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When,
in 1983, I decided to begin the construction of a locomotive, the
choice of the prototype was my first problem. In spite of the possibility
of many designs available on the British magazine Model Engineer,
the temptation to venture alone in the construction of an Italian
locomotive was enormous and I was not able to resist it, even if
I had imagined the large difficulties which I would have encountered.
However, in spite of my previous experiences in model engineering,
I could not have made the locomotive without the help gained from
many of the constructional serials in Model Engineer by expert designers.
At
that time my workshop was made of a lathe, a drilling
machine, a vertical slide and the hand tools that are
usually present in all model engineers' workshops. It was, therefore,
the lack of a milling machine that led me to choose 3 1/2" in. scale
because with my capabilities I would not have been able to machine
large components on the vertical slide
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Incidentally,
it was on the completion of the chassis that I had the opportunity
to buy a second-hand milling machine. Had I had it before,
how much easier the task would have been!
Choice
of Prototype
The
biggest problem remained the selection of the prototype. A
friend came to help me and solved the problem.
He told me that in a nearby town, in a children amusement
park, there was an old locomotive put aside by the Italian
Railways in memory of how the steam engine locomotives were.
The
possibility to have the original model to which make reference,
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with
all the queries that may occur, led me to see the machine immediately
and so I found a locomotive of the 851 group of 1908 preserved
in excellent conditions. I was very pleased, but the more I looked
at it the more I disliked it.
I
think it is the same for everybody, a specific design may be appreciated
or not. Well, personally, I did not like this 851-036 and this made
me decide, much to my disappointment, to abandon the project.
Fortunately,
when I spoke to my friend about my disappointment, he was very surprised
and told me that he did not refer to that locomotive, but to another
one located in a place nearby.
I did not believe him, but I went back and this time I saw in front
of me a locomotive of group 835.
Even
if it was different from the previous one only because of a few
particulars, it astonished me. Yes, it would have to be my next
realisation.
I had already written to the Italian Railways administration in
order to have the drawings of a locomotive of group 691 (Pacific)
sent to me, which I then sent to England to a friend of mine who
is now engaged in his own construction, and therefore I did not
hesitate to formulate a new request for the drawings of the 835
which were sent to me promptly and for a really moderate price.
When, subsequently, the castings for the wheels and the cylinders
that I had ordered from Messrs. Reeves reached me, I prepared
the scale drawings (naturally taking into consideration the limits
of miniaturisation and, above all, with reference to my skill
Construction
Begins
Finally
I began working. For the frames and the buffer beams it was a long
job, but relatively simple. The difficulties began right after that
and they terminated with the last touch of brush.
I
ordered in England steel strips for the leaf spring; lacking in
experience I believed it was necessary only to specify "suitable
for 3 1/2" scale" .
What they sent to me (and, I repeat , it was my fault entirely,
because I didn't give sufficient details) were very sturdy strips
that I believe would have been more suitable for a full-size locomotive
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I had to refold some materials that I found in Italy, but which
I had to work on to bring them to the right measurement. It was
another tragedy regarding the wheels.
I had always read that the diameter of the axles must be +0.001
in. or -0.001 in. for securing with Loctite, but I felt that the
problem was not so simple and, after having decided on the " press
fit" , I thought a trial would have saved me from ordering another
set of wheels.
The
axles with +0.001 in. did not fit into the reamed hole of the wheel
and when a friend of mine who works in a shipyard suggested that
I first warm the wheel until a drop of water, which I should drop
on it , "hisses" without evaporating, I thought I had found the
solution to all my problems.
After a few attempts failed, I found out that my friend was used
to working with axles of 15 in.-20 in. diameter and larger. Other
attempts which had been made with Loctite also failed. A great care
in the determination of the tolerance between the axle and the hole
has been fundamental in finally fixing the wheels with a "press
fit". For calculating the connecting rod, Martin Evans' explanations
have been of great help.
Without his advice, I believe I would not had got any result by
simply reducing in scale the full size measurements.
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The
Boiler
And
then the time for the boiler came. Certainly I would
have succeeded better in the venture with the help of some
of the more experienced members of a Model Engineering Club,
but unfortunately experienced members and Model Engineer Club
do not exist in Italy and therefore I had to do everything
on my own.
If the construction of the various components of the boiler
was a relatively simple job, its soldering gave me some problems.
However I managed to finish it and, with the little experience
I had, I could not have pretended much, so I was satisfied
with my result and submitted it to an hydraulic breaking my
heart to see that it leaked water from everywhere.
Discouraged, I took the torch once again in my hand and I
started working, but as soon as I would eliminate the leaks
from one part, others appeared. It was only with a lot of
patience (and a lot of gas) that I succeeded in finishing
the boiler that finally resisted the hydraulic test without
any leaks. |
Lubrication
and Boiler Feed
I
arranged the cylinder lubrication pump on the running board,
connecting the ratchet wheel to the steam chest spindle, it was
the only available place, but it definitely appeared very ugly.
I resolved the problem by covering the lubrication pump with a case
which, even if it did not appear in the prototype, it was clearly
indicated in the drawings as the one containing the engineman's
service tools.
I remember with great envy the letter of a reader in "Post Bag"
that more or less said "following the instruction of Mr. Laurie
Lawrence, I constructed ten injectors that functioned perfectly".
I
also constructed ten, but not one had a satisfactory functioning,
so reversion to the pump had been the only efficient solution in
order to feed the boiler. I prefer not to speak about when I had
to take the locomotive to pieces in order to paint them.
However, I was able to finish it and the only thing I can say is
that it was an enormous satisfaction to bring my FS 835- 049
to an end. In Italy we do not give locomotives a name and it is
because of this that I numbered mine 049 in order to diversify it
from all the others (the last one built by Italian Railways was
835-048)
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Why not have a look
at my "Canterbury Lamb" pictures ?Click
here
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