Magnet move summary, addendum to the previous lot
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Rolf, Thanks for the advice on the monitor, and some anecdotes about our
move of a live magnet (that QE-300) a few years ago. We had an ex-GE,
then Bruker field service guy come out and he just picked it up with an
engine hoist, unbolted the legs, and off we went. It went down the hall
to the elevator, down two floors and down another hallway to its new
location. It was not particularly difficult with some advance
preparation. Some Oxford magnets have base flange bolts that are changed
after installation to allow the seal to open a little bit in case the can
is ever accidentally brought to greater than atmospheric pressure (which
can happen, for example, if the main vacuum valve is opened with the
inside very cold, a lot of air condenses inside, the valve is closed, and
the can warms to room temperature). If so, the original bolts have to be
reinstalled. The magnet should of course be rolled very gently, with
particular caution e.g. going through steel door frames. We got a scrap
piece of thin masonite flooring, and each time we came to a joint in the
floor, we taped the masonite down over it so the magnet would not be
jolted by the passage.
We had a signal in the new location in just minutes, and the homogeneity
was as good as before. The magnet has been essentially fine ever since
except its helium boiloff ratcheted up somewhat. It is possible something
broke or shifted when we moved it despite our care, but the cost of the
extra helium is nothing compared to the cost of opening it up, so we have
left it alone.
The field service guy said he had done these live moves with magnets up to
an unshielded 500 MHz standard bore magnet. That was a somewhat nerve-
wracking move because the stray field was sufficient to cause some
unanticipated problems, like a fire extinguisher cabinet door suddenly
flying open as the magnet passed it (fortunately, the fire extinguisher
itself did not follow). With advance scouting, that could be avoided.
Good luck, Dave Vander Velde, University of Kansas
Rolf, I forgot to mention yesterday that the magnet was moved on the base
of the original plywood shipping carton, pulled by a pallet jack. The
engine hoist was just used at the beginning and the end to rig the legs.
Using the engine hoist alone would probably only be suitable for very
short moves, such as within a room. Dave Vander Velde
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Rolf, we moved a cold 250 MHz magnet about 3 years ago for 400m or so. I can
give you details if you cannot find anything in the archives.
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Dr. Iain Cook
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Hi Rolf,
I just moved a 360 energized with no problem. We just moved it across
the hall. But, several years ago we moved it from one building to another
one that was attached. The route was not very complex but did involve
putting it in an elevator and going up one floor. The elevator was rather
large. But the entire move was completely uneventful and we were down for
about one day. 360 is the highest I have moved energized.
Jane Strouse
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Rolf -
We recently had to move two systems: an NT-360 and a Varian
Unityplus 500, in order to make room for a new spectrometer. We had
previously purchased an aluminum tripod (B. E. Wallace Products Co.)
and have found this to be a good investment. We hoised up the NT-360
magnet, removed the legs, and lowered it onto a wooden dolley (sp?)
and just rolled it into another lab in the fully charged state. We
then hoisted it up again and replaced the legs. Amazingly, the
lineshape after the move was better than the value prior to the move,
adn this was all accomplished in a few hours. This has given me
considerable confidence about moving live magnets.
For the Varian 500, we were very tempted to follow the same
procedure, particularly since we were only moving the magnet about 15
feet. However, the round bottom dewar requires that the magnet be set
in the packing crate or some specially constructed support. In this
case, we were more concerned with being sure that the magnet survived
the move. Varian gave us an outrageously high quote for moving the
magnet, so we went with Cryomag services to take down the field, move
the magnet, and bring the field back up, and also hired Piotr
Starewicz from Resonance Research to re-shim the magnet after the
move. This was still a real nightmare and took many weeks of work.
Also, Starewicz could not get the field back to the previous level of
homogeneity, and we spent a great deal of time working on it
ourselves. I would strongly recommend moving a magnet at field,
particularly if the new site is on the same level, but with great
caution. Most of the magnet experts with whom I have spoken about
this are horrified by the prospect of moving a live magnet and claim
that a 500 would be MUCH trickier to move, but in our case, it worked
much better than the alternative approach. I haven't really heard any
solid reasons for why this is a bad idea (assuming that it is done
carefully and that one doesn't, for example, try to move it past a
large, iron object).
Hope this helps.
Bob London
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Rolf,
When Karen Ann worked here, she collected these stories in 93.Probably too old for the archives.
>Date: Tue, 20 Jul 93 15:09:10 CDT
>From: "Karen Ann Smith" <kasmith_at_iastate.edu>
>
>A couple of weeks ago I asked about moving magnets, in particular from the
>basement to the first floor. The replies have stopped, and I have sometime,
>so here are the results:
>
>I posed a question about moving nmr magnets to three groups, the AMMRL list,
>the Bruker Users list, and the Varian users list. I got back about 30 replies.
>They can be summarized as follows:
>
>Stories:
>
>About 5 people have moved magnets cold to another location on the same floor of the building.
>About 6 have moved magnets at field to another location on the same floor;
>several made a point of mentioning short distances or "just across the room".
>
>Several people warmed up magnets before moving them to a different floor or a
>different building. Nine moved magnets cold. Seven people responded with
>stories of moving magnets at field on an elevator! Two of these were
>second-hand or vendor stories. The rest were 200, 270, 200, 250 (all narrow
>bore), and a 200/89 plus 300/51. So it can be done!
>
>Advice:
>
>A couple people said to warm the magnets up; a couple voted for at field (at
>least the 200), and over 20 said move them cold.
>
>One vendor engineer replied and said cold is OK if we are careful. MR
>Resources, if we were to contract it out, would only move them warm. Oxford
>might move them cold, but would want to see the route before committing.
>
>Several people suggested using this as an excuse to warm the magnets up and
>replace seals and getter, etc. As one magnet had this done in 90, and the
>other two were new in 87, we are not really considering this. (All systems
>have like-new boil-off and hold times.)
We did move them cold on 1/2" aluminum carts with soft rubber wheels.
They're all still working.
hth,
dave scott
iowa state university
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Hi Rolf,
what exactly is your problem?
Maybe a few short comments.
Is this picture of interest for you?
http://www.org.ch.tum.de/pages/900mhz/bild4.html
This 200 MHz magnet is charged, the same transport was made
with a 250 Mhz magnet. No problem.
You even can move a charged 500 MHz magnet. Unfortunately I haven't the correct
translation for the device needed for this transport. "Forklift" is the wrong word,
it is a more flat device. Anyway, the procedure is as follows:
pressurize the damping feed
Take this difficult to translate device with 4 weels
One person must stand at this device
Move the two forks under the ground plate of the magnet
the person of course can leave this device now
Now you can move the charged magnet. Of course there must be
no even tiny obstacles along the way. Done more than once by
Brukers magnet specialist Neubert. And as a last possibility you can
even move charged 600 MHz magnets but you need these mini
hovercrafts for this action. These are the same devices as used for the
installation of the 750/800 MHz magnets.
Best regards
Rainer Haessner
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Hallo Rolf,
Wir haben unseren 250er Family inzwischen 5 mal umgesetzt, incl. Transport
durch Türen und Flure. Es war einfacher als gedacht.
Geholfen hat uns dabei Marcel Neubert / Bruker (+49-721-5161-154 bzw. über
-155).
Weitere Fragen?
Grüße aus Bankfurt von
Johannes Zimmermann
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Thank you all, and Cheers Rolf
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Rolf Tschudin Tel. 1 301 496 2692
National Institutes of Health Fax. 1 301 496 0825
Bldg. 5, Rm. B2-29
Bethesda, MD 20892-0505
USA e-mail: tschudin_at_nih.gov
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Received on Mon Aug 14 2000 - 16:28:52 MST