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Full text of "Modern Mechanical Engineering Vol-I"

16                    DRAWING-OFFICE   ORGANIZATION
retaining walls, and block plans have to be prepared for the local Building
Authority. These rules are generally very rigid, and must be closely adhered
to. If the contractor fail to comply with them, he is liable to be asked to
pull down much of what he has erected and to build afresh. It is therefore
important to get the plans approved by the competent authority as early
as possible.
Tests.—Another important aspect of the work of the design office is
to attend at all tests, and to collect and collate the results of them for future
guidance.   It is very essential to note very carefully the conditions under
f|                               which any test is carried out.    These conditions should be all carefully put
n                              down on the standardized data-sheet, in which the results themselves are
!                                shown.    The usual method of keeping these results is to have white prints
I                               made from a tracing, which show all the various items to be noted.    The
I,                              figures and remarks are marked on these sheets in pencil, and the whole sent
|                               into the tracing office and traced.    Photographs, either in white or blue,
I                               can then be filed for reference.    In addition, it is usual to enter the more
I                               significant items in a book, as, if dependence is placed absolutely on loose
I                               sketches, there is always the possibility of some of them being misplaced or
I                               lost.    It should be the duty of someone in the office to see that all data-
|                               books and sheets are carefully put away at night in the fire-proof safe gener-
'£,                              ally provided for this purpose.
1                                     It is usual to plot test results in a graphical form, and to find how much
;[,'                              any particular job may vary from normal practice, and if necessary to bring
F|I                              that normal practice up to date.    It may be found, for instance, that for
ftp                             some special reason higher working-stresses than usual have been used.
^                              If this special practice be repeated on several occasions, and the results are
');                             found to be satisfactory, it may be possible to bring the normal practice
into line with this special practice, and to alter the basic formulae accordingly.
Functions of Design Office.—The main detailed drawings and cal-
culations should be submitted to the design office, in order to ensure that
the general principles of the design have been carried out.
It will be seen that the design office has a double function in the pre-
paration of designs. In the first place, it has to prepare designs for esti-
mating purposes. The design for this phase must be accurate, but gener-
ally need not be given in so much detail as when prepared for the detail
office. Indeed, when prepared for the latter, it may be found highly desir-
able to considerably modify it so as to suit existing patterns, standard gauges,
templets, and conditions, which could not have been foreseen when the
original draft designs were prepared. The " estimate design " itself may meet
with considerable alteration at the hands of the purchaser.
Necessity for Full Information.—It is essential in the design office
that the fullest possible information should be put before the draughtsmen,
both in the shape of correspondence, similar designs from the firm's own prac-
tice and from elsewhere, and the latest scientific and technical information,
either in technical publications or the proceedings of learned societies.
Staff and Discipline.—From what has been said regarding the arrange-
i
f
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