PROCEDURES FOR DETERMINING COMBINED CENTER OF GRAVITY OF LOAD ON CAR ABOVE TOP OF RAIL OF LOADED OPEN TOP CARS

The following information is necessary to determine the combined center of gravity of a loaded open top car. A = Height of car deck from top of rail. B = Center of gravity of car above top of rail, obtainable from car owner. C = Center of gravity of load from base of load, obtainable from shipper. D = Combined height of center of gravity of load, (C), plus height of car deck, (A), that is (C) + (A). E = Lightweight of car, in pounds, as stenciled on car. F = Weight of load, obtainable from shipper.

The calculation to arrive at the center of gravity is as follows: (B x E) + (D x F)  = Combined center of gravity above top of rail. E+F

Example: A = 44 inches B = 27 inches C = 60 inches D = (60 + 44) = 104 inches E = 55,000 Lbs. F = 120,000 Lbs.

Formula: (B x E) + (D x F)  + C. G. ATR E+F

(27 x 55,000) + (104 x 120,000) 55,000 + 120,000

1,485,000 + 12,480.000 = 13,965,000 = 79.8 inches ATR 175,000 175,000

Notes: 1. The above is an example of a basic calculation for determining the combined center of gravity of load and car. 2. Where the load consists of multiple piles or pieces with differing centers of gravity, the entire C.O.  of the entire load must be calculated before it is combined with the car weight and C.O. 3. Acceptable centers of gravity for interchange purposes are governed by Rule 89.  Section B.  1, e of the Field Manual of the AAR Interchange Rules.