So pleased to see you have recovered full functionality again. Whilst listening to the loco on it's empty tender off run and as it passes through the tunnel I can hear what sounds like a slight short pause as if the loco is slowed for an instant, it may be worth checking for a track gauge pinch or kink within the tunnel. I have run the video a few times and I'm pretty sure something is occurring out of sight.
DERAILMENT ISSUES OF ALL HORNBY OO STEAM MODELS Running modern Hornby steam models has a number of issues relating to spurious derailments. First modern models (Post 1990) are made to suit CODE 75 track. Code 75 track has finer tolerances through pointwork checkrails & Frogs than old Code 100 track. Which means modern wheelsets have a narrower tread, not such deep flanges and a DIFFERENT BACK TO BACK Measurement, from old Code 100 wheels. My layout has over 100 steam locos and over 50% are Hornby. ALL Hornby steam locos I have found have a slightly too narrow back to back measurement NOT suited to Code 75 track, as do all their locos but not their carriages ! As a result you MUST use a Code 75 "Back to Back" Gauge to force gently between all the wheels on these locos, which will part them by a further 0.25mm. Most derailments due to this issue occur passing through pointwork. Modern models will NOT run properly on old Code 100 track, which is why this type of track is now virtually extinct in most European countries other than Spain & Britain. Where modellers appear to totally fail to understand the NEM agreements of the 1989 Conference in Germany on NEW Model Standards for Europe. (The USA has its own standards including code 83 track not suited to European models) !!! "Back to Back gauges" (made in brass) are available from more specialist Model shops in Britain, such as Marcway in Sheffield (but NOT Spain.) Too many LARGE Hornby steam locos are underweight to haul realistic 12 car trains, on the level. Some have required as much as an extra 100g of weight, especially the Hornby SR Lord Nelsons. Large steam locos need to be at least 300g (excluding tender) to avoid wheel slipping, which can damage the gearing and motors. Another issue with Hornby tender locos is of course the problem of the 4 wire connection between loco & tender. This often hangs too low, and can snag in pointwork. It is also vulnerable to assembly faults. I have had half a dozen Hornby locos fail, soon after being put on the track. In each case I found one or more of these wires had been damaged between the cab floor & chassis. Which required taking the loco apart to repair the damaged wires. NEM The NEM standard coupling pocket was unfortunately set for the larger HO market, so is slightly to low to suit British OO models. Having said that a number of British outline models from ALL the manufacturers often get the agreed height incorrect, and Oxford Rail have their own ignorant ideas of what the size of NEM pockets should be, especially on some of their wagons. Any NEM coupling should fit any NEM pocket, but some are just not produced on fine enough tooling creating minor size issues. I don't use the NEM Coupling (only the pocket). Instead I use the Kadee USA (British Buckeye type coupling). Designed to fit the European NEM pocket. Part numbers 17, 18, 19 & 20. (17 has the shortest NEM shank and 20 the longest). Being a magnetically uncoupleable type of more realistic looking coupling, they help on my large exhibition layout, as trains are often out of reach. So I've have used these for Decades, on all my exhibition layouts. CURVATURE A major issue few seem to understand. A real life Flying Scotsman cannot negotiate a curve tighter than 4.5 Chains (297 feet radius) or 1196mm in OO scale (around 4ft). And that's only at walking pace. A real life 40mph curve works out at around 5ft Radius in OO scale. So the more realistic a model becomes the more issues it will have with absurd tramway type radius curves. Indeed such horrid curves will also consume much of the locos power, leaving a lot less to haul any vehicles, as Real & Model trains do NOT have "differentials" in their axles like road vehicles !!! As I run full length realistic train formations up to a loco & 13 coaches, and I require for realism all corridor stock gangways to actually touch, and loco to tender gaps to be reduced to real life. I long ago discovered that the minimum RADIUS necessary is 5ft. (Diameter 10ft). This also hugely improves the running characteristics of ALL models, and itself abolishes roughly 95% of derailments, and makes locos run so much more smoothly and fluently. Being a real railway Engineer I expect my model locos to be able to move smoothly at a scale HALF WALKING PACE. Which has meant a number have had to have their chassis rebuilt to remove microscopic inaccuracies in production ! Happy Modelling. 😊
Thank you very much for that comprehensive reply it has given me a lot to think about and check as my track is code 75 on the main layout but for sturdiness and reliability I used code 100 in the storage area which is were the derailment occurred.
Glad you got the problems sorted out.
So pleased to see you have recovered full functionality again.
Whilst listening to the loco on it's empty tender off run and as it passes through the tunnel I can hear what sounds like a slight short pause as if the loco is slowed for an instant, it may be worth checking for a track gauge pinch or kink within the tunnel. I have run the video a few times and I'm pretty sure something is occurring out of sight.
Thanks, I hadn't noticed that I will have a look and check it.
well done
Lovely engine, pity you have had to do so much to it though.
DERAILMENT ISSUES OF ALL HORNBY OO STEAM MODELS
Running modern Hornby steam models has a number of issues relating to spurious derailments. First modern models (Post 1990) are made to suit CODE 75 track. Code 75 track has finer tolerances through pointwork checkrails & Frogs than old Code 100 track. Which means modern wheelsets have a narrower tread, not such deep flanges and a DIFFERENT BACK TO BACK Measurement, from old Code 100 wheels. My layout has over 100 steam locos and over 50% are Hornby. ALL Hornby steam locos I have found have a slightly too narrow back to back measurement NOT suited to Code 75 track, as do all their locos but not their carriages ! As a result you MUST use a Code 75 "Back to Back" Gauge to force gently between all the wheels on these locos, which will part them by a further 0.25mm. Most derailments due to this issue occur passing through pointwork. Modern models will NOT run properly on old Code 100 track, which is why this type of track is now virtually extinct in most European countries other than Spain & Britain. Where modellers appear to totally fail to understand the NEM agreements of the 1989 Conference in Germany on NEW Model Standards for Europe. (The USA has its own standards including code 83 track not suited to European models) !!!
"Back to Back gauges" (made in brass) are available from more specialist Model shops in Britain, such as Marcway in Sheffield (but NOT Spain.)
Too many LARGE Hornby steam locos are underweight to haul realistic 12 car trains, on the level. Some have required as much as an extra 100g of weight, especially the Hornby SR Lord Nelsons. Large steam locos need to be at least 300g (excluding tender) to avoid wheel slipping, which can damage the gearing and motors.
Another issue with Hornby tender locos is of course the problem of the 4 wire connection between loco & tender. This often hangs too low, and can snag in pointwork. It is also vulnerable to assembly faults. I have had half a dozen Hornby locos fail, soon after being put on the track. In each case I found one or more of these wires had been damaged between the cab floor & chassis. Which required taking the loco apart to repair the damaged wires.
NEM
The NEM standard coupling pocket was unfortunately set for the larger HO market, so is slightly to low to suit British OO models. Having said that a number of British outline models from ALL the manufacturers often get the agreed height incorrect, and Oxford Rail have their own ignorant ideas of what the size of NEM pockets should be, especially on some of their wagons. Any NEM coupling should fit any NEM pocket, but some are just not produced on fine enough tooling creating minor size issues. I don't use the NEM Coupling (only the pocket). Instead I use the Kadee USA (British Buckeye type coupling). Designed to fit the European NEM pocket. Part numbers 17, 18, 19 & 20. (17 has the shortest NEM shank and 20 the longest). Being a magnetically uncoupleable type of more realistic looking coupling, they help on my large exhibition layout, as trains are often out of reach. So I've have used these for Decades, on all my exhibition layouts.
CURVATURE
A major issue few seem to understand. A real life Flying Scotsman cannot negotiate a curve tighter than 4.5 Chains (297 feet radius) or 1196mm in OO scale (around 4ft). And that's only at walking pace. A real life 40mph curve works out at around 5ft Radius in OO scale. So the more realistic a model becomes the more issues it will have with absurd tramway type radius curves. Indeed such horrid curves will also consume much of the locos power, leaving a lot less to haul any vehicles, as Real & Model trains do NOT have "differentials" in their axles like road vehicles !!!
As I run full length realistic train formations up to a loco & 13 coaches, and I require for realism all corridor stock gangways to actually touch, and loco to tender gaps to be reduced to real life. I long ago discovered that the minimum RADIUS necessary is 5ft. (Diameter 10ft). This also hugely improves the running characteristics of ALL models, and itself abolishes roughly 95% of derailments, and makes locos run so much more smoothly and fluently. Being a real railway Engineer I expect my model locos to be able to move smoothly at a scale HALF WALKING PACE. Which has meant a number have had to have their chassis rebuilt to remove microscopic inaccuracies in production !
Happy Modelling. 😊
Thank you very much for that comprehensive reply it has given me a lot to think about and check as my track is code 75 on the main layout but for sturdiness and reliability I used code 100 in the storage area which is were the derailment occurred.