1. CMS Gantry for Detector Lowering
LCWS 2018, Texas, Arlington
CMS Gantry for Detector Lowering
John Osborne – Matthew Stuart SMB-SE-FAS

2. Contractor VSL – German Contractor, specialist lifting contractor;
Indoor ski slope in Dubai
Palexpo Roof – Jacked Roof
Specialist jacking equipment
CMS Gantry Crane

3. Scope of Work On completion of shaft excavation;
Concrete “plug” constructed in-situ;
Portique tower foundations constructed;
Building erected for CMS assembley;
CMS Gantry Crane installed.

4. Concrete Plug Concrete “plug Scope of Workconstructed in-situ:
Reinforced concrete with 150 tons of steel rebar.
To withstand a maximum load of 2500 Tons
Secondary function for radiation shielding.
Moveable slab to allow for lowering of detector segments.

5. Sliding Concrete Cover Included in Civil Engineering Contract approx
Sliding Concrete Cover Included in Civil Engineering Contract approx. 1MCHF (in 2004) for max 2000ton loading
Total steel rebar used: 150 tons 23

6. Completed Construction of Concrete Plug24

7. Gantry supports either side of SX5 building :
Piled reinforced-concrete slabs were constructed
8 piles for each concrete slab either side of SX5;
Pile type 2.2 – 15m depth, 1m diameter, 14 x 20mm diameter rebar. `

8. Erection of the Gantry Crane
Erection of CMS Portique over SX5

9. CMS Portique towers

10. Cost of gantry system (contracted by CMS) approximately 2
Cost of gantry system (contracted by CMS) approximately 2.5MCHF in 2005
1 beam approx. 61 tons

11. Main beams had a total height of 3300mm and the flange was 50mm thick, 1150mm wide and the vertical web was 25 mm thick, total effective length 27500mm

12. Gantry load test using the plug
pulling force
2400 t (125%)
Plug 1920t
Dead weight
>800t
Hubert Gerwig, CERN PH

13. 1000ton on mobile platform
Final 1000tons test load slid onto concrete plug
Concrete plug load test 2500 tons Max deflection = 2.8mm

14. Air pad photo 21

15. IRENG07 About the airpads
CMS is built in a surface hall and moves on air pads
These air pads are not really comparable to classical air cussions as
they have nearly no air losses due to a sealing ring
Air control valve
P0 from
Air bottles
2mm steel sheet
P1=30 bar
ground
Rubber sealing ring
Hubert Gerwig, CERN

16. VSL portique Static Test by PH-CMI
Static load test successfully carried out

17. How Strand Jacking Works
A strand jack is a hollow hydraulic cylinder with a set of steel cables (the "strands") passing through the open centre, each one passing through two clamps - one mounted to either end of the cylinder
The jack operates in the manner of a caterpillars walk: climbing (or descending) along the strands by releasing the clamp at one end, expanding the cylinder, clamping there, releasing the trailing end, contracting, and clamping the trailing end before starting over again. 
CE Group 14 September 2006

18. Strand coils and hydraulic jack
Hubert Gerwig, CERN

19. CMS Detector Assembly and Lowering20

20. Opening the plug under the 2000-ton load1 2 4 1 3
Plug 26

21. 2000ton lowering of CMS central barrel

22. 2000ton lowering of CMS central barrel

23. At the time there were some safety concerns about possible “Foucault” pendulum motion might hinder the lowerings, but this was not observed.
Could an earthquake during lowering cause problems?

24. End-cap YE+2
880 tons
Airpad
Hubert Gerwig, CERN PH

25. Some conclusions
CMS gantry concept worked very well with the largest item of 2000ton
CMS concrete platform 2000 tons
Friction factor of an airpad is <1%
Should be no problem for the 4000tons, largest detector item for ILC, BUT it has to be engineered correctly
More details about CMS gantry can be found in this document :