Doc #: 2100 AD Revision: A

Transcription

1 Doc #: 2100 AD Revision: A 4 Meter Cass Cage Bottom Removal Procedure Author(s): Hillary Mathis

2 Contents Contents... 2 Revision History Purpose Applicable To Scope Definitions Training Safety Personnel, Equipment and Materials Required Procedure Procedure Review Records References AD docx Page 2 of 8

3 Rev Revision History Date Approved Sections Affected Initiated Remarks and/or Change Details Name A 6/9/16 8. Added labels to photos, clarified wording B. McCollam Authorized by: SigEng Name, ME Title Hillary Mathis Name, EL Maint SigSci Name, SciOps Tammie Lavoie 9 June 2016 Tammie Lavoie, Safety Manager Date 2100 AD docx Page 3 of 8

4 1. Purpose To remove 4 Meter cass cage bottom 2. Applicable To KPNO 4 Meter telescope 3. Scope To be done for all work that requires access inside the cage, from the mirror lift 4. Definitions 5. Training No special procedure training required. On the job knowledge of Mayall dome environment required. Fall protection training required. Lock out tag out training. 6. Safety 1. JHA Form 2. Kitt Peak Emergency Manual 7. Personnel, Equipment and Materials Required 2 people, 1 person must have previously participated in procedure 1 cass cage cart 2 1 1/8 socket wrenches See JHA for PPE 8. Procedure 1. Turn off the large air mixing fan. 2. Ensure telescope is at zenith. 3. Place the Instrument Change in Progress sign on the console. 4. On the P floor, behind the screen room, turn off the breakers for the Dec and RA drives on the Brake Circuit Cabinet and the RUPS Power Panel 5 breaker. Lock out the RUPS breaker. (See Figure 1) (JHA Item #3) 2100 AD docx Page 4 of 8

5 Lockout/Tagout (Step 4) DEC and RA Breakers (Step 4) RUPS Power panel (Step 4) Figure 1 5. Contact Facilities supervisor to have the stay bar installed. 6. Turn on the cass cage light. 7. Hook up the 20 foot SRLs inside the cage; (JHA Item #1) (See figure 2) a. Hook up either two or three SRLs depending on the number of people working. i. With two people, the SRLs go on the NW and NE sides of the cage. ii. With three people, the third SRL is positioned in front of the case cage door. b. Feed the D ring straps through the mirror cell holes, make sure the padded side is down. (See figure 2) i. Ensure the strap goes under any wires that may be fed along the upper side of the mirror cell. c. Put the smaller D ring through the larger one and snug to the mirror cell. (See figure 2) d. Clip the SRLs to the smaller D rings with the clip on the top of the SRL box, NOT the one on the end of the nylon strap. (See figure 2) e. Extend the SRL strap and attach the clip to the lower part of the cass cage. (See Figure 2) i. The clip must be reachable from the lift after a small gap has been made between the upper and lower cass cage as the cage bottom is being removed AD docx Page 5 of 8

6 Mirror cell (Step 7.b.) D ring strap (Step 7.b.) Small D ring (Step 7.c. and 7.d.) SRL (Step 7.d.) SRL strap (Step 7.e.) Figure 2 8. Connect the 9 foot SRLs on the outside of the cass cage to the D rings on either side of the cage door. (JHA Item #2) 9. On the telescope floor, turn on the lights with the switches located on the west wall. 10. On the main telescope floor, under the telescope horseshoe, push the button to move the ramp East. (See Figure 3) (JHA Item #4) 11. Remove the safety straps from the net. 12. Lower the net 9 to 12 inches so the clips are more easily reachable. (See Figure 4) 13. Unhook the safety net. (JHA Item #5) 14. Push the net South, to the far end of its cables. (JHA Item #6) 15. Place the rolling toolbox on the lift. 16. Place the cage bottom cart on the lift; a. It can be found against the rails that surround the removable floor. b. Make sure the S (South) marking is facing the control room. c. Align the cart with the designated marks on the lift floor. d. Place the two 1 1/8 socket wrenches, from the tool box, on the cart AD docx Page 6 of 8

7 Cass ramp controls (Step 10) Figure 3 Safety net controls (Step 12) Figure AD docx Page 7 of 8

8 17. Put on fall protection harnesses. (JHA Item #7) 18. Remove the hand paddle from the compartment on the lift floor and turn on, making sure the e stop is disengaged. 19. Raise platform until the cart is 6 inches from the bottom of the cage; (JHA Item #8) a. Align cart legs with the cage bottom. b. Raise lift slowly until cart is touching cage bottom. 20. Clip the 9 foot SRLs to safety harnesses. (JHA Item # 9) 21. Undo the 12 captive bolts holding the cage bottom to cass cage. (JHA Item #10) 22. Lower lift slowly while making sure all the bolts are free. (JHA Item #11) 23. Once it is determined that all the bolts are free, lower lift 12 inches. 24. Unclip the 9 foot SRLs, unclip the 20 foot SRLs from the inside of the cage and feed them through the gap between the cage bottom and the upper cage. (JHA Item #12) 25. Clip the 20 foot SRLs to your fall protection harnesses. a. If a third SRL will be used for instrument installation this should be taken down, by hand, with the workers. 26. Lower the lift at full speed. (JHA Item #13) 27. Once down, unclip your SRLs from your safety harnesses and clip them to the net for safekeeping. (JHA Item #14) 28. Store the cart up against the rails where it was found before cage removal. 29. Follow procedure for the appropriate instrument removal. 9. Procedure Review Once a year or as safety procedures or instrumentation mentioned changes 10. Records 11. References See appropriate instrument installation or removal procedure See Dewar Filling procedure DOC # 2100 AD See NOAO LOTO Policy 2100 AD docx Page 8 of 8