MVD Access Lift Table

Debbie Clark, Jan Boissevain, Jehanne Simon-Gillo
Los Alamos National Laboratory

March 12, 1997

PHENIX-MVD-97-7

The Phenix Multiplicity Vertex Detector (MVD) will require an access system for installation and maintenance. The MVD will be located along the Phenix beamline, approximately 5.2 meters above the chamber floor in the 800 mm space horizontal between the large central magnet pole pieces. This position is 2.95 meters above the central magnet lower return yoke. The open space on the return yoke is approximately 1200 mm along the beam direction and 1600 mm perpendicular to the beam direction. Access of the MVD subsystem is best staged from this yoke.

When fully assembled, the MVD is a cylinder, ~600 mm in diameter and 752 mm in length. In addition to the positioning of the MVD in the magnet, workers need easy access to a hand-adjustable alignment system on the magnet pole faces. Workers also need access to the air/water cooling system and the electronic interfaces which will require periodic maintenance. As the available working area is limited, a stationary lift table is proposed for installation and working access to the MVD systems. See Figure 1.

Figure 1.

When the MVD is not installed around the beampipe, it will be transported in a wheeled support cart to and from a cleantent for storage or maintenance. The support cart is located on the floor level of the experimental hall, while the lift table is up on the Central Magnet yoke. A 'lift and slide' mechanism will be included on the cart to facilitate transfer of the MVD to the lift table. The magnet will be accessed from the east side.

Lift Table Requirements:

  1. Accommodate two workers, one on either side of MVD and beamline.
  2. Safe, stable, to include removable handrails and kickplate.
    Hand rails must not interfere with pole faces when table is raised.
  3. Fit in available working space.
  4. Accommodate work load of approximately 600 lbs. (2 people plus equipment).

In English units, the MVD is 18.74" diameter x 29.6" lg. Two workers each require 20" x 30" minimum working room. Therefore, the minimum work platform size is 60" x 30". The OSHA-required handrails for a 36" wide table could potentially interfere with the pole faces on each side of the 800 mm (31.5") gap. Also electronic and cooling connections will be made at the pole faces, so the handrails may need to be be modified to clear this area. A gap in the hand rails could be safely covered by safety chains or a built-in platform.

We propose a commercial lift table that will be permanently bolted to the lower return yoke of the central magnet. The table will be exclusively for the installation and maintenance of the MVD. See location in Figure 2.

Figure 2 showing location of lift table.

As the lower yoke of the magnet is 7.5' above the floor and will presumably have electronic racks and equipment packed around it, a permanent lift table is preferable. The table would be stored in the closed position, taking up little room, but be readily available. In the closed position, the lift table proposed below is only 12.5" high x 36" along the beam x 66" across the beam. The platform and base can be ordered in non-magnetic stainless steel. Additionally, the motor and valving can be located away from lift table if required by space allocation. The limit switch can be adjusted to define a positive vertical stop. We also recommend the incorporation of a velocity fuse for personnel protection, which is a safety lock feature to prevent accidental cylinder collapse. A description and cost estimate of the proposed MVD Access Table follows. This table, including desired options, costs approximately 5800$.

Proposed Lift Table

Southworth Products Corp
Portland, ME 800-743-1000
Albuquerque Vendor- Conveyors and Equipment 505-242-1811

Model no. LSH1-72, Spacesaver Lift, Steel, Weight - 900 lbs.

Capacity - 1500 lbs..
Stored height - 12.5".
Max height - 84.5".
Base dim - 24" x 53" x 3".
Max Platform dim - 36" x 66"
(could be 36" x 63" to fit yoke)
Max usable platform w/
handrails installed - 30" x 60"		.
Elevating time - 58 sec.
Motor - 1.5 HP / 115V.
Cylinders - 1.
Order with footswitch option. $ 5255

Order with these non-standard options:

Removable handrails, OSHA Standard
42" high, includes midrail and kickplate		 $385
Velocity fuse $ 45
Anti-skid surface
1. Diamond tread plate platform		 $ 50
Safety Snap Chains 4 $ 96
Total$ 5831

Special order Lift Table as above is available with stainless steel base and table top. This option will increase cost approximately $3000.