(created 8/1/07)

Raising the Dome

 

 

List of Ingredients:

-One Crane with two hoists

-Two handcranks

-Lots of spacers (old copper gaskets and foil-covered wood)

-Dome supports (threaded rods and large wooden supports)

-Lots of willing and able people (5 or 6 is ideal)

 

 

 

Before You Begin

 

 

The dome cannot be raised until the PF coils have been tilted and supported.  See Procedures for tilting PF coils

 

To raise the dome the bolts must first be untorqued and removed.  Only the four numbered bolts should be in (but slightly loosened).  For instructions on untorquing the bolts, see Procedure for removing bolts on dome.

 

This is a complicated operation.  More people helping will ensure that it goes smoothly.  Read through the entire procedure before starting to familiarize yourself with the task ahead.

 

Procedure

 

1.  Position the crane so that it straddles the chamber (east to west).  This will almost certainly be difficult because of the beams in the ceiling.  The crane may need to be lowered to straddle the dome. 

 

2.  Make sure the crane is on its highest possible setting.  For instructions on raising/lowering the crane see Procedures for Crane Operation

 

3.  There are 4 metal loops on the dome that are used to support its weight during the raising process.  Attach the black hoists (the ones that are on the crane) to the east and west loops using the large U-shaped shackle bolts. 

 

4.  Attach the handcranks to the north and south loops and to the eylets in the ceiling.

 

5.  Assemble a large number of spacers that can be used during the raising process.  Old copper gaskets work very well for the beginning (the large ones will need to be cut), and wood covered in vacuum foil works well for the end.

 

6.  Tighten the black hoists and handcranks just until there is a tiny amount of tension on each.  Make sure you do NOT start lifting the dome.

 

Now the dome is ready to be raised.  The lifting should be done only with the black hoists, while the handcranks should be tightened periodically to balance the dome.  Under no circumstance should there be a large amount of tension on the handcranks.

 

7.  Loosen the nuts on the four bolts so that there is approximately three millimeters (0.1'') between the lip of the chamber and the nut.   The length of  the bolt that remains under the lip of the chamber may be used to  gauge how much the dome has been lifted.  The goal is to keep this length approximately the same for all four bolts to ensure that the dome is lifted straight up.

 

WARNING: If the dome is not lifted straight up, the leads to the top IL coil may scrape against the chamber and become damaged.  Someone must keep an eye on the leads to the IL coil.

 

8.  Simultaneously lift the two black hoists a few clicks.  Walk around the chamber and insert a copper gasket between the chamber and dome (where there is enough room).  Do NOT force the gasket and make sure not to stick it in too far.  Avoid touching the knife edge with the spacers.  Loosen the nuts on the four bolts until there is again approximately three millimeters between the nuts and the lip of the chamber. 

 

9.  Continue lifting the two black hoists a few clicks at a time and adding more spacers (stacked one on top of another) whenever possible.   Continue to loosen the nuts after every few clicks in order to keep approximately three millimeters between the nuts and the lip.  The nuts are used as guides and should NEVER become tight against the lip.  If the nuts become tight lower the dome a bit and loosen the nut. 

As  the dome rises moniter the number of spacers around the dome and the length of each bolt sticking  out below the lip to ensure the dome rises straight.  If necessary, lift only one side to keep the number of spacers constant around the dome.

 

10.  After every few iteration of step (9) slightly tighten the handcranks.  However, there should never be a lot of tension on the handcranks.  Remember to moniter the distance between the nuts and the lip of the chamber and the space between the IL coil lead and the flange.  Step back after every few hoists and check how level the dome is (by eye). 

 

11.  Once the dome is approximately 5 copper-gasket-spacers above the chamber begin using foil-covered wood as spacers. 

 

12.  Remove the nuts when they come within 5 millimeters of the bottom of the bolts.

 

13.  When the bottoms of the bolt dissappear behind the lip of the chamber they may be removed.  First remove all the bolts that are loose enough to simply pull out.  There may, however, be one or two bolts that are tight against their holes.  To remove these bolts, momentarily rotate and/or tilt the dome until the bolt(s) may be removed by hand.  Moniter the space between the IL coil leads and the flange when tilting/rotating the dome.  Put the nuts in bolts with the other nuts and bolts from the dome.

 

14.  The lifting can now proceed faster.  Continue lifting the dome with the black hoists.  Spacers are no longer necessary.  Simply moniter the IL coil leads.  Periodically step back and inspect by eye that the dome is lifted straight up.  Continue to slightly tighten the handcranks as needed. 

 

15.  When the dome has cleared the IL coil leads, lift the dome even faster.  Periodically step back and inspect by eye that the dome is lifted straight up.  Continue to slightly tighten the handcranks as needed.

 

16.  Lift until the black hoists have reached their maximum height.  Place the knife edge guards and dome supports (four long threaded rods and bolts and large foil-covered wooden supports) in place. 

 

17.  Lower the dome on to the supports.  The weight should rest on the wooden supports.  The rods are simply a fail-safe.

 

18.  Unhook the crane.  Tighten the handcranks one final time.  There should be very little tension on the straps.  The weight of the dome should still rest on the wooden supports.

 

19.  Wheel the crane away.  This will be difficult and may entail lowering the crane to clear the ceiling beams and PF coil supports.  See Procedures for Crane Operation

 

20.  Pat yourself on the back.  Nice Work!

 

 

Lowering the Dome

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