BR Class 3MT 2-6-2T makeover

[RosiesBoss]

Introduction

82004 worked on the WR from new (Tyseley, 1952) until transferred to the SR (Bath Green Park, 1959)

 

This loco is still a favourite model. Probably my first second-hand loco, I originally bought it for about $5 from Searle’s hobby shop in Pitt Street, Sydney around 1965, while still attending high school. My mother persuaded me not to use it to motorise an Airfix 61XX, as it was (then) in such good condition. Around 2009, I overhauled the chassis, substituting Romford wheels and finer, more complete valve gear (probably current Hornby spares for a Stanier 4MT 2-6-4T). It looked much better for this. It still has its original X04 motor and Tri-ang gears and runs strongly and reliably.  It still awaited an overhaul of the body, which would include new, separate handrails, transfers and full repaint.

 

 Here she is, showing off her improved chassis:

 

Having just finished another makeover (Ref.1), I was in the right frame of mind to begin another.

 

I began by reviewing the official BR general arrangement drawing:

 

I then looked closely at Ian Beattie’s drawings in Ref.2.

 

These references confirmed my suspicions that the old Tri-ang moulding, though good for its time (it was introduced in 1956), had more than a few discrepancies. I chose to limit the makeover to the following:

• Lower the body on the chassis by about 3mm
• Fit larger cylinders
• Improve the buffers
• Fit separate handrails
• Replace some moulded pipework (as done with my GBL Britannia)
• Re-shape the front buffer beam and fit scale couplings to both buffer beams
• Fit front lamp brackets
• Fabricate and fit new steps to the footplate
• Reduce the width at the outer end of each pony truck
• Glaze the cab
• Recess the cab doors
• Repaint and apply new lining and numbers

I had no illusions that, once finished, this model could be mistaken for a modern Bachmann example. I would just be completing the overhaul which commenced in 2009. It would still be a re-worked Tri-ang model.

 

Principal Aim

To further improve the appearance of this old model to be more consistent with other models in my collection

 

Parts List

• Hornby X1809 Fowler 2-6-4T cylinders    
• Thin brass sheet
• Etched scale couplings
• Hornby X6206 28XX class buffers
• Bachmann slim tension-lock couplings
• Brass handrail knobs
• 0.4mm dia phosphor-bronze wire
• Humbrol enamels and acrylics
• HMRS Pressfix lining and number transfers

Actions

The model was test run “as is” to verify that there were no mechanical issues before dismantling  began. The body was then removed from the chassis and set aside.

 

Chassis modifications:

• Original cylinders replaced by Hornby Fowler 2-6-4T cylinder block
• Lower the motion bracket
• Grind back (trim/narrow) the front sandboxes
• Cut off the very front portion of the chassis
• Grind back the sloping section at the front of the chassis
• Refresh the 8BA hole for the body mounting screw
• Extend the 8BA threaded section of the body mounting screw
• Narrow the ends of both pony trucks, to clear new footplate steps

 

Body modifications:

• Open up new rear body mounting holes, 3mm above the originals
• Shave a small amount of plastic from the underside of the coal bunker
• Adjust the clearances for the connecting rod big end and expansion link
• Modify the front buffer beam with insets at each end
• Re-shape the ends of the rear buffer beam
• Fabricate 6 sets of steps for the footplate from 0.005” sheet brass
• Cut out existing cab doors and mount new, recessed ones
• Shave off moulded handrails and replace them with discrete wire ones on brass knobs
• Fit new buffers and scale couplers to both buffer beams
• Fit front lamp brackets, made from domestic staples
• Repaint the model with Humbrol enamels and acrylics
• Line and letter the model, using HMRS BR & GWR Pressfix transfers

 

Results

She looks a bit different, now:

 

 

Reflections

The replacement cylinders are still not quite big enough, but they were the largest that could be shoehorned into the chassis. It was quite challenging to get the modified mechanism to run smoothly and without binding anywhere in the valve gear. The rest of the upgrade was relatively routine.

 

For this project, the only component bought in was the cylinder block. The rest came from existing spares. It pays to keep a well-stocked spares bin and to replenish it when scarce items become available!

 

References

1. http://www.rmweb.co.uk/community/index.php?/topic/128181-tri-ang-dock-shunter-makeover/
2. Railway Modeller, April 1999.
3. http://www.rmweb.co.uk/community/index.php?/topic/108081-motorisation-of-gbl-britannia/
4. Richard Derry et al.: “The Book of the BR Standards” (Irwell Press, 1997)
5. Colour photo of 82030 here: http://www.82045.org.uk/82045_about.html

 

[bike2steam]

Nice, I have fond memories of seeing more than half the class at Nine Elms. A 'labour of love' given the excellent Bachmann example, I admire your persistence