Harrington Hoists and Cranes Series 3 End Truck - Manual (Page 20)

2.4 Bridge Crane Design Requirements - For proper selection of end trucks to meet your particular
needs, refer to the Harrington brochure “Choosing the Crane to Fit Your Needs” or our latest catalog.
2.4.1 CRANE RUNWAYS
Supporting Structure - Ensure that the supporting structure for the runways is adequate. If necessary
consult a professional that is qualified to evaluate the adequacy of the runway's supporting structure.

Installing a crane system on runways supported by inadequate supporting structure
could result in death or serious injury, and property damage.
Runway Design - Ensure that the runways meet the design requirements of the CMAA
Specification #70 or #74 whichever applies.
Runway Alignment - Ensure that the runways meet the runway alignment requirements of
CMAA Specification #70 or #74, whichever applies. For your convenience, Harrington has
provided these alignment criteria in Table 2-1 below.

Improper design, fabrication, or installation of crane runways could result in death or
serious injury, and property damage.
Table 2-1 CMAA Design Requirements
Item Overall Tolerance Maximum Rate
Of Change
Crane span (L) measured at crane wheel contact surface. L < 50’
A =
3
/
16
”
50’ < L < 100’
A =
1
/
4
”
L > 100’
A =
3
/
8
”
1
/
4
” in 20’-0”
Straightness (B) B =
3
/
8
”
1
/
4
” in 20’-0”
Elevation (C) C = 3 /
8
” 1 /
4
” in 20’-0”
TOP RUNNING Transverse rail to rail elevation (D). L < 50’
D =
3
/
16
”
50’ < L < 100’
D =
1
/
4
”
L > 100’
D =
3
/
8
”
1
/
4
” in 20’-0”
UNDER RUNNING Transverse girder to girder elevation (D).
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