AS ISO 3411:2020 Earth-moving machinery – Physical dimensions of operators and minimum operator space envelope.
5 Minimum operator space envelope
5.1 General
The minimum operator space envelope is the interior dimension of the operator’s enclosure. The minimum operating space envelope around the operator for operator enclosures (e.g. cabs, ROPS, FOPS) is shown in Figure 4 for a seated operator and in Figure 5 for a standing operator. The dimensions given relate to the seat index point (SIP), as defined in ISO 5353. The outline of the space envelope does not imply the shape of the enclosure. This shape can be different than those illustrated provided that the minimum dimensions are met.
The minimum operator space envelope is based on the large operator dimensions shown in Figures 1 2 and and is measured to the interior surface without visible surface deformation of the operator enclosure.
5.2 Allowable adjustments
5.2.1 Allowable adjustments to the minimum operator space envelope for particular machine applications and constraints are given in 5.2.2, 5.2.3. 5.2.4 and 5.2.5. The minimum operator space envelope requirements stated in this International Standard can also be supplemented or modified by standards for specific earth-moving machinery.
5.2.2 The operator enclosure minimum space envelope may be smaller than according to Figures 4 and 5. if the reduced operator space envelope for a particular machine application allows adequate space for operator performance and protection. Acceptable modifications for the operator enclosure space envelope include the following. An operator enclosure minimum height of 1 050 mm from the SIP is required to accommodate commonly used seats and provide clearance for an operator’s protective helmet. The operator enclosure minimum height may be reduced to 1 000 mm for machines used in applications for which a protective helmet is not required in the enclosure. The enclosure height may also be adjusted for the following variations in seat configurations as
defined in ISO 11112:
a) 40 mm reduction without vertical seat suspension;
b) 40 mm reduction without vertical seat height adjustment;
c) reduction proportional to seat back cushion angle greater than 15°.
5.2.3 The operator seat may be offset from the space envelope width centreline to allow direct visibility to the side of the machine, provided the minimum internal distance from the SIP to the side of the upper portion of the enclosure is at least 325 mm.
5.2.4 Some particular types of machines (e.g. compact machines) can necessitate the use of an operator space envelope smaller than the minimum recommended by this International Standard. For these machines, the internal operator’s space envelope width may be reduced to a minimum of 650 mm. This minimum width space envelope requires judicious placement of operator controls to ensure operator performance and comfort.
5.2.5 When the operator is normally inclined forward to operate the steering controls (e.g. compact excavator), or visibility to the immediate rear of the machine is required (e.g. small tractor dozer), the minimum clearance to the rear of the operator enclosure (R3) may be reduced to 250 mm plus one half of the fore-aft seat adjustment travel.AS ISO 3411 pdf download.