Talk:GWR 101 Class

Basic history
This little loco deserves some facts, given its original purpose as an experiment in oil-burning.

All I could find is on the Hornby website, so with thanks to John Faulkner who supplied the information, I have inserted an edited version. I trust that my editing and this acknowledgement are sufficient to avoid copyvio issues.

The info box seems to contain a lot of information inherited from some other class of loco. I have removed everything I considered suspect, but copy it below in case I have been overzealous.


 * leadingdiameter = 3 ft
 * driverdiameter = 6 ft
 * minimumcurve = 8 chain normal, 7 chain slow
 * length = 63 ft over buffers
 * width = 8 ft
 * height = 13 ft
 * axleload =
 * weightondrivers =
 * locoweight =
 * tenderweight =
 * fuelcap =
 * watercap = 4000 impgal
 * boilerpressure = 225 lbf/in2
 * firearea = 27.07 sqft
 * tubesandflues = 1686.60 sqft
 * fireboxarea = 154.78 sqft
 * superheaterarea = 262.62 sqft
 * cylindercount = Two, outside
 * cylindersize = 18.5 x
 * tractiveeffort = 27275 lbf

John M Brear (talk) 10:57, 30 December 2014 (UTC)
 * The best that I can suggest are
 * and maybe Ahrons wrote something in The Engineer or The Railway Magazine - several of his serial articles in those publications were later gathered into book form. Don't believe what you read in Hornby catalogues. They're not as shockingly badly-researched as the Lima catalogues, but there are still errors aplenty. -- Red rose64 (talk) 17:48, 30 December 2014 (UTC)
 * Thanks very much indeed! If you (or anyone else) can access these before me, then please amend as drastically as appropriate.  I do hope, however, that the essentials of the experimental purpose turn out to be correct!
 * I'm well aware of Hornby limitations (though it took me many years to discover that the Tri-ang Princess Elizabeth that I received for Christmas '58 was a bit on the short side!). It was, however, all I could find on the web and at least it has encouraged some constructive comments.  Best wishes for 2015!  .John M Brear (talk) 18:02, 30 December 2014 (UTC)
 * Thanks very much indeed! If you (or anyone else) can access these before me, then please amend as drastically as appropriate.  I do hope, however, that the essentials of the experimental purpose turn out to be correct!
 * I'm well aware of Hornby limitations (though it took me many years to discover that the Tri-ang Princess Elizabeth that I received for Christmas '58 was a bit on the short side!). It was, however, all I could find on the web and at least it has encouraged some constructive comments.  Best wishes for 2015!  .John M Brear (talk) 18:02, 30 December 2014 (UTC)


 * Incorrect to talk about a conventional boiler. According to RCTS it had 4 iterations of boiler design. 1 and 2 had very unconventional fireboxes surrounded by firebrick, not water space, the second with a much smaller box then the first. The third iteration was a Lentz boiler, also very unconventional, with a corrugated firebox and other unusual features, still oil fired. The last iteration was a conversion of the Lentz boiler to coal firing, still retaining the unconventional features, and this was when it acquired a coal bunker, hence source of Hornby Model. 212.159.44.170 (talk) 16:33, 6 January 2016 (UTC)

Holden's move from GWR to GER
Holden's page suggests a move before this loco seems to have been constructed. Does anyone know for sure? John M Brear (talk) 10:57, 30 December 2014 (UTC)
 * According to
 * James Holden joined the GWR in about 1865, and became Locomotive Superintendent of the Great Eastern Railway following the resignation of T.W. Worsdell (May 1885). -- Red rose64 (talk) 16:14, 2 January 2015 (UTC)
 * James Holden joined the GWR in about 1865, and became Locomotive Superintendent of the Great Eastern Railway following the resignation of T.W. Worsdell (May 1885). -- Red rose64 (talk) 16:14, 2 January 2015 (UTC)


 * Don't think there's any evidence for it being a Holden design. As noted Holden had long left the GWR. It did, however, use Holden's method of oil firing, which may be the source of the confusion.212.159.44.170 (talk) 16:32, 6 January 2016 (UTC)

Orphan and Ref flags
I have linked to-from Holden's page and the GWR locomotives page - hopefully this addresses the 'orphan' tag.

I have included the only reference I can find so far - is the Hornby site counted as reliable? They have at least made a model, so they must have some info, though they have released it in many non-authentic guises.

John M Brear (talk) 11:02, 30 December 2014 (UTC)


 * Yobot has kindly removed the orphan tag on 30-31/12/14 - thanks!
 * I shall follow-up RedRose64's suggestions for references, but happy if someone gets there first!. John M Brear (talk) 11:27, 31 December 2014 (UTC)
 * Hornby's loco isn't necessarily accurate, even in GWR 101 guise. It was introduced as R.077 in 1978, when they needed a small tank loco suitable for a basic train set, which therefore had to be cheap to make (just like its predecessor, the "Nellie" type freelance 0-4-0T, which ceased production in 1977 - last seen as R.255 in S&DJR blue livery, no. 7178, by which time it has acquired a fast-running Japanese can-type motor instead of the slower but more powerful (and more expensive, but easily maintained) Tri-ang X.04). At this time, Hornby often made compromises on economic grounds (they didn't really shake off that problem for another twenty years), and as a result, some of the components for their new R.077 were borrowed from existing locos in the range. These included the motor, worm, wormwheel, axles, wheels and coupling rods - all these came from R.255. Of the latter two components, the wheels were 16.5 mm diameter with 15 spokes, but should have been 14.667 mm with 10 spokes; and the coupling rods were 33 mm between centres, but should have been 36 mm. The plastic chassis moulding was new, but to spread the costs this - and most of the other components apart from the bodywork - would soon be shared with the Caledonian Railway 264 Class 0-4-0ST (introduced 1980 as R.057). Later on it was also used for the BR 0-4-0 Diesel shunter (introduced 1987 as R.874 & R.875) and the GKN (Dowlais) Class D industrial 0-4-0T (introduced 1991 as R.531). -- Red rose64 (talk) 16:29, 31 December 2014 (UTC)

No more Holden (mostly)
I have recast this article in the light of the information in Haresnape 1976, which clearly places it in the Churchward era and does not mention Holden.

However, the Model Rail Forum reference contains an extensive quote from 'the RCTS book' (presumably Tabor, F.J. (August 1959). Four-Coupled Tank Engines. The Locomotives of the Great Western Railway. Part 6. Railway Correspondence and Travel Society.) which states that the oil-burning mechanism was 'on Holden's system'. I am reluctant to rely on this reference for too much, as it does not seem a WP:RS, but if anyone has access to the RCTS volume and can confirm the quote it would be nice to add some extra details to this article. I am happy to do this if you can confirm the accuracy of the quote and the page number(s).

--Verbarson (talk) 18:58, 17 August 2021 (UTC) Its original boiler, no particulars of which have hitherto been published, was most unusual. It had an inner firebox consisting of a firebrick-built chamber 4ft. 10in. long × 4ft. 9in. wide; ... The backplate carried two oil-burning nozzles 2ft. 6in. apart." It goes on with plenty of detail for the various alterations that took place in the next few years. -- Red rose64 &#x1f339; (talk) 21:54, 17 August 2021 (UTC)
 * The RCTS books were very carefully researched, the authors had access to the records that were still held at Swindon Works.
 * In that book, the relevant pages are F45-F46 where we find: "Swindon's solitary 0-4-0T was an engine of considerable interest. Built in June, 1902, but not taken into stock until a year later, No. 101 was an experimental side tank locomotive burning oil fuel on Holden's system. ...
 * In that book, the relevant pages are F45-F46 where we find: "Swindon's solitary 0-4-0T was an engine of considerable interest. Built in June, 1902, but not taken into stock until a year later, No. 101 was an experimental side tank locomotive burning oil fuel on Holden's system. ...
 * , hi, thanks for taking the trouble. I wasn't meaning to cast aspersions on the RCTS books (who am I to question Holy Writ?) but rather wanting to confirm that the transcription from RCTS in this modelrailforum page was accurate. From a comparison with your transcription, it seems that some phrases were omitted. Can you confirm that what is there is correct, even if incomplete? --Verbarson (talk) 22:19, 17 August 2021 (UTC)
 * If you had linked that page at the start (and mentioned that Post #11 of Apr 11, 2012 was the relevant one), I could have made a comparison instead of typing in the text whilst deciding what to omit for copyvio purposes - that's what the ellipses are for.
 * That post does have some alterations. Text omitted by modelrailforum is indicated thus and text added is indicated thus :
 * 1902, Works No. 1969, but not taken into stock until a year
 * × X 22in. stroke, with $4 1/8$in . piston valves
 * on a wheelbase of 9ft. 0in. (Fig. F100)
 * Its original boiler, no particulars of which have hitherto been published, was
 * long × X 4ft. 9in. wide; this chamber, which
 * × X 5ft. 0in. and pitched at 7ft. 0in., con-
 * firebox —, for what looked like a Belpaire
 * within a cylindrical casing and a tapered barrel. (The type was revived in the U.S.A.
 * of ' the Vanderbilt design. Some such boilers were used on the Lancashire & ' Yorkshire Railway) . ) The date of fitting of No. 101's
 * front ring was coned from 4ft. $0 7/8$in. to 4ft. $10 7/8$in. 4ft. 0¾in. to 4ft 10¾in, The total length of the barrel was 13ft $6 5/8$  6½ in., but the length between tube-
 * of the boiler barrel. Pop safety -  valves of the rail motor type were placed over  fitted on the rear end of the barrel. This boiler had a
 * 3ft. 3in. long by 2ft. 8in Sin . wide in the corru-
 * removed and a small bunker fitted (Fig. F101). In this, its fourth and final condition , the dimensions (as recorded on 0-4-0 tank Diagram A) were:—.
 * [at this point there is a table of 18 rows]
 * for the Wrington Vale Light Railway, No. , 101's activities were confined to shunting at Swindon works. It was condemned in September, 1911 , with a mileage of 36,458;
 * So it's substantially correct, but with some alterations - particularly with fractions that are not halves or quarters. -- Red rose64 &#x1f339; (talk) 23:37, 17 August 2021 (UTC)
 * My apologies. I do have a bad habit of typing stuff from the writer's point of view (who knows what he means) and failing to consider adequately the readers' requirements.
 * I have incorporated details from RCTS into the article, though without overwhelming it with too many dimensions. I will probably add more to the infobox when I have a moment, and change some dimensions to use convert in the article.
 * One inconsistency I noticed: RCTS attributes the Lentz boiler to Gustav Lentz, but Wikipedia credits Hugo Lentz (properly spelled Lenz). Is this a clash or a transcription error?
 * --Verbarson (talk) 10:34, 18 August 2021 (UTC)
 * The RCTS book definitely says Gustav Lentz. There was indeed a Hugo Lentz, prolific inventor of (amongst other things) the poppet valves used by Gresley on about half of his D49 class. I suspect that Gustav predated Hugo. -- Red rose64 &#x1f339; (talk) 21:07, 18 August 2021 (UTC)
 * A quick google suggests that both Gustav and Hugo were railway engineers, and both are associated with some variety of poppet valve gear; but Hugo invented the Lentz boiler, while Gustav patented a system for placing the cylinders between the driven axles, to improve stability (but no sign of this having been implemented). Curious, but nothing I'd describe as a RS.--Verbarson (talk) 21:56, 18 August 2021 (UTC)

Not fast enough?
The Friends of the NRM website has an article on the genesis of the steam railmotors here, which includes an intriguing reference to oil-firing: "An experiment had started with a locomotive intended to work by steam fuelled by burning petrol, but they had been compelled to put it on one side as it could not achieve the speed wanted."

This was from a meeting of a House of Commons Select Committee in April 1903, and I can only imagine it refers to No. 101. Any ideas on where I would follow this up? -- Verbarson talkedits 22:10, 1 October 2022 (UTC)