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p 47
Chapter 2
Helical Foundation Systems
CHAPTER 2
HELICAL FOUNDATION SYSTEMS
2.12.2 Equipment
2.12.2.1 Drive Heads
FSI currently offers drive heads that range in
capacity from 5,000 to 20,000 ft-lb of torque.
This range allows for installation of the most
common helical products to their maximum
torsional ratings. Larger capacity drive heads
are available upon request.
Proper selection of the drive head should
consider the torsional rating of the helical shaft,
project installation torque requirements, and the
output pressure and flow rate of the hydraulic
system to be used. All drive heads have
optimum operating specifications that should be
partnered with an appropriate hydraulic system
to achieve maximum performance in the field.
FSI recommends that drive heads have a rated
torque output capacity at least 15 percent higher
than what is required by project specifications.
Hydraulic hoses and fittings should be rated
for the operating pressures required and
specified by the drive head manufacturer.
Hoses and fittings should be checked
periodically for damage and replaced when
in question. Failure to follow manufacturer’s
specifications may result in equipment failure
and/or personal injury.
Drive heads are generally designed with bail
assemblies for mounting to machinery such as
skid steers
(Figure 2.12.2.1.a)
, mini-excavators
(Figure 2.12.2.1.b)
, backhoes
(Figure 2.12.2.1.c)
,
and full-size excavators
(Figure 2.12.2.1.d)
.
Smaller, lighter-weight drive heads may also
be used with hand-held equipment for interior
or limited access installations. Machinery used
to power and operate drive heads should have
sufficient weight and structural capacity to handle
the output torque. A basic rule of thumb has
been a pound of machine weight for each ft-lb of
torque from the drive head. Although a somewhat
conservative rule, machine weight and structural
capacity become increasingly more important with
greater output torque.
Figure 2.12.2.1.a
Skid steer
Figure 2.12.2.1.b
Mini-excavator
Figure 2.12.2.1.c
Backhoe
Figure 2.12.2.1.d
Excavator