Working Drawings Handbook
benefit from separation into a drawing associated with
service runs (and more particularly any manholes or
inspection chambers within them).
When CAD is being used, of course, the problem is
simplified into a question of layering the information.
When the set is being drawn manually, however, the
remaining site works are best recorded on a single
drawing. If problems of clarity and legibility seem likely to
arise by virtue of the work being unduly complicated,
then common sense will dictate either further
elementalisation or producing the drawing at an
appropriately generous scale.
Most site plans that are unduly cluttered and difficult to
read suffer from two faults:
1 They are at too small a scale for the information they
are required to carry.
2 They attempt to include detailed information —
large-scale sections of road construction are a frequent
example—which apart from crowding the sheet would
more logically appear separately among the assembly
information of which they clearly form part.
Figure 2.23is a good example of how not to do it. There
is no room for the extraneous assembly information on
what should be regarded solely as a general
arrangement drawing, and it is interesting to speculate
on the reasoning that led to its being there. In most
cases it appears for one of two reasons. The first is that
the detail was an afterthought, and since no provision
had been made for its inclusion elsewhere in the set, it
seemed providential that the site plan had this bit of
space in one corner. The second arises in the belief
that it helps the builder to have everything on the one
sheet.This latter misconception extends over a much wider
field of building communications than the site plan and it
cannot be refuted too strongly. No single document can
ever be made to hold all the information necessary to
define a single building element, let alone a single
building. If to place the assembly section of the road on
the same sheet as its plan layout was deemed to be
helpful in this instance, then why not the specification of
the asphalt and the dimensions of the concrete kerb as
well? The road cannot be constructed, or indeed priced
by the estimator, without them. The essential art in
building documentation is not the pursuit of a
demonstrably mythical complete and perfect drawing,
but the provision of a logical search pattern which will
enable the user to find and assemble all the relevant
information rapidly and comprehensively.