Grant Minor wrote:

Grant Minor wrote this e-mail today: *** Hello all, During our planned operation of transporting TM4 from a storage silo to the Hot Cell, we had a problem with the East-West bridge drive on the Target Hall crane.  The crane bridge is currently stuck in position over the silo area.  We were unable to complete the transport operation.  TM4 has been placed back down into the silo and the crane hook block has been disconnected from the module lifting yoke. We have been on the phone with Norelco this afternoon and have determined the likely cause of the problem.  There is a splice joint in the crane rails at this position, where a small gap exists between the rail sections.  If the crane bridge is stopped during operation such that the wheel comes to rests in this gap, the crane motors have insufficient torque for the wheel to overcome the gap and ride back onto the rail.  The Norelco tech Mike Smith remembers encountering this problem several years ago (before my time) but cannot remember how it was overcome.  The fix likely involved moving the wheel out of the gap with pry bars. Target Hall Survey Needed at or before 7:00 am, Wednesday Oct 9th (Lynne, Fiona, Danka, Max or Dano?) Mike Smith and possibly a few others from Norelco will come tomorrow morning at 7:00am, and require access to the Target Hall.  Since we have opened the Hot Cell in preparation for the module move, we will need a survey as early as possible to allow Mike and his crew to enter the hall without a suit and respirator. Most of the Remote Handling group will be off-site for a Division meeting, but Travis and Maico will stay for the day to accompany the Norelco guys and help with the problem assessment. Travis: Please take Mike to the control room when he arrives, one of the cameras is currently zoomed in on the wheel and problem rail section. Maico: Scaffolding may be required to get access to the crane rail.  Unfortunately we don't have an operational crane to transport a man-lift into the hall ;)  Please see what you can do to get this ready in case we need it.  Max's leak check might have to go on hold until we get this resolved.  Please take responsibility for ensuring correct Fall Protection procedures are followed.  This means that nobody should be walking up on the crane rail unless they are tied in with harnesses, or there is scaffolding directly under them. I can be reached on my cell phone at 778-319-4612.  The Division meeting is on UBC campus so I can return to TRIUMF fairly quickly if needed. Thank you all for your assistance, Grant *** A photo of the THall camera view of the bridge wheel at the rail splice is attached, as well as Mike Smith's crane inspection report from March 2013.

E-mail from today:

Hello Dave, Jane, Franco, Michael, Don (controls + Franco), Remy,

We have lost the East-West bridge drive control functionality of the ISAC Target Hall crane, and unfortunately this very much prevents us from operating the ISAC facility.

The problem was originally thought to be a stuck bridge wheel but this was not actually the case.

Mike Smith from Norelco was on-site for most of today working with Michael Rowe in an attempt to diagnose the problem.

Mike believes the problem to be one of the following three items:
- input PLC board on the crane bridge
- output PLC board in the interface panel in B1 level Room 5 (ISAC remote crane control room)
- communication between the two boards (festooning hardware)

We are in a pretty dire situation without the ISAC target hall crane, and we lack the expertise within the Remote Handling group in PLC hardware to diagnose this on our own.  I need to ask for somebody's help from the controls group in diagnosing and repairing this problem.

I have notes from my telephone conversation with Mike Smith which I can discuss with a controls representative in the morning.  There is a pretty muddled history of the design and implementation of these controls but essentially Norelco outsourced the PLCs and festooning to a third party contractor, Seattle Crane in the US, which no longer exists anymore.  Neither Kone, Seattle Crane, or Norelco made appropriate as-built drawings of the wiring of the PLCs.  Mike Smith at Norelco had a stack of hand-written notes about the as-built configuration he made at the time of installation in the late 1990's but these notes have not been located yet.

The PLCs appear to be Allan Bradley but the modules are from approximately 1997 and we're not sure if spare units are available.

Mike Smith says the easiest thing to do at this point is install replacement PLC modules on the crane bridge and in the control room that have confirmed functionality.  If control is not restored then the problem is likely in the festooning.

Control of the crane bridge was temporarily attained by bypassing the controls (speed control / end limits, etc.) and sending drive signal directly to the drive motor controller in order to return the bridge to its home position at the access ladder.  This mode of operation is not safe as the crane has no speed reduction / limits to prevent driving the bridge into the walls at max speed.

Jane / Remy / Franco: please let me know who I should correspond with on the controls side and I will talk with them tomorrow morning.

Thanks,

Grant