
288
RADAR AND ARPA MANUAL
of a constant C, which is referred to as the
speed change
constant
and is defined as the time in minutes taken for a
vessel to reach a speed midway between her original
speed and the new speed ordered. It was believed that
the time taken for the speed differential to reach half its
original value would be much more meaningful to the
mariner than the factor of 0.37 (C is in fact 0.7fe).
Stopping distances are tabulated for increasing values
of speed-change constant or 'C value. Table 7.1(a) gives
the speeds which can be expected after a given number
of minutes from a requested manoeuvre. For example, a
vessel with a ...