BARKING OAK
Previous to the war the price of oak bark—about £2 10_s._ per
ton—rendered it questionable whether from a purely financial point of
view the operations of stripping and harvesting should be undertaken.
Now, however, with bark at fully three times that figure, the operation
is to be recommended.
The period of bark-stripping and harvesting is one of the most anxious
seasons of the year with the forester, as the quality of the bark is
so largely dependent upon the weather during the time that intervenes
between the stripping and stacking, or delivery, and not less so
upon the carrying out of the work at the proper time, to secure easy
and expeditious peeling. In most cases the time when the bud is just
expanding into leaf is that which gives the greatest weight of bark of
the best quality, with the smallest amount of labour. By deferring the
work, even for a few days, there is often a loss in weight amounting to
as much as 10 per cent., and a great deterioration in quality.
Even in the most favoured situations it is seldom that the season
for stripping extends beyond twenty-eight days. The advantages of
early stripping are so well known that any comment on the subject is
unnecessary; suffice it to say that, immediately the bark commences to
“run” freely, no time should be lost in making a start, and the work
should be prosecuted with vigour and dispatch until completed.
The proper time to commence barking cannot, however, be fixed with
any amount of certainty, much depending on the season, whether early
or late, as well as on the district of the country in which the
operation is to be performed. During ordinary seasons, and in most
parts of England, bark-stripping commences during the third week in
April and continues for about a month, or until such time as the trees
are in full leafage, whereas in some parts of Scotland, especially the
north, the operation is frequently nearly a month later. No mistake
can, however, arise as to the right time to start barking in any
locality, as in all cases the period when the bud is first bursting
into leaf will be found the proper time for felling to insure easy
stripping and the best quality of bark. As the season of bark-stripping
is, therefore, of short duration, every preparation should be made
beforehand—trees marked and numbered, tools in readiness, and squads
arranged—so that an early start may be made, as, by deferring the work
beyond the time stated above, there is not only a perceptible loss in
weight, but considerable deterioration in the quality of bark as well.
Elaborate directions regarding the arrangements of squads and tools
to be used are unnecessary, as almost every district has its own
peculiarities in this way. The tools generally in use are heavy axes
and the cross-cut saw for felling, hand-bills and saws for pruning,
peeling-irons or chisels for removing the bark, scrapers for removing
moss, and light wooden mallets for beating refractory bark or such as
cannot be removed by the peeling-irons alone.
Previously to felling the trees a man or stout lad is sent before,
who removes the bark from the root upwards for a distance of 2 ft. or
3 ft.; this not only prevents its being injured when laying in and
felling the tree, but is convenient for after-stripping as well. When
the stools are intended for reproduction great care is necessary to
avoid tearing or loosening the bark from the roots. After being thus
prepared the trees are felled in the usual manner, those under 6 in. in
diameter being cut with the axe; above that size it is found an economy
of time and timber to fell with the cross-cut saw. Following in the
rear of the cutters should be a squad of men, to clear the trunk and
larger limbs of all branches down to 1 in. in diameter, leaving the
limbs to be peeled as part of the tree.
Heavy timber and large branches are usually peeled where they fall,
but it will be found convenient to have the smaller trees and branches
carried out to some open space adjoining the stacking ground, and
peeled while one end is supported by means of two forked sticks placed
against each other. When the bark of small branches cannot readily be
removed by the peeling-iron, a smooth and flat stone is brought into
use, beside which the peeler sits, and with one hand holds the branch
on the stone, moving it along from one end to the other, at the same
time applying the mallet with the other hand until the bark becomes
loosened from the wood. Here it may be well to issue a caution against
a too frequent use of the mallet, which should never be brought into
request when the bark can be otherwise removed from the wood, as all
hammering and beating not only diminishes the quality of tannin, but
has a tendency to blacken the fleshy part of the bark and cause rapid
decay in a bad season. The body, or trunk bark, is removed in lengths
of from 30 in. to 36 in., and in as large pieces as possible.
[Illustration: BARKING TOOLS]
A dry, open and airy situation, convenient to the work, but without
the wood, should be selected on which to harvest the bark, and rather
than this should be done in a sheltered, humid spot, the bark should be
carted to some distance off. The drying racks, or ranges, may be fully
2 ft. high, drooping somewhat to one side, and formed of forked sticks
driven firmly in the ground, while stout rods are placed transversely
upon these. It should also be so arranged as that not only may the
rain be thrown off, but so that the ends of the bark may be facing the
prevailing wind, thereby insuring a current of air through and beneath
the mass. After being carted or carried to the drying-ground, the
small bark is spread out loosely on the stage to a depth of about 6
in., and thatched or covered over with the larger pieces as a means of
protection against rain. Each day’s bark should be cleared up, and put
on the range the same evening, and oftener, if found necessary, during
damp showery weather, keeping the white or fleshy part downwards and
using the larger pieces as covers to run off the rain.
During favourable weather the bark will be ready for stacking in about
a fortnight from the time it was placed on the stage, but should
close damp weather intervene, it may be found necessary to turn the
bark occasionally, thus adding to the length of time required for
harvesting. It should, however, be remembered that the less turning
the bark receives after being placed on the stage the better will the
quality be. Well-seasoned bark has the fleshy side of a creamy colour,
whereas such as has been exposed to the sun or rain is of a dull brown,
and is wanting in tannin matter, and consequently of inferior value.
As soon as the bark is thoroughly dry and ready for stacking, which
may readily be ascertained by its breaking freely across rather than
bending or yielding to pressure, it should be secured in a shed,
ricked, or delivered to the tanner.
In stacking bark the rick should not be made too wide—say about 9
ft.—but well hearted, so that the side pieces may have a good fall
or declivity outwards to throw off the rain. The rick may be of any
length, according to the quantity of bark on hand, and of a height
proportionate to the width. The largest pieces of bark should be
reserved for thatching the rick, the whole being covered over by a
tarpaulin or waterproof cloth of some kind. In most cases the bark is
chipped previously to being sold, but as this necessitates having a
large shed at command, the system is not generally adopted. There are,
however, several advantages accruing from this method, not the least
of which is that the bark may be chopped up as it is removed from
the drying-stands, thus saving the expense of stacking. Chopping the
bark can also be done by the workmen during wet weather, and when not
otherwise engaged.
In computing the quantity of bark before stripping, we have found the
following data fairly reliable:—
1. A well-balanced tree with a good head will yield about 6 cwt. of
bark for every ton of measurable timber, if branches down to an inch in
diameter are peeled.
2. Hedgerow trees usually yield about a ton of bark to every three tons
of timber.
3. Trees growing in close woodland are usually thin barked, the yield
being about a ton of bark to every 4½ tons of timber.
4. Oak poles will average five tons of timber to a ton of bark.
Tall, clean stems, as are produced when the poles are grown thickly
together, with small heads, give the smallest yield in proportion
to the quantity of timber, and short stems with spreading heads the
largest.
The cost of production is as follows:—
£ _s._ _d._
Labour, peeling and harvesting 1 10 0
Cartage to railway station, including loading
(this is the average from six districts) 0 7 6
Loss on four months’ delay in selling the timber,
which, but for the bark, would have been
felled in winter at 5 per cent. 0 5 0
Customary terms of payment, less 2½ per cent. 0 2 0
Superintendence, etc. 0 1 6
———————————
£2 6 0
It has been carefully estimated that there is a loss of fully 12 per
cent. of wood, caused by felling the oak during the barking season. In
other words, the proportion of sap wood to the whole tree is about 14
per cent., which, for the majority of purposes to which oak timber is
applied, is rendered by the peeling of little or no value.
We may say, however, that 2 per cent. can be profitably utilized, which
still leaves us with a considerable loss on the whole tree.
The average price of the best oak is 2_s._ per ft., 12 per cent. of
which is as nearly as possible 3_d._ per ft., or £1 17_s._ 6_d._ per
ton of bark to 150 ft. of wood.
This, with the £2 6_s._ per ton cost of production, brings the total
to £4 3_s._ 6_d._, leaving a considerable balance on the wrong side at
pre-war prices.