Re: comments to the draft Pb specifications

["George Lolos" <George.Lolos@uregina.ca>]

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