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New rtr locos(1) — maxtee — 01/02/2010 13:09:25 | When my Feb BRM finally arrived ( too late for the ad re the January Dartford show!) I was pretty amazed at the list of proposed new releases. Loco versions of earlier Hornby locos will be welcome esp the 28XX as the pile of coal needed on that low tender to cover the tender-drive was a bit like the Matterhorn!
A Sandringham with the original diddy tender will be nice too esp. as those earlier locos had all the best ( ie non-footballing ) names.
A Thompson L1 however! The basic body shown looks very detailed but who would have believed that this much derided class would ever turn up as a rtr? Tony Wright is wrong however when he suggests that this could lead to a K1 2-6-0 to be used with the B17 Group Standard Tender. The GS on the B17 was a 4200g one while the K1s were built with the much shorter 3500 GS type.
I suppose tender swaps can take place but I have been unable to find a K1 with a 4200g tender. I have tried because I have a kit-built K1 paired with a hornby tender drive in an ex "Shire" large GS tender. I have not applied a number yet in the hope that I might find one latterly paired with the larger tender. I suspect that sod's law will dictate that none ever were.
Here's a question. Since the L1 and K1 shared wheel size, cylinder dimensions, boiler pressure and tractive effort how come the tender version got rated 6MT while the tank was only ever a 4MT?
Here's another. Since Thompson built the prototype K1 and the changes between that and the production run differed only by the changes made to the L1 in its production run, how come Peppercorn gets credited for this loco. All he did was to wait for the funding to be there and then sign the order! Credit where it is due I think.
So, I shall look forward to being able to buy a rtr model of the LNER's biggest passenger tank and perhaps, in the fullness of time, a Thompson K1 too.
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New rtr locos(2) — Paul — 01/02/2010 16:02:18 | The K1 is rightly assigned to Peppercorn, Thompson was - hurrah! - long gone by the time they were built. Unsteady Eddy's prototype which became K1/1 was significantly different, largely due to its' origin as a K4 rebuild. The frames, firebox staying, ash pan, cylinder mounting and overall width all changed in the revisions under Peppercorn, and it was partnered with the same 4,200 gallon tender as standard for the B1, the K1/1 retaining the smaller 3,500 gallon unit standard with the K4.
Pity that Mr Peppercorn didn't have the chance to revamp the L1 and make it a good loco too. Anyone who has read Bill Harvey on the subject will wince at the description of the detail design defects of this class. As for the difference in power classification between the K1 and L1, tractive effort and the other dimensions quoted are no certain predictor of power output. Grate and superheater area make a very significant difference to sustained power output capability, and the freight rating of the L1 may also have been influenced by its' limited brake power compared to the K1. On test at least one crew working unfitted mineral had quite a scare on an L1. It had ample grunt to move the train, but with no tender, brake force was significantly less.
Why someone with Mr Wright's experience would not realise that the K3 makes a natural route to a K1, particularly from a maker already manufacturing a B1, is puzzling. It's a pretty straightforward DIY project for those so inclined.
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New rtr locos(3) — G King — 01/02/2010 17:30:33 | "the K3 makes a natural route to a K1, particularly from a maker already manufacturing a B1, is puzzling. It's a pretty straightforward DIY project for those so inclined."
Having done this myself I'd have to say that the answer to the question of whether it is "straightforward" is very much determined by the degree of accuracy wanted in the final model. Making it as faithful as possible to the true K1 outline and dimmensions involves a fair amont of work, as may be apparent if my own account of the job, written almost 2 years ago, eventually appears in the pages of BRM.
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New rtr locos(4) — Paul — 01/02/2010 17:52:03 | My standards are lower than yours Graeme! With a 'bash' my target is 'suggests the character of the prototype sufficiently to be unmistakeable'. Particularly applies when I have a sneaking suspicion that there may well be a RTR model in the not too far distant future. I reckon a RTR K1 in the next five years is fairly likely.
But what I returned to comment on, was something I forgot in my earlier post. The real amazement for me in this years RTR loco line up, is that if all goes to plan there will be two new high grade 2-8-0 models introduced to the UK market. Did you ever expect to read such a thing? And not just any old machines either, only the two most significant 2-8-0 designs introduced before WWI.
At this rate we can expect the introduction in future years of several 0-6-0/0-6-0T types, or perhaps a choice of 2-4-2T classes? | |
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New rtr locos(5) — DavidBroad — 02/02/2010 02:05:47 | L1 chassis, shortened B1 boiler extended cabside, if the LNER could cobble up a (Thompson) K1 so can we
I know Thompson actually transformed a K4 which only suffered from too small diving wheels so they couoldn't keep clear of Clyde Coast electrics, from a machine easily capable of Houling b9 bogies from Queen Street to Mallaig Junnction and beyond, into something that patently wasn't and then hobbled the L1s with the same 5'2" wheels and that funny outside Belgian valve gear the GWR abandoned about 1910 after they found it worked better inside, which fell apart with monotonous regularity.
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New rtr locos(6) — Paul — 02/02/2010 08:55:57 | David,
The L1 coupled wheelbase (6'6"+7' if memory serves) is much too short for a Peppercorn K1, which needs 7'6" + 8'9". Thus the reason for using the K3 chassis as a basis , just as was done to produce a K4, which is essentially a lightweight K3, smaller boiler and wheels.
What is interesting about the Peppercorn K1 is that it is similar to the loco Gresley proposed at the inception of the LNER as the group standard medium goods type. The board however preferred the cheaper (in first cost at least) 0-6-0 inside cylinder format as adequate for the class of goods haulage it was intended for, and the J38/39 design emerged as group standard.
The J39 was inevitably thrashed along on faster work than the design was intended for, with unhappy results for maintenance expenditure. Had the board accepted the slightly higher first cost, an earlier two cylinder K4 and K5 might have taken the rails. The 5'2" version, much as the Peppercorn K1, should have been a much better machine for faster work than the J39.
That's the other reason why I am not to particular about the precise looks of my 'bashed' K1 from K3 and B1 components. Should we be offered a RTR K1, my K1 bash will then be altered to a 'neverwazza' 4'8" wheel 2-6-0 equivalent to the J38, using the curved footplating and cab of a K3, married to a J39 boiler on the rewheeled K3 chassis.
While in this vein there is another neverwazza that tempts me, although not something that was ever proposed at Doncaster. Take one K3, and replace the chassis with a 4'8" 2-8-0 unit, coupled wheelbase of about 17'. Makes a very attractive loco... | |
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New rtr locos(7) — G King — 02/02/2010 23:59:29 | | Continuing the digression from the original subject, for another never-proposed Doncaster loco take a V2 body, re-extend the boiler back to A1/A3 length or lengthen the smokebox, and substitute a 2-8-2 chasssis with 5'8" coupled wheels (standard mixed-traffic mogul size) on a 6'+6'+6' coupled wheelbase. Suppose one set to be flangeless, or mounted on something like a Krauss/Helmholz truck, and there you have it: The P3 heavy mixed traffic loco they should have built with more tractive effort and adhesion yet lower axle load than a V2, plus less trouble going round curves than a P2, although fewer pretensions towards being a pacific substitute on high speed "flyers". Equip it with Kylchap, German smoke deflectors, BR livery and 8 wheel tender if you must...... | |
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New rtr locos(8) — maxtee — 05/02/2010 17:42:05 | My books say the K1s all had a 3500g tender so I am intrigued that Paul says only the prototype had this smaller size. I can see how a book can get this wrong esp. if the p/type was around a long time before the production run was commenced.
I should like to be pointed to a definitive reference regarding the tender sizes. I have looked again at some pictures and it still strikes me that loco:tender lengths on pics of B1s and K1s look in the same proportion which, since the B1 is much longer than the K1, tends to reinforce my view that the K1s have the smaller tender. It is always difficult judging that way though, Jubilees with 4000g and 3500g Stanier tenders are virtually identical too unless you actually count the rivets!
On the design though, in wartime Mr.T did not have much scope for new production so the K1/1 was a conversion of a K4 and retained a lot of K4 attributes/dimensions. The L1 design was clearly based on this but with many of the changes Paul attributes to Mr.P on the K1, incorporated.
It is significant that Mr.P chose to built based on the K1/1 in large numbers rather than build more K4s. Curious eh?
The derivation to my mind is clear in the name the drivers called the K1s, "Baby Bongos". Indeed, power classifications are an odd thing for few would doubt that a B1 couldn't handle heavier or faster trains than a K1. On a good day a good B1 has substituted for a Brit. I could not see a K1 doing that.
Gresley's lovely to look at V4 pair later got demoted to 4MT which is also rather curious is it not?
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New rtr locos(9) — G King — 05/02/2010 19:19:50 | It's nice to see that at least one other contributor is still here. I was beginning to wonder whether the "turn-coats" had all cleared off back to RMWeb in the last 3 or four days......
I think you'll find that both the relevant volumes of the RCTS series, and Yeadon, agree that the K1s as standard all had high-front 4200 gallon tenders of the later welded-tank variety, and I don't think you'll readily find a more authoritative source of information. My eyes tell me that photographs match the expected appearance of a high-front 4200 gallon flush-sided tender. Perhaps the high front ends of the side sheets on this kind of tender can cause the viewer momentary confusion with the proportions of the 3500 gallon type? | |
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New rtr locos(10) — Paul — 06/02/2010 11:06:43 | Regarding building K1s rather than K4s, Peppercorn was operating in the post war austerity environment. A general duties loco of that power class only required two cylinders, which is a significant saving as every additional cylinder requires both incremental parts, machining and assembly at build, and then additional maintenance through life. (Which is why three cylinders are better than four for express passenger purposes in the UK, the engine comes at three quarters the cost, for the same power output.)
Gresley could just about justify three cylinders on the K4 pre-war, for the reduced hammerblow on the West Highland line for which it was specifically built. Similarly the use of three cylinders on the V4 (which was actually commented on at time of introduction as a 'Rolls-Royce for a Ford car job') to give it the widest possible route availability, with good high speed characteristics for main line use. These things come at a price, and post war that price was too high.
The location of the 'break point', at which it is necessary to accept the additional cost of a third cylinder in the engine over the basic two cylinder format, was clearly advancing in power output terms to the end of UK steam development. The Britannia lcoomotives were discernably beginning to pull themselves apart once they had acquired a dozen years of intensive use. Now that was decent going, had Crewe, Doncaster or Swindon tried a design of that nature circa 1930, they would have been u/s in a decade. Had Riddles been a little less conservative, and adopted the proven US technique of a cast steel frame with integral cylinders, there would have been far fewer troubles. | |
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New rtr locos(11) — G King — 06/02/2010 14:33:06 | Another minor point regarding the business of attempting to identify the tender type from its appearance: In judging from size "in proportion to the loco" (B1 or K1) there is an inherent potentially misleading factor. The K1 cab, which is obviously the part of the loco in closest proximity to the tender, is not only taller but significantly longer than the B1 item. This may make the K1's tender look falsely small.
The long K1 cab derives from the K4 and in turn from the final group-standard version of the K3 cab, which had ended up being rather long as a result of a convoluted process of design development. | |
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New rtr locos(12) — DavidBroad — 08/02/2010 03:13:50 | I think all Peppercorn K1s had the 4200 gallon straight side tender.
I just checked for 62005 on line and it says she has a 4200 gallon tender and says as did all K1s.
Certainly the K1/1 had a 3500 ex K4 tender but the flush sided 3500 is quite distinctive being shorter overall, 6" shorter in the wheelbase and has a longer low section at the rear end of the side than a 4200.
The Ian Allen Locoshed books list a 44 ton (3500 gallon) tender for all Kis and K4s but I haven't found a photo of anything but a 4200 yet!
Which is good as I was plotting a battery powered K1 for the garden (1980s scotrail) and if I can use a 4200 gal tender then that's one less job.
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New rtr locos(13) — maxtee — 08/02/2010 22:45:25 | Thanks chaps, I am pleased that I can now number my tender-drive job with presumably any number from the series I choose. I admit that the ABC is a handy reference and I have a number of RCTS LNER "Greenies" but so far not the ones covering moguls.
I understand that Stanier and later Riddles toyed with the idea of cast bar-frames but the limits of existing casting facilities defeated them. The places where they cast the mighty guns of warships were presumably not available for hire.
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New rtr locos(14) — Paul — 09/02/2010 09:46:41 | Economics drove the decision. The railway workshops were fully tooled for plate frame design, shaping and assembly, using stock plate from any number of rolling mills. The investment in plant, a century of experience, and the competition in steel plate supplies; all combined to make the barrier to entry of an alternative technique too high.
The advantage of the integral cast frame would only have warranted applying it to the largest classes, 40 sq ft of grate and up; and that never even amounted to 5% of the UK steam loco fleet. No saving possible by closing the plate frame plant, it would still be needed to keep the 95% of the fleet operational. The way to have evaluated the technique would have been to order on a US plant; there was ample capacity as the US steam fleet ran down. The prevailing currency exchange difficulties from 1940 to 1970 ruled that idea out. | |
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