Wednesday, 23 December 2015

Maintenance Update (flame, bitumen, truck)

Wednesday 16th
Gil & John T were largely laying down on the job.  We need to remove a bridge section that holds the pony pivot pin, in order to ream the holes out to a known size; and then make a new pin to suit.  Needless to say, this bridge is underneath the loco, which means either laying on the floor and working upwards; or hanging over arbitrary beams and dangling downwards!

All morning, they tried to undo first the lock nuts and then (if they'd have got that far) the main nuts.  No joy!  A flame thrower was considered.  JC [Loco Dept] had a go, and even he gave up.  I suggested a nut splitter.  "Have you got one?" asked JC.  Have we as heck!  … but a chisel is almost as good!  Several chisels later, and they could see some progress … but only then with the assistance of Ian Grant [Loco Dept].  Many thanks, Ian!

Meanwhile, John G was working on the boot scraper production line.  The cafes had sold 9 between them, last weekend, so we did a restock at Todders and John painted five rail chairs that were already in primer coat.  At other times during the day, he acted as general gopher assisting me and the nut cracker team.

Clive & Ade [Loco Dept] applied a coat of bitumen paint to the rear section of the tender top.  A second coat in the coal space is planned for Saturday.

I removed the RHS sand box, which enabled me to get the delivery pipe out.  I then puzzled over how to stop sand from escaping, as there seems to be a 1 mm gap between the central rod and its surrounding pipe … ample space for the sand to escape through.  In the end, Gil decided to order some new pipe of a diameter to match the central rod.

Bruce called in (with two eyes now synchronised) and looked for some metal with which to make a couple of discs to replace those that were the wrong sort over the pony lubrication points.  He also suggested that, since the bracket that held the (broken) oil delivery pipe is bent, wouldn't it be a good idea to straighten it before fitting the new components?  My first thought was to take it off and straighten it, but when I tested the first of four nuts, decided that today was one of those days when all nuts were in refusal mode.  So, with assistance from John G, I fabricated a beam-and-screw set up, to pull the bent bracket straight.  By going-home time, this seemed to be working.

Saturday 19th
David & Gil spent much of the day measuring every conceivable angle & dimension of the wheelset.  Partly to check for any almost-invisible differences; partly to enable Carpo to machine the axlebox underkeeps while the actual axle is away!  To that end, Gil had two templates machined to the exact size of the journals on the right- and left-hand ends of the axle.

The white metal in the axleboxes was in good condition apart from being too "long" - that is, it protruded further than necessary, which had caused a slight difficulty in lifting the box from the axle.  David skimmed the excess off.

David & Gil finally turned their attention to that bridge section under the loco, again.  Even with the might of JC's arm, those nuts will not move!  Applying a bit of heat would probably loosen them, but it is in a very dangerous position.  The flame could only be applied from underneath, which is a serious health risk - if anything went wrong, it would be extremely difficult to get out of the way quickly.  So, we are still considering the options.

Bruce popped in to demonstrate his improved eyesight.  I think he's got x-ray vision after his operation.  Anyway, he took more measurements for his "homework" concerning the bush in the pony frame and the oil delivery pipes.

Cliff & Clive, assisted by Donna,  [all Loco Dept] applied a second coat of bitumen paint to the tender coal space.

On Tuesday, Gil & Geof are taking the pony wheelset to South Devon for truing-up.  To prevent the wheels from turning en route, I knocked up a wooden plinth that will spread the load, support the wheel (as opposed to the flange) and support chocks to prevent the wheels from rolling (plus some blocks to prevent the chocks from slipping!).

To prevent the journals from rusting, I smeared thick grease all over them (didn't do my gloves any good!), wrapped cloth round them, then bin liners and taped it all up.

Apart from straightening the bent bar that holds the oil delivery thingy, I turned my attention to boot scrapers ... cleaning four rail chairs and painting their bottoms.

Monday 21st
Because there has been a mini rush on boot scrapers, I popped down to Todders to slap a primer on the tops of the Saturday four chairs.

P&O was chuffing up & down, apparently testing out the third cylinder.  Previously, it had been running on only two cylinders!

Tuesday 22nd
I arrived at 08.40 and just managed to get a crimson lake top coat on the LMS chair before Geof & Gil arrived in the GWSR pick-up truck.  Carpo drove the fork-lift, and lifted the pony wheels onto pallets in the back of the truck.  The wheels were chocked and strapped.  Even the chocks were nailed down!  We certainly don't want the wheels to go a-wandering en route to Buckfastleigh.

On the way home, I called in at Winchcombe station, where they had sold 4 boot scrapers … so, back to Todders to pick up four and do a restock!

Next work days:
Wednesday 23rd will be a low-key day.  I expect I'll pop down and carry on with boot scraper production.
Saturday 26th is cancelled as a work day. 
So, next real work day will be Wednesday 30 December.


Sunday, 13 December 2015

Maintenance Update (pony, disc, sand)

Wednesday 9th
As it was a sunny day, we were able to put the pony outside.  Not out to grass, of course, but for a jolly good clean.

Meanwhile, there was much debate about that oil delivery pipe that had been snapped off in the dim & distant.  From the drawings that Bruce had found, what we had fitted was not correct anyway.  There appears to be a large disc that is pushed down onto the top cladding by the helical spring.  The drawing then says to insert rubber packing below that!  So we had a butcher's at the cladding piece, and, sure enough, there are signs of there being a large circular cover having sat on its top in the past.  You can just make out the impression of a ring around the hole in the cladding piece.

We had a look beneath the 38xx and also the 42xx to see what is there.  Yup.  A large disc.  Actually, one felt like a rubber disc, to me, whereas the other is shiny (brass or bronze, I guess).  We chewed over the options, and pored over the diagrams, and I think we've decided to make a pair of large rings out of brass (or similar).

Inevitably, neither of the drawing exactly matches our pony.  Ours closely resembles the diagram which shows coil springs (as "shock absorbers"), but ours has a rubber sandwich (like on the second drawing!).

Just out of interest (thinking about why the pony drifts to the left) I compared the pony wheel diameters …  :-)  …. you might have guessed!  The RHS wheel is approx 1/16" larger diameter than the LHS.

We rolled the pony back inside, and removed the tie-bars beneath the axleboxes.  This is necessary in order to drop the axleboxes out … well, you can't "drop" them, as they sit on top of the axle!  So, we need to lift the whole frame up off the axle, whereupon the boxes will swing round & drop off!  I recall well, the re-wheeling at Llangollen, and trying to keep axleboxes balanced on the top of their axles!

After doing all that we could, and wanting only to have some form of lifting gear, we were forced to adjourn.  There is a gantry .. in the far corner, behind Dinmore's tender, P&O, and the 55xx.  Some shunting is required to gain access, then we can wheel it round and tackle the lift.

Friday 11th
I popped down to do a couple of things.  First of all, I wanted to try to cut through the bush in the end of the pony truck, which would make it easier to press out.  With a new blade in the saw, this I achieved.

Secondly, I thought I'd do a second test of the pony wheel diameters.  I measured each wheel in two directions (at 90 degrees).  They are not far off being round!  There's only about 0.1 mm difference on each (which is probably within my measurement limits anyway).  However, the right-hand wheel is about 1.2 mm larger in diameter than the LHS.

Carpo very kindly rang up South Devon, who advised that the wheels do need to be turned down to remove this difference, otherwise the pony truck will veer to the left.  [… which it does!]

Saturday 12th
Having split the bush, it was easy to push out just using a lump hammer.  Gil was able to measure the internal diameter ready to order a new bush (i.e. with a "round" hole in the centre!).

John T, John G, David & Gil worked on the wheelset.  Careful lifting of the frame, pieces of wood beneath the axleboxes, and a touch of persuasion separated the frame from wheels.

The axleboxes were a fairly tight fit in the guides - probably a good thing (though Gil expressed concern that somehow they might have got twisted, and hence tight!  Ever the pessimist).  Photo: David & John T removing the lifting chains.

The white metal bearing surfaces are not bad.  One side thrust face is worn, where the drift to the left had applied more pressure to that surface.  The journals are in good condition, too.  Once apart, we could see that there is exactly the same number of rubbers in the LHS as in the RHS - it seems that the covers over them are different on each side (hence the apparent difference in height).

David and John T took the boxes outside and gave them a good clean.

Gil seemed to spend the rest of the day measuring things.  David had a go at removing the slide plates (the angled surfaces) which appear to be bolted down with counter-sink screws.  They wouldn't budge using an ordinary screwdriver, so David tried using an impact driver.  However, this was less than 100% successful, as the driver not only undid the screw, but promptly did it up again!  The mechanism's functionality is suboptimal.  David attempted to fix it, but gave up in the end.

Cliff & Clive [Loco Dept] spent the morning applying a layer of bitumen paint to the tender coal space.  Another coat will go on next Wednesday.

JC [Loco Dept] asked if we could do a bright red rail chair for next year's Santa Specials, so that the diesel rail car driver knows where to stop.  John G duly applied Signal Red to a chair.  I'll drop that down to Winchcombe today (Sunday).

Gil wants to measure the cylinder internals to check for wear, so John G removed the front cladding from the cylinder covers in readiness.

I have been slightly concerned about the RHS rear sandbox that permanently dribbles sand (provided the box started off with some in, of course), so I decided to investigate.  Removing the sandbox's bottom was a bit of a struggle - I think the protruding threads on the retaining bolts had suffered from being covered in sand.  John G toddled off and dug out 8 shorter bolts (which amazed both of us … not that he went, but that he found some!).  Buried in the sand I came across a spanner!

The delivery mechanism consists of an outer pipe with some slots in, and an inner rod with some lengthways recesses.  Turn the rod such that the recesses line up with the slots, and sand pours out.  Except that there is enough wear in the pipe that sand can squeeze between pipe and rod, and escape anyway!  Getting the rod part out was not too difficult, but the pipe part only comes out of the top of the box … and hits the running board before you can get it out.  This means that the whole sandbox has to come off.

But, one of the side bolts happens to also attach the battery box (batteries were used for the Automatic Warning System) .. so that has to come off, too!  … at which point, everyone else had gone home … so I did, as well.