Two-third rule than freight trains. On such tracks, the two-third rule applies to freight trains. The two-third rule means that the speed limit for a freight train is generally about two-thirds of the speed limit for an EMU. For example, the Dartford Loop Line has a speed limit of 60 mph for EMUs between Lee and Crayford. A freight train on this track is therefore limited to two-thirds of 60 mph, i.e. 40 mph. Two-third rule Two-third rule is British railway safety rule. For safety reasons, speed limits are imposed on trains running on a railway line. Many factors can affect the
Septimal major third 3:2 / 9:7 = 7:6 ). Similarly, the septimal major third is the interval between the third and the fifth of the septimal minor triad. In the early meantone era the interval made its appearance as the alternative major third in remote keys, under the name diminished fourth. Tunings of the meantone fifth in the neighborhood of Zarlino's -comma meantone will give four septimal thirds among the twelve major thirds of the tuning; this entails that three septimal major triads appear along with one chord containing a septimal major third with an ordinary minor third above it, making up a