Enhancements Applied To This Little Samson

Enhancements Made To This Little Samson Traction Engine

Both during the original building of this Little Samson Traction Engine and during the recent refurbishment project many enhancements over and above the original design have been incorporated. You may wish to incorporate some of these ideas into your own engine.

Sone of the items described are more in the realm of good practice or good maintenance rather than specific physical features but nevertheless result in an improved engine.

History

Dynamo and Canopy with lights added to convert the engine to a Showmans type engine with the ability to generate useful nominal 12V DC and 220V AC electrical power.

 Engine only steamed 10 times (covering approximately **km), not enough to cause any significant wear but sufficient to gain experience and feed useful knowledge into improvements.

Engine completely stripped down and refurbished 2024/2025 incorporating all ‘lessons learned’ from previous steamings.

Exhaustive Library of photos, videos and CAD drawings (in .dwg and some in .pdf format) generated both during and after the build. Not: CAD drawings were made for most parts during the build but not all represent the current state of the engine.

Several motion parts (e.g. expansion links etc) machined from CAD drawings by EDM or laser machining ensuring precise accuracy. Many other parts produced by Laser and/or plasma profiling to CAD drawings.

Boiler made professionally by AJB in the UK and is complete with all certification.
Water treatment used for each steam run and boiler drained dry at the end of each run.
Internal boiler condition looks very good – see photos.

Philosophy

Throughout the build great care has been taken to not only build as close as possible to the published drawings to maintain authenticity to the prototype engine but also to:-

  • Improve authenticity and ‘period look’ (1950) by incorporating period details like prominent nuts custom made to scale size, ensuring the correct stud length to avoid uncharacteristic over-long protrusion from the nuts, and avoidance of using modern commercial fasteners which would look totally out of place.
  • Reduce the need for constant maintenance and cleaning and the elimination of corrosion by selectively use of stainless steel parts and fasteners and judicious painting of otherwise bright steel (corrosion attracting) mild steel parts.
  • Avoid spoiling painted finishes caused by the corners of nuts when tightening (washers were not used on the prototypes) by machining “Micro Washers” into the undersides of custom-made nuts.

Details

Cylinder and Trunk Guide Bores lapped using Timesaver lapping compound.

Cylinder Steam Port passageways streamlined to remove sharp corners and restrictions thereby providing a smooth path for steam flow.

Custom-made copper washers soft copper washers provided throughout to seal piping joints and stud/nut joints.

All prominent (normally bright) nuts custom made to scale size – c 1900s – instead of off-the-shelf modern commercial nuts. Good examples are cylinder and cylinder head nuts.

Most prominent nuts are made from stainless steel.

Scallops machined into the Trunk Guide to facilitate spanner/socket access to fixing nuts.

Forcing screws added to cylinder joints – Front Cover, Valve Chest Cover, Trunk Guide – to make removable of parts easy without the need for destructive parting tools like wedges, chisels, or screwdrivers.

Dowels added to cylinder flange to allow easy re-alignment to the boiler in the case of cylinder removal.

Substantial outer bearing added to Trunk Guide to support Lifting Link Spindle. Prevents unwanted Spindle (and hence Expansion Link) movement.

Boiler Cladding is made from thick (3mm) steel to add robustness and eliminate accidental dents.

Boiler Cladding welded at top seam to provide strength thereby rendering Boiler Cladding Straps largely decorative. Easy to remove for polishing.

Tapped hole provided in Handhole Cover to accept threaded rod when it is removed. Prevents cover from falling into the Boiler.

Drilled holes provided in Connecting Rod Little End Bush and Crosshead to allow Little End Nut to be tightened.

Specially made Pin and Spanner provided to fit the Crosshead Nut, also to fit the Piston Rod retaining Nut.

Substantial steel drop arm provided to protect the injector pipes from damage from rocks, boulders etc. sticking up from the ground and/or when driving up/down steps or speed bumps in the road.

Arrangement of fixing bracket provided to secure the Exhaust Nozzle in the Smokebox.
All Crankshaft Bearings and Eccentric Straps lapped in with Timesaver compound.

Ball-Joint provided for the Boiler Feed Pump Ram to accommodate any misalignment between Feed Pump and Crankshaft.

All hot parts (Boiler Cladding, Smokebox, Chimney, Cylinder) painted with High Temperature (235 deg C) paint.

Disk valves provided for Boiler Feed Pump replacing noisy ball valves to reduce chatter and noise.

Fastener Security

Anti Loosening provisions applied for all screwed fasteners appropriate to their location and function.

  • Hornplate fixing screws provided with locking straps to prevent loosening from road-generated vibration.
  • All Gib Keys secured with hex headed screws bearing on the tight Gib Keys.
  • Second Shaft Gears secured axially with end-locating straps secured with hex headed set screws wired with security safety wire.
  • Steering Chain Shackle screws secured with security safety wire.
  • Locknuts fitted to all Valve Gear Eccentric and Feed Pump straps.
  • Unless otherwise secured, all fasteners subject to loosening secured with Loctite.

Injector and Injector Pipe Assembly mounted on an easily removable sub-frame to allow quick removal and re-fitting.

Ashpan pin fitted with quick pull-out pin on chain to secure the Ashpan Pin whilst still allowing fast and easy dropping and reinstallation of the Ashpan.

Ashpan Damper Pin fitted with quick pull-out pin on chain to secure the Ashpan Pin whilst still allowing fast and easy dropping and reinstallation of the Ashpan.

Enlarged elongated hole machined into the Frontplate to allow the Feed Pump Ram to pass through.

Anti Corrosion Protection

Anti corrosion protective measures provided to all vulnerable components.

  • All handles made from stainless steel.
  • All normally bare bright steel motion parts painted with very special ‘steel’ colour anti corrosion paint. e.g. Regulator and Lifting Link Reach Rods, Reversing Lever and associated assembly.
  • All “normally bright” steel pins/washers treated with anti-corrosion black oxide finish.
  • Water tank treated internally with 2-pack epoxy paint.
  • Specified rivets for removable parts e.g. chimney base replaced with stainless steel hex button-head screws with stainless steel nuts.
  • Back Wheel Retaining Collars painted ‘chrome’ to prevent corrosion.
  • Pins for Back Wheel Retaining Collars made from stainless steel.
  • Stainless steel split pins used in most cases.

Reversing Quadrant provided with multiple notches to allow expansive working as with locomotives. This works!

Reversing Quadrant notches and matching lever machined to micro tolerances by EDM (Electrical Discharge Machining) thereby eliminating any ‘slop’. There is none.

Drain point provided to Water Tank to allow draining down.

Lifting Link Reach Rod reconfigured to run horizontal rather than sloped. Looks much neater and smarter.

Easily removable twin Driver/Passenger Seats and safety foot platforms provided.