Top of container (spreader landed onto container) detectors at all four corners of spreader to detect the following shall be provided:a) full landing of spreader squarely onto container/ hatch cover, b) no container/ hatch cover under spreader; and c) container / hatch cover suspended under spreader. The above mentioned detectors shall be positioned such that it will function on the corner castings of ISO container and hatch covers as well as on those non ISO type found on some vessels. All limit switches on the spreader shall be easily accessible for maintenance and shall be protected from damages due to impact. All limit switches shall be proximity type.An ultrasonic sensor device shall be provided near the centre of the spreader to detect items underneath within the range of 0.8m to 6..The spreader must be able to self adjust and return automatically to its last telescopic position when out of positioning during operation.Spreader shall be of latest design incorporating shock-absorbing devices at twistlock corners. The shock absorbing device shall be compact, light weight and maintenance free. Hydraulic or air system shall not be accepted.Spreaders should be able to detect 2x20 feet containers when in the 40 feet mode shall be provided and shall be interlocked to the control system.A means to safely override and record the twin twenty function is to be integrated in the control system of the crane.One or more ultrasonic sensor to be installed underneath the spreader to detect container or object within a preset distance from the Spreader. For situations when lowering the Spreader to pick up a container, the sensor will trigger a signal to the crane to slow down its lowering speed.The Spreaders must be equip with Auto positioning system to self adjust and return automatically to its last telescopic position when out of positioning during operation. The spreaders must be able to couple with twin 40 headblock by means of twistlock without any chains and modifications for added versatility when future demand requires.