Introduction :

Work continues on the Class 12AR No.1535 ‘Susan’ with the addition of two more boiler tubes being found to have thinned out and needing removal.  The lil’ green critter, aka, the 150HP Hunslet Taylor Shunter was also one of the spanner stars for the day, with both the locomotive and the spread out bits being worked on.

We had a reasonable turn out of Reefsteamers, remarkable for a day when we had a train out on the high irons.

PROJECT – Hunslet Taylor Gear Box Assembly :  (2 August)

My gearboxes don’t leak!

Andrew King

Some work has started on getting the cog-box back together again for the Hunslet Taylor shunter.  So while Mister Berry & Son were working on removing the engine hood and door braces, and disconnecting the four engine mountings, to clear the engine for removal, the gearbox reassembly project was on the go.  Unfortunately, the day’s project ended up stymied with a binding jack shaft gear and a grumpy Chief Engineer.  (Well, grumpier than usual, anyway.)

The jack shaft assembly had arrived in state at mid-day two weeks ago from Surtees Engineering Works.  Andrew had taken half the depot day off to fetch the shaft.  The newly fabricated jack shaft gear had been pressed onto the shaft, the bearings replaced with a brand new set with self adjusting barrel rollers, the counter weights had been pressed and keyed back on and the drive rod pins had been polished.  To get the shaft off-loaded, the bakkie (Pickup) had to be reversed into the workshop ramp, bouncing over a set of wooden sleepers and hanging four on a 30 degree slope under the overhead walkway.  This was, of course, to be able to suspend a block and tackle from the walkway‘s structure to get the load off the vehicle.  We could have man-handled the shaft off the vehicle with enough people, slings and cross bars – but as solid and as indestructible as the shaft assembly looks, a single drop would damage that new gear.

The hoist gang got the asymmetrical load reasonably balanced on the third attempt (Pic J01 above) – that asymmetrically positioned drive gear inconveniently adding a lot of weight to one end of the load.  Andrew got the bakkie out from under the dangling load on the second attempt – literally using sleepers as stepping stones.  My respect for Isuzu went up a few notches.  And I’ll never lend my cute little city car to any of these people!  There’s a story that’s been doing the rounds; of a rented Toyota Tazz that did 140kph all the way from Jo’berg to Port Elizabeth with literally half a ton of steam locomotive spares on board!  **Cough**  Maurer!  **Cough!**

While the Chief Engineer was doing a stint of rubber-tired bronco busting, and Aiden McCarthy n’ me standing well clear and up-slope from this ominously dangling load, the nose-pivoted trolley was made ready.  Andreas Mathee did the honours and threw out everything he personally had in anchors to hold the load on the slope while the heavy load came down onto the load deck.  (Pic J02 above) 

These trolleys can sometimes be difficult to control as you have to hold the pivoted handle downwards as well as brake the load.  If the handle slips upwards, you stand to lose a few teeth.  The beautiful newly cut gear was protected with a fresh soft knotty pine palette, with one counter weight lying very conveniently in a slot left by a missing deck plank on the trolley.  Andrew and Aiden (especially Aiden) acted as drag anchors to get this lot down the slope.  The jack shaft tried to roll off sideways at the lower end as the opposite counter weight, at 90 degrees, flirted with gravity and its weight pulled the shaft around.  (Pic J03 above)  Three fellows struggled to control the trolley, act as drogue anchors and turn the shaft into a safe position, all at the same time – but they managed.  They trundled the shaft into the assembly shop with no chipped gear teeth and no fresh dents on the concrete slab. 

This week’s re-assembly work (2^nd August) started with the clearing up of the assembly area.  (pic J04 above)  This diesel locomotive’s gearbox is built like a cast iron layer cake, with the frame built from four stacked sections.  That makes for a lot of heavy parts lying around from where the outer bearing race spacers were being confirmed for fit in the newly oversize-machined shaft apertures.  Johann Breydenbach and Mark Berry did the initial clean up (Pic J04 below) using the 450kg column hoist.  (Pic J05 above)  The crawler beam was almost to the end of its run and that beam was quivering under the weight.  (But still within capacity)  Great care was taken with slings and where we were standing.

The rail trestles were brought out (last used under the Steam Crane’s Boiler) and with no further ado, the sump pan of the gearbox was hoisted out and laid flat.  Mark Berry ended up back on working on stripping the engine hood and door supports on the Hunslet Shunter itself, while Andrew King joined Johann Breydenbach and they got stuck in.  The oil pan was carefully cleaned out on all the inside surfaces and the sealing surfaces scraped down and degreased.  (Pic J06 above)  What looks like a depressed sump-oil reservoir (left of pic) is actually primarily a recess in which the large jackshaft gear runs. 

The jackshaft was then carefully slung up and hoisted several times until it would lay reasonably horizontal – no mean feat with such a heavy gear offset 2/3 along the shaft.  Johann took the opportunity to clean up the gear teeth with the shaft blocked up at knee height.  (Pic J07 above)  Then Andrew did something that looked a little odd – he lined up the shaft exactly over the bearing runs and then swung it away again.  (Pic J08 above)  

When he swung the suspended load out the way, he was careful not to move the chain tackle along the crawler beam – relying wholly on the radial swing of the hoist to clear the shaft.  We’d be using LockTite to help bind the outer bearing races.  But after application and smear session, it would be important to get the shaft bedded into the frame as quickly as possible before the LockTite dried and cured.  With this method, it would be much quicker to line up the heavy dangling shaft simply by swinging the radial arm of the hoist and not having to adjust the crawler as well.  The gift-bearings were then unwrapped from their cloth wrappings and checked for cracks and deformations, and basically just played with.  These are self aligning roller bearings and are able to run with the outer races slightly tilted.  Because this shaft drives a pair of cranks, the reaction against the train’s load will act at a point that constantly rotates around the bearing, 90 degrees to the crank.  These bearings will be able to constantly re-set their alignment, and that of the shaft, with the shifting, rotating reaction from the load. 

With the bearings played with, and a final wipe of the bearing shells, the LockTite came out and was rubbed into those saddles but definitely NOT licked off the fingers.  (Pic B10 below)  With that the shaft could be gently lowered into place and the bearings seated home.  (Pic B11 below)  The bearings were gently nudged inwards with a short, clean tommy bar levered against the counterweights. 

A problem arose because one end appeared to have too big a gap, and the seal cover wouldn’t be able to be screwed home against the protruding bearing.  (Pic B12 below)  Andrew wasn’t at all happy and probably quelling feelings of internal panic as he inspected the shaft and the bearings on both sides.  According to the visible marks on the shaft though, the bearings had been pressed into the correct locations.  It turned out that the entire shaft was originally built with the bearings slightly too far apart and it had settled in slightly offset along the longitudinal axis.  There was nothing for it but to hoist the shaft out again – from the half dry LockTite, which had already established quite an impressive grip on those outer races.  On the second alignment, both bearings were seated with sufficient clearance to be able to bolt their circular end covers in place. 

With the shaft in place and freely spinning, Lee was tasked with priming those new bearings with an oil can to get some oil on those rollers and spread around inside the races.  (These weren’t pre-packed bearings.)  A beautiful fine-nozzled antique valve-equipped oil can, courtesy of Patrick Ackerman, did the trick.  (Pic B13 below)  We fed oil onto the bearings with Andrew gently turning the heavy jack shaft over.  I even filled up the oil can before handing it back – scavenging for MH oil from mainly empty loco oil cans seeing that the oil drum was empty.

The second frame was then hoisted (Pic J14 below) and set up in an upside down position upon wooden blocks on the floor.  We scraped off the bare-metal sealing surfaces, (Pic J15 below) with some fine filing on the seriously crusty bits, before watching King do the cake decorating act with a tube of silicone sealer.  The caulkin gun appears to have disappeared, so Andrew simply pushed an adjustable spanner into the cartridge with the head pressing into his tummy.  He then pulled the cartridge back against his own stomach muscles (Behind his belt buckle) to extrude the silicone bead … talk about macho tummy crunches.  As I’ve said before, this little grey haired fella is a tough old rivet. 

I made some comments about potential oil seepage, aka, automatic built in locomotive frame rust proofing protection, which was the source of the quote at the start of this section! 

The center portion of the frame, the base frame, went onto the sump pan with little trouble but naturally needed some alignment.  (Pic J16 below)  This is the section of the gearbox frame that actually bolts into the locomotive’s frame plates.  Luckily the still semi-liquid silicone sealer provided some impromptu lubrication, and it was easy to line this heavy section up using the massive bolts through the jackshaft bearing cradles and the matching bearing caps. 

A nasty surprise ensued because the previously freely moving jackshaft had locked up tighter than a politician’s purse.  That’s always bad news as it usually indicates that a bearing has been crushed somewhere.  However, in this case, it turns out that the main gear for the jackshaft was slightly out of place.  It protrudes through a built in tooth guard into the base frame and was actually binding right up against the frame’s side wall.  (Pic J17 below)  Very disappointing and maddening. 

In similar fashion to the bearing displacement issue, the shaft was checked again and it turns out that the gear is properly located on its original marks.  But it always was slightly offset.  (Pic J18 above)  It turns out that the shaft and gear placements weren’t measured against the counterweights when the gearbox was dismantled by the day staff, and when Surtees used their 400 ton press to get the gear back on, and using the original marks for alignment, they innocently replicated the mistake.  The gear needs to be moved about 6mm but we don’t have the equipment to do this.  So the entire shaft has to go back to Surtees Engineering for a another game of 400 ton patty-cake

Thus, a grumbling and slightly despondent Andrew King had the delightful task of dismantling the day’s work.  He’s been itching for three weeks to get the job done only to have this set-back. 

Dismantling included the extra chores of cleaning the half-cured silicone off the mating surfaces and scraping the remains of the LockTite from the bearing saddles.  So it was a disappointing end to an afternoon’s work – but a potentially serious problem was found before gearbox assembly continued much further.  Imagine the waste of time and damage if the gear was found to be displaced after the gearbox had been assembled or even reinstalled between the loco frames. 

PROJECT : Hunslet Taylor Hood removal :

The lil’ green critter is to have the entire engine removed.  The suspected dirty oil galleries need to be cleaned out and of course, all the bearings and seals inspected.  The three pistons already exposed by the withdrawal of the rear engine block are to be treated to a new set of piston rings.  This being a diesel, a compression ignition engine, the condition of the piston rings is quite critical.  However, only replacing the piston rings on the rear three of the six cylinders will result in the rear half the crankshaft being subjected to higher compression and higher combustion pressure from cylinders that are running more efficiently.  This would impose a torsional stress on the crankshaft at the center bearing and lead to failure down the line. 

The engine cannot be withdrawn through the frames and neither can it be moved sideways.  It has to be hoisted upwards.  Thus, the green engine hood had to be removed.  Although the engine cowling and hood assembly may resemble that of an oversized old fashioned truck, the hood doesn’t hinge.  It is bolted and bolted and bolted and bolted and bolted in place with several dozen rather crusty bolts.  The hood was removed three weeks ago at the end of a quiet Saturday and was quite an aggravating job.  The basic game plan was to fire up the battered but useful LPG-powered Hyster forklift, bring it in perpendicular to the hood (Pic H01 below), and couple the tines to the central lifting-eye.  (Just in front of the shunter’s bell.).  (Pic H02 below)

Getting the bolts off the hood was an exercise in contortionism.  This simple little engine cover is massively over engineered – it’s almost as if Hunslet thought it might fly off over the cab at the blinding fast shunting speed of 15kph.  As is becoming usual with this particular locomotive, the bolts were of odd sizes and most of them quite awkward to get at.  The side brace bolts were easy enough, albeit with restricted swing on the spanners.  The rear bolts on the scuttle are hidden behind the diesel fuel tank, while the front bolts are nestled deeply in around the radiator and the fan cowling.  The exhaust stack’s upper bracket was removed and the stack pulled downwards into the engine bay.  (Pic H03 above)  Odd enough, although exhaust bolts on any vehicle are usually rusted and seized, these ones unscrewed by hand tools only.  Although the exhaust stack stands in line with the front three cylinders, which are still bolted down and intact, both the exhaust and induction manifolds are full length six-way units.  So the entire engine was innocent of manifolds, even though only the back three cylinders had been dismantled, and the exhaust stack was able to conveniently slide most of the way down into the manifold space.  You can see it in the retracted position in Pic H06 below.)

The vertical brace bolts along the hood were fairly simple.  The scuttle plate bolts were more awkward needing an individual in the cab to hold the heads.  The bolts in the rear corners, though, were seized and had to be cut out.  (Pic H04 below)  The faded forest green paintwork is now scorched and has burn streaks on it – but the shunter is to be completely repainted anyway.  The front bolts were seized as well and it was a weird sight to see the smoke wafting up through the riveted seems as the torch work was going on within.  The front bolts were badly obscured by the radiator’s header tank and no bolts could be found in the center line – which seemed odd and basically just too good to be true. 

The first attempt at lifting the hood with the forklift tines was a failure.  The forklift itself just about stalled trying to drive its own load-locked hydraulics, and the over-sized front tires visibly depressed as the poor little Hyster was basically trying to lift the entire locomotive.  Hunslet - 1.  Hyster - 0.  Interesting that the manky old hood bolts withstood the traction.  The missed bolts were undone and on the second attempt, the tension was unbearable.  The rust holding the rear end of the hood sheared (Pic H05 above) and it suddenly let loose and came up with quite a loud bang and a vicious jerk.  (Pic H06 above)  Luckily the rounded front of the hood wasn’t distorted.  We were also lucky not to smash the glass panes of the windscreen.  Although they are to be replaced, we’d rather not have scattered glass fragments decorating the workshop bays, thank you very much. 

With the engine hood sprung at the rear end, the front end looked ominously like the radiator would have to be removed, along with its necessarily large thermo-siphon top-tank and the deep fan cowling.  But that doesn’t really make sense to have to dismantle engine opponents to remove the hood.  Even Hunslet wouldn’t build a locomotive that badly!  Because of the tight clearances at the front end, we were working blind.  Technology came to our aid – my digital camera (both of them actually) has a pivoting and tilting LCD feedback display.  We set the LCD screen at 90 degrees ands used the camera optics to look around 90 degrees, right into the tight space in front of the header tank, with a torch shining up alongside the radiator.  The extra bolts were found – higher than expended and it turns out that the bolts that hold the ‘Hunslet’ script nose-badge also hold the hood down at the front end.  Naturally, they were dreadfully rusty – 56 years of rain water running down between the hood’s front bevel and the cast iron badge would have that effect.

Andrew ‘Noddy’ King did the torching, being very careful not to damage the precious cast iron Hunslet badge.  (Pic H07 below.)  That badge, behind the weathered, peeled paint, and the fresh scorch marks, is a beautiful casting and it was being looked at with envious eyes for wall décor!  Dr. ‘Smudge’ Ackerman, himself a collector of railway themed badges and name plates, jokingly laid down the line.  But maybe we can make a replica of this name plate... 

Because the bolts could only be cut flush with the badge and not the hood, the cut off bolts would obstruct the hood from being lifted.  So the hood had to be wriggled and walked forward on the vertical braces to help break the rust bond and to clear the protruding bolts.  The hood came off literally with a pop and it swiveled upwards at the front end without knocking anyone’s teeth out.  (Pic H09 below)  You can clearly see the rusty front plate that is normally inaccessible behind the radiator header tank.

The suspended load was a bit tricky to get out as the forklift had to be reversed at full steering lock.  The dismantled components had been thoughtlessly put in the turning arc so there was a mad scramble to get everything out of the way.  (Pic H10 below)  The GMAM Garratt No.4079 ‘Lyndie Lou’ got a gentle flank-on love-tap, but we avoided putting the hood through the cab windows and the wind deflectors.  It took three Reefsteamers and a forklift to walk the hood out and to put it safely out of the way in the open workshop yard.  (Pic H11 below)

What a palaver!

The next time you have to open your car’s hood (or bonnet), appreciate the fact that all you have to do is pull the release, uncouple the safety latch at the front end and swing it up on HINGES.  What a luxury!

The hood saga continued last week (2^nd August) with Mark Berry and his son, Ryan, being tasked to remove the side braces, the diesel fuel tank and to uncouple the engine mountings.  It was a simple sounding job complicated by bolts deeply recessed between flange webs and the now expected Hunslet assortment of odd bolt sizes.  They tackled the engine mountings first.  The engine is mounted on four pads, one at each corner and each with two bolts.  There are no rubber cushions.  (Pic H12 above)

It’s always great to see a father and son work together.  Ryan ended up working from the walkways (Pic H12 below) being smaller and more agile than his dad – who provided the torque and the technical expertise.  Because they worked on uncoupled the engine mountings first (as higher priority) the four vertical supports restricted the swing of the tommy bars.  (Pic H14 below)  The deck was completely cleared by the end of the day with the four vertical braces being removed and the diesel tank being nothing more than an empty space.  The last two remaining control rods had been removed (for the injector pump)   Apart from the radiator cowling and the hoses, and the starter motor\battery cables needing to be bundled up this engine is ready to be lifted for strip down and a good old fashioned Reefsteamers quality overhaul.

PROJECT : Diesel Shunter crown wheel gear stripping.

Yeah, more Hunslet work. 

This job is interesting to note as it shows how we Reefsteamers are not shy to IMPROVE the original engineering and design of our locomotives and rolling stock.  In this case, we are fixing up a poorly done modification as well.  The Vesconite™ bearing retrofit program is an ongoing example, but here is an interesting case of modifying original poor design in a 56 year old diesel locomotive gearbox.  (Pic G01 below)

Back in May, during the evisceration of the gearbox’s giblets, the crown wheel and dog clutch set wouldn’t come apart – even after being locked in a pipe vice and heated to try to break the grip through thermal expansion.  (Pic G02 below)  This locomotive’s gearbox has been modified over the years and the original reverse gear and friction clutch has long since been removed.  In the current drive train, the reverse gear set comes first (incorporated into the retro-fit torque converter), a short universal jointed drive shaft and then a set of original high and low speed gears.  There was a clutch and a reverse gear train up on the crown wheel shaft.  However, on this particular locomotive, the forward gear crown wheel gear has been locked permanently to its shaft via its dog clutch, the second beveled crown wheel omitted altogether and the extra gear linkages removed, making this gearbox a two speed single direction unit.  The reverse gear is provided (at 1:1 ratio) by the torque converter bolted directly to the engine. 

You can see the locked bevel gear in situ in Pic G01 below.  Notice that the dog clutch is permanently engaged and the other side of the dog clutch, as modified, never engages anything.  Those odd looking braces occupy the space where a second bevel gear would have been for reversing.  The retro-fitted ‘braces’ are actually oil channels designed to pick up oil dripping down the crown wheel and channel it through to the bearing at the outer end of the shaft.  This shaft, which would normally be a secondary main shaft after the 2-range gear set, is now simply used as an intermediate shaft.

This is a constant mesh gearbox, the same basic principle as used for motor car gearboxes except it doesn’t have the refinement of synchromesh and baulk rings of course.  In a constant mesh gearbox, the various selectable gears that are used to transmit the power are actually mounted on their shafts with bearings, and can spin freely on the shaft like a doughnut spinning on a broomstick.  But they cannot move longitudinally.  The dog clutch, is splined to the shaft and thus does not rotate freely – but it can slide up and down longitudinally.  When the dog clutch is shifted along the shaft by the selector fork, the axial teeth of the dog clutch engage the matching internal axial teeth on the gear.  The free running gear is thus now locked to the shaft by means of the dog clutch’s splines and can now transmit torque.  The other, unused gears remain engaged at their gear teeth (hence the term ‘Constant Mesh’) but they rotate at different speeds AROUND the shaft and not with it.  In a modern car gearbox, when you’re in top gear, the 1^st-4^th gears are all still driven by the engine and are revolving simultaneously at different speed around the main shaft while only one gear at a time is locked to the shaft and transmitting power.  The colloquial term ‘gear shift’ is actually incorrect and should be ‘gear selector.’  It is actually impossible to grate the forward gears of a car (or this locomotive) as they are always engaged.  It is the clashing teeth of the dog clutches that make that grinding sound.  (The only gear that is physically shifted is the reverse gear pinion.)

In the modified Hunslet loco gearbox, that permanently engaged bevel gear and dog-clutch combination was left with the roller bearing that would normally allow it to revolve freely around the shaft when the other bevel gear would be selected in a two speed version of this gearbox.  (Pic G03 above)  That ball bearing, although it hasn’t been rotating between the gear and the haft, has become worn and the stationary hardened rollers have indented the bearing races over the years.  This is allowing the locked bevel gear to tilt on its shaft, with the torque reaction.  An engineering principle is that a set of gears (and their shafts) always try to move apart under torque reaction.  The displacement in the shafts (or the bevel in this case) upsets the mesh pattern of the gear teeth.  This gearbox has been cut with involuted teeth of which their profiles maintain a point of contact at a constant radius from the shaft centerline as the teeth rotate in and out of mesh.  Spread shafts (or a tilted gear) results in a pulsating drive and the stress moving to the thinner, weaker parts of the teeth and premature disengagement of mesh of the individual gear teeth.  The result is the teeth start to chip and round off, the damaged teeth damage other gear teeth and you eventually end up with a stripped gear.

Although the crown wheel is still in reasonably good shape (Pic G00 far above), it would be false economy to reassemble the gearbox with those worn bearings, only to have the crown wheel damaged a year or two down the line.  The actual work started with the cleaning of the gear and removal of the roller bearings themselves.  They were, naturally destroyed in the process and left their indented outer races within the gear’s core.  The project is to re-assemble the intermediate shaft with the locked crown wheel supported on a nice solid bush the exact size of the unused roller bearings. 

Andrew King and Johann Breydenbach did the strip down.  The project proper started with removal of the spacer rings that ran outside of the bearing races.  A cold chisel was used to make three notches 120 degrees apart in the spacer.  (Pic G04 above)   Then the acetylene torch was applied to destroy the tempering of the steel of the spacer rings (Pic G05 above) – with deeper, localized heat penetration at the notches.  This facilitated further chiseling – with Johann holding onto that bucking gear for dear life, and the spacer ring eventually came out in two pieces.  (Pic G06 above)  It took much prying and whacking to break through the spacer and then to bend the halves inwards, as the ring of dog teeth prevented the drift from being tilted inwards.

The spacer ring was difficult to get out because the diameter was wider than that of the inward pointing dog teeth.  But the bearing races are of smaller diameter (otherwise you couldn’t fit the bearings in the first place.)  Getting them out was a matter of ‘springing’ the grip and then tapping them out from the other side.  The lipped outer race (Pic G07 above) was quite convenient as a drifting point.  The intercostal spacer, freed up by the removal of one bearing race, could now be slipped loose.  (Pic G08 above)  This component, originally used to hold the outer bearing races apart, it to be re-used to hold the new blank bushes apart.

James has already started selecting and cutting down cylindrical stock to make two blank bushes to support the crown wheel.  (Pic G09 above)  He’s basically making dummy bearings and those bushes should last forever.  Internal diameter is 95.25mm and the other is 171.46 and the thickness is to be 28.6.  The bushes are to be machined to a tolerance of 0.02mm!  But hat is an accuracy of work that comes naturally to our senior machinist, James Thomson.  You can see the start of the process in Pic G10 below, using the lathe’s tailstock to start drilling the center hole for the shaft.

PROJECT – 12AR Boiler tubes ;

Let’s see how thin the boiler tube is…

Patrick Ackerman

The boiler tubes for the Class 12AR No.1535 have been replaced, including an extra two that were found to have thinned out at the Smokebox end.  What is interesting about this job is that none of the men who did the work are over the age of 30. 

For a detailed description of the boiler tube operation, you need to read the last issue of the depot report.  I’m NOT writing all that lot again!  :o)

We lost a day’s schedule on the job as Shaun and Lee were to expand and fit the new tubes on a Sunday.  Unfortunately, the right sized expander had been locked away and we couldn’t track down the keys.  However, the delay was made up for the following weekend with two half expanded tubes being fully expanded and 4 new tubes being fitted from scratch.  

All the expanders were available today.  (Pic B01 below)  A range of four expanders and four mandrels were used.  As the various sized mandrels are all interchangeable with the expanders, This gives the operator 16 combinations.  Dawie and Patrick saved time using pneumatic assistance to both expand the copper pipe from which the ferrules would be made and later to expand the tubes within the tube plate.  You can see the very low-geared pneumatic motor in use in Pic B02 (Below)  The boiler boyz used the 7 ton Dean Smith lathe once more as a pipe vice. 

The operation went much quicker with pneumatic power (Pic B03 below) even though the motor isn’t running optimally.  Because of the increased rate of work, special care was made to keep the copper annealed – it told at the end of the day when the oxygen gas bottle prematurely ran dry!

In the smoke box, the two tubes that had been already fitted were not expanded at the smokebox end – as they protruded a little too far.  So the protruded ends were carefully ground down straight and even with the existing tubes.  (Pic b04 below)

Andreas Mathee came walking in for his Depot Day and he joined the boiler team ... and wouldn’t be clean again for the next 7 hours!  The youngsters got going with expanding the copper ferrules and cutting fresh tubes at the same time.  With the pneumatic ,machinery, expanding the remaining 5 ferrules (Pic B05 below) was quite easy – although the firebox stank of oily exhaust air.  It filmed up my camera lenses too, so I had to get out of there and clean up my optical gear.

Patrick Ackerman had brought in ‘The Bread Slicer’ for speedier cutting of the other tubes.  (Pic B06 below)  Although the could only be annealed at one end at a time (pic B07 below), ‘cuz we only have one acetylene torch, the dressing, descaling and polishing of the tube ends could be done at both ends simultaneously, which speeded up operations.

With plenty of sandpaper strips being on hand, the polishing went well.  (Pic B08 below)  The tubes went into the boiler with little incident.  (Pic B09 below)  Even author Paul Hloben, when he came in the afternoon, has a go at feeding a tube in.  The air motor came in useful to snug up the tube at both ends.  But the final expansion had to be done by hand as the motor had insufficient torque to complete the job to satisfaction. 

I wasn’t around to take photos of the smokebox end work being done.  But I was around to catch some photos of the firebox ends of the tubes being expanded.  The firebox end is done first.  Andreas was careful to ensure that the tube and the expander were well oiled.  (Pic B10 below )  Then he used a vernier caliper to measure the depth of the tube’s protrusion – which must be between 8-10mm for effective beading and welding.  (Pic B11 below)  An over-length tube can be ground down, but one that is too short basically means the tube has to be pulled out and replaced.  When the tube was 9mm out – Patrick clamped onto the other end with a vice grip and a large screwdriver as a tommy bay to stop the tube from rotating and moving inwards.  While one has leeway in fast set up at the smokebox end, one has to be careful to set things up slowly at the firebox end before the tube starts to grip within the ferrule.  (Pic B12 below)  Applying the air tool prematurely would overwhelm the grip the fellow at the other end and might push the tube right through into the boiler cavity. 

The expansion work, primarily done by Dawie and later, Andres, went with little trouble.  However, the finishing work had to be done by hand and a heavy ratchet.  But because the pneumatic motor wouldn’t be used for the full expansion work, it could be operated by one person.  (Pic B13 below) 

Two of the non-removed tubes had suspect looking ends, one of them definitely looking a bit ragged form a mixture of abrasive blast and corrosion.  It was quite obvious after some exploratory tapping during the process of latching onto the other end of tube No.7.  (Pic B14 below)  When Andreas finished his expanding and the smokebox end of the tube was fully seated in, Patrick ground back the ragged tube to check the thickness of the material.

What he saw wasn’t good and he called the Chief Engineer in for advice.  Andrew condemned the tube and so it was to be withdrawn – just when we thought we’d finished the job!  Andreas got to work with a small angle grinder, to cut away the rolled over bead at the firebox end.  (Pic B15 above)  It’s a nasty, noisy job and delicate too as you can’t cut notches and grooves into the tube plate.  Meanwhile Patrick fired up the torch and worked on cutting groves at the top and the bottom of the tube at the smokebox end.  With grooves cut in, the tube would collapse with the use of a chisel.  Naturally, one mustn’t torch a notch into the tube plate.  The process involved using the sides of the acetylene flame instead of the tip and center.  (Pic B16 below) 

7 tubes were replaced and two more tubes were withdrawn , so the boiler project isn’t quite done just yet!

PROJECT : Perimeter fencing project – new gates :

By Depot-Day, 2^nd August, the 5 new gates had been fabricated.  Andre van Dyk spent the day welding and supervising his brand new fencing team.  Newly joined Reefsteamers members Miles Buckton and Richard Marshall were put to work – probably a bit surprised at it not being locomotive work, but they did the job in good spirits.  Two gates had already been built and by the end of the day, three more gates had been fabricated from scratch and stacked against the walls.

As usual, the gates are being fabricated from scrap super heater elements.  However, stocks are running a little low and some conventional scrap piping (from a compressed air line) was used for cross braces.  Cutting of the main frames was done on a semi-mass-production basis with Miles wrestling the grinder and Andre acting as a highly skilled self-propelled work-weight.  (Pic F01 below)  The ends of the tubes were flattened for welding in the 50 ton press and welding done with an inverter welder.  The vertical sections were left circular but the horizontals and the diagonal braces all have flattened ends.  (Pic F02 below) 

Welding is thus along the full length of the flattened end that buts against the sides of the cylindrical verticals – these gates are going to be tough!  (Pic F03 below)  However, these gates won’t be locomotive proof.  But they won’t sag under their own weight – which is definitely irritating when you have to lift a sagging gate off from the rail heads to swing it around.  It’s even more irritating when a sagging gate tends to swing closed again, just as you are trying to roll a hundred tons plus of steamed steel between the gate posts. 

The gate gang were careful to get the gates square – using the diagonal measurements to proof and square the gates.  The fact that the other guys didn’t have welding masks slowed the job down a bit as they had to frequently stop work and face away from the welding arc.  (Pic F04 below)  The gate joints and diagonals were seam welded along one side and then, after confirmation of squareness, the gates were lifted on end and welded on the opposite side, especially at the braces.  (Pic F05 below)

‘Pops’ Frans van Dyk fabricated the three latch frames from a length of the pre stamped angle iron that were made as conductor carriers.  He was working at the main machine shop vice and usefully so, for he was also fabricating a seriously delicious chicken curry and was in close proximity to the kitchen.  The latch frames are not of welded sections.  They were slit down a web at 45 degrees and then bent in the vice.  (Pic F07 below) 

Miles and Richard had the repetitive job of mounting the insulators – using 90 of them – 15 per pole.  As these poles weren’t stamped, they marked a master pole with engineering chalk, drilled it out and then used the poles to transfer measurements.  (Pic F08 below)  These poor schnooks, on their first day at the depot, had to drill at least 90 small bore holes in circular section high grade steel.  The number of broken drill bits is off the record.  (I didn’t dare ask!)

The insulators were mounted with cadmium plated self-threading pins – and were applied with the drill.  It would have been dreadful work tapping the bolt holes by hand.  Even so, the drill worked jolly hard and some of the holes ended up with stripped thread, so fresh holes has to be made.  It’s not the fault of our guys, or the bolts, for that matter.  It’s just that the steel of the tubes is harder and thicker than the mild steel that you would normally find being used by electric fencing contractors.  The five gates were completed by sundown and stored next to the grinding station.  (Pic f11 below)

PROJECT : Catering :

People that love steam engines .will often put other talents into use apart from the footplate and the mechanical work.  Andre van Dyk is one of these, and he has proven to have a talent for bunk-house style cooking.  He also gets good deals on ‘bosveldt’ foods, particularly the meats.  Andre has, in fact, been cooking lunches for the Reefsteamers over the last year and a further fact that not many have realized, he has been feeding the entire club at his own monetary cost.

Thanks, Andre!

After a hard morning’s work, it’s pleasant to have a hot lunch to look forward to.  The arrangements were initially rather casual, which meant that we often went the whole day on a few biscuits.  This had been discussed and it was determined to properly feed the depot teams on Saturdays – but that it’s the least the club could do is provide food for those volunteers who have given freely of their own time.  It was determined then by the board to put a part of the monthly budget towards lunches and Andre van Dyk has committed to arranging ingredients and doing the cooking.  So we’ll be getting a warm meal every Saturday and usually a BBQ (Braai) on Sundays.  We usually do this on a bring-n’-braai basis or give Andre 20 bucks or so for the meat n’ bread.  Reefsteamers lunches are usually very social occasions!

For the benefit of overseas readers, a typical Reefsteamers meal, shown below in CS01, is what we call ‘wors and sous.’  (‘Wors’ is pronounced ‘v-w-orr-s’)  The sausages are what we call ‘Boerewors’, which is a spicy coarse grained ‘farmer’s sausage.’  There are many inferior knockoffs out there, but good quality Boerewors is hard to beat.  The white stuff is ‘pap’, a stiff maize meal porridge.  It is the staple starch of the African population but popular as a casual meal ingredient amongst the whites too.  In of itself, it can be stodgy stuff with little flavour.  And badly cooked ‘pap’ can be used to seal brake vacuum lines and smokebox leaks.  But its neutral flavour goes well with everything and it’s great accompanied with gravies or stews.  The sous, literally ‘Sauce’ or more correctly, ‘gravy’ is Andre’s specialty – sometimes curry, sometimes savoury, sometimes sweet n’ spicy, and sometimes blow-off-the-top-off-your–cranium chilli.  This kind of food cooks with little supervision, so this chef can leave the kitchen to do some work in the depot while lunch is going!  (Pic CS02 below)

It’s worth coming to the depot just for Saturday lunch!

Although we’ve seen a lot of Andre lately, as he’s the Project Manager for the fencing, his ability to be available on depot days is a bit cyclic.  Andre has a demanding IT job and is one of the few Reefsteamers with a young, growing family.  (Most of us are either single or widowed.)  It’s been frustrating for him, and for us, who need every pair of capable hands we can get.  But with the catering job, he can still be involved even on days that he has to be at home, or doing IT work.  He sometimes cooks at home and brings the food in at about mid day.  So our Mr. van Dyk is fast becoming one of the most popular men at the Depot over the next few months.

Actually, Frans van Dyk, Andre’s dad, made lunch last week – a piquant sweet fresh chicken curry and rice.  It was fantastic and I felt sorry for the 12AR boiler tube boys who took too long to extract themselves from the loco’s innards and pitched up while nearly everyone else were nearly finished.  Even Andrew King, who usually eats like a budgie on a hunger strike, had seconds!  (Pic CS03 above)  It’s clear to see where Andre got his talent from, as Pops Frans van Dyk has the same

PROJECT -  Sandstone Coach Re-Wiring (220V) :

Fred Sewell is cool!

A bit crusty at times … but generally cool. 

Not many people can rewire a coach in one afternoon – including tea breaks!

He’s done so many coaches in his time at the Steamreefers that he confidently approached this old creak box with a fully laid-on pre-prepared coach wiring kit and had the interior cabin lighting circuits all tested and running on 220V by the time evening came around.  Our own coaches, sleepers and day-sitters alike, have all gradually been converted to 220V mains power, from the original 24V DC power.  The SAR coaches used to run with massive lead-acid battery racks under-slung from their bellies, and self tensioned dynamos driven by belts running from one of the inner bogie axles.  Thus, the trains would switch from generator power while moving to battery backup when standing still. 

The systems had inherent problems.  Firstly the weight of the generators and wet-electrolyte lead-acid batteries added materially to the weight of the coaches.  The batteries, their terminals and their external cell bridges all needed maintenance.  The dynamos and belts themselves would be maintenance items with the bearings, commutators and brushes all needing attention.  And just like the dynamo in cars of that era, there would also have to be an electromagnetic regulator for over current, over voltage and the cut-out contacts.  The cut-outs were fitted so the electric current from the batteries would not be able to turn the dynamos over like a motor, when the dynamo voltage dropped under that at the battery terminals with the train at standstill. 

The lights themselves were prone to trouble.  The open type coaches, such as dining cars and day sitters, had their 24V inverters mounted inside their DB enclosures but some vehicles had local inverters inconveniently hidden behind panels.  The older discrete-component transistorized units were prone to failure, and an inverter driven lamp uses more energy anyway.  (Due to the extra losses involved in driving the inverter’s oscillator and transformer set.)  Lastly, a low voltage system inherently requires higher currents to transmit a decent wattage – so in respect to the power actually used for lighting and circuits, the inter-coach electrical connections had to be over-engineered to handle the extra amperage.  A faulty connector would materially reduce the voltage on all the coaches downstream of the poor joint, due to the series voltage drop across the coupler.  And when you’ve only got 24 volts to play with in the first place – the two or so volts lost is already a tenth of the capacity. 

The new AC powered mains system has the advantage of being able to use common domestic and industrial fittings and wiring.  It’s also easily compatible with the depot buildings and is ideal for coupling up to ground power.  With the modified coaches of both Reefsteamers and Shongololo Express, it’s not too unusual to see the train’s lights burning but the generator van is silent.  It also means that in the event of a generator van failure, standard retail or industrial generators can be used to power the train.  The electrical connections must have thicker insulation to withstand the voltage – but the current draw relative to the wattage is much reduced.  Thus, a bad connector won’t have such an effect on the coaches downstream.  (Less current through the resistance of a bad joint means a lower voltage drop.)  The elimination of the inverters and in some cases, transformers, improves both the reliability of the electrical system (less components to break) and also the efficiency, as you’ve eliminated the inverter quiescent and oscillator losses, as well as the hysteresis and impedance losses of the transformers.  As our trains are wired for three phase power – a failure on one line doesn’t black out the entire train.

Anyway – lecture over and onto the practical stuff.

There are two of the Sandstone-ex-Stilfontien Mine day-sitter coaches standing in the open area of the eastern Workshop Yard.  Coach No.25163, in the No.2 road, was the coach being rewired today – 2^nd August.  (Pic CW01 Below)  The sister day-sitter coach, No.25206, is in a bit of a mess with all the seats unbolted and stacked, and the badly delaminated floor covering completely removed for re-laying.  So Fred got to start his sparky work on a reasonably intact coach.  He had already prepared his inter-coach plugs and the fly leads during the week, and you can see the coach wiring kit in Pic CW02.  (Below)