Applied Ergonomics 40 (2009) 91–102 Assessment of controls layout of Indian tractors Adarsh Kumar à , Gaikwad Bhaskar, J.K. Singh Division of Agricultural Engineering, Indian Agricultural Research Institute, New Delhi 110012, India Received 14 July 2007; accepted 21 January 2008 Abstract Tractors in low-income countries are used both for farm and non-farm activities. Most of the tractors being manufactured in India are products of collaboration with other countries. The design of tractors manufactured in India has not changed much in the past five decades especially from an ergonomics point of view, because of economic considerations. This paper describes a tractor control layout assessment with respect to the Indian population and compares the location of controls with workspace envelopes and the IS12343 standard for commonly used tractors on Indian farms. Controls like steering, foot clutch, foot brake, foot accelerator are located in areas defined by IS12343 standard in some tractors but these are not placed in the workspace envelopes of the Indian population. This results in a mismatch between the workspace envelope and location of controls as defined by the standard. The controls need a complete change in their layout to be in the workspace envelopes, as this cannot be achieved by providing seat movement in the horizontal and vertical directions in the present tractor design. r 2008 Elsevier Ltd. All rights reserved. Keywords: Tractor; Controls layout; Workspace envelopes 1. Introduction The use of tractors on Indian farms has increased from a population of 52,000 in the 1960s to 3.2 million in the 1990s (Motor Transport of India, 2003). In low-income countries (LICs) ergonomic studies on tractors have been very few. In India the previous studies are confined to anthropo- metric surveys of agricultural workers (Gite and Yadav, 1989) and there are a few qualitative reports (Bhatia and Rawal, 1976; Rawal and Bhatia, 1978; Singh, 1979; Tandon and Sirohi, 1987), which highlight the problems related to agricultural equipment in general. The tractor is the most commonly used power source on farms throughout the year, unlike other agricultural machines that have specific and seasonal use. It is used as a prime mover with all kinds of mounted, semi-mounted and trailed equipment. The use of the tractor is not merely confined to farms, but it is also used as the main mode of transportation in rural areas. Tractors are also used for stationary application; taking power from power-take-off (PTO) pulleys for threshing operations and water lifting pumps. Indian tractors are equipped with 20–60 HP (15–45 kW) engines, which may be rated as small compared to tractors used in high-income countries (HICs). Studies from HICs underline the importance of ergo- nomics considerations for improving safety and comfort of tractor operators. In a recent study, Hsiao et al. (2005) used the anthropometric dimensions for tractor cab design and concluded that the SAE J2194 standard for ROPS is improper for the surveyed population. Thirteen anthropo- metric dimensions were identified for establishing body models to improve tractor cab design. Mismatches between tractor design and ergonomic criteria like operator capability in terms of body dimensions were studied. Duppis (1959) claimed that injuries could result from poor ergonomics. It was stated, ‘‘If the operator’s controls are not properly adapted to his harmony, the performance demanded of him may quickly reach and even exceed the lines of tolerance. As a result of excessive stress, premature fatigue and impaired health, the possibility of accident will result’’. Access and egress is also one of the common causes of injuries among tractor drivers (Suutarinum, 1992). ARTICLE IN PRESS www.elsevier.com/locate/apergo 0003-6870/$ - see front matter r 2008 Elsevier Ltd. All rights reserved. doi:10.1016/j.apergo.2008.01.017 à Corresponding author. Fax: +91 11 26858703. E-mail addresses: adarsh_iari@rediffmail.com, adarsh_iari@yahoo.com (A. Kumar).