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How I solved it….
By Matt Raw – Locksmiths of Knutsford
»»MATT RAW BEGAN
picking locks at an early age
when his father brought
home a set of locked drawers
with no keys. His passion
for picking locks and then
producing keys from blanks
never dwindled as he got
older, and after many years of
working in several industries,
Matt decided to take his
Locksmith exams in 2012
and set up ‘Locksmiths of
Knutsford’.
Matt will be running a
series of regular articles in
forthcoming issues – sharing
his tips for solving problems
Locksmiths come across in
the field.
It has been a busy year at
Locksmiths of Knutsford,
particularly with the unusually
damp weather conditions. We
all know that damp weather
brings bountiful quantities of
warped doors, crushed locks,
and various other problems,
but as summer draws to a close,
I’d like to look at one of the
most common problems that
we encounter as locksmiths
regardless of the weather
conditions or time of year: Snib
drop – causes, and solutions.
In the area in which I cover,
there are many older type
houses, with equally as many
old doors - in some cases fitted
with the original lock.
Age, however, does not
necessarily mean that the lock
is faulty, but you can bet your
life that someone has tried to
move the keep, rim cylinder, or
latch at some point in its life.
There are naturally some
installations that were never
completed properly from the
outset, but regardless of who
did what, where, when, and
why, all can affect the problem
that most of us refer to as ‘snib
drop’.
The snib is the little switch
that either holds back the latch,
or deadlocks the latch from the
inside, and if the snib has been
set to the deadlock position on
the inside, you will not be able
to open a night latch from the
outside.
A snib can have a number of
different locations, but for this
purposes, we will assume that it
is located as it is on a standard
mortice type latch as per the
example in figure 1.
Many people think that snib
drop is caused by the snib
mechanism suffering wear,
resulting in a slack movement
that eventually allows Mr
Newton’s laws to provoke
unintended operation when
the door is closed with just a
little too much enthusiasm.
In my experience, however,
I can count on a single hand
the number of times that I
have found this to be the true
cause.
Figure 1
SO, HOW ELSE CAN
SNIB DROP HAPPEN?
Typically, I find that it doesn’t
really matter which side of the
door the latch is on, and snib rise
is just as common to drop.
In most cases, the client has
unwittingly flicked the snib
whilst sliding their hand off
the latch as they move to pull
the door shut behind them.
We could easily write it off as
user error, but an accidental
operation of the snib should
actually prevent the door from
closing at all.
That said, with the latch
deadlocked, it can still move a
few millimetres before it stops,
therefore, if there is a large gap
between the lat ch and the keep,
it can slip past if enough closing
force is applied.
A second problem that I
regularly find, is that the keep is
‘secured’ to a piece of wood that
is old, bendable, or full of wood
filler. Whilst it is a mixture of
user error and installation error
that causes the problem, these
can sometimes work in our
favour when trying to execute a
solution.
Confronted with this, my
normal solution is to gain access
through the letterbox, or another
door, however this is not always
possible when one considers
working on an apartment block,
which compounds the issue
further, flats and apartments
seldom have letterboxes.
We could always take the
brute force and ignorance
approach, and try to smash the
lock off the door, either with a
battering ram, or by drilling the
barrel off and then trying to force
the latch and door to separate,
Continued on page 26 >>>
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