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Re: comments to the draft Pb specifications
Thanks George. Chuck and I will get together and incorporate this into
the schedule.
Tim
George Lolos wrote:
> Hi Tim:
>
> In response to my comment on the BCAL construction schedule1,
> particularly on the amount of time it takes to swage lead and bundling
> up the fibers, let me give you short take how these operations are done
> and to also answer Elke's question whether these preparatory operations
> are done in parallel or serially to the matrix construction. Feel free
> to ask for clarifications and to exchange ideas of how to incorporate
> the time it takes for this operation into the schedule.
>
> The construction operation goes like this:
>
> 1. The press frame(s) is (are) opened up in the morning. The last lead
> layer(s) is (are) cleaned and prepared for the day's construction. This
> takes about 30-45 min.
>
> 2. The results of the previous day's operations are inspected and
> dimensional measurements are made and recorded. This takes about 15
> min.
>
> Manpower for this "start up" of the day's activities is two students.
>
> 3. The fiber bundles for the first few layers for one module are laid
> up on the table, cleaned up from possible dust, discharged of any static
> build up and be readied for operations. Manpower for this is one
> student and this operation proceeds in parallel to operations 1 and 2,
> above. The student for this operation is dedicated to that particular
> task and he/she has to be kept free of any epoxy and keep the
> static-discharging gloves clean of all lead and epoxy. This operation
> takes about 30-45 min, depending on the number of layers prepared in
> advance. The student will keep on laying up fibers for the duration of
> the day's construction.
>
> 4. Epoxy is prepared when operation 1 is completed. Manpower required
> is one student. This takes about 10 min per batch. It has to be
> repeated every time the mix is depleted and, in order not to delay
> construction and waste time, the student cannot be one of the minimum
> number required for the matrix built-up.
>
> 5. With the first batch of epoxy at hand, lead rolls and fiber layers
> ready for construction for the step layers of the day, the matrix
> construction starts. Minimal manpower requirement is three students
> who will handle lead and epoxy. This takes about 90 min per module
> before viscosity of the epoxy demands end of operation and pressing and
> curing for the day.
>
> So, for the "prototype" or 49th module, we require a minimum of four
> students and the day's activities for one module take approximately 135
> min and to account for this and that that add up, I would say it takes
> realstically 2.5 hours from the time the students have their protective
> coats and gloves on to start pressing. For the second module it takes
> a bit less since things are already set up for the day. Therefore, for
> one day's module construction, the students are busy for approximately
> 4.5 hours.
>
> Lead cutting requires a minimum of three students. To swage the sheets
> it requires a minimum of two students. To cut 200 sheets it will take
> approximately a whole day, perhaps a bit longer since the cutter has to
> be adjusted for every "step width" of the pyramid construction.
> Swaging 200 sheets takes another day because slight "banana" effects are
> almost unavoidable and manual operations for straightening, labeling and
> rolling them take time. I would say that for the 49th module that
> starts operations we can count on three or four days for lead handling
> alone.
>
> The time management, however, is a bit more complicated because lead
> cutting and swaging can proceed in "serial-parallel" mode with
> construction. After the day's matrix construction is done, the
> students can spend another 3 hours preparing the lead for next day's
> operation and still have time to keep piling up grooved lead sheets as
> stockpile.
>
> I hope this gives you a time line of operations for us to iterate the
> construction schedule.
>
> Cheers,
>
> George
>
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fn:Timothy Whitlatch, PE
n:Whitlatch;Timothy
tel;work:757-269-5087
tel;fax:757-269-5279
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end:vcard