vel between any two points less than or equal to 62

feet. Warp is determined as follows:

(1) Use the line rail as the reference rail.

(2) Measure the crosslevel at any two points

less than 62 feet apart, normally at joints in the rail.

If the reference rail is lower than the opposite rail,

the sign of the measurement is negative (-). If the

reference rail is higher than the opposite rail, the

sign of the measurement is positive (+).

(3) To determine warp. If both signs are the

same, drop the signs and subtract the smaller

measurement from the larger measurement. If the

signs are different, drop the signs and add the

measurements. Figure 12-4 presents an example of

the warp calculation.