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Rebuilt Merchant Navy Class 'Belgian Marine'
This article was produced by R. Speare originally
for the website www.bulleidlocos.org.uk
By chance, the Company I was working for
went into liquidation, which being honest is the the best
thing that could have happened. So a new business was born,
Maiden Precision Engineering, doing work for local firms,
whilst allowing me to continue with model engineering, which I
was able to do between jobs.
So
summer - 1st September 1993 - etched in my mind for all time;
the start of an impossible dream that was going to take me 6
years of working in spare time, or 11470 hours - building two
Merchant Navy locomotives.
But no matter how good my engineering,
setting up a new business was a difficult time, and it was my
father who helped to finance the project and make it feasible.
There is a lot involved in building a Merchant Navy, and
building two allows me one to keep, and have one to sell and
offset some of the costs.
The materials - steels, bronzes, brass,
copper, stainless steel, silver solders, fluxes, gases,
fasteners, bolts, nuts, rivets, pins, plus postage and packing
all adds up to a very costly engine in its completed
form. Over 14 years later, the M.N. is out the
range of most people's pocket and has become unaffordable.
This is why such a high value has been put on the M.N. for
sale.
Really,
anyone attempting to build this loco should be capable of the
engineering involved, but I will explain the difficulties with
certain parts of the engine in very broad terms.
Being a skilled engineer I don't think there were any
favourite parts, all were done in the way that you were
trained, excepting to get a good finish.
The main frames first are straight forward,
but the thickness is doubled up at the rear to support the
weight of cab and fire box. Front buffer beams are o.k., the
rear ones are extended with locations for connecting to
tender. The spoons (connections) from the loco to the tender
are rods screwed at one end and slotted at the other.
Each of the stretchers and all brackets for
carrying the expansion links, slidebars for the crossheads (i/outside),
and screw reverser are fabrications, requiring between 18 and
24 individual pieces. This was extremely difficult, and I
found the best method was to braze using fluxed brass (though
careful setting-up is needed first).

Using tool room machines i.e. lathe plus
miller, the 2 outside cylinders and one inside were bored out;
M.J. Engineering was asked to quote a price which they did,
but recommended me to machine them myself. While machining the
outside cylinders caused no real problems, the inside cylinder
was extremely difficult, with an awkward setup as the block is
square with bores at an angle of degrees. This required
clamping the block relative to datum's for piston and valve
angles to bolting face of main frame.
The inside valve guide was badly drawn,
made up of bars and spacers in a narrow space, but a M.N.
builder in Australia re-designed the cylinder guide for the
valve end, although I had only photos to work from.
Wheels and axles are straight forward,
quartering of wheels was done using datum centres, slips &
gauges. Coupling rods are not fluted on M.Ns. (only on the
West Country class), connecting rods are fluted, as are radius
rods; but union links, combination levers, and suspension
links are plain. The expansion links radius was cut using a
rotary table; the crosshead is made up of 2 pieces and brazed.
With the front bogie accuracy is needed for
the lateral movement on bogie centre. The pony truck is a
tricky fabrication as it has to loop over and avoid the axle,
with all pieces brazed up.
Axle boxes have roller bearings throughout
on the loco and tender. Leaf springs are made up of 2 of
spring steel and the remaining leaves of hard bronze. The
brake assembly has 2 steam actuated pistons for operating
brake linkage and hangers. The buffers are a straight forward
turning exercise.
The aluminium casting for the Reverser
caused problems as it was too soft, and difficult to hold for
machining of the gear housing.
The smoke box was rolled from 1/8"
brass sheet and castellated, then s/soldered; door & wind
deflectors no problem. Running boards are quite long and a
folder was needed; and on the cab, allow extra length for
bends when forming.
I came across a number of errors in the
drawings, but in putting this to Keith Wilson, he said to me,
"If you've got this far what do you need me for ?"
I looked at the locos which were two thirds finished
and thought 'He's right, for all the cock ups I have got this
far !' He also told me this was not a loco he wanted to
do, and his words were "I've been shanghaied in to doing
the drawings".
The boiler drawing is wrong for the outer
& inner wrappers, too short on overall length, so an extra
width of material is needed here. The combustion chamber is
optional, but I decided to incorporate into both M.Ns.
But no real problems in building the boilers, pressure was
tested at 180 p.s.i. Safety valves are a straight
forward turning exercise.
The superheater and hot header is a bundle
of pipes, and a little awkward exiting through the smoke box
to the outside cylinders.
The Ashpan is a bit tricky as it is three
brazed fabrications that saddle over and fall between the loco
frames.
The M.Ns. had a generator fitted for cab
lighting, and following an article in the 17 Jan 1986 Model
engineer, I redesigned the '3T' alternator to look like the
Southern version. There are problems finding a position under
the cab floor as there's not much room; and when winding the
alternator coils, the wire needs to be taut.
The tender chassis has double frames, and the
body side plates have a curvature inline with the engine cab.
The tender is also fitted with an axle driven pump, and a
normal hand pump inside the water tank.
Below is a summary of some drawings that have
not been issued, so not covering the external details for the
M.Ns., these details I obtained by inspecting 'Ellerman Lines'
at York Museum.
The Diane Carney made nameplates required
fixing brackets but there was no drawing available. Photos are
required from full size version for the cab layout, and steam
& vacuum pipe work on backhead; wind shield canopy between
loco & tender. Neither do the drawings cover steam
generator parts list, the whistle fabricated under running
boards, mechanical lubricators and linkage, sandboxes bridging
main frames, sand pipes with steam connection; lamps, flags,
handrailing or ladders. 24 drawings were issued when probably
an extra 6 are really needed.
I liked the name 'Belgian Marine', and my
father picked 'Royal Mail' for the other one. Both were built
simultaneously, the second to the same standard as the first,
and I'm finish lining them both (which has been quite tricky)
and will have a photo of both fully painted soon.
The project probably equates to a 15 year
project for an average hobbyists (if it gets finished). So
potential builders beware, and all the best on project M.N. -
you will need all the the help possible!
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