[alma-config] move antennas starting from

[Leonia Kogan]

Hi Max,

Thank you very much for your response.

I'd like to clarify my idea of eating the configuration from inside.
First of all I want to lay aside the problem of repair of antennas.
I have excluded the requirement o to have an access to any antenna at any time.
Let me discuss this requrement later.

Now lets consider the R150_NOROAD.6 configuration specifically.
I do not consider the two circles as roads. I consider only one road (30m width)
leading from the right to the inner antennas 1, 6.

I see the following sequence of the antenna transporting:

1. Got to antenna 1. I think(?) there is a good access to the antenna 1.
   take it and remove it.
2. Do the same job with antenna 6

   Now we have pads 1 and 6 without antennas and the spase between the 
   centers of the pads 1 and 6 >=15m
   Here is the crucial point: Is this space enough to pass transporter 
   with antenna. I thought it is enough. If not the following does not work.

3. Pass through the gate between the pads 1-6 to the center and pick up 
   the antenna 3. Return back with the antenna 3 passing through the gate 
   between the pads 1-6.

4. Repeat the item3. with antenna 4, 2, 5

   Now have the six inside pads without antennas. The distance between 
   the pads is >=15m. Again if this space is enough to pass 
   transporter with antenna, we can get the access to the antennas of 
   the second circle passing between the epty pads of the inner circle.

5. Having finished the second circle we have epty pads of the second 
   circle and can start removing of antennas of the third circle.
   (again if the space 15m between the empty pads is  enough to pass 
   transporter with antenna)

An so on.

   So the crisial point is:
  
   Is the space 15m between the empty pads enough to pass 
   transporter with antenna?

Thank you 

Leonia

----- Begin Included Message -----

>From mkraus at eso.org Thu May 10 09:26 MDT 2001
Date: Thu, 10 May 2001 17:26:26 +0200
From: Maximilian Kraus <mkraus at eso.org>
Organization: European Southern Observatory
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To: Leonia Kogan <lkogan at zia.aoc.NRAO.EDU>
CC: Torben Andersen <torben.andersen at astro.lu.se>
Subject: move antennas starting from
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Status: RO

Hi Leonia,

finally I imported your 2 compact config's with the names(?)
R150_NOROAD.3 and R150_NOROAD.6 into Autocad, to get a picture and the
distances between antennas.
Concerning your proposal, to remove antennas starting from inside, I
would prefer to use the still existing '20m ring road', instead of
driving between 1 and 6,  etc. The reason is, that in my opinion we
should avoid to drive over the pad foundations, although they are
specified for that.
I assume they will be calculated 'classically' for resistance against
stresses, but it will be difficult to assess, if there are
micro-movements, e.g. because of the non-linear behaviour of the soil.
Avoiding driving over the pads would be a desirable goal in my opinion
for many reasons.

In principle, removing antennas with both conifg's  would be o.k.,
because the ring road has the minimum width of 20m. But the config
R150_NOROAD.6 has very narrow entrances to the ring road (20.3m and
21.1m), and there the transporter has to drive  a curve, therefor
R150_NOROAD.3 is much better for the transporter.

Antenna removal from inside makes the situation easier, because we have
antennas only on one side close to the transporter. We can start with 1,
then 2, then 3 ... to eat first the inner ring while driving on the 20m
inner ring road, then 7, 8, 9... eating the second ring. There is enough
space in both config's.

But we must consider also picking out an antenna for repair.
Also that is possible, if we allow to remove 1 or 2 antennas before
getting to the broken antenna, and switching off few antennas for few
hours.

 As a conclusion, R150_NOROAD.3  is better from the transporter side of
view.
R150_NOROAD.6 is still feasible, but at the limit. The antenna pairs 1-7
(20.3m), 6-18 (21.1m) and 4-14 (19.9m) are critical.
I will do some more detailed investiagtions, and tell you, if I ffind
something new.

Sorry for the late reply.

Max Kraus
ESO Garching
phone +49 89 32006 - 392
fax      +49 89 32006 -358




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