Greenlee Textron Inc. / Subsidiary of Textron Inc.
6
8,000 lb. Capacity Hook-Type Cable Sheaves
Example:
In this example we’ll pull up out of a manhole using the Ultra Tugger
TM
cable puller. The pull force is unknown so
we’ll assume the maximum rope tension will be 8000 pounds. First, we’ll need to measure some angles.
1.
We measure angle
θ
between the rope legs as 70 degrees.
2.
We measure angle A between the extended line of the frame and one anchor line either directly as 35 degrees
or by measuring angle C as 110 degrees and calculating angle A from Formula #2:
A = 180 - 1/2 x
θ
- C = 180 - 1/2 x 70 - 110 = 35 degrees
3.
We measure angle B between the extended line of the frame and the second anchor line either directly as 45
degrees or by measuring angle D as 100 degrees and calculating angle B from Formula #2:
B - 180 - 1/2 x
θ
- D = 180 - 1/2 x 70 - 100 = 45 degrees
4.
Calculate the hook load “R” from Formula #1:
R = 2 x T x sin((180-
θ
)/2) = 2 x 8000 x sin ((180-70)/20) = 16000 x sin(55) = 13106 pounds
5.
Calculate the loads on anchor points 1 and 2 from Formula #3:
R1 = R/{cos(A) + sin(A) / tan(B)} = 13106 / {cos(35) + sin(35) / tan(45)} = 9410 pounds
R2 = R/{cos(B) + sin(B) / tan(A)} = 13106 / {cos(45) + sin(45) / tan(35)} = 7633 pounds
Summary:
Rope Tension: 8,000 lbs.
Load on Hook: 13,106 lbs.
Load on Chain 1 and Anchor 1: 9,410 lbs.
Load on Chain 2 and Anchor 2: 7,633 lbs.
8000 LBS.
ANCHOR
#2
ANCHOR
#1
ANGLE B (45
°
)
ANGLE A (35
°
)
ANGLE C (110
°
)
ANGLE
θ
(70
°
)
ANGLE D (100
°
)
www.
.com
information@itm.com
1.800.561.8187
