INTRODUCTION :

Two weeks ago was a cold, grey, overcast day – where most sensible people sneak a few extra hours in bed.  Of course, we aren’t all that sensible and were happily pottering around the chilly, gloomy depot.  The day started off slow.  You could see people were still spooling up.  But it turned out to be a productive day with our people working in the workshop, amongst the coaches and on the fencing lines.

The photographs from that day aren’t that good – but at least you don’t get such harsh shadows. 

Last week was a pleasant day at a very busy depot.  We basically had 5 teams at work.  Hunslet Taylor Strip-down, perimeter fence gate fabrication, Class 12AR boiler tube preparation + installation, Electrical repairs and rehabilitation work on the ex-Sandstone Coaches.  Scrap recovery company, Reclam, was on the premises finishing up the cutting job on the burnt out Transnet couches out back – and the Sitemela Contractors were hard at work.  I was buzzing around like a blue-arsed fly trying to keep up with everyone.  The photographer probably walks more than any other person at the depot when everyone is so spread out.

But isn’t it so much better to hear of a live, busy Steam Depot than of a stripped, derelict depot, up to the window sills in weeds and the gaunt leaf-drifted remains of locomotives sinking into the ground under knarled tress? 

PROJECT – Booth Crane No.96 - Cleaning a Steam Crane’s Boiler :

Patrick Ackerman and Dawie ‘Swak Hart’ Viljoen were the two boiler boys today.  (Two weeks ago)  Patrick arrived at normal Depot working hours and had come with a secret weapon.  He had his own brand new needle gun, in flawless satin black finish and stainless steel.  (Pic B01 below)  He had also come fully equipped with his own hoses, hose couplings and a filter + moisture separator set for the air compressor’s lines.  Our air compressor plant has little filtration on the intakes and the entire system is very prone to condensation – which would mess up a pneumatic power tool fairly quickly.  This is true even when we blow out the lines to atmosphere upon the first opening of the valves.  The filter and separator set fitted against the air-line’s I-beam column after some juggling of nuts and fasteners, as it could not be rotated around its axis.

David Jacobus Viljoen sneaked in later – obviously after a late night of carousing and chasing girls.  Actually, Dawie lives in Potchefstroom, a university town that is just CRAWLING with girl students, but is 1 ½ hour drive away from the depot.  The two of them got stuck into their all-day task of de-scaling and de rusting the boiler.  Patrick operated the needle gun – with great gusto (Pic B02 below) as he was enjoying operating a decent functioning power tool for his second round.  He was concentrating on the rivet heads, seams and the flanges while Mr. ‘Swak Hart’ got stuck with the rotary wire brush and got the loose powdery stuff off.  (Pic B03 below)    
        

The boiler’s grate and fire bars had been removed during the week and had been placed in their relevant positions on the workshop slab.  (Pic B04 below)  No abnormal wear was found.  The grate was found to be in fairly good condition, with the exception of a deep crack on one side of a removable sow-bellied fire bar.  (Pic B05 below)  It isn’t a crucial problem though, as it can be cleaned up and re-welded closed again. 

The Chief Engineer came poking around later on and inspected the work, with close attention to the flanges and a once over of the foundation ring.  In this boiler, once the two large oval shaped inspection hatches at the ends of the two tube bundles are removed, you can stick your head in through the holes (Pic B06 below) and you can actually look down into the water space between the firebox \ flue assembly and the outer shell.  It’s not possible on a steam locomotive without using mirrors, or a fiber optic type viewfinder – or by literally cutting away some of the plating. 

He pointed out potential weak points and re-affirmed the issue of the pitting on the crown sheets.

We ended up in discussion about the odd measurements used for the rivet hole spacings – as the overlapping curved sections are drilled as flat plates.  But the holes drilled in the outer plates have to be fractionally further apart than the corresponding holes on the inner plate, because the plate’s final curvature is a higher radius.  Some complicated calculations there and when this boiler was made, calculators were mechanical devices and slide-rules, no electronic aids and computer-based drafting.  <<Tips hat to those long ago engineers and artisans.>>  Andrew was confident enough to let the young men continue with their cleaning work.  Or, he just wanted to keep them occupied and out of mischief.  Anyway, the cleaning work continued and the bolted-on firebox door frame and assembly (Pic B07 below) was removed for cleaning, and for access to the boiler shell behind it.

Tony ‘Shakey’ King had a go with Patrick’s descaler on the removed firebox door.  Meanwhile, Dawie moved around to the dark side of the boiler and found that the rust was too much to handle.  After blowing powdered ferrous-oxide dust out of his nose, he rigged up a bandanna to continue his work.  (Pic B08 above)  

I climbed up onto the empty and still rust-piled boiler deck of the crane itself and took some detail pictures of the crane for later use.  Eventually I climbed up on top of the water tank, standing astride the dynamo and took a rare shot of the top of the boiler.  (Pic B09 above)  Doesn’t so bad from this angle does it?

Our usual boiler inspector, Dawie Olivier (From OSG) came by on Tuesday (15 July) and examined the boiler.  To our dismay, but not total surprise, he pronounced it unfit to use.  The pitted ‘crown sheet’ (Pic B11 below) and the foundation rings are a problem, and there is evidence of metal thinning around the firebox door.  I must emphasize that this boiler CAN be repaired.  It’s just going to cost money and mucho-time with the fabrication work to be done.

In the meantime, it is likely to end up partially reassembled, the firebox doors put back, carefully painted for weather proofing and put on static display around the new formal club house.  (Where it will keep the existing ornamental smokebox door and the loco driving axle company on the lawns.)

There is another vertical flue boiler at Millsite – but that’s a larger boiler for a 65 ton crane.  It is compatible with the Crowans Sheldon No.50 that is standing against a set of buffers in open air storage.  The Sheldon crane, by the way, appears to be complete apart from the boiler fittings, but due to long term storage in the open air, all the bearings have rusted solid.  Thus, the Booth Crane No.96 ‘Shosholoza’ boiler rebuild project has been put back onto hold.  (Pic B12 above)

However, it is not the end of the drive to get the Booth Crane back into steam.  (Stubbornness is a well known steam preservation trait!)  Preliminary discussions are under way to create tap-offs from one or two of our locomotives, and to pipe locomotive boiler steam to the crane to operate the crane’s power mechanisms.  It would be a similar concept to the old fashioned American Snow Plow (American spelling!), where the rotating machinery in its own cabin was actually powered by the locomotive pushing it. 

Although the Booth Crane No.96 is actually self propelled, it has a mind blowing top speed of about 5kph and is safely operated at half that speed.  The crane’s propulsion system and gear train is designed for final positioning rather than relocation – the work crew’s locomotive is required to shift the crane and the accompanying job car around.  So you’d have an attending locomotive anyway.  The Chief Engineer still needs to approve of the concept.

The concept is sound as it’s possible to procure high-pressure high-volume flexible steam piping, which is basically flexible, reinforced piping with armouring.  Many of the large later model SAR locomotives already have a tap off valve anyway.  A valve could be fitted to any engine with very careful positioning and attention to the flanging.  These are sometimes called ‘filler valves’ and were sometimes used to pre-charge a locomotive’s boiler with steam and\or hot water to speed up the time to get a cold locomotive in service.  If we do choose to fit a valve, the 15CA No.2056 ‘Dorothy’ would be fitted with one.

There would be no need for a reducing valve, even though the locomotive boiler runs at a higher pressure than the crane’s boiler did.  The steam gaskets will need to in tip-top condition to handle the pressures – but the pressure in the crane’s cylinders is determined by the load, not the incoming steam pressure.  (The boiler engine(s) don’t have variable cut off.)  The gaskets would naturally be overhauled, as the steam crane’s cylinders, pistons and valve chests would be overhauled anyway if we put the crane back into steam-powered service.  We’d upgrade the motion by fitting the crane with a mechanical lubricator.  The main challenge would be to allow for the crane’s pivoting.

PROJECT : Class 15F No.3052 ‘Avril’ Stoker Motor Overhaul : (19 July)

The methodological strip down of the mechanical stoker’s two-cylinder engine for the Class 15F No.3052 ‘Avril’ has been continuing, courtesy of our favourite Stoker Man, Michael Thiel.  The project has advanced to the dismantling of the individual bit’s n’ pieces and including the possibility of losing a few in the process. 

Seriously though, when one is looking at the overhaul of a reciprocating steam engine, all the parts need to be cleaned up carefully before measuring up and making an assessment of what needs to be done.  Clearances can be so fine that dirt or even layers of oxidation can upset measurements. 

As befits the finer work required, Michael ‘Stokes’ Thiel had moved his workstation, kit n’ caboodle, indoors next to the machine shop with better and more consistent lighting.  It was more sociable for him too (Pic S01 below) – rather than being stuck out in ‘depot limbo’, hidden out of sight in the dark, cool shadows cast between massive dozing locomotives.

With the recent publicity concerning a certain crankshaft, ‘Stokes’ Thiel was nervous and defensive having me around with a camera.  Such is the price of fame.  But I got a pic of the crankshaft measuring that is under way.  (Pic S02)  Michael measured up the clearances twice, once after an initial wipe down of the working components and once again after the journals and eccentrics had been rubbed down with very fine grade wet and dry emery paper.  It might seem like an odd and destructive procedure, as you wouldn’t want to apply too much emery to a car’s crankshaft.  (Especially if it’s case hardened.)  But remember that the parts for these locomotives are no longer available off the shelf – so components don’t have to be machined or manufactured to fit theoretical standard parts.  Obviously we try to conform to the original standards in terms of dimensions, but more importantly they have to fit each other and the frames or casings where-in they work.  That’s why this is called ‘fitting’ and the built-in ingenuity and craftsmanship extends the lives of these increasingly rare parts – but it does mean that internal parts from one locomotive may not be interchangeable with another. 

It’s an interesting remake of history.  Before Henry Ford pioneered the concept of mass production for motor cars, many Edwardian and early 20^th century vehicles had to have parts lapped, cut and fitted by hand and these parts were not interchangeable.  Those long ago mechanics had to be fabricators as well – real craftsmen. 

But back to the depot … When the crankshaft was first removed it was found to have normal slight circumferential wear marks.  The crankshaft journals were found to have ovality of 0.15mm.  With the big ends assembled with the original shims, there is a clearance of about 1mm between the crankshaft journal and the internal diameter of the bearing shell.  Yowch!)  If this was a car engine with those clearances, it would have destroyed the crankshaft and big-ends in short order.  On the stoker it results in knocking, which spalls the surface of the journals, degrades the oil film and tends to hammer the journals oval, which gradually makes the problem worse. 

As stated, both the ball bearing type crankshaft main bearings are to be replaced.  The replacement bearings and the oil seals have already been purchased – safely wrapped in air-tight zip-lock bags and smeared with white grease.

The big end bearings are shimmed as standard and are currently fitted with a pair of 1.7mm brass shims brass shims on either side.  (Thus, the original caps are shimmed at 3.4mm)  Michael is preparing to make up his own shims from brass stock and tighten up the big ends, without the hassle of re-metalling and machining the bearing surfaces down again.  (Pic S04 below) 

Pic S05 (Below) shows a picture of a valve spindle as just withdrawn upon the initial dismantling.  The spindles were cleaned up today with very light machining on James Thomson’s lathe and you can see the gleaming results in Pic S06 below.  Everyone wanted to feel how smooth the finish was and James Thomson was swatting us away because of our oily, acidic finger prints.  The valve ring grooves were re-cut and James is preparing to cut new valve rings to suit.  With the inherent accuracy of James’ work, the final fit will probably be better than when the Stoker first left the works.  Michael will be cutting and filing the slots of the eight fabricated cast-iron valve rings to suit the measurements of each valve chest.  (Four on each side.)

All the other parts were cleaned and inspected, including the crosshead slides, the clevis pins, the gudgeon pins and the pistons themselves.  They are booked for the next polishing exercise.  In amongst all the cleaning, the castellated gland nuts received some attention.  There are eight of these in two sets of four, all of brass, and all a bit awkward to get at within the rod chamber.  They are meant to be removed with a C-Spanner, but it is all too easy to just whack away at the radial slots with hammers, chisels and the like.  Naturally, over the years of service, and possibly attention from an indifferent fitter or two, the castellations get mauled and rounded.  Eventually the c-spanner no longer works and the fitter has to resort to more brutal methods, which messes the nuts up even more.  This was a monotonous job, as Michael had to hand file each one of the slots.  Luckily Michael was able to watch the antics of the 12AR boiler tube gang, which kept him amused and occupied while stroking the brass.

A little more machining was done, based on our experiences with the chevron seals that leaked so badly on Class 15F No.3052 ‘Avril’s’ debut run.  The glands ‘crush up’ and seal better against a tapered surface, rather than a flat.  The stoker piston rods use a split conical ‘olive’ to hold back the steam and these are ever more suitable for a tapered conical sealing surface.  Each one of the piston rod gland nuts, after cleaning and dressing, was machined by James and the refurbished results are visible in Pic S09 above.        

PROJECT – Class 12AR No.1535 ‘Susan’ Boiler Tubes

Yeah…this project is finally moving after months of us all seeing the seven boiler tubes lying uselessly next to this old engine. 

The delay was in the availability of the boiler inspector and the fact that he had to make some extra calculations to verify a potential issue that he found.  The lower section of the front tube plate is a bit thinned out and was subject to extra scrunicity.  It’s a vulnerable part of a steam loco, as that’s where ash and char tend to collect.  When the deposits get damp via water ingress through the chimney, or form a half hearted smokebox washout, the sulphur leaches into the water and forms corrosive sulphuric acid.  After a series of complicated calculations and more measurements, the front tube plate of the 12AR was deemed fit for another three year’s service after the boiler has been tubed up and recertified.

Phew!

We’re keen to get this engine running again, not just for her own sake, but because she’s economical and yet a sure footed hauler.  She has a good turn of speed, in site of the small driving wheels.  The engine is hand fired, and is thus a great training platform.  Our Class 12AR No.1535 ‘Dorothy’ is the last Class 12AR in existence, let alone still running and is an unusual sight.  As strange as it seems, overseas photographers do get a bit bored with the 25 and the 15’s, whereas the 12AR is an unusual earlier class and always popular.

The boiler project was handled by the Ackerman brothers today, each working on their own tasks.  Shaun Ackerman worked on preparing the boiler tubes and the tube plates, while Patrick rounded up some tools and got busy fabricating the copper ferrules for the tube ends.  But firstly … Ackerman Slightly Senior, hard at work in the steely sarcophagus of the firebox.  You could see the guys were psyching themselves up for the job – collecting the tools and rigging up the 32 volt boiler inspection lamp. 

The 12AR has a short but tall firebox and it’s always strange climbing in through the firebox door and sitting on the grates, surrounded on all for sides and overhead by solid steel plates decorated with the riveted heads of the boiler stays.  You can see through the grate to the ash pan below, and in the center area – you can see right through the ash chute and into the boiler trench.  It’s dark and chilly inside the firebox of a dead locomotive – in such contrast to the bright inferno that is resident when the engine is running.

The first job of the day was descaling.  There’s nothing like a good stiff brushing and then a tapping with a drift to knock the scale off.  You can see the newly cleaned area in Pic R01 below.  The entire firebox is covered with a thin, brittle black scale which comes off after the surface is fractured and you can get behind it.  Patrick and I had much tactile satisfaction picking off the scale later in the day while waiting our turn to work.  When the boiler inspector comes, the entire firebox has to be chipped out and cleaned to the bare metal.

With all the loose stuff taken off, it was time to cut and punch out the old tube ferrules.  The 2 ½ inch diameter copper rings that act as crush rings to seal the ends of the tubes usually remain behind when the tubes are withdrawn.  Dr. Smudge Ackerman cut the rings down using the edge of a half round file.  (Pic R02 above)  The job could have been done quicker and cleaner with a hacksaw blade, but apart from the risk of cutting into the tube plate, the resultant slot wouldn’t be wide enough to allow the crushed-in copper ring to collapse.  This was uncomfortable work on these tubes in the lowest rows – as the tapered file has to be held horizontal while the operator is squatting on the haunches.

The tapping then began (Pic R03 above) and it could be heard from the front of the engine as the sound passed through the boiler tubes.  The ferrules were tapped diagonally along the side of the newly-cut slots to force them to twist, and one side of the slot to wrap and telescope over the other half.  They would then reduce in diameter and collapse.  Some of then stayed within the tube plate, and some of them got punched right through into the boiler cavity and had to be fished out.  Plucking the ferrules out took care as those edges were sharp but the clearances too fine to have clumsy thick-skinned protective work gloves on.  (Pic R04 below)

Patrick then climbed in to ask some questions about the new ferrules he was making, and to compare a sample with the originals.  So there were three of us in the firebox.  Patrick tied the work light up to one of the fusible plugs with a piece of wire that he had (Pic R05 below) – so Shaun could use both hands.  (I had no goggles and wouldn’t be able to safely get close to hold the work lamp during the grinding.)  The yellow ear muffs came on to muffle the acoustic dingbats flying around that steel echo chamber.  (Pic R06 below)  I turned my hearing aids off – which then act like highly efficient custom fitted ear muffs, and Patrick got his tail out of there.  He’s built like a rake and literally SLITHERS through the oval shaped firing hole.  Bit eerie to watch, actually….

The tube plate dressing operation commenced with much noise and dramatic spark trails firing against the right hand plating and skirling down through the ash pan and visible from the outside.  (Pic R06 above)  The objective was to strip the tube plate surfaces down to bare shiny steel around the empty tube holes.  Apart from the rust and dirt that may remain after the initial descaling work, there may be remnants of the original bead and welding remaining.  When the tubes will be fitted, the new ferrules are expanded into the holes, and then the new tubes slipped in and expanded into the ferrules.  Then the ends of the tubes are ‘beaded’ – that is, bent through 180 and welded against the tube plate.  The metal-to-metal contact has to be almost perfect, and the material needs to be 100% clean for a good, safe pressure and expansion proof weld.  (You can see some existing beading in Pic R09 below.)

The grinding went quickly (Pic R07 below), even with frequent breaks to run a finger around the holes to check for imperfections.  Of course, it had to be allowed to cool down a bit from all the grinding work.  Luckily, the heavy mass of the tube plate and tube metalwork acts as a good heat sink.  The power drill came into play next, fitted with a 2 ¼ inch grind stone.  (Pic R08 below)  Shaun ran this carefully around the inside surfaces of the holes to polish them up. 

PROJECT – 12AR Boiler Tube Ferrules ;

While Ackerman Slightly Senior was getting closely acquainted with a series of 7 holes in the steel and carborundum scented air of the firebox, Ackerman Slightly Junior was standing comfortably fully upright and tinkering with a 2 ½ inch diameter copper pipe.  His job would be to expand the pipe to 2 ¾ inch outside diameter and to cut it cleanly into rings.  The individual rings needed to fit the width of the rube plate exactly as well have having perfectly straight edges.  These would be the copper ferrules that would form a crush sealed joint between the tube and the tube plate, and also to prevent water from getting in behind the welded beading from the boiler’s water space.

Patrick’s copper ferrule project started with a lot of necessary faffing around to get all the tools together as they were to be found in various places.  He had to find his temper a bit too – it’s possible to waster over an hour looking for tools and supplied in our sprawling depot.  The tube expanders are kept in their own lockable store at the Top Shed, as are all the boiler tools and there was a delay in getting the keys.  Refractory bricks had to be found for the annealing, and the acetylene torch set brought out.  Even a bucket of cold water had to be arranged.

Patrick was planning to use the chuck of the nearby 7 ton Dean Smith lathe as a pipe vice, as it would be vital to keep the copper pipe circular.  However, the lathe’s chuck key had gone missing.  A new one had to be fabricated before the job could continue. 

The first stage of the job proper would be to heat up the working end of the copper tube and then plunge the red hot end into cold water.  (Pic CF02 above)  This is the process of annealing the copper and actually softens up the material to make it workable.  The torch burns off the impurities and oxidation from the surface too.  The mass of the pipe was small in relation to the water so it could be picked out fairly quickly and placed into the chuck of the Dean Smith lathe (Pic CF03 above)

Then the tube expander could be applied.  I never thought to get a close up picture of one of these devices.  They are that special combination of simple and ingenious.  Basically a tube expander comprises of a top hat shaped cage, fitted with tapered rollers.  The rollers can move radially in and out.  The cage is inserted into the pipe (or boiler tube!) with the rollers slack, and then the tapered mandrel is installed and gently tapped in.  This pushes the rollers out and firmly against the interior walls of the pipe.  Because the taper of the mandrel matches that of the rollers, their outer edges line up parallel with each other and the pipe’s internal surfaces.  After a few taps to snug everything up, you then turn the mandrel.  It drives the three rollers, (by friction) which rotate the cage by counter reaction.  As the rollers are slightly tilted from the longitudinal axis of the tool, they roll with a slight helical motion and gradually screw the cage inwards.  The tilted tapered rollers also grip the mandrel, so it automatically moves inwards into the cage.  The rollers are automatically driven outwards by the increasing diameter of the tapered mandrel.  The radial outward movement of the rollers is was stretches the tube – with an unsettling rippling movement, rather like the rippling eyelids of someone who is asleep and deep in REM sleep.  (Dreaming.)

Pipe Expansion went as planned.  Unfortunately, if you stretch copper, it becomes work-hardened.  Patrick had to redo the annealing several times in between judiciously adjusting the expanders (in three different sizes) and the depth of the various tapered mandrels.  It’s a fine balance between getting the job down sometime today, and pushing it too far and splitting the work piece. 

The rings were to be cut in the Top Shed’s lathe.  This required that the tube be carefully clamped in the chuck and the pipe yoke to prevent it from shifting under tool pressure.  Patrick had a surprise when he couldn’t find a suitable tool and had to try and sharpen one for the job.  The second surprise came when he discovered that the top shop’s pedestal-mounted grinder won’t start up and the power switch is hanging out.  Looks distinctly like a failure and somebody had hopefully done some testing.  Fortunately, the bench grinder halfway along the shop, even with worn stones, at least powers up on demand. 

The cutting job didn’t go so well with a tendency for the copper pipe to run out of true in the lathe’s chuck.  (it is soft material)  Patrick persevered though and not forgetting oil for the yoke and the cutting tool.  The job was finished with a hacksaw and then some careful filing.  The hacksaw, of course, was accurately guided by the deep cut all around the pipe circumference.  You can see the results on Pic F06 above.

Meanwhile, back at the ranch, or between the locomotives, Smudge has unfolded himself from smokebox guts and started to prepare the boiler tubes.  When we did the 15CA, the tubes had expanded ends and they were done with a dolly.  These new 12AR tubes are to be mechanically expanded and beaded – as requirements are that replacement boiler tubes must be re-installed with the same techniques as originally used in the boiler.

Shaun’s primary job was cutting, de-scaling and polishing.  These boiler tubes came in a standard length of 6500mm and needed to be cut down to approx 6000mm.  When one measures boiler tubes, the tape must be passed through tubes in each of the quadrants and the center as sometimes the tube plates aren’t quite straight.  Often they are bowed out slightly in the middle, or may even be bowed inwards.  The cut edges of the tubes have to be 100% straight so the work, as clumsy as it looks with a big grinder, was actually a precision operation.  (Pic BT01 below)  The tube was carefully marked around its circumference with tape before marking with engineering chalk.  There are no spare tubes and thus no chances of fixing up a bad cut.  There have been stories of other steam people stretching tubes that are too short or splicing tubes together – but we Reefsteamers work to a higher standard than that!

The ends of the tubes were then heated to an even medium orange before being allowed to cool naturally.  This anneals the ends, as well as burning off the black protective coating applied by the manufacturer as well as any impurities on the surfaces. 

After the heating, came the meticulous cleaning and polishing with fine graded strips of emery cloth.  The tube ends were cleaned inside and out.  (Pic BT02 above.)

Tube installation started with the installation and expansion of the new copper ferrules in the recently cleaned holes of the tube plate.  Patrick did this with care, after filing down the sharp-ish corners of the tube plate and making doubly sure the mating surfaces were clean.  The ferrules also had to go in dead straight and be of suitable width for the possibly variable width of the tube plate.  The ferrules fitted well enough and required a minimum of tapping to get them in.  (Pic BT03 above)  This was done with frequent checks behind the copper ring for protrusion and it was tapped down to be totally flush with the firebox surface. 

During the day, with various issues and delays, Patrick had only managed to make two new copper rings for fitting as tube ferrules.  (His third ring was the sample) so it looked like only two tubes would be fitted today.  While Shaun was double checking his cleaning (by feel) and preparing to slide the tube in through the front, the expander was in play.  It took quite a few rounds of expansion, adjusting and up-sizing to get the copper ring to crush up evenly against the tube plate.  (BT04)  And somehow you have to stop the tube itself from turning so there’s relative movement between the expander and the tube and so it can screw itself in.  (The fellow at the smoke-box end does the holding)  By modern boiler standards, a large expander has to be used as the ferrule goes around the OUTside diameter of the boiler tube. 

We were ready to try and put a few new tubes in.  They are literally fed in through the front tube plate and because the holes are slightly wider than the tubes, it can tilt downwards as it wriggles through the open space in the boiler.  (Pic BT05 above)  The boys in the firebox have to try and catch the end of the tube with a tool – a pry bar in our case, and feed it into the appropriate hole on our side.  My trusty powerful MagLite torch can actually fir through the tube holes so Patrick and I had the extra luxury of a decent spot light to try and pick up the wavering, dipping end of the tube approaching us.  (Pic BT06 above.)

It wasn’t too difficult to make the catch although, due to the length and the weight of the tube, it’s quite difficult for the fellow at the smokebox end to hold the tube straight and still.  The tubes came in just a tad loose.  There’s a problem visible in Pic BT06 (above) – you can clearly see the scale that got picked up inside the tube as it dipped within the boiler barrel.  This was mainly raked out but the boiler will need cleaning before re-commissioning and testing.  During the first expansion operation, Patrick aborted it due to newly deposited dirt that he found between the tube and the copper ferrule.

The expansion operation went well but was a drawn out affair with frequent adjustments of the tapered awls and switching between two sizes of tube expander.  The unlatched drop grates were open too – so the risk of dropping tools down through into the ash pan added to the interest of the operation.  (On the following day when Lee did some expansion work, we couldn’t get No.1535 ‘Dorothy’s’ drop grates to latch closed – so Lee blocked the open hole with a loose fire bar.)   The drop grates are actually functional, but somehow the grate levers for the Class 12AR locomotive have gone missing.  While the levers from another locomotive mated with the pegs, the angle of the ‘foreign’ lever was such that the handle bumped the boiler backhead before the grate’s latches line up.

Initially one can turn the expander by hand and then with an adjustable spanner.  Then comes the ratchet.  (BT09 above) as the clearances close up and some grunt needs to be put into the full expansion.  But while doing all this, the tube work piece must not be allowed to shift back and forth within the tube plate.  A protrusion between 8mm to 10mm into the firebox is required to make the beading.  Because it’s a circular tube, it only contacts the tube plate on two points.  Thus, in spite of the weight, an un-expanded boiler tube shifts surprisingly easily when it is suspended loosely between the 2 tube plates.  I almost pushed the bottom tube right through on the following day and had to use the expander as a puller to get it out again. 

We ran out of time and only two tubes could be expanded into the firebox end.  It was decided to leave the tools in the firebox and the team would have another go tomorrow – Shaun in the smokebox again and little me handling the tubes in the firebox.  Unfortunately, one of the expanders went astray and we couldn’t finish the job on Sunday either.  Maybe this week….

PROJECT : Hunslet Taylor Shunter engine removal :

Like many jobs at the Depot, the Hunslet Taylor gearbox repair project has become a big strip down project.  While the box of cogs were out, and a new final-drive gear being fabricated for the jack shaft (At Surtees Engineering) , Reefsteamers took the opportunity to fix a long standing irritation with the diesel’s 150HP type LX6 Gardner engine.  It’s an old fashioned 6 cylinder in line pushrod motor – with the cylinder block cast in two blocks of three cylinders each.  There’s a plate at the end of the blocks, which closes in the cooling water jackets.  The front block’s plate was weeping and they are totally inaccessible in between the two engine blocks when the engine is assembled.  Piss poor design – if you get the pun.  It’s only been a slight weep but it has ensured that it’s uneconomical to use antifreeze.  (There’s a lot of rust visible within the water passages.)  And all it would take would be for someone unfamiliar with the fault to start the engine without checking the water first, innocently do some shunting and overheat the engine.  The locomotive does not have a temperature gauge.  This engine’s cooling system is of the old thermo-siphon type and doesn’t have a water pump.  A dangerous characteristic of the thermo siphon system is that if the water level drops below the bottom of the top radiator hose’s entry into radiator’s header tank, the water circulation totally ceases.  This large engine has tolerance of less than a 2 inch drop in the water lever whereas a road vehicles engine would continue to run. 

The oil pump isn’t working properly either.  Dropping the oil pan to reach the pump turned out to be a major awkward job – testing patience to the limit.  It’s been decided to bite the bullet and just take the entire engine out.  There have been some grumbles about the continued stripping and thus the extended unavailability of this shunting engine.  But it’s uneconomical to do just half a job.  For the cost of a bit of extra downtime now we’ll have a solid reliable diesel shunter locomotive for years to come.  Furthermore, this engine has never really been restored – so it needs a lot of work to get it to standard.  And to be honest, it hasn’t really been all that well looked after – often being parked out doors in the weather and the maintenance has been reactive instead of pro-active.  We plan to tidy up the cab, replace the missing windows and to repaint the engine in Hunslet green, with a black under carriage and the buffer beams, rods and counterweights in red.  Should look great when it’s done!

But firstly, some photos of what’s been done for the gearbox. 

The gearbox case has been externally cleaned and the sections loosely stacked (Pic G01 below) but the interior needs to be thoroughly cleaned out as there are still metal filings and shavings in there  All the exterior bearing bosses have been machined to 6mm wider than standard to be able to accept 3mm thick spacer rings.  (Pic G02 below) 

There is evidence that the fixed outer races of the bearings were turning within the case, especially on the bearings with contamination and rust damage. 

As the gearbox casing material isn’t designed to withstand friction – it created an extra wear point between the bearings and the frame as well as within the bearings themselves.  It was the resulting misalignment in the shafts, which naturally tend to separate under geared load, which was causing abnormal gear wear and rough operation. 

It looks as if the gearbox has been removed and stripped before.  The previous mechanics had attempted to resolve the bearing carrier wear problem by putting in thin brass strips as shims between the outer races and the frame.  This is bad practice as it puts uneven stress on the outer bearing race and the shims eventually grind down with the relevant movement anyway.  You can see the tattered remains of one of the spacer shims in Pic G03.  (Above.). 

All the bearings are to be replaced with brand new ones of the original, slightly more expensive, imperial sized bearings.  There was originally a debate about refitting the gearbox with modern metric sized bearings – but the cost of the outer spacers, and then re-machining the shafts, outweighs the advantages. 

The main shaft has been serviced and cleaned up.  The worn splines at the pilot end had been re-chromed and then re-machined.  (Pic G04 below)  Two of the stop nuts had been remade from scratch, using an intact existing one as a pattern.  You can see them at either end of the main shaft in pic G04 and a contrasting pair of loose nuts in Pic G05.  (Below)  These nuts are deeply grooved to accept a large spring clip.

The diesel engine itself has turned out to a bit of a nightmare project for Andrew and Aiden who both would like to get involved in a locomotive boiler removal and refit as a light diversion..  For such an old fashioned engine, which are usually simpler and more accessible, it has a lot of accessibility problems and these fellows have spent many uncomfortable hours sitting on their haunches on the narrow running boards.  (Pic G07 below)  There isn’t enough room to sit on the running boards and put your legs down by the side of the engine, and if you sit cross legged, you can’t get close enough. 

The engine’s bolts are of strange sizes too.  Some old spanners had to be filed thin, and jaw sizes altered to suit.  The photographs were hard to get in the confined space and the fact I was shooting into the work light.  And Aiden was looking a bit grumpy...  But I did get some pictures of the later stages of the operation.

Today (12 July) while Andrew and Aiden were tackling the removal of the oil pan to get to the suspect oil pump, a brand new Reefsteamers member, Lucas Dreyer was tasked with cleaning the removed parts.  He did the job in four stages.  First came the crude oil and dirt wipe.  (Pic G08 above)  The rocker chamber and the pushrod risers were found to be filthy.  In fact, there was no bare, clean cast iron visible.  The extent of the dirt is one reason why Andrew wants to drop the oil pan and also to inspect the oil pickup strainer and blow out all the possibly half-clogged oil galleries.  You can’t run an engine like this as a blocked oil gallery will seize a bearing. 

After a wipe down, both the cylinder block and the head were brushed with paraffin to loosen and shift the oily deposits.  Then they were treated to a WAP high pressure steam wash.  Lucas uses these machines in his place of employment, so he’s been added to the limited list of Reefsteamers permitted to use the WAP machine.  After the WAP steam lance treatment, came the wipe down and dry off.  The oil passages still need cleaning but at least the castings can be inspected.  The inlet and exhaust valves are to be removed as new valve stem guides and oil seals are to be fitted. 

The sump oil pan was a bugger to drop with very stiff and awkwardly sized bolts.  In fact, only the very front and rear bolts (Pic G10 above) were directly accessible from underneath, the most natural location for working on a jacked up engine.  The rest of the bolts had to be undone from the sides with modified spanners, applications of vice grips and the like. 

The sump pan would only go down a few inches and the removal of the oil pump as actually a side-ways caesarian operation through the small gap.  The cute lil’ green critter is rapidly becoming a bit of a monster.

The oil pump came out in the late afternoon and was immediately dismantled.  (Pic G11 above)  Wear in the pump was found to be moderate and the gear teeth have worn sharp.  This means a lower volumetric displacement.  The gear teeth were found to be of helical cut.  It reduces the contact pressure between the teeth and makes for a quieter running device – but it’s an unusual feature in a diesel engine of this vintage.

It seems odd that an oil pump, that runs in oil, would ever wear out but one needs to remember that the oil that is pumped is unfiltered.  Only the gauze pick up screen protects the pump itself.  (The oil filter is always after the pump in the lubrication circuit.)

PROJECT : Sandstone Coach Repairs

The pressure is definitely on for the coaching team and they are creaking a bit as they take some strain.  And I mean that literally – after seeing ‘The Sarge’ limping after wrestling with mounting bolts under coach seats.  Many of our original 2^nd Class main line sleepers are out of action as they are presently being converted into luxury coaches with on-suite bathrooms for the Sitemela Consortium – a new railway touring company.  So we’re a tad short on coaches.  And Lawrence ‘Sputnik’ Posniak, of the South African Railway and Steam Museum (SANRASM) has worked his usual magic and has booked over 600 passengers for our next trip when the new season starts in two weeks. 

On day trips, we would typically use a sleeper compartment as a private compartment to seat up to six adults although eight ‘smalls’ can fit in and the kids can recline on the upper bunk.  But because these compartments are accessed by a corridor, there can be no seating right opposite.  So in the space where a sleeper compartment seats six people – a day sitter coach (basically, a bus) can seat ten.  Because we are limited in the number of vehicles we are allowed to haul, and one of them has to be a water tanker and the power car (with crew accommodation) the seating capacity on a trip is limited.  Take away one or two vehicle ‘slots’ to allow for the kitchen, lounge or bar car and you’re left with about 8 coaches that can earn ticket revenue.

It is high time that the four privately owned coaches that were transferred from Sandstone Estates (Pic C00 above) to earn their rail-space.  Of particular interest in this exercise are the two ex-Sandstone 3^rd class day sitters – each with a maximum seating capacity of 96 people.  For safety and insurance purposes, we can ‘only’ take 76 seated people in each coach, but that’s almost twice as many as a sleeper coach.

These coaches are basically running okay with decent (rather vintage) bogies and brakes.  Before they are put into main line service, they will obviously have to be inspected and running faults put right – but all four coaches behaved well on their last 460km trip from Ficksburg.  They looked decent upon arrival too, with fresh solid red paint jobs and recently painted undercarriages.  However, the interiors are a little ratty from many conversions, the interior floors have delaminated and some of the seats are in poor shape. 

Perhaps the most time consuming problem is that the toilets had been blanked off with sheet metal over the doors – and we had some unpleasant (but non-organic) surprises when opening up the toilet compartments once more.  It wasn’t really an optional job though, as 150 plus passengers without toilets could be nasty.  One of the gangways had been blocked off too – for service at the end of the train – instead of the proper double-leaf vestibule doors and the external man-gate as used by SAR.

The Reefsteamers started this project last week after the coaches had been shunted out into the open after the elliptical roofs had been re-painted.  The original roofs were painted silver.  They have since been repainted dark grey with weatherproof polyurethane paint.  (Pic C01 below)   

Victor did the painting – he started as a casual labourer but due to his reliability and skill, he has since become a permanent employee.  He also masked out the sides and applied the French grey strip that runs alongside the windows.  The original paint job was solid gulf red all over.  As the paint was in good condition, it just needed cleaning before applying the masking.  After the painting, the high mounted marker lights, the bogies and the center lamp shields would be the only end feature that would easily distinguish the ex Sandstone Coaches.