1. Cryomodule Shipping at JLab: SNS and LCLS-II
Naeem Huque
On behalf of the transportation teams of LCLS-II and SNS
TTC2019, Vancouver

2. Introduction
Cryomodules have been fabricated and shipped from JLab for SNS and LCLS-II
Twenty four SNS cryomodules were shipped from JLab to ORNL (~500 miles)
So far, two tunnel-ready LCLS-II cryomodules have been delivered to SLAC (~3000 miles) from JLab

3. LCLS-II Shipping System
Shipping System Features:
Shipping Frame with an inner bed attached via springs
Trailer fitted with Air-ride suspension
Shipping caps restraining the movement of the cold mass during shipment
The system was designed to limit shocks on the CM to +/- 1.5g in all directions

4. LCLS-II Prototype Testing
Road testing of the JLab Prototype (pCM) was intended to commission the shipping system
The pCM traveled:
JLab to Bristol, VA (750 miles)
JLab to FNAL (900 miles)
FNAL to JLab (900 miles)
The pCM was tested at 2K before and after the trips
Fiducial points on the cavities, gate valves, support posts, and vacuum vessel were measured to check for deformation
Cavity passbands were compared before and after each trip
Beamline and Insulating Vacuum was monitored
After reported failures, J07 also taken on Road Test to Bristol, VA

5. Road Test Highlights Shocks higher than 1.5g spec
A number of nuts and bolts found loose
Some fiducial points found to be out beyond the +/- 0.2mm spec
No loss in beamline vacuum
Cavity performance unchanged
No additional field emission
Tests considered successful on pCM and J07
For J07, beamline vacuum intact, alignment within spec
High shocks on first test run alleviated by changing strapping system
Gate Valve Fiducials
dX (mm)
dY (mm)
dZ (mm)
Specification
± 0.20
Upstream
-0.02
-0.38
-0.19
Downstream
-0.05
0.04
-0.44
Error
± 0.10

6. Road Test Issues
Clamps securing the pCM to the frame came loose during the JLab – FNAL trip
The pCM’s movement caused unusually large shocks on pCM
Cavity performance still unchanged
No extra field emission
Beamline vacuum intact
Fiducial positions mostly within spec
Gate Valve Fiducials
dX (mm)
dY (mm)
dZ (mm)
Specification
± 0.20
Upstream
0.433
-0.010
-0.134
Downstream
0.178
0.251
Error
± 0.10

7. Production CM Shipping Failures
Shipping caps on F06 were installed incorrectly, and pushed against the cavity string
The FPC bellows in F06 failed on its trip to SLAC
The bellows failed due to excessive motion in the beamline direction
The assembly had a resonant frequency of 15 Hz, which was excited during transport
Fasteners in the BPM assembly also became loose, breaking the vacuum seal
The fasteners were found to be Grade-2 Titanium instead of the specified Grade-5
The SHCS were installed without washers
Photos courtesy FNAL

8. Production CM Shipping Failures
Why were the JLab pCM and J07 trips successful?
BPM on JLab pCM used SS studs and bronze nuts, as Gr-2 Ti SHCS used on production CMs were not available
The bellows spool may have been in contact with G10 Shipping Support on J07, restricting movement, and raising the resonant frequency above the excited 15 Hz
A bellows convolution protector present on pCM and not production CMs. The protector reduced bellows motion.

9. Shipping Remedies: Softer Springs
The shock spec was changed to from +/-1.5g to:
+/- 0.3g Beamline
+/- 1.0g Vertical
+/- 0.3g Lateral
A parameter study with different spring configurations found a reduction from 32 to 8 springs met the new spec
Road tests with a concrete CM were used to prove the results

10. Shipping Remedies: Bellows Restraints
Bellows failed due to excessive motion in the beamline direction
A neoprene restraint, the M-Mount developed to reduce the motion
M-Mount could be installed on completed CMs through the tuner access port
Restraint was tested on a shaker table and F05 (after failure)

11. Shipping Remedies: Bellows Restraints
On shaker table, M-Mount reduced bellows displacement from +/-1.2mm to +/- 0.4mm
On F05 road test, the displacement on Cavity 4/5 was reduced from +/- 2.6mm to +/- 0.85mm
Resonant frequency in the beamline axis was increased from 15Hz to 30Hz
The restraint was considered successful
To date, five CMs have been delivered to SLAC using the M-Mount
Analysis courtesy of Jeremiah Holzbauer and Chris Adolphsen

12. SNS Shipping System
Shipping Fixture consisted of two frames, separated by 12 helical isolator springs (Aeroflex CB C2)
1 inch thick rubber between CM and cradles on the inner frame
Fixture is designed to reduce shocks by a factor of 6
Cryomodules held on to the frame by ratchetting straps
Shipping assembly was fitted on a drop-trailer with air-ride suspension
SNS CMs were designed to withstand:
Vertical: +/- 4.0g
Beam-Axis: +/- 5.0g
Transverse +/- 1.5g

13. SNS Shipping Tests
A preliminary test was carried out at JLab using a Quarter-Cryomodule (2000)
The QCM was fixed to a rigid frame, with 1 inch of rubber padding on the cradles
Sensors to measure vibration and shocks
QCM was cold tested after the road test
After the test, vacuums and cavity passbands were unchanged
One beamline flange moved 0.3mm (vs. +/- 0.5mm spec)
All shocks were below the SNS design loads
Maximum Shocks (g)
Vacuum Vessel
Beamline
Vertical
2.8
0.9
Beam-Axis
1.9
1.3
Transverse
1.6
1.4

14. SNS Shipping Tests
The test was repeated with the prototype High-Beta cryomodule (2002)
The CM was loaded on to the shipping fixture, and the assembly installed on a trailer fitted with Air-Ride suspension
The load was driven 400 miles around Virginia
The inner conductor of the FPC was restrained
Maximum shocks all within design limits
Shipping Fixture deemed successful

15. SNS Production Shipping
After successful road tests, SNS cryomodules shipped to ORNL at a rate of one per month
Shocks and vibration data were recorded for all shipments
High shock was recorded while loading the CM into the fixture; procedure was modified to be ‘softer’
Highest shocks were found to be at the ORNL gate!
One cryomodule, HB01 suffered a beamline vacuum leak during shipment
Not initially reported, and CM functioned with field emission and lower energy
The Shipping Fixture is to be modified (due to changes in End Can design) to transport 7 SNS-PPU cryomodules to ORNL from JLab in 2021

16. Cryomodule Shipping Lessons
Install maintenance ports on vacuum vessels
Tuner access ports on LCLS-II CMs have been used for nearly everything but repairing tuners
Conduct shipping road tests prior to starting production shipments
Include shock and vibration spectra separately when creating a shipping specification
Consider sub-component testing of sensitive items (e.g. couplers, tuners, bellows)
Ensure assembly used as testing bed is identical (in sensitive regions at least) to production units
Involve industry at an early stage of shipping scheme development
In addition to paid consultants, some specialized transportation companies may provide advice as part of bidding process
Only employ companies that work with special loads
Variables such as route, speed, road conditions and weather cannot be controlled; a shipping system should be able to handle deviations

17. Acknowledgements LCLS-II Transport Team: SNS Team:
Brian Hartsell, Jeremiah Holzbauer, Josh Kaluzny, Chris Adolphsen, Rob Coy, Ed Daly, John Fischer, Jared Martin, Peter Owen, and Larry King
SNS Team:
Tim Whitlach, Katherine Wilson, Mark Wiseman, and Ed Daly