Half Step March Procedures
To alter the march to a 15-inch step while marching with a 30-inch step, the command is Half step, MARCH. This command may be given as either foot strikes the marching surface. On the command of execution MARCH, take one more 30-inch step and then begin marching with a 15-inch step. The arms swing as in marching with a 30-inch step.
To resume marching with a 30-inch step, the command Forward, MARCH is given as either foot strikes the marching surface. On the command of execution MARCH, take one more 15-inch step and then begin marching with a 30-inch step.
Video:
http://www.pdf-archive.com/2014/01/22/army-tc-3-21-5/army-tc-3-21-5.pdf
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