JimC

With my lowered boiler I suspect I may have drawn a footplate height that is actually above the firebox door! I had trouble with access into the cab. Perhaps the tank needs to be set back on the tender so the crew climb onto the tender footplate, not the locomotive one? So if we do that and raise the boiler back to a more conventional height so the firebox is accessible... Umm, maybe that's not an improvement! Its starting to make the Kruger's look pretty! Incidentally, how does one describe that wheel arrangement? I suppose its a 4-2-2-0 of sorts, or perhaps 21A for the continental?

Something odd. I replaced the images on the page below after the outage, but when I looked at it just now the graphics were just a broken link, but nevertheless the images were still attached to the post, so I just had to delete the broken links and hit insert again. Don't know if this is an artifact of the image restoration, bit awkward if it is. Doesn't seem to have happened to any of my other blog entries though. https://www.rmweb.co.uk/blogs/entry/25015-rhymney-railway-k-class-0-6-2st0-6-2pt/

Slung some GW components together. Sadly the more I looked at it and the more design problems I picked up the more ridiculous the whole concept became... and if you think that's dreadful you should have seen some of the rejected features!

Propping up a door with a random baulk of timber has obvious dangers, but I'm not sure that resting the door on a solidly constructed sound wall would be any more dangerous than resting it on a goods platform. But the point seems moot as there appears to be no evidence of it being done.

Interesting to consider whether they are original or a later fitment. You'd think for new construction they are a bit inelegant, but if as noted above the clerestory was weak in that area its an obvious quick and dirty reinforcement/repair if required.

Would closed side pens towards the track permit resting the wagon door on the back of the pen, which I would guess could make unloading easier and maybe even safer?

I believe this is overstated. On both exchanges, LNER and LMS, the Castle used the local coal.

Don't forget 40 only retained the scissors gear until 1929: it wasn't retained when she got Castle cylinders. There's an argument to say that there's a region between "not good enough to repeat" and "good enough to live with". And if I understand what Don Ashton had to say correctly the vast majority of locomotives had worse valve events than the GWR ones. Cook says in his book "GW locomotives had extreme regularity in their exhaust beats" . But I must admit I have my doubts about the patent argument too, since 40s gear was rather different (and superior in detail) to Deeley's concept and there had been others in the same vein before. But patents are funny things, so much is in the fine detail of the wording as to whether something is covered or not. Holcroft says that the timing of the patent application and grant and 40s construction was such that 40 was in the clear, but any more would have had to pay a license fee.

Yep, and Gibson's conspiracy theories often don't stand up to detailed analysis. I know of four issues with the scissors gear in various sources, and of course they could all be true! Limp home on two cylinders after a failure, accuracy of valve events, Deeley's patent and valve setting as per Gibson. Personally I don't find any of them very convincing on their own, but add them all together... As for the inside Walschaerts, I've tried drawing outside Walschaerts for the Stars and Castles I can't make it fit, hence the 4 sets of gear on the first Stanier Pacifics. To have outside gear with rockers to drive the inside cylinders it either needs rockers in front of the cylinders, with all the valve timing issues from expansion, or else a complete reworking of the cylinder/wheel relationship as with the Duchesses. Only two sets, and being Walschaerts there were only two eccentrics plus the big ends, as opposed to four eccentrics and the big ends on all the thousands of inside cylinder locomotives with Stephenson's gear.

Probably fair to say, though, that a larger boiler and cylinders can be fitted on a ten wheel locomotive (even within UK loading gauge) than four driving wheels can provide adhesion for.

Pros and cons. Connecting and coupling rod bearings could be attended to without disturbing the valve gear. Loco preparation was a piece work task, so little saving by taking a few minutes off the job.

The coal merchants building in the model is in the same position on the 25" OS map on NLS. No sign of the staithes, but not sure if that is expected.

I'm confident I've posted this before, but its probably missing at the moment. Its basically the Great Bear truncated into a 4-4-2, lightly crossed with a Scott 4-4-2. It ought to have made for a more effective boiler. Factor of adhesion and weight limits? Err, lets conveniently gloss over those shall we?

Odd, isn't it. There were cut down locomotives for various highly restricted lines, but you'd think they'd start with an 850 or a 2021 for something like that.

They certainly vary. I have a lot of trouble with cab heights, they often don't seem to scale well on the drawings when you have a measured dimension. The dimensions I have for 645/655 are: K - 10'10 3/4 (equiv of M but 645 class) B28 - 11'4 5/8 B65 - 11'4 5/8 The others are scaling from the drawings I have, which are often distorted. I usually have boiler pitch and wheel centres and try and make those fit the measurements. The diag M was particularly difficult, I only have a photo with much distortion and had to manipulate more than am really secure with to try and make parallel lines parallel.

Enthusiasts often refer to this Wolverhampton built class as the 655 class, but the GWR usually described them as 1741s. Thirty-two were built from 1892. They were essentially similar to the earlier 645 and 1501 classes, but were just a little larger with longer overhangs front and rear. The bunker was actually the same size as the 1501 bunker, so the extra three inches of overhang presumably provided more room in the cab. Again they were built with T class boilers. They were numbered rather eccentrically: the first two, 655 and 767, were given numbers previously used by 645s that had been sold. The rest were numbered 1741-1750 and 1771-1790. Almost a subclass were the last 'large' Wolverhampton engines, 2701 to 2720, built 1896/7. The boilers were T class, but had small dimensional variations. Otherwise they were very similar to the 1741s. The 655/1741/2701s tended to merge with the earlier 645 and 1501 classes as time went on. They were fitted with the larger P class Belpaire boilers and pannier tanks. The majority were given enlarged bunkers. Around half were superheated at one stage in their lives and a number gained enclosed cabs. By the 1930s all four classes/sub classes were being treated as a single class. Some were scrapped in the 1930s, but most survived the war. Some twenty-one made it onto the BR books and the last were scrapped in 1950. There were five diagrams for the 1741s and 2701s, covering the variations in boilers and tanks. The last diagram, B65, covered 645, 1501, 1741 and 2701 classes, demonstrating how the classes had merged as they were updated. This first sketch is rather loosely based on diagram M, but the cab in particular has been amended from photos. A cab entrance with a single large radius as shown seemed to be something of a Wolverhampton thing. Swindon cabs usually had a larger radius on the bottom of the cutout than the top. This is the T class boiler, which was pitched appreciably lower than the later P class. Oddly the precise combination of dome position , firebox and T class boiler on the GWR diagram is not known to have actually been fitted to the class. Fortunately for my sketch the firebox top is hidden anyway. This is more closely based on diagram A18, the first diagram with the P class boiler The odd stumpy chimney was by no means universal on this variation. This sketch is based on diagram A42, which is an earlier pannier tank fitment with the P class boiler. And finally this is based on diagram B65, with a full length cab roof and a much extended bunker. The resemblance to the 57s is getting quite marked, but pre group Wolverhampton locomotives could always be recognised by the footplate valance and the shape of the front step. Its important to note that the sketches show just a few of a considerable number of variations. The Wolverhampton pre group classes are something of a modeller's nightmare, since Wolverhampton had their own style, but Swindon tended to put Swindon design features on locomotives that came into their hands. So photos, photos.

I'd be a bit nervous of the amount of metal dust flying around a running motor if you did it like that!

Nah, still bonkers, because the efficiency of electricity -> steam -> rail is a fraction of electricity -> electric motor to rail. Although you could make a case for bi-mode steam/electric it would still be far more sensible to use the sparks to run a motor rather than heat steam.

I found a nice works photos of one of the Ms as built, and decided that, with the dimensions in RCTS, gave me just enough information to attempt a sketch of the M Class as turned out by Stephensons. The main difference is a smaller diameter boiler, which I think is just different enough to lose some of the brute strength appearance of the other 20thC RR classes. But there's one little peculiarity I'd like to highlight. In this sketch the tank/cab and cab/bunker corners are both radiused, as are all 4 corners of the cab. This is as per the Stephensons' works grey photograph in wikipedia and other places as shown below. All these corners are also shown radiused on the GWR arrangement drawing for 106/47 when she was fitted with a GWR boiler. However all photographs of the class (with the later RR boilers) I have found show a 90 degree transition at bottom left of the cab door/window cutout, and between cab and tank, and a radiused transition between cab and bunker. Photographs of 106/97 with GWR boiler and bunker , however, clearly show both cab/tank and cab/bunkers with 90 degree transitions, whilst the cab window corner is hidden behind the cab shutter. So I've amended the GWR sketch to show what's in the photos rather than what is in the works drawings. RCTS doesn't record whether it was Swindon or Caerphilly factory who ignored this detail from the drawing office.

I think there are two things that could be done to evaluate it a bit. The first is to burn a tiny little bit which would tell you whether its plastic or natural fibre, and the other would be to see if a similarly printed tape is available contemporarily.

Another observation is that they appear to have simply removed the brakes rather than create a new arrangement. So may we guess the idler wheel is one side only and this was a very quick and dirty short term experiment?

In that case may I challenge one of you to produce an image of 4-4-0 trailing wheels with balance weights as small as that:-) I didn't think there was a chance of that tiny weight doing anything useful vis a vis a coupling rod, but was successfully proved wrong a couple of posts down!

I hunted out some other photos of the Samsons. Most have coupling rods down, but on the others it seems to me evident that the tiny balance weight on that locomotive is far smaller than they were on the coupled locomotives. Just big enough to balance the off centre crank web perhaps?

Having lined up sketches in different ways, If you line up the driving wheels then the cylinders, boiler and cab also line up, but the rest of the wheels have moved. The other two driving wheels have moved back 6 inches, the front buffer beam and leading pony wheel back 2 inches and the trailing pony wheel back 6 inches. The rear buffer beam, of course, was something of a moveable feast anyway. I think the 4'1.5/4'7.5 wheels is interesting, because the 4'1.5 wheels were well established for branch etc with the 850/1901/2021 classes as against 4'7.5 on the larger 0-6-0Ts. You'd think they would have known what the limitations were. I wonder if there was something of a speeding up of trains?

They're even more different than that. If you look at the weight diagrams the entire relationship between chassis and superstructure is subtly different: look at the cylinder positions relative to the wheels and the overhangs front and rear. There must have been a considerable redesign done: it was anything but a straight rewheeling. The relationship between the front of the water tank and the leading driving wheel is worth noting too.