Left Arm Gas Cerenkov Installation Procedure

1. Define the scope of work
• Arrange, rig, and install the Left Arm Gas Cherenkov counter.
• The lift involves picking the detector up with a 45 degree tilt using a chainfall on the bottom end of the counter.
2. Analyze Hazards

• Task Hazard Analysis Worksheet

   

  Date: 02-22-2008     Task #_______      Frequency of use: Recurrent

   

  Complete all information. Use as many sheets as necessary
  Task location: Hall A	Task Title: Left Arm Gas Cerenkov Installation
  Division: Physics	Prepared by: Jack Segal
  Department: Hall A	Reviewed by (employee): Ed Folts
  Supervisor: Kees de Jaeger	Approved by:
  Standard Requirements: hard hat, safety shoes (PPE, TOSPs, SOPs, etc.)

   

  Sequence of Job Steps	Potential Hazards	Risk Code before mitigation	Safe Procedures/Practices/Controls	Risk Code after mitigation
  Stage, lift and install Left Arm Gas Cerenkov detector.	Arial lift, crane, chainfall, rigging. Loss of control of load. Accidental contact with equipment or personnel. Damaging the detector. Muscle strain.	4	Training. Spotter. Pay attention to clearances. Careful handling of the detector. Ergonomics. Hard hat, safety shoes.	1

   When a completed analysis indicates that the estimated risk code for any of the steps of this task is "medium" or higher (RC≥3), then develop a formal written procedure for the task and have it reviewed and approved prior to beginning the work.

• Examine the task for hazards with the Task Hazard Analysis worksheet
• Look at all aspects of job and its associated hazards.
• Assign a risk code for each hazard before mitigation
• Perform a pre-job walk down
3. Develop and implement Hazard controls
• Explain how risk(s) is/are mitigated
• assign one person to be in charge of the lift
• review rigging equipment required
• review procedure and responsibilities of participants
• Assign a risk code for each hazard after mitigation
• Write work procedure and incorporate hazard mitigation.
4. Perform work within controls (follow procedure)
• Summary of job
• notify Hall A Work Coordinator when the task will be undertaken
• inform relevant personnel the left spectrometer should not be moved during the task
• disable spectrometer motion if deemed prudent
• stage, lift, and install the detector
• remove equipment used for the task
• notify Hall A Work Coordinator when the task is completed
• Affected systems
• left spectrometer motion system
• access to Detector Service Platform and left side of spectrometer
• crane and possibly arial lift
• List of PPE
• hardhat
• steel-toed shoes
• Identify danger zones
• Detector Service Platform and left side of spectrometer
• Number of people needed
• 2 at minimum, beyond that is at the discretion of the person in charge of the lift
• List of materials
• one 3 foot, one 4 foot, two 8 foot, and one 10 foot slings (10 foot sling not needed if using the arial lift)
• four 1/2 inch shackles
• 1 ton chainfall
• laser plumb bob
• angle indicator
• red support beam with modified jackstand
• appropriate rail extensions
• Procedure
• Position red support beam over the bayonet box
• Ensure the 1/4-20 screw (it is a hard stop) is removed from the left end of the bottom rail
• Insert appropriate rail extension into the left end of the bottom rail
• Place modified jackstand support on the red beam, under the rail extension. Adjust to support the rail extension in a horizontal position.
• Insert appropriate rail extension into the left end of the top rail. We have, at present, two methods of doing this:
1. Use a 10 foot sling doubled over in a choke at the C.G. of the rail extension. This gives enough play in the sling that a person on the top electronics platform can guide the rail extension into the top rail. Remove the sling after the rail extension is fully inserted into the top rail.
2. Bring the arial lift alongside the spectrometer. Take the rail extension up in the basket and manually insert it into the top rail.
• Position detector on the floor of the hall for lifting. The best placement is on a radius from the pivot, in line with the bridge of the crane.
• Attach rigging to the detector. Weight is 1200 lbs.. 4 foot strap in a basket with an 8 foot strap in an inverted basket attached to the top. 3 foot strap in a basket to a 1 ton chainfall with an 8 foot strap in an inverted basket at the bottom. Inverted basket ends should be attached to the threaded rod the roller assemblies are mounted on. Use 1/2" shackles.
• Lift the detector off the support stand.
• Adjust the detector to hang at a 45 dgree angle from horizntal.
• Lift the detector and position it above the rail extensions.
• Set the detector down on the rail extensions.
• Remove the rigging from the detector.
• Move the detector into its final position on the rails.
• replace the 1/4-20 screw (it is a hard stop) in the left end of the bottom rail
• Secure the detector in place using C-clamps on the bottom rail, one on each side of the bottom roller assembly to block the detector from rolling to either side.
• Attach grounding cable to the detector, used to ground the detector to the Detector Stack.
• Remove rigging, rail extensions and modified jackstand.
• Post job briefing and cleanup
5. Provide feedback and continuous improvement. (Document any mistakes, corrections, changes and pictures and implement changes.)