OverWatch - User - Overwatch EWP Safety in Industry (Software V9)

OverWatch - User - Overwatch EWP Safety in Industry (Software V9)

Notes
This Tech Doc applies to: MEWP Operators, Site managers and supervisors, Ground staff
What is EQSS Overwatch?
The EQSS Overwatch is an Elevated Work Platform (EWP) operator monitoring and cutout type of crush protection system (sometimes called Secondary Guarding). The Overwatch system is installed on EWP machines to monitor the operator's physical movements and then cut all machine movement, should the system recognize a potentially dangerous situation. The system thereby removes the risk of the operator being crushed against the controls and the machine guard rails. The EQSS Overwatch can be fitted to all scissor lifts and vertical masts.

Why is this important?
Operators can be crushed when operating a scissor lift? Know the risks and how to use the machine safely. Working at height requires moving the work platform near fixed structures. The operator and occupants can be in exposed positions “in the line of fire” when driving or raising the work platform.

What you need to know
You should know how the Overwatch works, how to be in correct position to operate the machine, when it is active (and not active), how to override and how to react in an emergency.

How it works
The Overwatch system is made up of a Lidar sensor and a machine control unit that monitors the Lidar and creates cutouts. The Lidar sensor sends an infra-red beam of light to measure the operator’s position. This signal occurs thousands of times every second, so it quickly identifies the operator’s movements. The system then detects the operator’s position and movements, with respect to the scissor lift’s direction of movement. This information is used to determine if a potential crushing event is about to occur. The system will trigger and cut the machine operation if the system detects movements above the pre-set limits.

When it is active
It is important that protection is provided for the high-risk movements – elevating the work platform and driving both backwards and forward.
The Overwatch is active for the following movements:
  1. Lift
  2. Drive forward and backward when elevated
  3. Drive forward when stowed
  4. Drive backward when stowed
*** It is not active when lowering the work platform - the work platform is never inhibited by the Overwatch from being lowered ***

On rough terrain “big deck” scissor lifts, it is not active when driving forward with the platform in the lowered positioned (this is identified as low exposure to crush points). When a movement is selected, you will hear the command “Elevate” or “Drive”
What operator movements will stop the machine?
The Overwatch detects the operator’s position and movements, with respect to the scissor lift’s direction of movement. Under certain circumstances the Overwatch will then apply a cutout to stop the machine to reduce the risk of harm to the operator. 
​
Cutout Behaviour - Elevate Mode - Elevate Upward Action
  1. Operator is not in front of the sensor at the start of the machine movement - machine will remain in cutout until operator is detected
  2. The operator is too close to the sensor at the start of the machine movement - machine will remain in cutout until operator is at the correct distance from the sensor
  3. Operator moves out of the sensor beam or ducks down - machine will remain in cutout until operator is in the position
  4. Operator moves rapidly toward the sensor  - system judges that an incident has occurred and will cutout
  5. Operator moves out of the sensor beam, whilst the machine is elevating upwards - will create a cutout
Cutout Behaviour - Elevate Mode - Elevate Downward Action
  1. It is not active when lowering the work platform - the work platform is never inhibited by the Overwatch from being lowered
Cutout Behavior - Drive Mode - Drive Action
Drive Forward
  1. Operator is not in front of the sensor at the start of the machine movement - machine will remain in cutout until operator is detected
  2. The operator is too close to the sensor at the start of the machine movement - machine will remain in cutout until operator is at the correct distance from the sensor
Drive Backward
  1. Operator is not in front of the sensor at the start of the machine movement - machine will remain in cutout until operator is detected
  2. The operator is too close to the sensor at the start of the machine movement - machine will remain in cutout until operator is at the correct distance from the sensor
  3. Operator covers the sensor - cutout as the operator is too close to the sensor 
  4. Operator moves rapidly toward the sensor - system judges that an incident has occurred and will cutout
What to do when it Activates and cuts out
To restart movement the operator must:
  1. Stand in front of the controls
  2. Release the joystick
  3. Hold the joystick and squeeze the trigger
What operator movements create an alert?
  1. Out of beam audio alert will sound only when driving forward. When driving forward, if the operator moves out of the sensor beam then it sounds an audible alert of three short beeps. This notifies the operator and any occupants of the operator’s changed position.
  2. The alert is only provided for slab scissors and vertical masts, the alert sound is not applied on rough terrain scissors.
Obstructed Sensor
The Overwatch detects if the sensor is blocked (you will hear the command “Sensor obstruction”). The operator must remove the obstruction and can wipe the sensor with a hand, glove or cloth. Neither drive nor elevate will function on the EWP until the sensor is cleared of any blocking material.

Prone Operator Alarm
The alarm will sound after a cutout to alert the worksite that the operator may be trapped. The alarm will repeat at short intervals until the operator moves away from the sensor and the controls are returned to neutral position.
Prone alarm will sound after a cutout if:
  1. Operator remains motionless
  2. Joystick is not returned to idle
  3. Trigger remains active
Operator and Occupants
The Overwatch monitors the operator ONLY. This reduces the risk of being crushed onto the controls or nearby guardrails. For their safety, take extra precautions if there are other occupants in the work platform.

Override
A short override on the Overwatch system is available to allow for precise maneuvering of the work platform. It is limited in duration and in how often it can be used. To override the sensor, tap the joystick trigger three times. It is not possible to permanently disable the sensor. The override feature can also be used in an emergency situation when a machine has been placed in an awkward to maneuver position. 

Calibration
System calibration was completed during the installation. There is no further calibration required.

Ground Rescuer
When working at height, the best advice is to have someone available in case of an emergency. They should be competent to lower the work platform and know how to use both the lower ground controls and the emergency descent. The Overwatch allows these controls to be used. If the operator is trapped against the control box without moving for a short period, then the machine horn will sound at regular intervals (Prone operator alarm).

Revison of Key Points:
  1. Understand how the Overwatch functions and when it will be active
  2. Always stand directly in front of the controls to operate the scissor lift
  3. Understand how moving outside of the operator zone will impact upon the Overwatch
  4. Know how to use the override for careful positioning of the work platform
  5. Identify the Prone Operator alarm and know how to lower the work platform in an emergency
Alert
Clear Operator Understanding of how to effectively use Overwatch on an EWP will greatly increase operator safety

    • Related Articles

    • OverWatch - General - What is EQSS Overwatch and how does it work?

      Principle of Operation The OverWatch™ is an innovative system designed as a safety aid to the operator. The system does not replace operator training. The system works on the premise of detecting the operator’s position and movements, with respect to ...

    • OverWatch - Software - Hybrid Overwatch ECU Module

      Some Overwatch Kits contain a Hybrid ECU module and are NOT compatible with standard 6253 Overwatch software The Skyjack SJ12/16/20 - E series, some LGMG EWP machines, some Haulotte EWP machines are equipped with an Overwatch Hybrid system and ...

    • OverWatch - Software - V9 Firmware Update and Installation Test

      Before applying the update, understand and ensure the following: Follow all steps in this procedure, exactly as written and in the correct order. If this procedure is not followed, the update will not be successful. Do not modify or deviate from this ...

    • OverWatch - Configuration - Make Overwatch work on a different compatible EWP model

      There is a very small quantity of EWP control boxes that are able to be used on a number of similar scissors/vertical masts (from the same brand). However, for the integrated EQSS Overwatch to also know that this change has taken place, it's ...

    • OverWatch - Software - Installation Test (Software V9)

      Select MEWP & Run System Test Stand in front of the control box as though you are about to drive the MEWP. The sensor expects to see you at arms length. Power on the MEWP. When the OverWatch starts up, Overwatch Version 9 is announced, put the ...