The Steam Locomotive: a Machine of Precision

GREAT WESTERN ECHO
The Steam Locomotive: a Machine of Precision
PAUL CARPENTER BRINGS US UP TO DATE ON STEADY PROGRESS WITH ‘NIGHT OWL’ 4709
I
the four faces of one axle in a single set-up to Swindon tolerances.
n September 1955 Ken Cook (sometime Principal Assistant to
This has been quite a voyage of discovery we have received a lot of
F W Hawksworth and later Mechanical and Electrical Engineer of
help on the journey. Bob Meanley at Tyseley has long since appreciated
the Western Region, subsequently Chief Mechanical and Electrical
the value of such a tool and he was kind enough to show me his set up
Engineer, Eastern and North Eastern Regions) became President of the
when he worked on the ‘County’ mainframes. We haven’t copied his or
Institution of Locomotive Engineers and gave a presidential address
anyone else’s machine, but it was helpful to discuss aspects of the design
whose title I have borrowed for this article. For me that paper represents
and challenges encountered. We have also had help from many other
something of a milestone in railway technical literature as it not only
sources but I must thank Colin Driver who patiently produced drawings
revealed some of the precision production practices within Swindon
for eight revisions of our machine (!) and Dave Ham whose machining
(which were usually not shared) but it did so to the very audience that
expertise has produced a device that is capable
the GWR had all but snubbed for many years
of working to very close tolerances. It is hoped
previously. Swindon engines were known
that this piece of equipment will help other
to be built to closer tolerances than other
projects to get this critical alignment right and
railways and ran significantly greater distances
also generate funds for 4709.
between shop visits as a result - but how they
The Night Owl project has been quietly
achieved that was something of a secret.
progressing on several fronts recently. Our
As the Night Owl project prepares for
Resident Engineer Don Ashton is ever busy
horn alignment and re-wheeling I revisited
designing and producing CAD drawings to
the Cook paper looking for a technique we
allow manufacture of parts for which works
could replicate and achieve the Swindon close
drawings have not survived. This is tricky
tolerances. I knew they had a huge mainframe
work and requires a thorough understanding
jig that could grind all loco horns in the one Above The Swindon photo from Ken Cook’s
paper that provided inspiration for our own
of the mind of the 1920s Swindon Design
setting but this was clearly not appropriate for horn grinding machine.
Engineer. We are planning to show his work on
our job. Then I noticed a small photograph Top Even in its final days, the majesty of
a new section of the website which will make
in the paper. This was a mobile jig that was Churchward 47XX Class 2-8-0 No. 4703 is
radiant in one of the roundhouse bays at
interesting viewing. Recently Elliot Powick
used to true up a single horn face as a quick Old Oak Common on Sunday 3 May 1964 - a
joined the team and has been producing 3D
repair. This faded image became the starting precision machine, built to last. On the left is
versions of 4709 parts. This is ‘state of the art’
point of the 4709 Horn Grinding Machine and 4082 Windsor Castle, while in the background
lurk two Class 52 ‘Western’ diesel hydraulics,
technology and allows us to ensure that parts
after almost a year of development we have which in little more than a decade would
fit together straight off the board. Again we will
produced a machine that can effectively grind themselves be history. Geoff Plumb
26 AUTUMN 2015 211
GREAT WESTERN ECHO
be showing these assembly
helpful with the Horn
drawings on the website
Grinding Machine and
and they will reflect the
has offered to sponsor the
current stage of the engine.
grinding wheels – Thanks
Richard Croucher and
Chris. Such sponsorship
I have been working for
really helps us move
almost a year to procure
the project forward so
a fourth axle and ten new
please consider helping
When the extension frame
has been joined to the mainframe
tyres for 4709 at the right
in this way – it doesn’t
we shall be at this stage...
price. We made enquiries
have to be large sums of
as far afield as Germany,
money – although these
China and USA before agreeing a contract with the Wheel Set and
move progress even quicker! With such support 2016 should to be a
Brake Company in Derby. Although this has taken time we have been
significant year for 4709.
able to achieve significant reductions in the cost of the forgings and
Unfortunately in 2015 we lost one of our true allies – Bob Fry. He
these are now on order. They will be delivered early in 2016 and form
was a real supporter of our project and went to extraordinary lengths
an important next step towards wheeling the loco.
to help us. Earlier this year he sourced all the exhibits for the Night
Work at Llangollen has also been progressing, the extension frames
Owl stand at the London Model Engineering Exhibition. This is a
now having been completed
three day show and he
and the extension frames are
willingly supported our
imminent. Once completed,
team in manning the
they will be permanently
stand. Together with
fitted to the mainframes
Richard, Bob and I would
and reveal for the first time
regularly meet in London
the huge and majestic size
to plan the next steps for
of the Night Owl. We will
4709. He had a real ‘can
then grind the horns and
do mentality’ and was
Acquisition of tyres, crankpins and
fit the axleboxes ready for
always encouraging in his
springs will enable us to move to
wheeling. Axlebox overhaul
friendly and affable way.
this stage!
follows accepted practice,
He will be greatly missed.
except that these are donations from other classes.
We have been invited to present a display for our engine at the
Sometimes there are nasty little addenda to upset the apple cart and
London Show again in January next year and new members of the
the main drawing may not be specific. On one occasion two holes in a
stand team would be very welcome.
casting clearly sported a dimension of 5in, but an added remark, ‘4.5in
In an effort to attract funding we are keen to learn more about the
on Class 47’, was a physical impossibility.
freight activities of the 47XX class, especially in the years after the first
The Brakes Worksheet is a preliminary design sheet on which to
world war but also throughout their long lives. Please share with us
sort out missing information and test out veracity. Scouring drawings of
what you saw, what you know, or what you did with 47xx freight trains.
other close items, hunting through our generous library of photographs
On 28 September this year, Richard Croucher and I gave a
(thank you kind donors) and having regard to the proposed duties of
presentation entitled ‘Return of the Night Owl’ to the Railway Division
4709 may suggest a small refinement or a change in principle. The
of the Institution of Mechanical Engineers. This is the current form of
worksheet showed up the original problem areas, points of suspected
the Institution of Locomotive Engineers and hence the same audience
changes and finally allowed considerable use of parts rescued from
that Mr. Cook addressed sixty years ago almost to the day – truly the
2861.
return of the steam locomotive to the Institution. They are proud to
The ongoing major challenge is funding and it controls our rate of
be associated with our project and are keen to assist us in delivering
progress. If you would like
this fine example of
to see 4709 on its wheels,
British manufacturing and
now would be a good time
the final masterpiece of
to come forward. Help could
G J Churchward.
be in the form of a monthly
We welcome volunteers
contribution – every little
to help with all aspects
helps – or perhaps consider
of the ‘Night Owl’
sponsoring a part. Recently
project, especially handswe have been very fortunate
on engineers, marketing
with
two
companies
and sales people. Please
prepared to sponsor scopes
contact me, by email at
of work. The first is CoMech
pcarpenter100@btinternet.
who have generously offered
com if you would like
to undertake the UAT tests
to become involved and
on the donor axles – Thank
support us. For offers of
you Keith and team. Chris
financial support please contact
Watson of Watson Abrasives
Richard Croucher, chairman@
is an expert on grinding One of Don Ashton’s worksheets for the brake gear on 4709 exemplifies the quality didcotrailwaycentre.org.uk,
processes has been very of work being carried out on development of the project.
or phone 01235 817200.
211 AUTUMN 2015 27