There are basically two different types of backpack
so when choosing a backpack the first thing to consider is what will it be used
for:
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Rambling?
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Backpacking?
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Climbing or caving?
Otherwise known as hill-walking,
is basically a short walk in the country so a small pack, known as a
‘day-pack’ or ‘day-sac’ is used to hold your packed
lunch, thermos, waterproofs, a few field guides, etc.
These generally range from around
12 litres in size up to about 35 litres with one main compartment and can
either have a few small pockets or none at all on the outside.
They don’t really have a
frame as such as they are not really intended to carry much weight, but modern
ones do have a well padded back that is slightly
stiff to give some lumbar protection.
These are similar to the packs
used for rambling but have no external pockets or loops and tend to be rather
slender. This is because, whether you are climbing or caving, you do not want
anything sticking out that could catch on a protruding rock, or restrict your
mobility, as this could be potentially fatal.
This is nothing more than extended rambling, with at
least one night out and so a larger pack is used, the size being determined by
the length of time away from home and also the ambient weather. In cold weather
more, and thicker, clothing is required.
The pack size can vary from
around 30 litres for overnight trips in clement
weather, up to over 100 litres for extended trips.
These packs generally have a
number of external pockets, which may be detachable and may the facility to be
turned into a day-sac.
No matter what the type of
bag, there are a number of features that are common to most if not all.
These are fitted to all types of bag and are
adjustable to allow you to wear different thicknesses of clothing and also to
adjust the pack comfortably and securely to your back. On larger packs some
even have adjustable straps that connect from the shoulder strap to the top of
the pack for further adjustment.
Modern shoulder straps are
normally padded to some extent to make prolonged use, or carrying heavy loads
more comfortable.
These are a small, detachable, two piece belt,
attached to the shoulder straps that connect across the chest.
The purpose of the harness is to
secure the pack more tightly to the wearer and stop the pack from moving
around.
There are however two schools of
thought regarding the use of chest harnesses.
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For
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The harness does stop packs moving around reducing
chaffing and possible over balancing with a heavy pack.
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Against
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The harness constricts the ribcage and so
affects the breathing.
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In a fall it may be possible for the harness to
prevent the wearer from undoing the harness and shuck the pack – this may
result in the wearer becoming trapped or if the pack is heavy and the wearer
has fallen into water, it may pull them under the water and drown them.
Again this is an area where there are two schools of
thought – one compartment taking up all the internal space or two
compartments.
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One compartment.
o The
advantage of this is that you can fit a single dri-pack
into the bag and there is nothing to snag or catch anything put inside the main
compartment.
o The
disadvantage is that you have to remove everything from the pack to find what
you want if it is at the bottom of the bag…
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Two compartments.
o The
advantage of having one large main compartment and one smaller compartment is
that you can separate out things you need to get to quickly and put them in the
smaller, lower compartment.
o The
disadvantages include the fact that the partition, or draw cord, can catch on
things making it difficult to remove items, you need two dri-packs
if you want to keep your gear dry increasing outlay, and there is another seam
that can fail or let water in.
Whilst not all sacs have a waist or hip belt, they
are becoming increasingly common on day packs and are found on all good main
packs.
On smaller sacs they may just be
an unpadded tape with a buckle of some type, or may be fully padded.
The main purpose of the belt is
to help support the weight of the pack on the hips to make extended use and
carrying heavy loads more comfortable. Obviously a padded belt will do this
much better than a thin tape.
Some belts even have a zipped
pocket sewn into the belt to act as a purse, or may have loops of some kind
attached to allow you to hang things from them.
As mentioned above, these may be permanently
attached or detachable. They are used to stow small items of kit that you may
need to get at fairly quickly such as first aid kits, brew kit, gloves, etc, and vary greatly in size. Some are large enough to
take a set of waterproofs, whilst others will only take small wallet.
Detachable pockets have a number
of advantages in that they can be removed turning the sac into a climbers-style
sac, and most modern ones can be zipped together and a harness added to form a
day-sac.
There are several ways that a pocket can be closed
– with a waterproof sock of some type, a rain flap or
simply an lid, each with its own advantage or disadvantage.
Buckles can be of three main
types – quick release, strap and buckle or a combination of each. Again
each has its own advantages and disadvantages.
Most buckles are now made of
nylon rather than metal as they do not warp or bend and also are warmer than
metal reducing the chance of the buckle adhering to cold wet hands.
Zips and Velcro are also used as
closures and need a certain amount of maintenance to keep them in good working
order. And both have one disadvantage – they can freeze shut!
Many packs have loops and attachment points that can
either be for specific purposes such as ice-axe/walking stick loops or for
attaching pockets, or other items such as rope, bed rolls etc.
Most packs these days are made
from materials such as Cordura and Goretex, which are both hardwearing, abrasion resistant and
in the case of Goretex, waterproof.