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3.6 INSTALLATION OF BOTTOM BRACKET AND
CARRIER CABLE TENSION ADJUSTMENT:
Before installing the bottom bracket it is recommended
that the ladder and/or climbing structure be evaluated by
a qualifi ed engineer to determine if the load requirements
for the system specifi ed in section 2.3 are met.
NOTE:
Depending on the length of the system, and
the environment in which the system is installed,
it may be necessary to periodically re-tension the
system. Extreme temperature ranges and very long
systems will likely require periodic re-tensioning.
The tension indicator can be purchased separately.
Contact DBI-SALA for details.
A. INSTALLATION OF BB-1, BB-2, BB-3, AND BB-9
BOTTOM BRACKETS:
Direct Connection to Ladder:
See Figure 22 for a typical installation of the bottom
bracket onto a ladder. Some brackets utilize “U”-bolts
while others utilize bolts and clamp plates to attach
to the ladder (see Figure 2). The bottom bracket
should be positioned to allow users safe access when
connecting or disconnecting from the system. The bottom bracket must be mounted in-line (vertically)
with the top bracket.
WARNING:
One rung clamp is designed to bolt through
the bracket and onto the rung. This clamp must not be
omitted, or the bracket may slip under load.
Install the rung clamps using hardware provided. Do
not substitute other fasteners. Torque fasteners to 20-
25 ft-lbs (27.1-33.9 N-m).
Stand-off Support Connection:
Figure 23 shows the installation of the above bottom
brackets using a horizontal stand-off bracket. Use hex
bolts provided in place of U-bolts to attach the bottom
bracket to the horizontal stand-off. Torque fasteners to
20-25 ft-lbs (27.1-33.9 N-m).
Carrier Cable Tension Adjustment:
Figure 22 shows the assembly of the tension rod to the
bottom bracket and carrier cable. Loosely clamp the
saddle clips around the carrier cable. Slide the tension
rod down the carrier cable and through the hole in the
bracket until suffi cient threads are exposed to allow
the installation of the tension indicator, washers, and
nuts. Remove the slack in the carrier cable by the
pulling cable though the saddle clips. Tighten saddle
clips to 35 ft.-lbs (47.5 N-m). Tighten the tensioning
nut until the ring on the tension indicator is sheared off.
A small amount of grease on the tension rod threads
will reduce the effort required to tension the carrier
cable. If there are insuffi cient threads exposed to
fully tension the carrier cable, pull more carrier cable
through the saddle clips on the tension rod and repeat
the procedure. When correct carrier cable tension is
reached tighten the jam nut against the tensioning nut.
Cut off excess cable just below the lower saddle clip.
Figure 22 - Installing Bottom
Brackets
Figure 23 - Installing Bottom
Brackets to Horizontal Standoff
