Accucraft KERR STUART WREN 0-4-0ST User manual

Accucraft Trains • 33260 Central Ave., Union City, CA 94587, USA • 510-324-3399
www.accucraft.com • www.accucraftestore.com
1
ACCUCRAFT UK LTD
Unit 4, Long Meadow Industrial Estate,
Pontilas, Herefordshire. HR2 0UA.
Tel: [phone]
www.accucraft.uk.com
OPERATING INSTRUCTIONS
KERR STUART ‘WREN’ 0-4-0ST
SAFETY FIRST
All our locomotives are safe to run, and will give many hours of
pleasure, providing the following safety procedures are followed: -
1. Please read the instructions thoroughly before running for the
first time.
2. Always do a complete refill of gas, oil and water. Never refill just
the gas to prolong the run.
3. Never let the engine run out of water.
4. When refilling the gas, do not have any naked flame present, and
NO SMOKING!
5. Do not pick up the engine by the bodywork, chimney or boiler,
especially when hot.
6. Only pick up the engine by the buffer beams and, when hot, use
old gloves or a cloth.
7. Do not stand over the chimney. Ejected boiling water or steam
may cause serious injury.

Accucraft Trains • 33260 Central Ave., Union City, CA 94587, USA • 510-324-3399
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8. Do not open the smoke box door while the engine is alight.
General Hints
As with all operating machinery, whether model or full size, wear
will occur. In the model steam locomotive much can be done to
help prolong its life and decrease the amount of time required in
the workshop for servicing.
Keep the engine as clean as possible, and the motion free from dirt
and garden debris. The valve gear, axles and crank pins should be
oiled sparingly with light oil, e.g. “3-in-1 Oil”. Over-oiling
attracts dirt and grit, which will increase wear.
Regularly check that all screws and motion bolts are firm. Do not
over-tighten, as this strips threads and shears bolts. When filling
the lubricator, always use a high temperature steam oil such
as 460; this is available from other retailers. FAILURE TO
USE THE CORRECT GRADE OF OIL CAN LEAD TO
BLOCKED STEAM PIPES AND WILL INVALIDATE THE
GUARANTEE.
When running your engine avoid excessive speed and
acceleration, both will cause premature wear in the valve gear.
Prototypically, narrow gauge locomotives ran at a speed of
between 10 and 20 m.p.h., and never exceeded 25 m.p.h.
Positions of Fillers and Drains etc.
The gas tank is under the cab footplate, and the gas tank filler
valve is at the top of the gas tank turret, set at an angle to the rear
of the cab. The gas control valve replicated the locomotive’s
brake lever and can be operated from the back of the cab. Owing
to the small space available for the gas tank it may be best to fire
the locomotive up and raise the pressure to an operating level

Accucraft Trains • 33260 Central Ave., Union City, CA 94587, USA • 510-324-3399
www.accucraft.com • www.accucraftestore.com
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before extinguishing the fire to re-gas the tank – the gas should
then last for the full duration of a run.
The lubricator is under the running plate in front of the
smokebox, accessed by unscrewing the cap with a screwdriver.
The lubricator drain is underneath the footplate just ahead of the
offside cylinder. To drain, un-screw the drain pipe cap.
The boiler water filler is hidden under the tank filler in the middle
of the saddle tank. Lift the dummy cap off and undo the knurled
cap with a screwdriver to fill with water. This may be replaced
with a Goodall valve to facilitate topping the boiler up while the
locomotive is in steam.
The boiler/water gauge drain valve is located under the nearside
bunker, turn clockwise to open, anti-clockwise to close. The drain
is best left open between runs and can be used to clear bubbles
from the glass.
The safety valve is found in the steam dome. To access it use a
fine pair of tweezers inserted in the vent holes and unscrew the top
of the dome. The valve can be adjusted by turning it down
clockwise to increase the pressure, anti-clockwise to reduce it –
the valve has been factory set at 60psi.
The main steam regulator valve is the lever projecting towards
the back of the cab from the steam turret.
The direction control is the lever in the offside of the cab. To
operate pull gently outwards and move to the desired direction.
The control is “gated” and will therefore hold itself in the full
forward or reverse position.
Preparation for Running

Accucraft Trains • 33260 Central Ave., Union City, CA 94587, USA • 510-324-3399
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Always service in the following order; first gas, oil then water.
To fill the gas tank: invert the gas can and apply the nipple to the
gas inlet valve on the top of the tank turret. It is advisable to
support the loco under the gas tank whilst filling, to prevent the
engine tipping over. You will know when the tank is full; gas will
blow back from the inlet valve in a strong jet. A small amount of
gas and air will escape during filling, but the difference between
this and when the tank is full is always clear. You may find this
easier with a long-necked gas adapter.
Filling the lubricator: as you will read in the instructions for the
end of the run, the lubricator should be empty of oil and water. To
replenish this, remove the lubricator filler cap. Fill up the
lubricator with steam oil to about ¼ of an inch below the top.
Leave the filler cap off for the present, so that any trapped air can
escape. It can be refitted after you have filled up the boiler.
To fill the boiler: remove the dummy tank filler cap and then the
filler cap. The boiler is fitted with a water sight glass. Fill up the
boiler so it is about ¾ full. Replace the boiler filler cap, check
that the lubricator does not need topping up, and then replace its
filler cap also. Filler caps should be firm finger tight. They are
sealed with a trapped ‘O’ ring and, therefore should not be over-
tightened.
Lighting Up
Open the smoke box door; just pull it open by the door handle.
Light your lighter/match etc. and gently open the gas control valve
until a gentle hiss is heard in the burner. Apply your light into the
smoke box and the flame should ‘pop’ down the fire tube and
ignite the burner inside the fire tube.

Accucraft Trains • 33260 Central Ave., Union City, CA 94587, USA • 510-324-3399
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If the gas valve is opened too much the flame will not pop
back; it will either fail to ignite, will roar in flame out of the
smoke box, or there will be a ball of flame around the front of the
engine, which will then blow the whole fire out (after giving the
driver a fright)! When the fire sound has stabilised, after about 30
seconds the gas can be turned up until a healthy roar is heard. The
smoke box door may be shut after about two minutes. Now leave
the locomotive to raise steam.
Running
When the engine has raised about 40 psi, you are ready to start
running. It is advisable to run the engine in reverse first; it clears
the condensed water from the cylinders best this way. Before
commencing your first run of the day, it is advisable to put a cloth
loosely over the chimney for a few minutes, as condensed water
will be ejected from the chimney. This is quite normal; the
motion of the engine will be jerky until all condensate has been
ejected. DO NOT stand over the chimney as ejected boiling
water/steam could cause serious scalding.
Place the direction lever into the reverse position, and then open
the main steam valve. The engine should start to move off in the
reverse direction. When starting from cold it will be jerky, this is
normal as it must clear the condensate from the system. The more
the main steam valve is opened, the faster the engine will go; our
advice is to start slowly and learn the road with your engine.
After a minute or so, remove the cloth and continue running. In
running it is correct practice to balance the boiler pressure against
the load being pulled and the track conditions. With a light load
and level track the pressure may need to be only 25-30 p.s.i.
therefore, turn the gas control down to keep this pressure. When
running a heavy train with steep gradients, increase the pressure
by turning up the gas. The ideal running pressure can be learnt by
experience and is one of the pleasures of running a live steam

Accucraft Trains • 33260 Central Ave., Union City, CA 94587, USA • 510-324-3399
www.accucraft.com • www.accucraftestore.com
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engine. There is no need to have the safety valve constantly
blowing off (it is what its name implies – a safety vent for excess
steam pressure). When the gas runs out a complete gas, oil and
water service must be done (remember GOW, also remember to
shut the gas regulator before refilling, and DO NOT refill with gas
near any other live steam loco). When the locomotive slows as
the pressure falls at the end of a run, stop the engine. Open the
lubricator valve and blow out any condensed water. If you intend
to continue running, close the drain when you see oil coming out
of it and carry out a general refill. If it is the last run of the day,
leave the lubricator drain cap loose.
End of Run
As previously mentioned, the locomotive will slow (due to
pressure dropping) when the fire has gone out, stop at a
convenient place and open the lubricator drain valve. Blow out all
condensed water and the remaining oil. Leave the boiler valve
open and allow all the remaining steam to blow out. The
locomotive should be allowed to cool. When cool, clean the
engine, check the motion and oil if necessary. The locomotive
should always be put away in a clean condition as it attracts less
dust and is always ready for the next run (or to be shown to an
admiring friend). Always leave the lubricator drain valve and the
boiler drain valve open so that the boiler will not be strained if
subject to any temperature change. It is advisable to store the
locomotive where any residual drips of oil or water do not matter.
Blocked Gas Jets
If the gas jet becomes blocked with particles of dirt within the gas,
the jet will have to be removed and cleaned. With a spanner or
pliers carefully undo the pipe union on the gas control valve.
Remove the pipe and jet holder assembly from the burner.
Holding the jet holder gently in a vice, unscrew the jet. To clear,
place the jet nozzle against the inverted gas can nozzle and clear
the jet with a blast of gas. Under no circumstances use a pricker

Accucraft Trains • 33260 Central Ave., Union City, CA 94587, USA • 510-324-3399
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wire, this will damage the jet hole. Replace the jet in the
holder, ideally using a thread sealant sparingly on the threads.
Ensure it is tightened up firmly. Replace the assembly into the
burner and re-connect the pipe to the control valve. Ensure this is
done up tightly, test CAREFULLY with a flame and the gas “just
on”, for gas leaks. Tighten if required.
Identification of Controls and Fillers
1. Steam regulator
2. Reverse lever
3. Gas regulator
4. Lubricator filler cap
5. Boiler water filler
6. Gas tank filler valve
7. Burner air control ring
8. Water gauge
9. Pressure gauge
Identification of Accessories

Accucraft Trains • 33260 Central Ave., Union City, CA 94587, USA • 510-324-3399
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A. Protective gloves
B. Boiler filling syringe
C. Small syringe
D. Syringe extension tubes
E. Hex nut spinners for
2mm and 3mm hex bolts
F. Allen keys, 0.8mm for
cranks and 1.5mm for
wheels

Accucraft Trains • 33260 Central Ave., Union City, CA 94587, USA • 510-324-3399
www.accucraft.com • www.accucraftestore.com
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A Bit of History
Kerr Stuart produced 163 ‘Wren’ type locomotives before they
ceased trading in 1930 and a further four were constructed
thereafter by Hunslets. The ‘Wrens’ owe their origin to the ‘Buya’
class of 1903 although the type encompassed a huge number of
variations including inside and outside frames and inside and
outside valve gear. Our model is based on the 2’ gauge ‘new type’
developed in 1915 with inside frames, Hackworth valve gear and
cast-iron wheels fitted with steel tyres. In due course ‘Wrens’ were
sent around the world, many to Africa and Asia whilst in the UK
they found homes with construction companies and the Ministry of
Munitions, some being used by the Ministry of Defence in the
building of airfields. No fewer than 27 were purchased by
R.H.Neal & Co. for sewer contracts and several of these were sold
on to Devon County Council for road construction. A few ‘early’
type ‘Wrens’ survive around the world and half a dozen ‘late
types’ have been preserved, five of them in the UK.

Accucraft Trains • 33260 Central Ave., Union City, CA 94587, USA • 510-324-3399
www.accucraft.com • www.accucraftestore.com
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HINTS ON GAS FIRING CONTROL
CONTROLLING THE GAS FIRING OF YOUR LOCO MUT BE DONE WITH
CARE AND ATTENTION. TURNING THE FIRE UP TOO MUCH CAN
CAUSE GREAT DAMAGE TO YOUR MODEL SUCH AS BURNING OFF
THE PAINT, MELTING THE INSULATION OFF THE WHEELS, AND
CARBONIZING THE STEAM OIL IN THE SUPERHEATER WHICH
BLOCKS IT. NONE OF THE ABOVE DAMAGE WILL BE COVERED BY
WARRANTY AS IT IS ATRIBUTED TO OPERATOR ERROR.
AT ACCUCRAFT WE GIVE YOU THE ABILITY TO RAISE A GOOD HEAD
OF STEAM BUT IT IS UP TO THE OPERATOR TO CONTROL THE GAS
FLOW SO THE FIRE DOES NOT ROAR OUT OF CONTROL AND BURN IN
THE SMOKE BOX. IT IS VERY MUCH LIKE THE ACCELERATOR OF
YOUR CAR, HOW YOU USE IT IS UP TO THE USER, DRIVE SENSIBLY
AND YOU WILL NOT HAVE AN ACCIDENT; PUT YOUR FOOT DOWN
AND YOU WILL PROBABLY END UP IN THE HEDGE. HARDLY THE CAR
OR THE MANUFACTUER’S FAULT!
NEVER LEAVE THE LOCO UNATTENDED WHEN RAISING PRESSURE,
AS THE HEAT INCREASES THE PRESSURE IN THE GAS TANK ALSO
RISES AND YOU WILL HAVE TO TURN THE GAS DOWN. IF THE GAS
CONTROL VALVE SPINDLE IS A BIT STICKY IT COULD NEED
LUBRICATION WITH STEAM OIL. WHEN YOU UNSCREW THE NEEDLE
VALVE TO OIL IT ALWAYS DO IT WHEN THE GAS TANK IS EMPTY.
KEEP LOCOMOTIVE ORIGINAL PACKAGING
WE WISH TO ADVISE YOU THAT IT IS IMPERATIVE THAT ALL
ORIGINAL LOCOMOTIVE PACKAGING, BOTH OUTER AND INNER
BOXES AND ANY OTHER TYPES SUCH AS SHAPED POLYSTYRENE,
SHOULD BE RETAINED.
SHOULD YOU NEED TO RETURN YOUR MODEL FOR ANY REASON,
EITHER FOR SERVICE OR WARRANTY WORK, IT MUST BE SECURELY
PACKED IN ITS ORIGINAL PACKAGING SO AS TO PREVENT DAMAGE
IN TRANSIT.
IF THE MODEL IS PACKED IN ANY OTHER WAY WE CANNOT BE HELD
LIABLE FOR ANY DAMAGE CAUSED BY IMPROPER PACKING. ALL
ITEMS COVERED BY OUR TWO-YEAR WARRANTY WILL BE COVERED
BUT ANY PARTS AND LABOUR ATTRIBUTED TO RECTIFYING
DAMAGE CAUSED BY IMPROPER PACKING WILL BE CHARGED FOR.

Accucraft Trains • 33260 Central Ave., Union City, CA 94587, USA • 510-324-3399
www.accucraft.com • www.accucraftestore.com
11
GUARANTEE
Accucraft UK Ltd will remedy any defect or malfunction occurring with this product during a two-year guarantee period
from date of purchase. This guarantee does not extend to malfunctions or defects caused by damage or unreasonable use,
including the failure to provide the correct types of lubrication and water or by not controlling the gas correctly.
If a claim is to be made within the two-year guarantee period, in the first instance, return both the product and guarantee
card to your dealer. In the event of your problem not being able to be fixed by your dealer, he will contact us for advice.
If necessary, we will arrange for the product to be returned to our service department for repair.
This guarantee is quoted in addition to all legal rights of the purchaser under the Sale of Goods Act and shall expire two
years from the date of purchase. Under no circumstances shall Accucraft UK Ltd be responsible for any consequential
damages arising regarding any Accucraft UK Ltd product .
__________________________________________________________________________
CARE OF YOUR LOC0MOTIVE
•Proper lubrication is most important but must not be overdone.
•Care should be taken when removing the loco from its packaging, as any levering action using projecting
parts (e.g. buffers) may result in damage.
•Check with your dealer that these locomotives wheel standards are compatible with your track system.
Ensure that your track is in good condition and well maintained.
•Keep the engine free of dust and dirt. Debris such as earth and gravel in the motion will lead to premature
wear and failure.
•Always use steam oil in the lubricator, never ordinary household oil.
•Never light the burner without water in the boiler.
•Always control the gas correctly and do not have the fire too high so it goes into the smoke box and damages
materials, paint, or wheel insulation.
__________________________________________________________________________
SAFETY
•Always use this product in a well-ventilated area. Never get directly above the chimney, boiling water can
sometimes be ejected from it.
•When in steam, and for some time afterwards the engine will be very hot. HANDLE WITH CARE.
•This model has many small parts and should be handled with care. It is not suitable for children under the
age of 14 years old.
__________________________________________________________________________
ACCUCRAFT UK LTD, UNIT 4, LONG MEADOW INDUSTRIAL ESTATE, PONTRILAS,
HEREFORDSHIRE. HR2 0UA.
LOCOMOTIVE LOG BOOK
Loco Serial No: ……................................ Boiler Serial No: ……………………………….
Gas Tank Serial No: …………………………..
First Registered Owner: …………………………………………………
Date Purchased: ………………………………………………………….
Second Registered Owner: ………………………………………………
Date Purchased: ………………………………………………………….