Lochnagar Crater on the Somme by Alertomalibu
Friday 27th
August: Following their unsatisfactory experience of crater fighting at
Givenchy-lès-la-Bassée on 16th-17th June this year, it is with some wry
amusement that the adjutant of the 2nd Battalion has sent us the following, to
our mind rather chatty, instructions on how to do it.
1. Size of Craters.
For the
benefit of those who have had no experience of craters formed by mine
explosions - both our own and those of the enemy - these notes are intended as
a guide. They are all based on actual experience gained whilst in the trenches
in the Givenchy and Cuinchy Sections of the line.
It should be
remembered that craters formed by a mine explosion are as a rule not like
glorified shell holes, but something totally different, and on a far larger
scale. It is difficult to give exact measurements but some that have been seen
are fully 50 feet deep with very loose, steep crumbly sides and 30 to 40 yards
in length; the circumference of these can only be imagined, until actually
seen, and then only an approximate idea can be obtained as the whole cannot
usually be seen at once and often only through a periscope. If it is possible
to look at them with the naked eye, it can be necessarily only for a moment. These
craters, therefore, are something out of the ordinary, and cannot easily be
crossed without the assistance of much material and engineer labour, even if it
is then possible. As to filling them in with sandbags which has been suggested,
this is quite impossible and the idea could only have been originated by someone
who had never been near one.
2. Actions when enemy's mines are
expected.
In many
instances the miners working in various shafts can give warning when an enemy
mine is about to be exploded, or at any rate when an enemy shaft is approaching
or in the vicinity of the trenches. Then is the time to withdraw the garrison
for some 60 yards or so, on either side, keeping them in support trenches ready
to rush in as soon as the explosion takes place. But sometimes warning is
impossible, and such instructions should be issued as will ensure certain men
in support trenches being ready always to rush in when an explosion does take
place. The reason for this action is obvious for two reasons. First because it
is probable that the men in the front trench will be so shaken - if they are
not destroyed - as to be incapable of any immediate action; and secondly, this
being so, it is imperative at least to reinforce the front line trench in case
of an attack. It is sometimes the case that in certain parts of the line there
is always a possibility of a mine explosion. Then, it is generally wise to hold
this part of the line very lightly, preferably with outposts only, having men
in support trenches ready to move forward at once when the explosion occurs.
3. How to deal with craters.
The question
now arises, how should these craters, formed by the explosion of the enemy's
mines, be dealt with? Naturally much depends on the circumstances but it seems
advisable to establish men first of all on the near tip of the crater, and
gradually to work round on either flank. It must be borne in mind that it will
be impossible to get across the crater, anyhow those which are being described,
and if this is attempted, it is probable that the men who get into the craters
will fall victim to the enemy's bombers. Therefore it is suggested that this is
not attempted, but efforts should be made to get round the flanks, and patrols
be sent out to protect the working parties who would dig a trench round the
near lip, with saps forward so as to look down into the crater, and, of course,
communication trenches back to the main line, if necessary. When once men have
been established in this position circumstances will be the best guide as to
the future procedure. By the above means it is likely that the crater will at
least be denied to the enemy.
4. Action when our own mines are
exploded.
Much the same
method should be adopted when one of our own mines is going to be exploded,
except that, in this case the actual time of the explosion is known, and men
should be withdrawn from the front trenches if necessary at the last possible
moment so as not to cause any suspicion to the enemy, if the lines are very
close, and placed in communication trenches with definite orders how to act
when the explosion takes place.
5. An example.
It might be
well to give an actual example of exactly what did occur, and arrangements made
on the explosion of a mine at Givenchy early in August.
The enemy had
been heard working near our shaft head and it was decided to explode three
mines in close proximity to one another in this region. The Officer Commanding
the Battalion engaged, having settled with the mining expert as to the best
hour for exploding the mine - in this case it happened to be 8.30 p.m. -
arrangements were made with the artillery to bring fire to bear, when the
explosion took place, on certain enemy communication trenches and fire trenches
which it was thought advisable to block by fire. It was arranged to have the
trenches cleared on either side for a distance of nearly 100 yards, with the
exception of a few men left for the purposes of security, and to deceive the
enemy as to what was going on; this was to be completed by 8.15 p.m. and the
remainder were to be withdrawn at 8.25 p.m. Two parties of about 12 men each
with Bombers were told off to immediately rush forward and seize the near lip
of the crater, and patrols from these were detailed to push round on either
side if possible and get up to the enemy's trenches to see if they had been
damaged, and if so to send back word so that men could be sent up to enter
them. Behind these two parties came men with spades and sandbags ready to start
digging a trench round the near lip, and back to the main line from both flanks
of the crater formed. The distance between the two lines before the explosion
of the three mines was roughly 80 yards, but there were other craters close by.
The effect of the explosion of the three mines, which was simultaneous, was to
form one huge crater fully 60 yards long, and very deep and wide. The northern
end joined up with another enemy crater so it was impossible to get round this
flank, but patrols pushed round the Southern side as far as the enemy's wire
which was intact. The enemy did not reply for nearly 20 minutes and then began
to fire machine guns, and bombs and a little artillery. The working parties
were covered by bombers who continued to throw grenades throughout the night.
Under cover of this a trench was dug during the night round the near lip of the
crater which bent back to the main line and the occupation of the crater was
completed by the digging forward of saps from the trench so as to look into the
crater itself. This is only just an instance of what did occur, and may perhaps
form some sort of guide to any future operations of this nature.
6. Saps and forward posts.
It is usually
advisable to consult the mining officer as to how far forward saps and posts
should go because they can tell how far their shafts go, and if these posts are
pushed out too far to the front they are apt to come within the danger zone of
the enemy shafts and therefore liable to be blown up without warning. For this
reason saps and forward posts in craters should be held rather lightly until
the mining officer reports that his shaft is ahead of them. The idea that when
once a crater has been formed no further explosion can take place in it is
wrong, for in certainly one case at both Givenchy and Cuinchy craters were
considerably enlarged by further explosions.
Source: X550/3/wd
