Jim's 7mm workbench: LNW 17" Coal Engine build

[Marshall5]

Hi Jim, I've enjoyed following your build and a fine looking model has resulted.  However, and no criticism is intended but merely to set the record straight, no Princes actually carried B.R. livery but it really does suit it (as it should), and of course, modeller's rule #1 applies!   According to Casserley "None of these engines survived to carry their new B.R. allocated numbers (58000-3) and all were scrapped by1949 under their LMS numbers, 25648, 25673, 25752 and 25787".  At least one of the Hughes 4-6-0's, 50455, certainly carried fully lined B.R. mixed traffic livery and was widely photographed on its final railtour to York before withdrawal in 1951.

Cheers,

Ray.

[jim.snowdon]

With the Prince of Wales now essentially complete, ignoring the odd missing oil box and handrail, the next project is now on the workbench. This time, sticking with my predeliction for pre-grouping classes that made it through to BR and which would be at home on our 1950s BR(M) layout, it is an example of Mr Webb's 17" Goods Engines, otherwise known as the "Coal Engines" (and from which the better known "Coal Tanks" were descended.

The kit that will form the basis of this build is one from Modeller's World, who existed at one time in Coventry. How old it is, I have no idea, but the fact that the box gives the telephone number as Coventry rather than an STD exchange code is something of a clue. I suspect at least the early 1980s, if not earlier. It is, by modern standards, a distinctly basic kit.

The chassis, always the first stage in construction for me, consists of a mere four parts - a pair of etched frame plates and two screw in spacers machined out of square brass. Assembled, the frames would be only 23mm across the faces, which, even allowing for the flanges on the bearings, would have resulted in a rather generous amount of sideplay! It also leads me to suspect that this kit is a blow-up from a 4mm scale version designed for 00 track.

Either way, it will not do, and the first task, apart from deciding where the motor and gearbox will have to go, is to design a set of new frame spacers.

 

The drive is my usual ABC VML2/Canon combination, and there is little option but to drive onto the middle axle, with the motor sat upright in the firebox, where there appears to be just enough headroom. The fact that this one will be given a Belpaire firebox in due course will help. Drivingon the rear axle, which would have given me a chance to install the Laurie Griffin motion kit I have, is not practicable due to this axle being behind the firebox and directly underneath the cab floor.

The blue marks on the frames indicate where I will be putting spacers - an L shaped one at either end to keep the frames square and to provide the mountings for the body, one flat spacer corresponding to the motion plate, and (not visible) another vertical spacer immediately behind the motor. The latter will form part of the means for restraining the motor.

The spacers themselves were cut from scrap nickel-silver etch and the two angled ones bent up using the miniature press brake.

 

 

This came from Micro-mark in the US (http://www.micromark.com/ ) and whilst it doesn't see much use in the workshop, it comes into its own for scratchbuilding as an alternative to the bench vise.

The result.

 

I will, as per my usual practice, be springing the loco so the frames need marking up and cutting out for the hornguides. Despite the protests of some about their lack of adustability, I have been impressed by Slaters' cast brass hornguides, not least by the fact that they need next to no fettling and the axle bearings drop straight in. The only snag with early locomotives is the relative lightness of the frames either side and above the hornguides as can be judged from the before and after picture below.

 

The openings were cut with the piercing saw and I find that with good quality Swiss blades it is possible to cut to the marked line quite easily (although I will admit having had some practice, as well as the trials and tribulations of Eclipse blades that were liable to cut in odd directions at the best of times). Only minimal cleaning up with a flat needle file would have been necessary to get the hornguides all in the same place in the frames. However, having the facilities, I chose to put the frames, clamped together, in the vertical mill just for added accuracy. The following picture is added just to show how it was done, for the curious.

 

I haven't at this stage made any arrangements as regards pickups, as I think these will have to be flange scapers instead of my usual plungers. The problem is again a consequence of the relative light frames of these early locomotives - ideally, the plungers want to be level with the axle centreline so that as the wheels move vertically, the plungers do not come off the back of the wheel rim. In this instance, the frame simply isn't there, unlike more modern locomotives with deep plate frames.

Next is the erection of the frames -

 

At this stage, I have fitted only the front and rear spacers. The motion plate will go in once I have some idea of where the slidebars will lie - I may not be able to fit full motion, but they will go some way for filling in the space that will otherwise be there - and the firebox front spacer will wait until the motor is positively located, for which I need the hornguides in place.

Jim

[Crewe North]

'The fact that this one will be given a Belpaire firebox in due course will help'

 

I hope not as the Coal engines were never fitted with a Belpaire box unlike the 0-6-0 18inch Goods (a.k.a Cauliflowers) that were.

 

The Modellers World kits were 'interesting' to say the least, purely 7mm scale i.e. not a 4mm kit enlargement but , with care,built up into reasonable models.....they are still around as part of the Mercian range of kits.

 

John

[jim.snowdon]

John,

 

I am indebted to you for that little gem of information. My library is not well provided when it comes to the earlier LNWR engines and photographs of Coal Engines in their final days are about as common as rocking horse poo. Thinking about it, I probably had got the issue confused with the 18" Goods engines, for which I also have a kit (with round top boiler) in the queue.

 

The origins of this kit are interesting, especially as the comings and goings of these early kits as they got sold from one owner to another are largely shrouded in mystery. It is nonetheless curious that the chassis as dessigned is quite so narrow, a feature that is often a consequence of adaptatin from a 00 kit, hence my (incorrect) supposition.

 

Jim

[Crewe North]

The chassis width was somewhat 'variable' , the one that was in the MW 5ft 6ins 2-4-2 tank kit was at the other end of the width spectrum ....about spot on for scale7 !!!!

 

John

[jim.snowdon]

Next, fitting the hornguides. After developing my own etched units for the Snowhill/Roxey WD kits, and using these as standard, I have become converted to the Slaters cast brass hornguides. Apart from being good value, they look the part and don't need any fettling just to make them work, making them very convenient to use.   With the frame cut-outs already prepared, all that is needed is to drop them in, using extended axles to get the spacing from the rods. For this build, I am using the rods available from Premier, listed for the Coal Tank. They are perhaps a little heavy compared to the prototype, which were distinctly economical in material, but for what will be a working locomotive, a degree of robustness is a good thing.

 

For a six-coupled engine, I start with the middle axle, so that any variation due to tolerances is spread both ways, rather than building up at one end. The guides are held in place against the inside of the frames by a spring threaded over the dummy axle, as per -

 

 

The bearings are the standard Slaters design, and come with the same etch of top plates for creating the spring pockets. The easiest way to attach these is to tin the back of the etch and then, with the bearings sat of top, to heat the lot whilst sitting on top of a jewellers refractory block.

 

 

Once cool, they are sawn out of the etch and cleaned up.

 

Although the cassis design might have been quite basic, the designer did at least think about the bottom end of the firebox, a good bit of which is visible below the frames. The two side etches were intended to be soldered directly to the back of the frame plates, but that was without the added depth of the hornguides, which get in the way since the trailing axle is pretty tight up against the back of the firebox, as usual with 0-6-0s. The solution was to insert a spacer between the two, in this instance a length of 1.5mm H section that I had to hand (and hadn't found a use for in decades). Using H section might seem a bit extravagant, but it has less mass to heat up than the equivalent 1.5mm square rod. Fitting the firebox sides away from the frame also has the useful effect of creating some proper depth in the assembly.

 

 

Actually fitting them in place might look simple, but ended up being the cause of a lot of dark muttering and use of the gas torch to undo things before having another go. The culprit, essentially, was the use of a temperature controlled soldering iron, in this case, an Ersa 80. It may have a few more Watts than the old fashioned iron I used to use, but the lack of a large lump of copper at the business end means that it cools quite quickly when it meets the job, before recovering. As a result, it is not very good at soldering through the thickness of a 0.75mm thick brass frame plate.

 

 

The result, enhanced by a back made from scrap etch, is quite acceptable.

 

Then, with that out of way, the wheels can be fitted, thereby also establishing just where the motor will go. I had planned on using my usual ABC Canon/VML2 combination, but I had last year acquired a job lot of motors and gearboxes from Fine Scale Brass. It is one of these that appears in the photograph, and turned out to be a better fit, being shorter and lower as a consequence of being a 3-stage bearbox compared with ABC's 2-stage unit. One result of that is that I could have driven the rear axle instead of the centre one, which would have allowed me to try installing a proper crank axle and the Laurie Griffin Joy valve gear. The knowledge will be useful when I get round to building the Cauliflower that is sitting in the queue.

 

 

that is probably as far as I will go with the chassis just for the moment, as the next task, given the somewhat sparse guidance provided by the instructions - essentially two exploded views - and the tweaks I have already made to the chassis, will be to construct the key elements of the upperworks so that I can see what fits where.

 

Jim

 

 

 

 

[Crewe North]

Jim,

 

Don't knock yourself out about not being able to fit Joy's gear........the Coal engines and Coal Tanks were fitted with Stephensons

 

John

[jim.snowdon]

John,

 

Thanks. You can probably guess that the earlier LNWR is a subject I am still learning about, largely as a consequence of our current club layout being 1950s ex-LNW with Western Region running rights.

 

Jim

[jim.snowdon]

First, via feedback on RMWeb, I understand that this kit formed the basis for Mercian’s kit for the Coal Engine. However, and unlike some kits of this era that have been passed through several hands to their present ownership, Mercian have updated it by correcting some of the fundamental errors in the etches, for which they should be praised  . Trevor at Mercian has promised me further details later this week, so I will add those once I get them. Consequently, this thread has to be viewed as the trials and tribulations of building the original Modellers World kit, and not necessarily a reflection of the Mercian kit as it currently stands.

 

And now, with that out of the way, on to the upperworks. At first sight this looks as if it ought to be straightforward, being based on a flat footplate. A characteristic of many Webb locomotives is that the footplate does not carry round the front of the smokebox, leaving an open space behind the buffer beam, which, just to add to the fun, is a substantial piece of timber, faced front and back with steel plate. Looking closely at photographs, it was also clear that the footplate on either side ran only as far as the back of the buffer beam. The solution, since I wasn’t happy with the cast buffer beam anyway, was to model this as a proper metal/wood/metal sandwich, with the inner face soldered directly to the front of the frames. In principle, this meant cutting a copy of the etched front face out of scrap brass and laminating the two either side of a suitable piece of 1.5mm beech, which I found by way of a pack of plant labels that had been got as paint stirrers somewhere back in history. The only snag, discovered as I measured up the etched front face, was that the buffer centres were too wide by several millimetres. So instead of simply copying the etch, it meant cutting two new pieces from scratch and detailing the front one with the bolt heads that are a prominent feature of the prototype.

 

 

 

The cab end headstock was also a thick whitemetal casting of a shape that didn’t look right, either in terms of shape or thickness - whilst the prototype engines might have had a timber buffer beam at the front end, the rear end headstock appears from the photographs to have been steel plate.

 

Making up the underside of the footplate appeared straightforward - fit the rear headstock, followed by the valance either side from 2mm brass angle (the kit came with two lengths of 4mm scale rail) and add the cab steps, in this instance using the brass castings available from Laurie Griffin. (The steps in the kit might have been perfectly adequate, but given the complex shape of Crewe footsteps, the brass casting was simply much easier.

 

 

There are times when, with a kit of this vintage, if everything is going too well, something is amiss  . And so it turned out to be when I turned the footplate over and started to look at how the cab fitted. The distance between the cab side sheets and the edge of the footplate was large enough to have accommodated even the broadest of Broad Gauge drivers. It looked wrong, and when compared to the photographs, clearly was wrong. Given that the cab front was proportionately correct, what was obvious was that the designer of the kit had got the footplate too wide, by about 6”. Back to square one; take the valances and steps off and reduce the width of the footplate by sawing a tad under 2mm off each side, bringing the width down to a scale 7 feet. (This is one of the defects that Mercian had already discovered and corrected.)

 

 

With that sorted, the next step was to locate the cab, as the fixed point for locating the boiler. The cab front fits into a transverse slot in the footplate, as should the side sheets, except that they don’t as their slots are set too close together, making the cab width less than that of the front plate. Fortunately, not the end of the world, as the redundant slots will simply disappear inside the rear splashers. A standard feature of Crewe cabs is that the lower part of the sides extend forwards before turning into meet the firebox. The sides are half-etched so as to provide the rivet detail (as with many of the parts on this kit - the more common method of pushing the rivets through from etched impressions on the inside face does not seem to have crossed the designer’s mind.) The consequence of this is that there is now way of indicating the bend location on the inside of the side sheets, so the only way to establish this is by measurement against the cab front and the etched infill piece that form the top of the “box”. The snag is that the front of these boxes needs to be shaped to conform to the shape of the firebox, which can only be established by tacking the cab sides in place, and then offering up the boiler (once it has been made).

 

The boiler comes in the flat, half-etched so that the boiler bands are in relief, with an additional overlay wrapper for the smokebox. There are no internal formers to hold it in shape, only the smokebox front, and it is far from clear whether that fits inside the boiler or on the front. In the end I concluded that it fitted onto the front of the boiler, but inside the overlaid smokebox wrapper. It was also apparent that the two edges of the barrel would not meet. The firebox end was even more uncertain in terms of design, with nothing to close off the front where it meets the boiler and nothing to establish the shape. In fact, looking at the slots in the footplate, my impression is that the design simply thought that the firebox sides simply carried straight down below the boiler centreline. Photographs show it to be waisted in the usual manner, necessary so that the lower part can fit down between the frames.

 

Fortunately I have quite a good stock of scrap nickel silver from etches that was raided again to cut a pair of circular formers for the boiler barrel and a pair for the firebox. A complication with the latter is that the motor extends partly into the boiler barrel, with the result that the front former for the firebox has to be cut away substantially. Quite a lot of forethought is required in building this kit, especially as the instructions are next to non-existent.

 

 

 

 

 

 

With the boiler made (easier said than done, and helped no end by having a Kevlar heat resistant glove, obtained from a supplier of kitchen wares), it could be offered up to the front of the cab extensions and the firebox outline scribed thereon so that they could be cut to shape, one by one.

 

 

 

The other end of the boiler can then be dealt with , the first task being to tack the smokebox front in place so that the whole unit sits square on the footplate. Again, some thinking ahead is necessary, as it turns out that the spigot on the back of the smokebox door casting is larger by quite a bit than the hole in the smokebox front (a not at all unknown problem). This would be difficult to correct once in place, so out with the piercing saw again to cut a larger hole. The etched front also needs modifying slightly for a locomotive in post-Grouping state, by way of removing the downward extension that is meant to represent the hopper that Crewe designed into the smokebox so that the ashes could be emptied onto the track, rather than being shovelled out at the end of the run.

 

 

 

And with the smokebox wrapper attached, it is beginning to look like a locomotive, altough there is a fair bit of detailing that can now be done now that the fundamentals of what goes where have been established.  

 

[jim.snowdon]

By now, it will not have taken much to spot that not only is the smokebox wrapper not long enough to reach right round from one side to the other, but also that the smokebox has a front but no back.

 

The kit does provide an etched filler piece for the back of the smokebox -

 

 

which might be fine but for one basic snag. It is difficult, even with rolling bars (which I don't have), to roll a boiler truly circular - the edges always come out flatter so that the bottom of the boiler, where the seam is, is never circular.Having encountered this problem before, rather than attempt to make the filler piece fit, I cut a 1mm wide segment out of the arc in order to provide clearance -

 

 

This does leave a gap under the boiler, but from normal viewing angles and distances, it can't be seen. Now, the next problem is how to not only hold this rather small piece in place to solder it, but also to ensure that its bottom edge is parallel to the wings on the smokebox front, which sit on the cutout in the footplate. That caused a fair bit of headscratching until, i none of those lightbulb moments, I hit upon the idea of temporarily fitting a straight bar on either side, running from the bottom edge of the smokebox wings to the bottom of the firebox front (that I had created and installed earlier as the firebox as designed had nothing other than the two sides). Rather conveniently, the makers of the kit has included two lengths of 4mm scale flatbottom rail with the intention that these should be used for the footplate valance angle. I had used proper brass angle instead so these rail lengths were spare.

 

 

With these in place, the smokebox back piece can be wangled into position, with its side extensions hooked under the rails, both keeping it in place and parallel to the rest of the boiler bottom. A little light finger pressure on the two rails is sufficient to keep the smokebox back trapped against the bottom of the boiler for long enough to get it soldered in place, after which the rails can be removed.

 

So far, so good, but this still leaves the problem of the short smokebox wrapper -

 

 

Although much of the bottom of the smokebox, and the top of the cylinder block, is hidden away behind the leading sandboxes, it is nonetheless visible in part, so the gap needs making good.

 

The solution was to insert two longitudinal slices of some 5.5mm (7/32") brass tube that I had to hand, this being a good match for the outward turn of the wrapper where it meets the top edge of the cylinder block. Making a straight cut down the length of a round tube is not the easiest of tasks, but it was made a lot simply by having the small vertical mill. This allowed the tube to be slit with the edge of an end mill nominally aligned with the tube diameter -

 

 

 

The result, when cut free from the tube, is two roughly semi-circular pieces of brass tube each with one straight, square edge. The bottom edges of the wrapper are trimmed as necessary and the tube sections soldered into place, after which ther are trimmed to final shape.

 

 

 

As with so many Victorian locomotives, the leading sandboxes are integral with the leading splashers. Some designers get round this by making the splasher itself as a simple etched assembly, with the sandbox added as a casting. Not this designer, however; the whole thing is a single fold-up etching with the curved top of the splasher integral with the reverse curves that form the back of the sandbox.

 

Folding up the top and front is easy enough, but forming the compound curves where the sandbox is blended into the curve of the splasher top requires the brass to be annealed first by heating it to bright red and leaving it to cool. I find that this process leaves an oxide layer on the brass that is impervious to any sensible flux and which must, therefore, be cleaned off before proceeding any further. This is one of those instances where mechanical cleaning is next to impossible due to the limitations of access, however a solution is available by way of kettle descaler. I discovered by trial and error that the W5 descaler available from Lidl is very good for this; a little in a flat lid and brushed onto the brass cleans it whilst you watch, bringing the brass back to a bright surface in no time.

 

 

 

And the finished article - wisely (or was it purely by accident?), the designer left the splasher top over length this time, so all that is needed it for it to be trimmed back. Not surprisingly, though, the tab on the bottom edge of the splasher front, that should fit into the opening in the footplate, doesn't and will have to be filed flush before fitting.

 

 

Jim

[jim.snowdon]

Before the leading splashers can be fitted, the boiler needs to attached permanently, and one last job before that can be done is to finish off the front of the cab whilst there is still access. Crewe (and several other railway's designers) had a predeliction for extending the lower part ofthe cab side sheets forward of the cab front to create a sort of box. Why, I do not know, as there generally doesn't seem to be anything to go in it. As far as the model is concerned, the tops to these boxes need to be fitted, having first reduced the width of the etched parts to what will fit between the boiler and the cab side. Holding them in place to get the first solder tack in is tricky as well until I recalled a trick I must have seen somewhere in the past - soldering a length of rod, or in this case the rail that had thoughtfully been provided in the kit for making the footplate valance, to the box lid to act as a handle.

 

 

Then, to finish it off by adding the cab beading. Herein lies another one of the designer's errors - it is too long. Either that or the "lids" for the cab front boxes (which I used to measure where to make the turn-in) are too short. Either way, 2+2 does not equal 4 in this instance.With the beading being over length, the solution is simple - cut it and assemble it in two parts.

 

 

And one last thing before fitting the boiler - drilling the hole in the right hand cab front for the large steam pipe that runs down the side of the boiler, presumably for the vacuum ejector, which would only have been needed for the locomotive brakes. With the boiler in place, getting access to drill this would be well nigh impossible.

 

 

Now for the sandboxes and leading splashers. As someone on the Guild forum pointed out, the inside side of these is visible, although not by much; The etched boxes as built are only three-sided, so this would show. The simple approach would be solder some scrap etch onto the inside edges of the box and trim it to shape, but this would have the disadvantage of growing the width of the box by another half millimetre, and they are already over wide as a result of the compromises inherent in Finescale 0 gauge. The best I could do (and would have to do) would be to cut a piece of scrap etch to size and fit it inside the sandbox. Holding that in place to solder it requires a little cunning in the shape of several sacrificial fingers soldered to the infill plate so that it can rest inside the edges of the sandbox. These are then unsoldered and discarded once the infill is in place.

 

 

And the finished splasher/sandbox fitted in place.

 

 

 

Not surprisingly, the splasher is wider than the cutout for it in the footplate, into which a tab on its front edge is intended to locate. With hindsight, always a wonderful thing, I might have done better to have cut down the width of the splasher but that is a task that is easier when it is still in the flat.

 

The centre splashers share the same problem, but building and fitting them is relatively straightforward, save that it would have been much easier if the designer had arranged the front to fit inside the curve of the splasher top, where it would also have been neatly hidden by the beading.

 

Last but not least, fitting the cab floor and the rear splashers. Just to get things off to a good start, the kit provides an etched cab floor that is way too wide for the inside of the cab (the width of which is defined by the etched cab front plate). To add to that, the instructions, such as they are simply advise banding the rear edge downwards to meet the footplate, "according to the drawing". Now, it may be that, as this was a kit picked up on ebay, that the drawing has gone missing, so we will have to give the manufacturer the benefit of the doubt.

 

 

Nonetheless, a solutin has tobe found, largely by working backwards from the etched cab splashers -

 

 

By deduction, the back of cab floor needed to be spaced clear of the footplate by 1.5mm, achieved by recourse to the box of miscellaneous brass sections, in this instance for a length of 1.5mm H section. Without any detailed photographs of the back of the engine, it is essentially a matter of guesswork. Along the way, the nut that had previously been soldered to the top of the footplate to take the chassis securing screw from underneath had to go, not so much as it was lightly too thick but more because any over tightening of the screw would bear on the underside of the cab floor. Instead, I fitted an 8BA screw from the top, modified by having the thickness of the head reduced. Conveniently, this will help later on when it comes to attaching the tender drawbar, which will use the same screw.

 

Curiously, the cab floors on Crewe engines slope upwards towards the front and at least the designer of the kit had provided a slot on the inside of the cab front to provide a location. Then, with the cab floor installed, the splashers can be fitted.

 

 

That, at least established the basic outline of the locomotive, so the next steps will be to go back to the chassis and start on the detailing and such necessities as pickups.

 

Jim

[sej]

A fascinating build and I love the sacrificial fingers Jim, what a brilliant idea!

 

Cheers

Simon

[jim.snowdon]

Getting back to the chassis, the next step is to do something about the brakes. As the kit comes, it is provided with etches for the hangers and wooden brake blocks with which these (and other Crewe) engines were fitted by the LNWR. Even then, as befits the fairly basic nature of this kit, each brake unit is nothing more than a profile of the shape; no depth at all   . Tolerable, perhaps for a 2mm scale model, but not in 7mm, especially where the brakes on the leading wheels are in full view from anywhere ahead of the engine. In any case, not correct at all for an engine in post-war condition, so a solution is needed. The wooden blacks and their hangers were replaced in LMS days by the typical Crewe double hanger, with the block sandwiched in between, not somethin gI wanted to have to make from scratch. The Coal Engines used the same size wheels as the 0-8-0s, for whose brakes brass castings are available from Laurie Griffin, and from whom a set were procured. There is a slight snag, in that the hangers on the 0-8-0s are curved, whereas photographs of the Coal Engines them theirs as being nearer straight. Curiously, the Coal Tanks, which share the same basic design, seem to have curved brake hangers, so on the basis of if they were on the tank version of the class, there is no reason that they could not be fitted to the tender version.

 

An immediate problem that emerges is that the holes in the frames are too high up for the Griffin castings. Ordinarily, this might not be a problem but for the fact that the brake pull rods are either side of the wheels and need to be below the throw of the coupling rods. Marking a new set of holes below the existing and set at a constant radius from the wheel centres revealed that the original etched holes were all over the place anyway (no surprise, there ). They got filled with pieces of 12BA screw soldered in place and ground flush. Thinking that it might be sensible to make the brakes removable, the new hangers were made from 14BA screws, threaded through the frames from the inside, with sleeves from brass tube slipped over them to allow the brake hanger castings to sit at a constant distance from the frames.

 

 

 

The tube itself is from the Albion Alloys range and, being thin walled, is easily cut by rolling it under a scalpel. However, how to get six pieces all the same length, ie about 3mm long? The solution was to drill a hole of the correct depth in the end of a piece of brass bar -

 

 

and with that clamped to the workbench (actually, the piercing saw table), push the tube in to the full depth, then roll it in the hole whilst at the same time applying the scalpel blade tight up against the end of the rod. The cutting jig could then be used to hold the piece whilst the end was cleaned up with a fine needle file and the sleeve extracted by putting the jig over the end of the 14BA screw and letting it pull the sleeve out whilst the jig was withdrawn. Easier to do than write about, and impossible to photograph with only two hands. The brake hanger castings, with the brake shoes fitted, are then simply threaded over the screws and retained with a 14BA nut, following the prototype, albeit perhaps a little overscale.

 

Since the kit came with only the outer brake rods etched, I opted to fit lengths of brass wire across the width of the chassis, from the bottom of one brake hanger to its opposite number. It's not quite as per prototype, which had independent sets of inner and outer pull rods on each side (and hooked extensions on the brake blocks to fit round the flanges so that the blocks didn't creep outwards with the taper on the wheel treads), but it is prototypical practice.

 

With the brakes fitted and the excess bits trimmed off, the coupling rds can be fitted. I had elected to use the ready made jointed rods from Premier, although there are a bit beefier in appearance than the Crewe originals. This one place where, for a workig 7mm model, a little compromise is justified. As usual, I have fitted 10BA crankpins to the Slaters wheels and the 10BA nuts holding them on are just temporary until I make up some suitable flanged nuts.

 

The motor can also be secured at this stage, in this instance by two 1.5mm bars soldered in place across the chassis. These prevent the motor from rotating round the axle, yet still allow the motor and gearbox to rise and fall with the axle, which is sprung. Fitting them is straightforward enough, in that they are cut slightly over length and then filed back, if necessary a stroke at a time, until they are a comfortably tight enough fit between the frames to stay put without assistance prior to be soldered in place.

 

 

 

And now for the electrics....

 

Jim

[N15class]

I will be using your tube method of cutting tube. I normal cut against a ruler and waste tube until I have 6 the same.

[jim.snowdon]

With the motor now restrained, the next step is to make the whole chassis go, a stage that I always find distinctly stisfying in any loco build. My preference is for the PFS plunger pickups that are still marketed via Gladiator, albeit modified by the addition of a plastic bush to give the plunger more stability and reduce the likelihood of jamming. However, a characteristic of early locomotives such as the Coal Engine is that their frames are much lighter than on 20th century examples, which leves nowhere to put the plungers, especially as the best place is on the same level as the axle centres as this minimises the effect of the springing on the plunger's contact with the back of the flange. So, for this one it was a case of back to more basic methods using pcb and flat phosphor bronze strip.

 

 

 

Fitting inside motion was out once I had decided to fit the motor onto the middle axle, however I did think it would be better to put something between the frames than just leave a space. The four-bar slidebars are from a Laurie Griffin Joy valve gear kit and even if these engines didn't have Joy gear, are typical of the arrangement used almost universally on inside cylinder locomotives. Fitting them required making up a motion plate (this being one of the frame spacers I had planned earlier but not fitted until this stage) and a representation of the rear of the cylinder block.

 

Having given the bare loco a test run at our club's regular open day, I could turn my attention back to detailing the body, starting with the front sanding gear, which is incredibly prominent on these Webb locos. As with many Victorian locomotives, the operating rod for the sanders is taken down the inside of the boiler handrail and used to operate the sand discharge via a vertical rod down into the top of the sandbox. Despite the driver being on the left side of the engine, the sand control is taken down the right hand side of the boiler and linked across to the left side by a rod passing through the smokebox, presumably in a tube. Laurie Griffin does castings for the operating gear, but whoever made up the patterns (they probably go back to the original Shedmaster days) didn't pick up the fact that they should be left and right handed. That deficiency is something of a pain, but unless you want to view the locomotive from a scale six feet (and I don't), it is the presence of the vertical linkage that is more important to the overall visual impression.

 

 

 

At the other end of the boiler, the designer had thoughtfully included etched impressions of the firebox washout plugs, but only on one side, which is not much help. They got ground off and replaced with turned brass plugs from Warren Shephard ,let into 2.5mm holes drilled into the firebox wrapper.

 

 

The other holes are for the handrail knobs. For whatever reason, the Crewe draftsmen chose to put the handrails almost in line with the washout plugs, which must have made them popular with the shed staff come boiler washout days, but then that was an era when feedback from the users was largely unheard of.

 

Another one of those examples of Victorian elegance (?) was that of fitting the control for the blower valve down the left hand handrail (again, remembering that the person most likely to want the blower is the fireman, who is on the right hand side of the footplate). Again, there is a useful casting in Laurie Griffin's range, derived from the Shedmaster kit for the Coal Tank. The only catch is that it needs to be drilled for the handrail - or how to put a 0.7mm hole dead centre into a casting that is barely 1.0mm in diameter and lacking any form of centre location. The first task is getting hold of the casting at all and it is at this point that my newly acquired Instrument Vice proved its worth. This device, strictly an Eclipse No. 180 Instrument Vice, consists of a small vice that can be articulated and clamped in all three axes; the snag is that they are no longer made and whilst they do turn up on ebay from time to time, they are rare and command auction prices of around £100-110.

 

 

 

Getting the hole started is very much a trial of patience and a steady hand. Putting a punch mark into the end of the casting is a non-starter, which leaves the only option that of putting a very small drill, ie about 0.5mm diameter, in the minidrill and, with a moderate speed and a very steady hand, plus a magnifier, aiming for the centre of the casting boss. It isn't easier than it sounds, but I have found by experience that whereas a larger drill will skitter about on the surface without a punchmark to locate it, the very small drills, particularly if gripped with only the flutes visible, can be coaxed into cutting into the flat surface at the desired point. Once the hole is started, it can then be opened out with a larger drill. It is, though, an example of where the patternmaker can help the modeller by providing a small dimple in the casting, rather than, as I suspect was the case, trying to include a hole. With the latter, the tiny plug that is on the mould for the waxes soon breaks off with use.

 

One of the other snags with the Victorian pursuit of elegance (even if it is just a humble goods engine) is that the boiler handrails have to be carried through the cab front instead of stopping short as on more modern engines. Typically, the kit designer never thought to provide the strategically placed holes in the etch for the cab front, and with the boiler fitted, it is impossible to drill them from the front. The only method is to fit the handrails, using the turned knobs that are available and inevitably not quite the right length for the prototype, and mark where the handrails meet the cab front, then transfer this position to the other side by measurement. In this instance, the designer had etched in the row of ventilation holes along the top edge of the cab front, making it possible to transfer the hole positions by using dividers centred in these holes.

 

 

 

At least, with the handrails soldered in place - I see no need to make them removable for painting unless modelling the pre-WW1 era, when engine cleaners were cheap and handrails could be cleaned back to bare metal - the engine is beginning to look more finished. There is still quite a bit to do by way of fitting cylinder lubricators and what have you before the large whitemetal castings can be fitted. I like to get all the soldering out of the way before the whitemetal bits go on as I prefer to use epoxy for these and it doesn't take kindly to getting too hot.

 

Jim

 

[jim.snowdon]

On with the detailing. Next on the list was the reversing gear, or at least the bits of it that you can see.

 

 

The bearing blocks for the reversing shaft are from Laurie Griffin (again) and were fitted as is to the inside edge of the footplate. Not quite as per prototype, but then prototype engines are designed to be taken to bits, not split into body and chassis as are our models. Soldering them in place was straightforward enough with a length of 1mm rod passed through them as a means of holding them in place whilst the iron was applied to the edge of the footplate, letting the solder flow under the casting. The reach rod and crank turned out to be trickier, as although Laurie does a casting for the Coal Tank, it turns out to have a longer crank and a shorter rod. The latter was excusable as it only has to reach as far as the tanks, not all the way to the cab, but the crank was a little more of a pain. Working by eye, a new hole was drilled and the crank shortened. The reach rod was cut off at the point where it splits to form the fork end and a rebate filed on the back of the stump end, into which a length of scrap nickel silver etch was soldered. Most etchings contain their fair share of straight edged infills between components and around the edges - always worth keeping apart from the pile of scrap etch that mounts up as the components are cut out.

 

Laurie also does a set of the cranks that do the actual lifting of the valve gear, including the prominent balance weights. The only snag is that because of the limited space under the boiler of the 17" Goods, these have to be modified by cranking them. Following Lauries advice to cut a slot out of one side at the shaft hole, one bent to shape neatly; the other decided it was was going to crack, and sure enough, when it came to soldering that one in place, it came apart  . After quite a lot of dark muttering, the only solution was to solder the lifting rod end to the bottom pf the boiler, which is where I guess it would have been with the engine in full forward gear, and then solder the balance weight end onto the shaft.

 

 

Not the prettiest of jobs, but thankfully it is mostly hidden once everything has been painted black.

 

Now for the top side of the boiler. As expected with Crewe engines, the chimney came as two whitemetal castings - the square base and the chimney itself. The base might have been tolerable, but the chimney definitely wans't, being solid to within a couple of millimetres or so from the top and oval, with a noticable offset at the mould split line. Cleaning it up would have meant quite a loty of work, and drilling it out another task altogether. Finding that LG had none available, due to his supplier having unfortunately having gone to the celestial version of Crewe Works, it was a case of biting the bullet and turning a chimney barrel from scratch, for the first time.

 

 

I think it turned out quite reasonably, although the saving grace of a Crewe chimney is not having to machine the flared base . The dome was a rather better casting and needed only a little cleaning up, and the peg removing from its base. Not for the first time, the peg that is obviously provided to locate in the hole in the top of the boiler barrel was larger than the hole into which it should fit. Do some designers ever bother to tell their patternmakers what size hole has been provided so that the pattern can be got right from square one?

 

Still, with the chimney, dome and safety valve base attached to the boiler, using epoxy, the locomotive is starting to take on its proper proportions, making it obvious just how small the cabs were.

 

 

 

Someone raised the question a long time back as to how I was going to model the front buffer beam, as this is a steel and timber sandwich on the prototype, and all that has been fitted to the model thus far is the inner plate. Now for the answer.

 

 

The model replcates the full size arrangement, using a piece of real wood for the core, in this instance a piece of 1.5mm thick birch sold by Wilkinsons for use by gardeners as seedling labels. Just like coffee stirrers, but larger and thicker. The front plate, with all the bolt heads, that I had to remake after finding that the etched one was both the wrong length and had the buffer holes in the wrong place, was epoxied to the wood core and clamped. What is obvious from the picture is that simply clamping it at the ends allowed the brass to bow due to the thickness of the glue in the joint, as a result of which the assembly ended up being clamped against another seed label stick in the vice, the extra piece being needed to protect the raised bolt heads. It did the job, but doesn't exactly photograph well, hence no picture. The front and middle layers, once cured, will be attached to the back plate on the chassis by the same method shortly.

 

Turning attention now to the other end of the boiler, I like to be able to fit the boiler back (or is it the front) before the cab roof goes on, whilst everything is accessible. The kit comes with what looks like a nice casting, until you attempt to put it inplace.

 

 

It might look good, but it patently wasn't intended for this class of locomotive . The width across the barrel may be correct, but it certainly wasn't designed to fit around and between the rear wheel spashers. AlthoughLaurie Griffin does one for the Coal Tank, the risk is that the tanks make the cab too diferent for it to fit the Coal Engine, and its cost makes it a risk not worth taking. So, the next step will be to make a replacement boiler back from plastic card, using the casting as a pattern and shaping it to actually fit between the splashers.

 

Jim

[jim.snowdon]

Given the wonderful fit of the cast whitemetal backhead, the alternative was to make a new on from scratch. If it was good for nothing else it was to act as a pattern for the replacement. The key dimensions were transferred onto a blank made from two layers of 3mm plastic card bonded together. That at least provided the outline, but the question remained of how to accurately mark out the umpteen holes required to hold stub lengths of styrene rod to represent the stays. The conventional approach would have been to mark them out by hand, centre punch them (delicately) and drill. Do-able, but tedious and fiddly. Having invested in a small milling machine a while back, the alternative was to use it an x-y table. The blank backhead was clamped in the machine vice and the stay locations marked by setting the required offsets from a known datum and impressing them with the point of a darning needle held in the machine's chuck.

 

 

Drilling all these holes into styrene is not a simple matter of charging ahead with the minidrill, unless you want the holes to come out oversize and with the drill bit coated in melted plastic. Key to the whole process is turning the drill speed right down to its minimum, taking each hole a bit at a time and clearing the swarf from the dril lbit after every "bite". The result, after cutting the backhead to shape and boring the hole for the cast firebox door from the kit, is....

 

 

Each of those holes, except the few for the boiler fittings, is plugged with a short length of Evergreen rod - 0.75mm for the stays and 1.2mm for the top two rows, which are the bolted stays that in reality run the full length of the boiler.

 

 

...and trial fitted in the cab. A distinct improvement over the cast version that came with the kit.

 

 

The designer of the kit had thoughtfully provided a casting for the regulator handle, but not for the regulator spindle gland or the quadrant plate that defines the regulator travel. Back to making more tiny parts, this time from a slices of Evergreen tube cut to shape and attached with solvent.

 

 

and with all the fittings in place -

 

 

 

With that out of the way, time to fit the cab roof. A quick check showed the dimensional accuracy of the etched roof to be somewhat suspect -

 

 

To get it right, 3mm had to come off both sides before it could be secured in place and the edge angles fitted.

 

 

Meanwhile, at the other end of the engine, we had left the saga with just the inner layer of the sandwich that makes up the buffer beam in place, attached to the frames. I had already bonded the outer plate and the wood core, thereby leaving a trap for Sod's Law to enter into the process. I had predrilled the holes for the buffers I had originally intended to use, left over from the Andrews Prince of Wales build. The snag was that I could only find three of the four, and the spigots on the Slaters buffers that I am using instead are a tad larger. Opening out the holes on the pillar drill ended up splitting the wood from the front plate, making it a case of starting again. I did things a little differently this time, fitting the buffer guides at the same time as bonding the front to a new section of wood.

 

 

then bonding it with epoxy to the inner plate and the frames.

 

 

With all the soldering on the boiler done, the last major job was to insert the ballast weight, in this instance a length of 1/2" brass bar (it was handy, heavy enough and avoided messing about with cutting lead sheet and rolling it up). That was epoxied in place, followed by the smokebox door casting, which makes the locomotive look altogether more complete.

 

 

Purists will note that the cover plate for the slide valve chamber is missing. This is one of those times when the S7 modellers get the last laugh, as the omission is caused by the frames being closer together than they should be, resulting in the space between the front cylinder covers disappearing to not very much. The end result is one of creating the right visual texture in the space behind the buffer beam rather than absolute accuracy.

 

From a more normal viewing distance, the omission is less noticeable and the locomotive is starting to look the part. There are still minor details to add to the smokebox door, then I can make a start on the tender.

 

Jim

[Sandy Harper]

JIm 

It is certainly worth taking extra care with the inside of the cab with these 'open' cab engine. Not so easy to hide detail as you can in the 'gloom' of a larger enclosed cab loco. Also your efforts with the buffer beam have certainly paid off.

Sandy

[jim.snowdon]

Deciding that the little details could wait until later, especially the large pipe down the right side of the boiler, for which I was awaiting an elbow casting, time to make a start on the tender. Unlike most modern kits, where the tender has an internal functinal chassis that can be removed from the body and outer frames, this one has everything built onto the tender body. That may in part be down to the whim of the designer, and part to the fact that these early Crewe tenders had much less substantial frames than most 20th century types. Either way, it means making a start with the tender tank, the front, sides and back of which all come as a single etched piece. Probably because this is half-etched over the entire area of one side, it results in the residual internal stresses in the brass sheet twisting the thing quite badly.

 

 

The instructions rather cheerfully suggest that this piece of twisted metal is attached to the tab on the back of the tender floor and then bent into shape using a 7mm drill as a former. This might work if the metal had been annealed first, but it is so thin (0.15mm) that I didn't really fancy heating it up to red heat. It is of course true that to get a bend radius of 3.5mm you need to use a rod that is smaller by an amount that only experience can judge.

 

Nonetheless, by dint of careful measuring and marking out the bend positions I managed to get the tank sides to the required shape, albeit still twisted quite markedly.

 

 

The inner part of the tank that forms the coal space is etched on the same basis, and suffers some of the same problems. Getting the outer shell attached to the floor plate is straightforward enough, as access is tolerable, but attaching the coal space wrapper can only be done from the visible side. The whole exercise is not helped by the way that the tender, as designed, has no internal structure to assist in squaring everything up. I decided to fit internal bulkheads, cut from scrap 0.75mm nickel-silver etch as a means of getting everything to sit square, as well as giving the tender top some support. The extra support was essential to getting the corner join between the inner and outer wrappers together, as otherwise the springiness of the metal and the lack of support was turning the thing into a three-handed job.

 

 

 

Flared top tenders can be bad enough at the best of times, but on these early tenders, Crewe decided to make the flare taper from back to front. For this kit, the designer chose to get round the construction by making the flared section as a set of whitemetal castings, designed with a rebated edge (actually a double rebate) so as to fit inside the top edge of the outer wrapper. At the same time, another rebate was provided on the inside of the castings to support the tank top plate. Dry fitting the castings as they appeared they ought to fit produced a surprising result -

 

 

Patently two and two was not equalling four, and given the design peculiarities of the locomotive, my first instinct was to think where had the designer cocked it up this time. A night and a day later the penny dropped that the cock up was mine in assuming the wrong rebate engaged with the top edge of the tank wrapper.    After cutting some 2mm off the bottom of each casting so that it would fit over the notches I had already cut in the internal bulkheads, the castings could be fitted in their correct position using 100 degree solder.

 

 

 

Even then, dimensional problems struck, in that the casting for the rear section was wider than the tender, even when checked against the tender floor.

 

 

 

It ended up having to be cut in two at re-joined in situ. The end result -

 

 

Not surprisingly, to make up for the rear flare being too wide, the side sections are short by about a millimetre, leaving a gap that will have to be filled later, when the hot work is complete.

 

 

And at least, the tender top now sits where it ought to, or will do when it has been adjusted to size. The one good thing is that it is flat, unlike the tops of the later Bowen Cooke era, which slope inwards on all three sides. The geometry of that might have been a challenge too far for the designer to get right.

 

 

Jim

 

 

[jim.snowdon]

The longer I looked at the tank top, the less happy I was about it. It didn't really fit and the top and bottom etching tools had been out of register, resulting in the edges being none too neat. In the end, I decided to start again, not least as it would mean that I could fit it to the coal space as built, which wasn't quite the same as as designed. Out with the scrap etch again and a relatively straightforward job of cutting a new piece to the outside dimensions, with the coal space cutout left undersize to start with. That was cut nearly to size by marking it out from underneath (now I know what the angled point on a traditional scriber is for) and finished to size once the tank top has been soldered in place.

 

 

 

Getting the box that forms the body of the tender complete establishes a firm foundation on which to hang everything else, especially since this tender does not have a separate inner chassis.

 

Nonetheless, the running gear is quite intelligently designed, in that it is built round three inside bearing units, one of which is fixed solidly to the floor of the tender whilst the other two are free to pivot and float so as to provide a form of compensation. The etched bearing units are provided with cut outs into which the supplied bearings are soldered, which is fine except that the bearings are quite thin, giving a width over bearings that is far less than the distance between the wheels. As designed, containing the rather excessive end float would require a pile of washers. I chose to go the other way and turned up a new set of rather longer bushes, sized to give the outer axles about 0.5mm float, with a little more on the centre axle. The difference is quite substantial -

 

 

 

There is a fundamental snag with the design, in that oce the wire that secures all three units is in place, it becomes captive once the front and rear headstocks are added. On top of that, once the outer solebars and axlebox castings are fixed in place, there is no way in which the wheels can be got out of the frames. I did think about modifying the outside frames so that they could be removed, but in the end plumped for a solution that allowed the bearing units to be removed as well as improving on the design of the suspension. The fold up tabs intended to support and locate the longitudinal pivot wire were delicate, to the extent tat I suspect one is already hanging on by very little.

 

The solution I opted for was to attach the units using 10BA screws into tapped holes in 1.5mm thick brass pads soldered to the tender floor. The rear unit is fixed, whilst the front and middle units are connected by a strip of 2.5mm x 0.4mm brass running longitudinally between them and attached to another brass pad that can be screwed to the tank floor. The brass strip is sufficiently wide to keep the two bearing units in the right place  whilst allowing them to rise and fall as well as rocking left to right, thus keeping all six wheels on the track.

 

 

 

Interestingly, but not surprisingly, the fixed bearing unit does fit slightly on the squint, resulting in the tender having a small but noticeable lean to one side. That was corrected by soldering a short length of 0.3mm wire under the floor, between it and the locating tabs for the bearing unit.

 

 

 

Now for the decorative frames and axleboxes....

 

Jim

[jim.snowdon]

To be any use, an engine has to have brakes, which means, on the tender, somewhere to hang them. As designed, the kit came with a profile shape representing the original wooden brake blocks, and apart from having no depth to it, these had been replaced by cast iron blocks on conventional hangers longbefore BR came on the scene. The kit comes with a representation of an inner frame that sits just outside the bearing units -

 

 

Replacement brakes came from Laurie Griffins's range and were hung from brass rods threaded across the frames -

 

 

Although the arrangement is very traditional, working out where to drill the holes required some cunning.    The obvious place to start with is the rear axle, as this is fixed. Howver, just fitting the wheels to get a reference point revealed another conflict that, to be fair, the instructions had given due warning. For some reason best known to Crewe drawing office, the rear wheels on these Webb tenders are placed so far back as to foul the rear headstock to the extent that a not insignificant cutout is required.

 

 

 

Fortunately, this is only the inner plate, as the rear headstock is another steel/wood/steel sandwich that I shall assemble in the same way as the front headstock on the locomotive, so the relief will not show on the outside.

 

Locating the holes for the cross rods is a matter of offering up an assembled brake block/hanger unit to the wheel and eyeballing where the suspension hole sits relative to the inner frame behind, marking it and them re-marking it a little further forward so as to ensure clearance to the wheel tread. Copying this to the other five positions is a matter of setting out a line parallel to the bottom edge of the frames using dividers (the simple bit), and then using dividers to mark an intersecting radius from the wheel centre, using the handy hole provided by Slaters forthe socket key (the not so simple bit). What makes this tricky is that the front and middle axles aren't fixed, the chassis being compensated, so it is a matter of judgement holding them in the normal position whilst using the dividers.

 

At least, with them done the outside frames can be fitted.... As designed, these are half etched to allow the few bolts to be represented, however with the brass being fairly thin to start with, these frames are a mere 0.15mm thick, and are supposed to be substantial enough to carry the whitemetal castings for the axleboxes and axleguards. Added to that, the front headstock is a hefty great casting, to the underside of which the designer expected the builder to add the etched brass steps. I didn't fancy that idea, nor the thought of fabricating the footsteps, and had already bought a set of cast brass steps from Laurie Griffin. These could only be fitted behind the frames, so the whitemetal headstock was discarded in favour of extending the outside frames and making a new headstock. That neatly fitted in with the decision I had already taken to use the etched frames as overlays on new frames cut from 0.5mm brass etching scrap.

 

 

 

 

Cutting a new headstock from scrap nickel silver also allowed me to provide a better opening for a proper drawbar between the engine and tender. I have always preferred a drawbar pivotted at both ends over the crude hook and loop system used by some (mostly older) builders. As with the locomotive, the pivot is an 8BA screw with its head thinned down in the lathe, soldered to the underside of the tender tank. The special flanged nut will come later.

 

One the full size tenders, the outer ends of the headstock project a little beyond the frames, which feature had been lost by my substitution of a thin (0.75mm) plate headstock. I could have represented this by filing the ends of the hew headstock flush withe frames and adding a plate "extension" however I indulged in a little fun with the milling machine and cut two very shallow L section plates instead. The mill comes in very useful both squaring up the sections of brass angle and reducing one leg of each.

 

 

and the result, once fitted -

 

 

The kit comes with two etches for the coal space floor and for the footplate extension that overlaps into the cab, both half etched over their full area and thus very thin. Checking the tender against the loco showed that the tender floor plate would be too low by a considerable margin (5mm! ), never mind that it did not fit between the sides of the tender. Cue for more nickel-silver scrap to be cut to shape and a new cab footplate to be made. This also allowed for the error in the length of the tank sides that I had created way back at the beginning to be accommodated (the tender tank is longer on one side than the other by 1.5mm ). It is attached to the tender floor plate by a length of 5mm brass channel that happened to be handy and which is sufficiently robust to provide good support for the overhang. The coal space floor I will treat similarly, but that will end up glued in place simply on account of the lack of access for the soldering iron.

 

 

So much for the front end, but the back end of these Webb tenders is equally quaint in as much as there is a modest platform extending back over the buffers. Again, this had been provided as a casting in the kit, intended to fit on top of the cast headstock. The first problem is that it is more than likely that the geometry of the tender tank as built does not match that of the cutout in the cast part, hence an  early decision, once the tank had been assembled, was to mark out its profile on a piece of scrap etch whilst it could still be traced around. Having now got this far, it was cut out and checked for fit against the back of the tender tank and, surprisingly enough, it fitted -

 

 

Once trimmed to shape, using the casting as the pattern, it could be attached permanently, the corners resting on top of the end of the headstock.

 

 

and the lamp irons, again from Mr Griffin, soldered in place.

 

The tender is, by now getting substantially complete, which brings on the next, and hopefully last, major challenge in the shape of the coal rails. These had been provided as a single piece etch in the kit, but had suffered badly at the hands of the previous owner of the kit, being  buckled and with the feet for attaching it to the tender top being distorted and missing.

 

 

I did make a start on trying to fit what was left, but even the simple process of bending the feet to a curve that would match the flare was barely achievable without ricking further distorin and breakage, not to mention the task of forming the radius round the rear corners of the tank in situ. It soon became apparent that starting from scratch would be easier and a length of scrap etch was found from the odd ends box that would do for making new mounting brackets.

 

These were bent to shape and fitted one by one, soldered to the brass tank top rather than to the whitemetal flare castings. Being 0.5mm thick they are robust enough to stand up to normal treatment, and soldering only to the tank top avoids the risk of damaging the castings, which are not easily replaceable.

 

 

With all the brackets in place, the rails were added from 0.7mm brass wire and the excess bracket length trimmed off with the piercing saw.

 

 

Bending the wire round the corners was made a lot easier by a pair of ring forming pliers I had obtained a while back from the US. These have matching convex and concave surfaces and make it possible to manipulate the curve to shape a bit at a time whilst watching it take shape.

 

 

There are still a few bits to solder on to the top of the tank, as well as making up the rear headstock, then it is down to attaching castings with epoxy.

 

 

Jim

 

 

[jim.snowdon]

Meanwhile, back at the other end of the tender, the rear headstock needed finishing off. Like the front headstock on the loco, it is a steel/timber/steel sandwich, except that what the kit provided was a hefty whitemetal casting that I didn't really want, and to which the guard irons, which appeared to be missing from the kit, would need to be attached. As with the front end of the loco, I replaced this with a proper metal/wood/metal sandwich, using the detail on the casting as the guide for the various substantial bolts that patently held the lot together and attached it to the tender frame. The guard irons, which are attached to the outside of the headstock by an L section foot, were made from 3mm brass angle.

 

 

That was soldered in place, remembering to keep it clear of the buffer footprint, and then the holes drilled through for short pieces of 1mm brass wire to be soldered in place as the bolts.

 

 

 

Finishing the guard irons was a matter of cutting off one leg of the angle from headstock level downwards, after which the wood core could be attached using epoxy. It will be remembered that when the inner headstock plate was fitted, substantial cut-outs had to be provided in order to clear the rear tender wheels. Similarly, sections need to be cut out of the inner face of the woodwork, although this time they are rather smaller and contained entirely within the wood section, after which the complete unit can be attached to the tender using epoxy.

 

 

 

 

 

There is still work to be done on the tender, mostly detailing, but paired up with the loco, the ensemble is beginning to come together quite nicely.

 

 

Jim

[jim.snowdon]

The last great challenge on the tender was to make a new floor for the coal space. The kit did provide one, etched down to half thickness across the whole of its surface bar two tiny hinges, and undersize. Just to complicate matters, largely as a result of the insubstantial nature of the tank itself, notwithstanding the additional reinforcement I had built in, the sides of the coal space aren't straight either.

 

 

Marking out a fresh piece of metal is fine when you can place the object on top and scribe round it, but here the situation is reversed. After some head scratching and thoughts about cutting bits of card to shape, a penny dropped. Since the kit part was undersize, and going to go in the scrap box anyway, why not put it in the space and solder fingers along its edges. Then use the ends of the fingers to mark out the required profile on the new metal.

 

 

The result, albeit with a bit of further filing to get the fit right. Importantly, the technique had got the edge profile pretty well right, so most ofthe filing was smiply reducing the width overall to compensate for my cutting slightly oversize and for getting it past the etched rivets. With it in place, the elegant curves (!) of the coal space are evident, although in time they will end up being lost under the coal pile.

 

Back at the front end on the engine, one task I had had to put by whilst waiting for castings was the pipe down the right hand side of the boiler. What I got was a set of elbow castings from Laurie Griffin, and a slight surprise in that whilst every kit I have had supplies this as a single casting, Laurie's came in two parts - the elbow and a pipe coupling. Both needed drilling out to get the spigots to fit properly, not that I mind that - I would sooner have a casting intended to be drilled out than one where the patternmaker has intended to cast the full depth of the hole, only to find that the rubber "pin" in the mould for the waxes breaks off with use, leaving an irregularly shaped impression that is difficult to get a drill started in. Holding these small castings whilst drilling them has always been a problem, however not long ago I acquired an Eclipse instrument makers vice after seing one being used in an article in the MRJ. Although they can only be acquired second-hand, and are not cheap - typical prices have been around the £100 mark - I have have found mine to be very useful for holding small items securely at all sorts of odd angles.

 

 

A catch for the unwary (which included me) is whilst it is a very nice casting, it was obviously made for a locomotive where the elbow entered the smokebox above or below the centreline, as the mounting flange was at an angle to the axis of the elbow. It is not something that can be altered, so the only solution (bodge, really) is to glue the elbow in place perpendicularly to the smokebox and allow the epoxy to form a wedge shaped bed between the flange and the smokebox. It might not stand really close scrutiny, but at normal viewing distances, it is tolerable, helped by everything being black anyway.

 

So far, I have got an engine and a tender, but nothing to connect them. My preference is always to use a drawbar pivoted at both ends, and for this loco a suitable one was found by raiding the left-over etches from other kits. Way back at the beginning, to avoid putting a screw up under the cab floor I had inverted the rear body attachment, instead soldering in an 8BA screw under the floor, pointing downwards. The drawbar pivot on the tender was arranged the same way for much the same reasons.

 

The drawbar is retained by a pair of flanged nuts that I turned up from brass bar, with a couple of flats milled on the flange for tightening. However, for those without access to machine tools, an equally good substitute is a length of brass tube threaded over the screw and retained with a washer and nut. The important part is that the nut, whatever its form, is tightened down onto something solid, otherwise it will simple come loose unless retained by either a second nut (if there is room) or an adhesive of some sort.

 

 

 

With that in place, the locomotive is now a compete unit, nearly ready for the paint shop apart from making a set of proper crankpin nuts. Quite often, I will use the Slaters crankpin bush, tapped 10BA, with the flange outwards, but on an inside cylindered locomotive with no clearances to worry about and everything visible, these look rather plain. Both CPL and Griffin do sets of cast crankpin nuts, but I find these rather on the small side for 10BA, so it will be back to the lathe and mill to make up some new ones, of which more anon.

 

 

Jim

 

[jim.snowdon]

And finally, with the "proper" crankpin nuts made up and fitted, and everything trimmed, the Coal Engine is as near finished as it is going to be before it gets to the paint shop -

 

 

 

 

Building it has certainly been a challenge, although I have to say I have met worse. In part, this is down to the standards and expectations of its day, the kit being somewhere around 35 years old, when etching was viewed by more as an aid to scratchbuilding than is now the case. Equally, there have been moments when (a) you could have wondered what drawings the designer used, and (b) how he could manage to make things that should fit together different sizes. Like many early kits, it is still with us as, I understand, the basis for the current Mercian kit. How much of the original kit remains is a moot point, as although Mercian have said that improvements have been made, including changes to the etchings, they have not been forthcoming with the details.My build of the original Modellers World version of the kit should not be taken as a review of the Mercian kit.

 

I will add the final pictures once it has been painted - BR black with the early totem - but possibly not for a while given the season.

 

Now, to decide what to embark upon next.....

 

Jim