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Below is a report on the ISAC Target Hall crane brake issue observed yesterday and addressed today:
- On April 13th, both the East and West hoist brake assemblies were replaced by Gordon Crane & Hoist, after David observed a burning smell
- The East assembly was replaced with a completely new brake assembly from Kone crane
- The West assembly was replaced with a refurbished assembly, which used the East assembly housing fitted with a rebuild kit by Gordon Crane
- Yesterday while preparing TM3 for a lift, David noticed a vibration / rattle sound coming from the West hoist brake
- This issue was only observed when starting the hoist from a complete stop, at the slowest possible upwards hoist speed
- Once the hoist speed increased, the sound went away, even after returning to a slower speed
- Tom from Gordon Crane & Hoist came in this morning at 7am and replaced the new West assembly with the original West assembly, which had at that point also been fitted with a rebuild kit at Gordon Crane’s shop
- Tom also inspected the East brake assembly again
- Tom commented that he had issues setting the right gap between the friction plates and the brake rotor – too close and the brake would not release properly, too far and the brake rattle issue would be observed
- He also commented that during this most recent repair of the West brake, he applied never seize to the shaft and spline to ensure that this friction point was not an issue
- After Tom finished his repair and inspection of the brakes, David attempted a test lift of an SEG block (10 ton) at the slowest lift speed
- The rattle noise coming from the West brake was still observed
- Travis also tested the slowest speed in Remote Test mode from the control room, with David and Grant present in the Target Hall, the rattle was also still observed
- Tom advised that the rattle would not affect the safety of the hoist, and no damage would be done to the brake assemblies by running the hoist normally with the rattle noise
- Tom ensured that he would consult with Aiden and they would likely order a brand new West brake assembly from Kone
- Tom called Aiden Gordon to confirm that it was ok to proceed
- Aiden called me around 1:30pm and left a message that the slow speed rattle sound was benign and that we could proceed with normal operations, but he would definitely address the problem moving forward, and we should standby for his report
Photos and video have been uploaded to Docushare. The hoist noise before the repair and after the repair during the test lifts can be heard in the videos.
https://documents.triumf.ca/docushare/dsweb/View/Collection-19812
Thanks and regards,
Grant
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Grant Minor, M.A.Sc., P.Eng.
TRIUMF Remote Handling Group Leader
Nuclear Engineer
4004 Wesbrook Mall, Vancouver
BC, Canada, V6T2A3
gminor@triumf.ca
(604) 222-7359
http://www.triumf.ca/profiles/4557
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