| GENE SLOVERS US NAVY PAGES USN RANGE TABLES COLUMN 19 |
Hitting space is defined as the variation in sight-bar range, at a fixed target distance, between the trajectory which intersects
a given target at the waterline and the trajectory which intersects the top of the target. Column 19 of the range table, headed
“Change in height of impact for variation of 100 yards in sight bar,” is the column used for determining hitting space.
(Sight-bar range is the range shown on the sight scale of the gun at the instant of firing.)
17B11. Danger space and hitting space
For a given target and trajectory, the danger space is the greatest distance through which the target may be moved in the
line of fire and still be intersected at some point by that trajectory. Column 7 of the range table is composed of values of
the danger space for a target 20 feet high and of zero depth in the line of fire.
Referring to the 5”/38 range table, range 10,000 yards, it is seen that the danger space is 18 yards. The value of the
danger space at this range for a target 30 feet high is 30/20 X 18 = 27 yards. Now if this 30-foot target has a beam
of 105 feet (35 yards) it is apparent that its danger space is 27 + 35 = 62 yards.
Hitting space is defined as the variation in sight-bar range, at a fixed target distance, between the trajectory which intersects
a given target at the waterline and the trajectory which intersects the top of the target. Column 19 of the range table, headed
“Change in height of impact for variation of 100 yards in sight bar,” is the column used for determining hitting space.
(Sight-bar range is the range shown on the sight scale of the gun at the instant of firing.)
To find the hitting space for a 20-foot target at range 10,000 yards, column 19 is entered, and the value obtained is
112 feet; i.e., a variation in sight-bar range of 100 yards will move the point of impact 112 feet in the vertical plane of the target.
To raise the point of impact 20 feet (to the top of the target) the sight-bar range would have to be increased
20/112 X 100 = 18 yards.
This value for hitting space is the same as that earlier obtained for danger space. For most battle ranges,
this relationship holds; for the shorter ranges, however, there may be a considerable difference.
For example with a 20-foot target at 3,500 yards the range table gives a danger space (column 7)
of 157 yards and a hitting space of 20/14 (column 19) X 100 = 143 yards.
EXTRACTS FROM 5”/38 RANGE TABLE
EXTRACTS FROM 8"/55 RANGE TABLE
a given target at the waterline and the trajectory which intersects the top of the target. Column 19 of the range table, headed
“Change in height of impact for variation of 100 yards in sight bar,” is the column used for determining hitting space.
(Sight-bar range is the range shown on the sight scale of the gun at the instant of firing.)
17B11. Danger space and hitting space
For a given target and trajectory, the danger space is the greatest distance through which the target may be moved in the
line of fire and still be intersected at some point by that trajectory. Column 7 of the range table is composed of values of
the danger space for a target 20 feet high and of zero depth in the line of fire.
Referring to the 5”/38 range table, range 10,000 yards, it is seen that the danger space is 18 yards. The value of the
danger space at this range for a target 30 feet high is 30/20 X 18 = 27 yards. Now if this 30-foot target has a beam
of 105 feet (35 yards) it is apparent that its danger space is 27 + 35 = 62 yards.
Hitting space is defined as the variation in sight-bar range, at a fixed target distance, between the trajectory which intersects
a given target at the waterline and the trajectory which intersects the top of the target. Column 19 of the range table, headed
“Change in height of impact for variation of 100 yards in sight bar,” is the column used for determining hitting space.
(Sight-bar range is the range shown on the sight scale of the gun at the instant of firing.)
To find the hitting space for a 20-foot target at range 10,000 yards, column 19 is entered, and the value obtained is
112 feet; i.e., a variation in sight-bar range of 100 yards will move the point of impact 112 feet in the vertical plane of the target.
To raise the point of impact 20 feet (to the top of the target) the sight-bar range would have to be increased
20/112 X 100 = 18 yards.
This value for hitting space is the same as that earlier obtained for danger space. For most battle ranges,
this relationship holds; for the shorter ranges, however, there may be a considerable difference.
For example with a 20-foot target at 3,500 yards the range table gives a danger space (column 7)
of 157 yards and a hitting space of 20/14 (column 19) X 100 = 143 yards.
EXTRACTS FROM 5”/38 RANGE TABLE
EXTRACTS FROM 8"/55 RANGE TABLE
