Redoubts.
The question of redoubts has been a vexed one for years; partly they
were thought to be unnecessary in view of the resisting power of a
line of trenches, but chiefly because the redoubt was always imagined
as one of the older type, with a high conspicuous parapet. Of course a
redoubt of such a nature would be readily identified and made
untenable. But the idea of a redoubt does not necessarily imply
command. Its object is that it shall be capable of all-round defence.
There can be no doubt that as there is always a possibility of lines
being pierced somewhere, it is desirable, unless the whole line is to
be thrown into confusion and forced back, to have some point at which
the defenders can maintain themselves. This is not possible unless at
such points there is provision for defence towards both flanks and
rear, that is to say, when there are redoubts, which can hold on after
certain portions of the line have been lost and thereby can localize
the enemy's success and simplify the action of supporting troops. In
order that redoubts may exercise this function, all that is necessary
is that their defenders should be able to see the ground for a furlong
in front of them in every direction. Their parapets, therefore, need
be in no way more conspicuous than those of the neighbouring fire
trenches, and in that case there is no fear of their drawing special
attention from the enemy's artillery. Whatever theories may have been
put forward en the subject, in practice they are constantly used, and
in the Russo-Japanese War, where the experience of South Africa was
already available, we find them in the fighting lines on both sides.
[Illustration: FIG. 86.]
The modern type of field redoubt is a fire trench, no more conspicuous
than the others, in any simple form adapted to the ground that will
give effective all-round fire, such as a square with blunted angles.
Enhanced strength may be given by deepening the trenches and improving
the overhead cover; and special use may here be made of obstacles.
[Illustration: FIG. 87.]
Within the redoubt cover may be provided for men in excess of those
required to man the parapet, by means of cover trenches and field
casemates. Fig. 86 gives the general idea of such a redoubt, and figs.
87, 88 the plan and section of the interior shelters. Such a work can
easily be made quite invisible from a distance. It gives excellent
cover against shrapnel, but would not be tenable against howitzer
common shell, if the enemy did manage to bring an accurate fire to
bear on it.
[Illustration: FIG. 88.]
Fig. 89 shows the section of a parapet with two shelters behind it for
a work with a high command of 5 or 6 ft. This work would require a
concealed position, which can often be found a little in rear of the
firing line.
[Illustration: From _Mil. Engineering: Field Defences_ (1908), by
permission of the Controller H.M. Stationery Office.