[Corey, Hugh, Scott]
In a continued effort to figure out the Support Tube/V-block discrepancy noticed between H1 & H2, Scott and I tried a couple more measurements (vs the Air Bearing/Air Bearing measurement we made Fri). On Friday, we determined that the distance between Crossbeams is the roughly the same for H1 & H2, BUT visually it looks like the Support Tubes appear to be different lengths between H1 & H2 (on H2, the Support Tubes look smaller and instead of being flush with the V-Block, they are inside the V-Blocks.
Today, we removed the Accelerometer plates of a few H2 Support Tubes, hung plumb bobs off the end of the Support Tubes, made a mark on the floor and then measured the length of the Support Tubes via these floor marks. This was also done on H1 (it was noticeably harder because of all the cables and cable trays).
Aiming to have an accuracy within 1/16th, here are the results from the random chambers we looked at:
Now as a comparison, the drawing for the Support Tube (D972610) shows a Support Tube length distance of 93.190" (~93 3/16"). So, it appears our H1 Support Tubes are longer (whatever that means....beause H1 Support Tube/V-block connections look better).
It appears the extra distance is all in the "nose". We made a measurement from the outboard surface of the Bellows out to the end of the Support Tube, and we could see an obvious length distance here. For the H2 Support Tubes, this distance is ~3 19/32" and for H1 this distance was ~4 3/32".
Notes on attached photos:
Photo#1: The "inboard" H2 Support Tube in its V-Block (at HAM7)
Photo#2: The "flush" H1 Support Tube in its V-Block (at HAM6)
Valved-in IP1, 2, 3, and 4*Valved-out Vertex MTP
Oscar was bailing tumbleweeds Work was done on the automatic raising and lowering of the clean room over HAM6 Dani took Greg, Mark and Bram on a laser safety tour of the LVEA The H1 PSL was turned on for the squeezer experiment
Actually, "motorized" would be a better term than "automatic". For the BSC cartridge install we need the ability to lower the cleanroom to make room for craning the cartridge overhead. Since the crane is occupied with the cartridge we need an alternate mechanism to lower and raise the cleanroom. The prototype system is being tested at the HAM6 cleanroom.
SUS finished the installation (swapping out defective OSEM and rebuilding the flag mounts on the Top Mass) of the OSEMs in the FM Top mass and Penultimate mass. All ten OSEMs in FM1 have been aligned, centered, and zeroed. Mark B. is starting the testing cycle
[Corey, Scott]
Hugh noticed some discrepencies between how the ends of the HAM Support Tubes looked with respect to the V-Blocks (basically, all the H2 ones looked inboard everywhere, and H1 looked better). Scott and I went around to each chamber and took a measure of the distance between bolt holes on the top of the airbearings (to get an idea of the crossbeam/crossbeam distance for each HAM chamber).
Below, shows the measurements we made between Air Bearings. Took linear measurement between Air Bearings (i.e. inline with the Support Tubes). Overall, the measurement looks similar. So, the notable issue is why the Support Tubes on H2 are all in-board of the V-blocks. Are these Support Tubes smaller??
(*Didn't make measurements for HAM6 since there was a suspended Clean Room over it)
| #1 | #2 | Visual Observations of Support Tube wrt V-Block outer surface | |
| HAM1 | 69-5/16 (east) | 69-5/16 (west) | Nice & flush |
| HAM2 | 69-7/16 (east | 69-8/16 (west) | Support Tubes translated to south |
| HAM3 | 69-5/16 (east) | 69-7/16 (west) | Support Tubes translated to south |
| HAM4 | 69-4/16 (south) | 69-6/16 (north) | Support Tubes translated to west |
| HAM6 | Flush with V-Block outer surfaces (very good!) | ||
| HAM7 | 69-4/16 (east) | 69-5/16 (west) | Inboard on both sides by quite a bit! |
| HAM8 | 69-4/16 (east) | 69-5/16 (west) | " |
| HAM9 | 69-4/16 (east) | 69-6/16 (west) | " |
| HAM10 | 69-9/16 (north) | 69-5/16 (south) | " |
Highlights: - Hanford Fire Department work. - Problems with chiller fans, temperature anomalies across the site. - HAM10 staging. - Laser Hazard -> Squeezer work at the PSL table -> Laser Safe.
[Bubba, Corey, Hugh, Nicole, Scott]
After surveying work yesterday (level of the Support Tubes), we leveled up the Support Tubes via the Scissors Tables. Once this work was done, we pulled out the Support Table so Jodi could go in and do some fit checks for cleaning work. The Support Table is still out, and will hopefully get re-installed on Fri.
Restored YBM to nominal status. Also, valved-out XBM MTP and valved-in IP6
BS/FM 1 fully assembled. BOSEMs installed on Top Mass and PenRe. Full/No Light counts completed for Top Mass BOSEMs, and flags have been centered at 50%. PenRe BOSEM Light Counts will be completed today and then the flags will be centered. BS/FM 1 will be ready for testing and TF by the end of the day. Working with Rai Weiss to determine secondary prism location on FM Dummy Test Mass.
CP1 and CP2 may alarm during the night if the outside temperature drops too low for too long (ongoing issue with moisture in actuators freezing). I will monitor from home. Permanent fix pending time availability.
No major work done today
FMCS was down, I restarted it by running the fmcs.pl script on h0tempmon - the wiki says this is supposed to run on h0vacman, but that computer is not connected to the network.
FMCS software does indeed run on h0tempmon, I have modified the cds wiki entry
Highlights (times in PST): 09:19 - Hanford Fire Department done at MX 09:35 - MX alarm system is back online 09:53 - Praxair leaves 10:00 - UniFirst arrives 10:10 - Door forced at Fiber Lab, Doug informed, could be Richard/HFD working on something 10:35 - Sewage maintenance arrives 10:51 - Staging for putting anchor bolts at HAM12 13:49 - HFD returns 13:51 - Jodi sends crew to clean chamber at MX Rai Weiss will be giving an introductory LIGO talk on Thursday at 1:00 PM in the LSB auditorium. All are invited.
[Chris, Corey, Greg, Rodney, Zak]
The BSC4 SEI System was disassembled, put on pallets, and rolled out of the LVEA (Down Tube will be cut so the Support Table can be used), and eventually will be rolled outside to await recycling.
Entered BSC4 via HAM10 to check on accesibility of lower Support Tube bolts to "vertically challeneged". It's possible to reach the bolts, but it's a little bit of a stretch. (the use of Jim may need to be entered into the De-Install procedure)
The Dome was re-installed on BSC4 with no issues.
This completes removal of H2 iLIGO in-vacuum Seismic Isolation systems from the LVEA (except for the HAM Support Tables...they'll stay in until after HEPI installation).
[Chris, Corey, Dave, Jim, Mark, Nicole, Randy, Rodney, Steve, Zak]
After a late morning start, we commenced taking the BSC4 Dome at around 10:30am, and finished this around 11:40. After lunch, on O2 sensor reading was taken of the BSC4 chamber, Jim accessed the chamber via HAM10 (Zak & I acted as "spotters" to keep an eye on him while he was in a non-permit confined space), Jim disconnedted the Support Tube Bolts & the cabling from inside the chamber. Platforms were then installed and the Seismic Stack was pulled out from the chamber and laid down near the Large Roll-Up door. The Down Tube was rotated and laid down on the top of the Optics Table (we can de-stack this assembly tomorrow). Note: 8' straps don't allow for easy twisting of the Down Tube.
The other theater of SEI work in the LVEA was the cutting of the BSC8 Down Tube. The Down Tube was cut so the Support Table could be pulled out. The Support Table will be used as a hard fixture to maintain Support Tube rotation and position for the Mid-Station Chambers that get moved to the End Stations. (photos of the hacked Down Tube are attached)
Forgot to make mention of this in the elog from yesterday, but while inspecting the seismic stack for BSC4, just before lifting it out, we found an oddity: a rogue aluminum part. For the BSC Seismic Isolation stack, the Optics Table and Down Tube fit through a hole in the Support Table. There is a gap here between 0.5-0.75". But yesterday it was discovered there was a loose part closing this big gaps to just millimeters (see the 4th & 5th photos from the elog above). This part was loosely laying on the Support Table. It wasn't contacting the Down Tube, but perhaps during a big enough seismic event, this could cause a "seismic short" between the "ground" and the isolated Optics Table.
Attached is another photo of this mysterious part.
Wanted to write up a little something from the recent BSC4 work--especially while it's still fresh in my brain. This is mainly with regards to Safety related items.
The De-Install of an iLIGO PISI (Passive Internal Seismic Isolation) system is a major site activity encompassing several different and unique safety situations. Some of the issues have been documented and are familiar, but there are also other issues we need to be aware of or address in the future. Mark Hankel has brought up several points while observing our recent de-install, which will be helpful for next time. Below, I've bulleted some safety-related notes to keep in mind for this (and similar) activities.
Working From Elevation
Fair amount of work requires personnel to work at high elevations within a Clean Room (i.e. on top of Beam Tubes, Cross Beams, etc.). When one needs to work from these high elevations and can't work from a platform ladder, they must first connect to a Deceleration Device. On our BSC Cleanrooms the Deceleration Devices will be left connected to the recently-installed Anchoring Brackets on the Clean Room. We need to also leave a "tag line" connected to the Carabiner of the Deceleratin Device so one can pull it to one's person and attach it to their harness for high elevation work.
On a related note, there was some work/observation from the nearby Mezanine. We want to make sure personnel do not climb on the railing; the railing is the designed fall protection for the Mezanine. If viewing is an issue, perhaps the manlift can be used. Or simply rely on the hand signals of the person directing the craning activity.
Something to consider with all of this safety rigging: we now have much more combersome straps and gear on us. It does make walking around a little tougher than what we are used to. Sometimes it feels like there is a potential for the fall protection to actually cause a fall. The other issue is our Deceleration Device Anchors. We only have two Anchoring brackets in our cleanroom. It would be nice to have another pair of anchors available such that we don't have to extend the Deceleration Devices to their limits (this is what happened during Platform installation).
Mark has mentioned that our Fall Protection rigging should be all purchased from the same vendor. Mixing different componenets may nullify their ratings.
The ring at the back of our harness can be hard to access. An extension proved to make connecting the Deceleration Device easier. (we only have one on site as of now)
Non-Permit Confined Space
Mark et. al. have classified our Dome-less BSC2 & BSC4 (with an adjacent HAM Chamber door removed) as Non-Permit Confined Spaces. With this space, we decided an O2 reading should be taken of the chamber before occupying it. The cover was partially removed from the top of the chamber and an O2 Sensor wand with ~6' of tubing was dropped into the chamber to take readings. This is a dirty device, so did our best to not contact/contaminate in-vacuum surfaces. Readings were taken outside the chamber (20.8% O2), ground-level within the chamber (20.9% O2), and chest-level within the chamber (20.9% O2). We used an OXOR III O2 Sensor. After we saw adequate levels, entry was made, and a "spotter" was located at the HAM10 door entry the entire time someone was inside BSC4.
Critical/Heavy Loads
For this work we have several lifts of heavy loads. During these activities we do not want anyone under a load under a load. The toughest action related to this is draping covers under the Dome and over the BSC Chamber while the Dome is suspended inside the Clean Room. It is possible to walk a cover from one side to the other without needing to put a hand under the load; it was helpful to have spring clamps to help hold the initial end of the cover on the flange.
When handling the individual Leg Element masses it is acceptable to pull stuck Viton Spring Seats off from underneath the masses by hand, but using a tool could also be an option here.
Without the crane, the other tough loads to handle are the BSC Chamber Platforms. These need to be kept clean and taken up to the top of the BSC Chamber by hand. This can be a cumbersome task.
Discussing/Talking Out Activity Before Starting Work
We currently meet and go over the procedure and hazardous analysis for activities such as this amongst all people who will be involved with the work and Mike Landry. This has been a one-time occurrence at the beginning of the first time one is involved with the procedure. It may be beneficial to have more of a "before work" talk about the work. Here we can go over what we're doing, safety issues, input from people to make it go smoother, etc.
Received 12:30 phone call notifying monthly testing of Hanford alarms. Hanford fire department was performing regularly scheduled maintenance at the outbuildings. BSC4 Passive ISI stack was removed. The dome will be replaced and the stack disassembled tomorrow. Oscar was bailing tumbleweeds. There was an oil drum delivery for Hugh. The metal recycling was picked up. h0epics2 was restarted, and the motor controllers running on h0epics1 were moved over. I had to restart dust monitor locations 3 (BSC4) and 6 (Diode Room). Location 1 (ISCT4) still needs to be restarted. They had been on hold for an unknown period of time. There is an unresolved problem with the central control for FMCS.
