostly by the tractors's over-turning.Investigation have been carried out to lay down mi-nimuwn reguirements concerning the strength of a protectiveframe or cab to be mounted on the tractor, The equipment oftractors with a frame or cab of an approved type is com-pulsory in Sweden since a number of years. They have prov4,dto be very effective.