FORCES ON GANTRY (CRANE BEAMS)

1. VERTICAL FORCE=WHEEL LOAD X IMPACT FACTOR

2. HORIZONTAL LOAD =( TROLLEY& HOISTWT +RATED CAPACITY) X

IMPACT FACTOR

3. LONGITUDINAL FORCE = (SUM OF EACH WHEEL LOADS) X IMPACT

FACTOR

NOTE 1 :

AS PER MBMA , HORIZONTAL FORCE SHALL BE DISTRIBUTED

WITH REGARD TO LATERAL STIFFNESS OF RUNWAY BEAM.

i.e FIRST CHECK THE CROSSSECTION OF GANTRY ON BOTH

SIDES FOR VERTICAL IMPACT ;

IF BOTH THE BEAMS HAVE SAME AREA ; HORIZONTAL IMPACT WILL BE 20/2 =10%

ON EACH GANTRY.

IF BOTH THE BEAMS HAVE DIFFERENT AREA ; HORIZONTAL IMPACT WILL HAS TO

MORE FOR GANTRY WITH HIGHER AREA.

NOTE 2 :

IMPACT FACTOR(FOR EOT CRANES)

MBMA-1996(SEC.6) & AISC 89(SEC.A4)VERTICAL LATERAL LONGITUDINAL

CAB OPERATED 25%

20% 10%PENDANT OPERATED

10%

MONORAIL 25%

IMPACT FACTOR(FOR EOT CRANES)

IS-875 1987(PART 2 ,SEC. 6.3)VERTICAL LATERAL LONGITUDINAL

FOR ALL CLASSES OF CRANES

25% 10% 5%

FOR COLUMNS SUPPORTING CLASS 3 & 4

25% 10% 5%

FOR COLUMNS SUPPORTING CLASS 1 & 2

10% 10% 5%