a) All limit switches shall be reliable, weatherproof, water tight and of heavy duty type suitable for rough operations. Proximity type limit switches which has no moving parts and require no maintenance shall be used for all non-critical applications. Proximity switches shall in-built short circuit protection. b) All geared limit switches and over speed control switches (if used) shall be coupled by flexible coupling or equivalent. Geared limit switch unit for main hoist (if used) shall have two spare limit switches. c) Cables for limit switches shall be connected in water tight boxes, for easy maintenance and troubleshooting. d) All limit switches shall have safe easy access for repair and maintenance.Limit switches for sensing of end of travel for trolley and boom shall be heavy duty type which have long mechanical life.All geared limit switches and over-speed control switches (if used) shall be coupled by flexible coupling or equivalent. No chain drive is allowed.Electronic absolute digit encoders shall be used for position feedback for main hoist, trolley travel boom, list and trim systems. Cables for limit switches shall be connected at terminal blocks in water tight junction boxes, for easy maintenance and troubleshooting.