Of the light steel forms, the most important on the market are the
Metaforms and the Morrill forms. The Metaforms, originally the
Reichert forms, are composed of individual form units. All units are
standardized and interchangeable, and equipped with the necessary
clamps and locking devices. These units are built of sheet steel,
strongly reinforced, and measure 2 feet square. A single course of
Metaforms is composed of an inner and outer shell of plates. As the
work progresses the bottom course is taken off and placed above for
the next, there being usually three courses of forms in operation.
The Morrill form is also a sheet-steel form, only it uses a hinged
“swing-up” construction, by which the lower courses of the form can be
swung up into position for the new course as the work progresses.
The Van Guilder double-wall machines have been gradually
increasing in use throughout the country. They are not for
sale, but the company establishes a contracting organization in
different centres. The machine is a steel mould which is moved
along and upward as the concrete wall is tamped in it. It builds
a double wall in tiers. Each tier is 9 inches high and 5 feet
long. A complete circuit of one tier is made around the wall,
and then the next tier is begun on top.
[Illustration: 23. A double monolithic wall built by the Van Guilder
machine.]