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

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

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.

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.

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

Completed Construction of Concrete Plug 24

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. `

Erection of the Gantry Crane Erection of CMS Portique over SX5

CMS Portique towers

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

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

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

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

Air pad photo 21

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

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

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

Strand coils and hydraulic jack Hubert Gerwig, CERN

CMS Detector Assembly and Lowering 20

Opening the plug under the 2000-ton load 1 2 4 1 3 Plug 26

2000ton lowering of CMS central barrel

2000ton lowering of CMS central barrel

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?

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

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 : https://edms.cern.ch/document/1715491/1