Help needed with old Hornby smoke unit please!!

[TVR1707822112]

Hello!

An uncle recently gave me an old Hornby Railways Midland compound, R376 I think, which has a smoke unit fitted. It has not been run for roughly 35 years. I have managed to get the motor and the rest of the locomotive serviced but have not yet attempted to do anything with the smoke unit, which I believe is part number X1489. I have multiple questions:

A: Would the locomotive run on standard Seuthe oil?

B: Would It run? If it wouldn't, how should I try to restore it?

C: How is it wired? It makes no sense to me, pictures would be appreciated please.

D: How does it work? I'm a stranger to smoke generators, any help is appreciated!

Thanks! grinning

[Chrissaf]

A: More than likely - yes.

B: Don't fully understand the question.

C: In principle the early Hornby smoke units fell into two types, "Synchrosmoke" which can be easily recognised because the loco wheel drive also drove a cog that operated bellows. The bellows produced 'puffs' of smoked air synchronised to the wheel rotation. The other type of Hornby smoke unit is more basic and looks more like a 'Seuthe' unit. The Synchrosmoke unit and some of the other smoke unit types typically used the case of the smoke unit as a current return path via the metal loco chassis to the wheels. A wire from the wheel pickups on the other side of the loco provided the feed current to the smoke unit in parallel to the motor feed. The other side of the motor typically also being retuned via the chassis to the rail.

D: In principle, there is a coil of special wire that glows red hot when a current is passed through it. The concept is similar to an old one bar electric fire that were common in the 50's & 60's. This wire coil was wrapped around fire proof wadding - a sort of asbestos type product, which these days would be banned hence the non [very limited] availability of spare replacement wadding. The smoke oil would be dribbled onto the wadding down the Chimney [not soaked] and the heat from the coil would cook the oil and make it slowly turn to smoke. The oil had a cooling effect on the heating coil, thus running the smoke unit without oil could burn it out prematurely.

Modern after-market Seuthe smoke units use a similar operational process, but modern design means that there are a range of Seuthe units to suit different electrical characteristics. Generating smoke consumes a lot of power, there are some low current Seuthe units designed to operate on about 80 to 100mA which can make them suitable for operation via a DCC Decoder. But typically the modern Seuthe smoke unit will draw nearer 150mA. The old Triang Synchrosmoke era smoke units drew even more current than that and are not suitable for use with Hornby Branded DCC decoders or modern Hornby Analogue 'set' controllers that can not provide the power needed for smoke in addition to running the loco as well.

[TVR1707822112]

Thanks for the response.

It's not a synchrosmoke unit as far as I'm aware - I think it's one of the more basic types.

Sorry to have confused you with my second question! I was wondering whether if the loco has been sat in a box in a loft for the best part of 40 years would the smoke generator run without any type of maintenance? If not, how should I go about replacing/servicing it?

If it contains asbestos, is it safe to run without any oil in the generator?

Thank you very much for your help - I really appreciate it!

TVR

[Going Spare]

The Compound was fitted with the plastic bodied smoke unit which is quite a tight fit in the smokebox and is wired to the locomotive chassis as per Service Sheet 134 downloadable via the Useful Links sticky post at the top of this forum section.

Many locomotives have suffered melted smokeboxes by the overheating smoke unit if run for any lengthy period without any oil in it, a particular problem if you are running under DCC control as the track is live the whole time, for which reason Hornby no longer offer any smoke units.

[Chrissaf]

I said it was a "sort of asbestos type" material. Whether it is actually true asbestos or not, I couldn't say, but whatever material it is actually made of, the official wadding is 'hen's teeth' - in terms of identifying suppliers, there is one known ebayer that sells an alternative material on ebay.

There are no moving parts in the generator section, just the wadding and the coil of wire. After 40 years storage, the wadding and the coil could be extremely dried out and brittle and could break if physically disturbed. I'm no expert on these old smoke units, but I would think that adding a little 'Seuthe' oil as lubrication would be a wise move before powering up the loco after a 40 year break, as would performing a full oiling service of bearings, gears and other moving parts.

As I said, in my original reply. I would not try running the unit dry, as it is more likely to burn out. Note that these locos almost certainly do not have a separate 'on/off' switch for the smoke function. I have seen many posts on this forum recommending that the smoke unit be disabled and not used by disconnecting and insulating one wire that feeds into the smoke unit.

[TVR1707822112]

@Chrissaf

 

 

Thanks again for your response - as I said, its really appreciated! I'll order some Seuthe oil and see if it works - if it doesn't would it be easy to change for a different generator, either TRS Trains type or Seuthe?

I appreciate you taking the time to help me with this - I just know that my Uncle (and me!) would love to see it steaming again! steam_locomotive

Thanks, and best wishes.

[TVR1707822112]

@Going Spare

Many, many thanks for taking the time to get back to me about this.

I'm going to try running it with some oil in, if it doesn't work I'll disconnect it and try to replace it with a different type of generator.

Best wishes

TVR

[Chrissaf]

Suitability to accept an alternative smoke unit is not within my remit to answer. I don't model steam era and everything I have is DCC.

Either way, fitting an alternative unit is not likely to be a 'plug n play' solution and likely require ingenuity and modelling skills, plus an understanding of electrical wiring circuits.

As a moderator and since you are a new poster, could I humbly ask you to ignore the 'blue button with white arrow' which is not a 'Reply to this post' button. It is far more efficient and easier on the eye of the readers if you just scroll to the bottom of the page and write your reply in the 'Reply Text Box' and click the green 'Post Reply' button. If you want to bring your reply to the attention of an individual, just start with the @username tag as I have done when editing your previous later replies on this page.

[Tony57]

Hi

You need to look at Service Sheet 26 which covers the R520 smoke unit fitted to the locomotive in question

The smoke unit does not have any wadding in it but it does have a smoke tube from which the oil vapour vents from which can become blocked by old oil deposits

[96RAF]

@TVR

The TRS Trains unit works on a completely different principle. The ‘fuel’ is water which is atomised by an ultrasonic generator to produce ‘steam’. It also has its chuffs synchronised with a sound decoder, so only suitable for use on DCC. Unfortunately due to the bespoke nature of the parts required it is not offered as a retro-kit for installation by owners, only as a ‘factory’ fit unique to each loco and due to the additional sound decoder at a considerably greater cost than the Seuthe oil burners.

Based on the recent Hornby -A Model World TV Series it is believed Hornby intends to market a similar system but again due to the bespoke nature of the fit it will be a factory installed system unlikely to be offered as universal retro kits.

[Going Spare]

@Tony57

The smoke unit in the Hornby 1981 Compound is the plastic bodied X1489 unit, not the very early Tri-ang tube.

[TVR1707822112]

@96RAF

Many, many thanks for your response - I wouldn't have known this otherwise! I think what I'll do is buy a spare smoke unit, and install the replacement if the original doesn't work.

Best wishes.

[TVR1707822112]

Thanks so much for your help with this - as I've said - I have no idea about any of these things, and you have been really helpful - I appreciate it immensely.

I'll try the original unit and see if it works. If it doesn't I'll source a replacement somewhere...

Thanks again and best wishes steam_locomotive

[ColinB]

I have this loco with the smoke unit. Hornby at the time made a range of 4-4-0 locos that had the same smoke unit. Most of mine still work although I have removed them from all my locos as they tend to distort the body. There is supposed to be a piece of tin foil around the unit to stop some of the distortion but it does not work that well. I think when I looked the coil was wrapped around mica, it didn't look like asbestos. I used the Seuthe or the normal smoke oil on mine when I ran them.

[atom3624]

Do the different 'Vape' liquids work - could add some 'freshness' to the room perhaps? ...

Al.

[TVR1707822112]

Hi all,

Thanks for your help with this topic - I'm going to buy some seuthe oil and have a go with that to see if it works, if it doesn't I'll try something else.

Watch this space...