15
fi g. 1.18
fi g. 1.19
1 - M
OTORIZED
U
NIT
Positioning the Motorized Unit
Mudsill
Jack
Cribbing may be
required to distribute
reaction depending
on the bearing
surface
WARNING
Make sure the ground or support surface capacity meets with values
included in the
Minimum Bearing Surface Capacities
table (fi g. 1.18). Soil
compacting, cribbing or shoring can increase bearing capacity. Contact an
engineer for assistance.
Minimum Bearing Surface Capacities
Height
Motorized unit
(pressure per mudsill)
Load under
mast
Mudsill: 14" x 28" (35,6 x 71 cm)
Contact surface: 392 sq in (,25 m
2
)
(ft)
(m)
Load reaction
Load
pressure
(psi)
Load
pressure
(kpa)
Load reaction
35
10,7
15 972 lb
41
283
21 880 lb
7245 kg
9925 kg
50
15,2
15 005 lb
38
262
22 735 lb
6806 kg
10 312 kg
75
22,9
15 830 lb
40
276
23 985 lb
7180 kg
10 879 kg
100
30,5
16 655 lb
43
296
25 235 lb
7556 kg
11 446 kg
150
45,7
18 305 lb
47
324
27 735 lb
8303 kg
12 580 kg
200
61,0
19 955 lb
51
352
30 235 lb
9051 kg
13 714 kg
250
76,2
21 605 lb
55
379
32 735 lb
9800 kg
14 848 kg
Bearing surface
Before installing the motorized unit, make sure the bearing surface under it is level, clear of
debris and has the proper bearing capacity. When required, appropriate cribbing must be
placed under the mudsills on the base to distribute the load. It is important to make sure that
the bearing surface is stable and has not been subject to any type of erosion or deterioration
caused by weather conditions (snow, rain, etc.).
General Concept
C ibbi
b
Cribbing may be
Freestanding installation
Tied installation
Load reactions under each mast must be considered for an installation using mast base plates. For
more information about mast base plates, refer to p. 115 of the
Accessories
section.
Load reactions in above table include a dynamic factor.
