306 
ARTILLERY IN COAST DEFENCE. 
Under the Group Officers are the gun captains in charge of the 
detachment and stores of a single gun, for which they are responsible 
to the Group Officer. The single gun is the unit of organisation 
though, as said above, the group is the smallest tactical unit. 
In some cases a single gun constitutes a group by itself; when the 
gun captain may be required to perform the duties of Group Officer 
as well as his own. 
Under ordinary circumstances then the chain of responsibility is as 
follows :— 
The Section C.R.A. directs the action of the forts in the section. 
The Fort Commander controls the fire of the groups in his fort. 
The Group Officer is responsible for the fire discipline of his guns. 
But circumstances sometimes render necessary additional links in 
the chain. 
For instance, as has been said above, the Section Commander should 
only have to conduct one action at a time, but for various reasons it 
may be thought advisable to put under his administrative command 
forts which do not bear on the water area with whose defence he is 
primarily concerned; and which might, therefore, become engaged in 
a distinct action with a detached squadron of the enemy’s fleet. 
In order to avoid the loss of control and consequent loss of power 
which would be involved if the Section Commander had to give his 
attention to two separate battles, a link is interposed between him and 
the Fort Commanders for that part of the section which is the least 
important, the tactical control of that part being placed in the hands 
of a “ Sub-section Commander” who exercises over it in action the 
same control as a Section Commander, subject only to general 
directions as to his tactics from the officer commanding the whole 
section. 
An isolated fort might sometimes be constituted a “ Sub-section,” 
in which case the Fort Commander would become also Sub-section 
Commander. 
Similarly some faces of a fort or flanking batteries may be so placed 
that their guns could not be engaging the same vessel as the main 
fronts. Loss of control and power would result if the Group Officers 
of these faces or batteries were left to direct their fire on objectives 
of their own choice, so “ Sub-Commanders ” are appointed for such 
parts of a fort, who have the same powers of fire control over the 
groups placed under them as a Fort Commander, receiving from him 
general directions as to the objectives they are to attack. 
In cases where the most important groups of a fort are fought by 
position-finder, whilst less important groups are fought by depression 
range-finder, Sub-Commanders would be appointed for the depression 
range-finder groups as also for batteries of movable armament 
placed outside the fort. 
Where a sub-command consists of only one group of guns, the 
Group Officer would be treated as a Sub-Commander. 
Certain groups of heavy guns having a wide field of fire and fought 
by position-finders are sometimes taken out of the Fort Commander’s 
control and kept directly under the orders of the Section C.K.A. ; who 
