Civil Engineering Reference
In-Depth Information
building up stone walling. Consideration of this question in the past has centred
on the numerous (ca 80) juxtaposed radial passages forming the substructural sup-
ports of the
maenianum secundum immus
. h ese passageways were carried up to
2 stories in height and their wall construction has been the subject of controversy.
h e i rst storey of the walls is of sizeable ashlar masonry, but of an idiosyncratic
construction. h e body of the wall is built of relatively sot and weak volcanic stone
(tuf / tufa), but within the run of the walls are several rough piers of hard strong
limestone (travertine). Above the vaulted rooi ng of the i rst storey the limestone
piers continue uninterruptedly up to the inclined rooi ng which supports the cavea
seating. Some writers (e.g. Cozzo) have seen in these piers a rapid structure to
allow the concrete rooi ng to be got under way as quickly as possible, so that the
building of the cavea could proceed without delay, leaving the intervals of wall-
ing to be i lled in with tuf blocks (or
opus testaceum
concrete in the upper l oor)
without prejudicing the overall scheduling of the building.
On the contrary some have seen a more signii cant concern to lie in the uninter-
rupted completion of the vertical passage of similar masonry—i.e. here the stone
pillars. h us they would wish the construction of the stone pillars to their full height
without interrupting the work by construction of the concrete vaulting, and then
all the vaulted rooi ng to proceed subsequently (cf R. Taylor, pp. 145-48).
h is instance is advanced as an example of the divergent ways possible in plan-
ning the building schedule of the Colosseum. In fact the instance does not appear
a good one. h e construction is surely simply an instance of
opus
africanum
, a
construction designed to achieve wall strength as economically as possible by stif -
ening inferior materials and construction through incorporating piers of superior
strength in the walling (v Vol. 2, I, pp. 60, II ills, 112-113).
h e study by R. Taylor,
Roman Builders
, includes a detailed consideration of the
building procedure at the Colosseum, and it should be referred to as a background
to the following brief remarks.
h e building programme formulated by Taylor is based on the assumed use for
ashlar construction of two legger (
dikōlos
) cranes (cf s
upra
, pp. 79, 80) which he
correctly identii es as the “work horses” of Roman building construction, and
which appear on several ancient representations (e.g. the well known relief of
the Haterii funerary monument). h is in some measure conditions his approach
because the multi-l oor nature of much of the building programme involved the
repeated necessity for dismantling and repositioning the cranes when the area of
operation is being roofed. However this assumption of the general use of
dikōlos
cranes is not automatic in view of the ideosyncratic nature of the monument
which requires the cranes to be raised up and installed in lot y, cramped positions
of the building fabric under construction. Certainly although this type is shown
on ancient reliefs etc., it is always shown working on the ground never installed
in such a fashion.
h e Col-
osseum
88, 91
