01/11
rev. 3/6/2017
LM, MANUAL
Copyright 2016 Vestil Manufacturing Co.
Page 8 of 28
The center of gravity of the boom changes as boom length changes. As shown in the diagram below, the horizontal
center of gravity may be located at any point from RHCG to EHCG:
Retracted horizontal center of gravity (RHCG): boom fully
retracted
, and load attached at position A. RHCG is
measured from the “origin point” of the above diagram (edges of the fork pockets);
Extended horizontal center of gravity (EHCG): boom fully
extended
with a load attached at position J. EHCG is
also measured from the “origin point” of the above diagram (edges of the fork pockets);
All other combinations of boom extension and load position produce a horizontal center of gravity located
somewhere between RHCG and EHCG.
FIG. 2D: LM-OBT- 4k, 6k & 8k Centers of Gravity and Maximum Load Ratings for Varying
Load Attachment Point and Boom Extension Combinations
Hook
position A B C D E F G H I J
Distance from mast
end of boom
36”
(91cm)
48”
(122cm)
60”
(152cm)
72”
(183cm)
84”
(213cm)
96”
(244cm)
108”
(274cm)
120”
(305cm)
132”
(335cm)
144”
(366cm)
Maximum rated load of a load suspended from a
single
hook located at the corresponding “Hook position”.
LM-OBT-4k
4000 lb.
(1820kg)
3750 lb.
(1705kg)
3500 lb.
(1590kg)
3250 lb.
(1477kg)
3000 lb.
(1363kg)
2750 lb.
(1250kg)
2500 lb.
(1136kg)
2250 lb.
(1023kg)
2000 lb.
(909kg)
1750 lb.
(795kg)
LM-OBT-6k
6000 lb.
(2727kg)
5000 lb.
(2272kg)
4500 lb.
(2045kg)
4000 lb.
(1820kg)
3500 lb.
(1590kg)
3000 lb.
(1364kg)
2600 lb.
(1182kg)
2300 lb.
(1045kg)
2000 lb.
(909kg)
1800 lb.
(818kg)
LM-OBT-8k
8000 lb.
(3636kg)
6650 lb.
(3022kg)
6000 lb.
(2727kg)
5300 lb.
(2409kg)
4650 lb.
(2113kg)
4000 lb.
(1820kg)
3500 lb.
(1590kg)
3000 lb.
(1363kg)
2600 lb.
(1181kg)
2200 lb.
(1000kg)
J
I
H
G
F
E
D
C
B
A
Model
Extended
horizontal center
of gravity
Retracted
horizontal center
of gravity
Vertical center
of gravity
A B
C
D
E
F
G
Net
weight
LM-OBT-4-24 47
1
/
8
” (119.7 cm)
31
13
/
16
” (80.8 cm) 14
3
/
8
” (36.5 cm) 86
5
/
8
”-146
5
/
8
” 27
11
/
16
” 32” 24” 6” 7
1
/
2
” 2
1
/
2
” 433.9 lb.
LM-OBT-4-30 47
1
/
8
” (119.7 cm)
31
13
/
16
” (80.8 cm) 14
3
/
8
” (36.5 cm) 86
5
/
8
”-146
5
/
8
” 27
11
/
16
” 38” 30” 6” 7
1
/
2
” 2
1
/
2
” 451.5 lb.
LM-OBT-4-36 47
1
/
8
” (119.7 cm)
31
13
/
16
” (80.8 cm) 14
3
/
8
” (36.5 cm) 86
5
/
8
”-146
5
/
8
” 27
11
/
16
” 44” 36” 6” 7
1
/
2
” 2
1
/
2
” 469.1 lb.
LM-OBT-6-24 44
3
/
16
” (119.7 cm)
31” (78.7 cm)
14
3
/
8
” (36.5 cm) 86
5
/
8
”-146
5
/
8
” 27
11
/
16
” 32” 24” 6” 7
1
/
4
” 2
1
/
4
” 481.9 lb.
LM-OBT-6-30 44
3
/
16
” (119.7 cm)
31” (78.7 cm)
14
3
/
8
” (36.5 cm) 86
5
/
8
”-146
5
/
8
” 27
11
/
16
” 38” 30” 6” 7
1
/
4
” 2
1
/
4
” 501.1 lb.
LM-OBT-6-36 44
3
/
16
” (119.7 cm)
31” (78.7 cm)
14
3
/
8
” (36.5 cm) 86
5
/
8
”-146
5
/
8
” 27
11
/
16
” 44” 36” 6” 7
1
/
4
” 2
1
/
4
” 520.3 lb.
LM-OBT-8-24 51
11
/
16
” (131.3 cm)
35” (88.9 cm)
15
1
/
4
” (38.7 cm) 85
1
/
4
”-145
1
/
4
” 28
7
/
8
” 32” 24” 5
1
/
8
” 7
1
/
4
” 2
1
/
4
” 665.0 lb.
LM-OBT-8-30 51
11
/
16
” (131.3 cm)
35” (88.9 cm)
15
1
/
4
” (38.7 cm) 85
1
/
4
”-145
1
/
4
” 28
7
/
8
” 38” 30” 5
1
/
8
” 7
1
/
4
” 2
1
/
4
” 684.1 lb.
LM-OBT-8-36 51
11
/
16
” (131.3 cm)
35” (88.9 cm)
15
1
/
4
” (38.7 cm) 85
1
/
4
”-145
1
/
4
” 28
7
/
8
” 44” 36” 5
1
/
8
” 7
1
/
4
” 2
1
/
4
” 703.3 lb.
FIG. 2E:
LM-OBT centers of gravity and dimensions
