Giles Posted November 29, 2020 Share Posted November 29, 2020 (edited) Simon, Here's the view of the RH side of cab.... The highlighted bits are I think the reversing linkage to the steam reverser, but what the lever is like..... Edited November 29, 2020 by Giles Link to post Share on other sites More sharing options...
Simond Posted November 29, 2020 Author Share Posted November 29, 2020 Right, cab beading swapped from side to side, and a short length of 2mm tube let into the boiler so the aforementioned displacement lubricator valve can be installed after paint. I think a short handrail knob, with the pipe sticking out one side and a hand wheel on the other will suffice. I think the boiler/cab assembly might have reached the end of the brasswork and can be cleaned prior to sticking the manifold, dome, chimney & smokebox door in place. ah, no. Cab sliding shutters, or at least, sliders for same. Bah! more soon... Simon 4 Link to post Share on other sites More sharing options...
Simond Posted November 29, 2020 Author Share Posted November 29, 2020 (edited) A potential Eureka moment... the reversing lever, I suggest, is the short lever ahead of the handbrake, and just below its shaft, which appears to be connected by a short vertical-ish link to the crank-thingy that Giles has highlighted in his recent post. It even has a quadrant, and a sort of handle and catch that you’d expect a reverser (or a signal lever) to have. it’s in a logical place too, assuming left right (the handbrake is on the left!) hand drive, reverser & brake together, the regulator is a long see-saw affair. the downside to this hypothesis is the diagonal linkage leading forward & down to a lever ahead of the firebox, just below the barrel dimension which appears to operate a valve, though it’s not at all clear. Is it attached to the same lever? mmmm... Edited November 29, 2020 by Simond Link to post Share on other sites More sharing options...
Giles Posted November 29, 2020 Share Posted November 29, 2020 Phil Parker has taken some very useful photos on his Flickr blog, which includes the cab showing the various levers. Meanwhile here's the plan and elevation. That lever looks as if it's the water feed to the injectors ( which should be two separate levers...?) It's all a bit confusing on the drawing. Link to post Share on other sites More sharing options...
Simond Posted November 29, 2020 Author Share Posted November 29, 2020 Thanks Giles, the problem with the drawings is that they are drawn as a transparent GA so unless you have all the views (and I don’t have the end elevations or sections) working out where things are is a challenge. there must be: Water taps & steam for both injectors - the steam feeds are adjacent to the whistle. Not sure where the water valves are, but given the pipe down the lhs under the footplate, I assume they’re on the left. Could they be levers, I guess they’re on-off so possibly. Reverser, it’s a servo, so a little lever, but it needs a catch. Servo is on the right under the footplate, control lever on right, some kind of crank linkage? Handbrake - whacking great two-handled thing on lhs of firebox, operating screw to pull the lever that connects to the mech on the underhung structure ahead of the grate. Steam brake control. Some locos had vac brakes too. My drawings show the piping. Not fitting it to my model. Firebox doors, water gauges seem pretty conventional Dampers what else? couple of fold down seats on the cab rear wall. slacking pipe? thanks for all your help Simon Link to post Share on other sites More sharing options...
Giles Posted November 30, 2020 Share Posted November 30, 2020 Here's the mystery of the steam reverser..... although this is from a larger Garrett 1 Link to post Share on other sites More sharing options...
Giles Posted November 30, 2020 Share Posted November 30, 2020 (edited) Water valves are on / above the injectors, one on each side, operated by the sloped rods emerging from the Firefox cladding. Inside the cab they are simply bent TO THE LEFT (both sides) at 90 degrees like damper handled commonly are. One seat only for the driver on the Bressingham loco Can't find a slacking pipe... Edited November 30, 2020 by Giles 1 Link to post Share on other sites More sharing options...
Simond Posted November 30, 2020 Author Share Posted November 30, 2020 (edited) thanks for this info, I went looking for Hadfield Power Reversing gear and Wikipedia supplied some useful info as usual; Great way to spend lunchtime at work! The two pistons of the steam reverser can be seen at the extreme left on this Bulleid Merchant Navy class Power reverse gear With larger engines, the linkages involved in controlling cutoff and direction grew progressively heavier and there was a need for power assistance in adjusting them. Steam (or later, compressed air) powered reversing gear was developed in the late 19th and early 20th centuries. Typically, the operator worked a valve that admitted steam to one side or the other of a cylinder connected to the reversing mechanism until the indicator showed the intended position. A second mechanism, usually a piston in an oil-filled cylinder held in position by closing a control cock, was required to keep the linkages in place. The first locomotive engineer to fit such a device was James Stirling of the Glasgow and South Western Railway in 1873.[2] Several engineers then tried them, including William Dean of the GWR and Vincent Raven of the North Eastern Railway, but they found them little to their liking, mainly because of maintenance difficulties: any oil leakage from the locking cylinder, either through the piston gland or the cock, allowed the mechanism to creep, or worse “nose-dive”, into full forward gear while running. Stirling moved to the South Eastern Railway and Harry Smith Wainwright, his successor with that company, incorporated them into most of his designs, which were in production about thirty years after Stirling’s innovation. Later still the forward-looking Southern Railway engineer Oliver Bulleid fitted them to his famous Merchant Navy Class of locomotives, but they were mostly removed at rebuild. Henszey's reversing gear, patented in 1882, illustrates a typical early solution.[3] Henszey's device consists of two pistons mounted on a single piston rod. Both pistons are double-ended. One is a steam piston to move the rod as required. The other, containing oil, holds the rod in a fixed position when the steam is turned off. Control is by a small three-way steam valve (“forward”, “stop”, “back”) and a separate indicator showing the position of the rod and thus the percentage of cutoff in use. When the steam valve is at “stop”, an oil cock connecting the two ends of the locking piston is also closed, thus holding the mechanism in position. The piston rod connects by levers to the reversing gear, which operates in the usual way, according to the type of valve gear in use. Steam reverser on a Southern Railway 2-8-0. The Ragonnet power reverse, patented in 1909, was a true feedback controlled servomechanism. The power reverse amplified small motions of reversing lever in the locomotive cab made with modest force into much larger and more forceful motions of the reach rod that controlled the engine cutoff and direction.[4] It was usually air powered, but could also be steam powered.[5] The term servomotor was explicitly used by the developers of some later power reverse mechanisms.[6] The use of feedback control in these later power reverse mechanisms eliminated the need for a second cylinder for a hydraulic locking mechanism, and it restored the simplicity of a single operating lever that both controlled the reversing linkage and indicated its position. The development of articulated locomotives was a major impetus to the development of power reverse systems, because these typically had two or even three sets of reverse gear, instead of just one on a simple locomotive.[7][8] The Baldwin Locomotive Works used the Ragonnet reversing gear, and other American builders generally abandoned positive locking features. In British use, locking cylinders remained in use. The Hadfield reversing gear, patented in 1950, was in most particulars a Ragonnet reversing gear with added locking cylinder.[9] Most Beyer Garratt locomotives used the Hadfield system. [10] The US Patent makes things clearer https://patents.google.com/patent/US2523696 the locking (RH) cylinder is full of oil supplied from the pump. The connections "H" ("U" below) are non-return valves, so once filled, the piston in this cylinder is locked. The valve block at the top contains another pair of poppet valves that can be opened by the rotation of a cam - thus once opened, the piston can be moved, and once released, it is then locked again. "In order to permit of the interconnection or isolation of the ends of the hydraulic cylinder 13 the hydraulic cylinder is provided with an improved type of hydraulic control valve as shown in Figure 6. This valve consists of two spring loaded poppet valves W which are operated by a cam X through intermediate rockers Y, this arrangement ensuring that the two ends of the hydrau'l'ic cylinder are positively isolated when the cam X is in the shut position. It will be obvious that the higher the pressure occurring in the hydraulic cylinder by the action of the locomotive valve gear the more tightly closed become the valves W, thus eliminating all tendency for the reversing gear to creep." It does appear that the word "automatic" is a bit excessive where applied to the oil top-up pump, it's only automatic in the sense that if you pump it, the valves do not need to be set by hand! It appears that the lever EE in your drawing is the means by which the device is controlled. If the top of the lever is shifted by the driver operating his control, the valve on the steam cylinder and that on the locking cylinder are opened, and the steam piston will move the mechanism until the lever EE is vertical again, at which point, the two sets of valves will be closed. Condensation in the steam cylinder will not affect the position as the liquid filling the locking cylinder cannot move. Damn clever! In principle, I think it only needs one input control (and the oil topping up, of course). It may also be that the strange supply pipe on the RHS of the boiler goes to a displacement lubricator, and thence to the steam cylinder, so it is the reverser supply, I guess. What fun, thanks for the picture! Simon Edited November 30, 2020 by Simond 1 Link to post Share on other sites More sharing options...
Simond Posted November 30, 2020 Author Share Posted November 30, 2020 Well, after all the excitement about power reversers, I added the cab roof vent ... it’s another (baby) step... atb Simon 5 Link to post Share on other sites More sharing options...
Simond Posted December 1, 2020 Author Share Posted December 1, 2020 Correction to my notes about steam reverser. I misread the drawing Giles posted, and it was nagging at me. The lever EE does combine the input and output signals, but in that version, the output shaft moves in the opposite sense to the input shaft. There is a rocker on the slide valve input which reverses it. Thus the servo stops operating when the central pivot of the lever returns to the centre point of the slot in its supporting trunnion. This lever will thus not be vertical unless in mid gear. I can sleep better tonight for working that out... atb Simon Link to post Share on other sites More sharing options...
Giles Posted December 1, 2020 Share Posted December 1, 2020 Absolutely correct! And of course our Garrett is slightly different in that the rod EE doesnt continue up vertically as this diagram, but horizontally as per the yellow highlight on the GA. I think I've got it at last...... That nice little lever with the lock IS the reverser, and there is a bellcrank off of it, forward, with a lifting link to a further bellcrank on the shaft highlighted yellow, which in turn operates the reach rod previously highlighted. It's a little convoluted, but practical, and it's there..... 1 Link to post Share on other sites More sharing options...
Giles Posted December 1, 2020 Share Posted December 1, 2020 I'll just dump these 'ere. Let me know if there's anything in particular that you want to see - I may have taken a photo of it... 1 1 Link to post Share on other sites More sharing options...
PhilMortimer Posted December 1, 2020 Share Posted December 1, 2020 (edited) Stop it! Stop it! You keep adding details for me to add on mine! Both of them! I will never get these done. But thank you, they are very useful pictures! Edited December 1, 2020 by PhilMortimer 1 1 Link to post Share on other sites More sharing options...
Simond Posted December 1, 2020 Author Share Posted December 1, 2020 At least I’ve only got one to build... Link to post Share on other sites More sharing options...
Simond Posted December 5, 2020 Author Share Posted December 5, 2020 (edited) Following on from the steam reverser with hydraulic locking discussion above, I was chatting with a pal who recalled a tale, possibly from the Southern, in which the cap of the oil reservoir had not been fitted correctly, presumably the NRV failed and when the loco was reversed, the entire cab interior and everything within it, including the crew was plastered in a porridge of emulsified oil. my, I bet they laughed... Edited December 5, 2020 by Simond 1 Link to post Share on other sites More sharing options...
Giles Posted December 5, 2020 Share Posted December 5, 2020 Reminds my of the time I had to check the oil level in the fluid flywheel of a coach that had only just come in. I took a ply out - above the oil level line - and instantly got accurately and thoroughly drenched, head to foot in aerated pressurised oil. Everyone else was very interested, as they had never seen this happen before...... 1 1 Link to post Share on other sites More sharing options...
Simond Posted December 6, 2020 Author Share Posted December 6, 2020 Bit of backhead this weekend... I wanted the fire doors open so the light could shine through when the coaling sound operates, so I made these. I suppose, with 12 days of Christmas, I could have made them work and be servo controlled, but that would be overkill... actually, I doubt very much will be visible, but the light will add something, I hope. quite pleased with that, and I’m sure the skin will grow back on the tips of my fingers I didn’t make the water gauges, they were from an unnamed sprue for which I paid the king’s ransom, a whole £2.00. more soon Simon 8 1 Link to post Share on other sites More sharing options...
steveNCB7754 Posted December 7, 2020 Share Posted December 7, 2020 22 hours ago, Simond said: I wanted the fire doors open so the light could shine through when the coaling sound operates, so I made these. I suppose, with 12 days of Christmas, I could have made them work and be servo controlled, but that would be overkill... Working firebox doors - pah! (child's play). Now, working gauge glasses ('water level' goes down over time and you need to use boiler water feed via DCC to keep it 'in the glass'), now that would be impressive, if not a little annoying after a very short time!! LOL Yes, the future of DCC - you let the level in the boiler get too low and the DCC decides the fusible plug has gone, 'dumps the fire' and refuses to let you run the loco until a considerable period of time has elapsed. Welcome to the (un)real world ;-) Link to post Share on other sites More sharing options...
Simond Posted December 7, 2020 Author Share Posted December 7, 2020 (edited) Ahem,.... no, thanks, most kind of you but... the fire door mech did strike me as a miniature for the valve gear, and if you were both patient, and masochistic enough, making it move doesn’t pose any insurmountable difficulties. Probably easier to do the bits on a CNC milling machine of some kind, though etching would be an option. Scratching it is obviously possible, but honestly, it’s not going to be visible, it would add very little to the loco, and I’d like to finish the build some time in the next five years. I’m an enthusiast, not a martyr! I did consider the Perspex water gauges (see Nick Dunhill’s models, on Western Thunder) but concluded that a drop of white in the “glasses” of the cast brass gauges will do more than enough to maintain the illusion. cheers Simon Edited December 7, 2020 by Simond 1 Link to post Share on other sites More sharing options...
Simond Posted December 7, 2020 Author Share Posted December 7, 2020 More baby steps... Regulator handle, brake handle and two water handles. A pleasant & easy hour with Mary Beard on the telly in the background. Regulator valve body and quadrant needed to mount the regulator. There’s quite a collection of pipes & levers to the right to be built. Happily there’s a piece of metal higher than the floorboards on which they can be mounted and fitted to the backhead, which you will see has two threaded studs to attach the sub-assembly to the floor. Atb Simon 5 Link to post Share on other sites More sharing options...
RMweb Gold Regularity Posted December 7, 2020 RMweb Gold Share Posted December 7, 2020 4 hours ago, steveNCB7754 said: Yes, the future of DCC - you let the level in the boiler get too low and the DCC decides the fusible plug has gone, 'dumps the fire' and refuses to let you run the loco until a considerable period of time has elapsed. Welcome to the (un)real world ;-) You don’t need DCC for that: would not only be relatively easy to put into a computer interface, but it was done many years ago: there was a rather dismissive review in an early MRJ in the 1980s, iirc. 1 Link to post Share on other sites More sharing options...
Simond Posted December 8, 2020 Author Share Posted December 8, 2020 (edited) I’m still waiting for Giles to make a radio controlled shuntin’ ‘orse... Edited December 8, 2020 by Simond 1 Link to post Share on other sites More sharing options...
Giles Posted December 8, 2020 Share Posted December 8, 2020 I'm going a little deaf..... 4 2 Link to post Share on other sites More sharing options...
Simond Posted December 8, 2020 Author Share Posted December 8, 2020 it's a horse...! 1 2 Link to post Share on other sites More sharing options...
steveNCB7754 Posted December 9, 2020 Share Posted December 9, 2020 On 08/12/2020 at 12:49, Simond said: it's a horse...! Mr Ed?? ("A horse is a horse of course of course...") Showing my age now (of course) ;-) Link to post Share on other sites More sharing options...
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