Sunday, 26 February 2017

Maintenance Update (coupling, nut, magic, suspect)

Wednesday 22nd
The day began with Gilbert moving the chocks and Brian moving the engine. This was just to open up the gap twixt loco and tender for John T to get in there and complete the coupling gadget. There was some discussion about how best to attach the gadget to the tender.

The idea is to make it handy and visible (we have to apply the lowest common denominator for when 2807 goes away). So, John made some brackets and Joe [Loco Dept] welded them in position just below the footplate on the tender. This will normally be out of sight and hidden below the fall plate (that covers the gap between loco and tender floors).

Bruce spent most of the day working on the 42xx! He’d been asked if he could apply his skill and experience to lapping in its safety valves. This he did and reassembled them. There was a spacer missing, so Bruce will make them a new one, too.

Brian and I took up the shovel plate from the floor of the tender in order to apply bitumen to the area below it. Also, Brian modified the edges and corners with an angle-grinder to make it a better fit.

We did a bit of de-rusting on the floor panel and the area below it, and then applied bitumen both to the underside of the floor panel and all around the well area below. We’ll let that dry before putting the panel back, else it will be fun trying to get it up once the bitumen has set!

John G was on the go all of the time, assisting everyone; fetching everything, and slapping black paint on things (notably the completed coupling gadget support brackets and half-a-dozen rail chair bottoms.

Loco Dept chaps re-cleaned and filled the hydrostatic lubricator glasses with water (and possibly antifreeze).

Then somebody (who shall remain nameless!) discovered that the draw hook on the loco was loose. This being at almost-going-hometime!

There’s a whacking great nut on the back of it, and to get at the nut you have to remove a panel from the front running board. The nuts to this panel are inside a box section underneath … luckily there are only six of them. That’s Brian underneath, undoing the nuts. John T was being gopher this time.

Brian clambered out from underneath and up on top. Using his full weight, he was standing on the spanner to tighten the nut up. However, when Carpo took a look he ordered us to take the whole hook off and inspect it! So, we turned the spanner round …

I say “we”, because somehow I had got involved, too! In fact, when it came to lifting the draw hook off, there was only one volunteer. We took it all apart - the rubbers, spacers, cup and all. Then we put it all back together again!

The thread is OK for now, but Carpo insisted that we put a replacement down for the 10-year overhaul.

There was much debate about size of split-pin and if/how to make a washer to fit between it and the nut. However, the gap is too narrow for a washer, so it’s all back together as was (but tighter!).

Saturday 25th
The day began with David, Gil and John T coupling up the loco & tender, and then the loco was pulled out over a pit in the yard. The valve travel was able to be measured (but how this gets converted into an indication of the valve timing is all done by magic, I think).

With the loco/tender links all in place, Bruce tidied up the footplate - replacing the wooden floorboards, and so on. He checked that the blow-down valve was turned off. With loco over a pit, he was able to clamber below and fit split pins to the securing pins in the three links. A group of Loco Dept chaps offered to connect up the hoses twixt loco and tender, so Bruce (being still in the pit) supervised, and indeed instructed them on how to do it. Having not been in a pit for many weeks, you just couldn’t get Bruce out of it! While down there, he partly dismantled the gland on the bottom of the vacuum cylinder, because he was not happy with the free movement of the piston therein. However, all seems reasonable, so he reassembled it again.

Bruce had machined a steam safety valve spacer for 4270, and in a spare moment or two he fitted that in place. Also, another important job that he did was to repair 2807’s footplate broom. A person who shall remain nameless (but happens to be the usual suspect) had attempted to use the broom to lift up one of the loco/tender links! It didn’t work …

There were other people here today! John T began with cleaning and fitting PTFE to the two valve chest end-covers. Having done so, he had to wait for others to finish (notably the measuring of the valve movements) before he could progress their fitting. So, John helped the boot scraper production team (i.e. me) by applying a primer coat to the six chairs in the container.

Having checked the weather forecast, I had decided to spend the morning needle-gunning and wire-brushing more chairs. Sure enough, rain interfered with play on schedule at 12.30.

Lots of small jobs were undertaken by individuals during the afternoon …

… but it took all five of us (plus assistance from a couple of Loco Dept chaps) to get the valve covers back on. They are quite heavy, and aligning the centre on the valve spindle plus the holes on their respective studs generally took three people for each one. Then the running boards could go back on in front of the valves.

The bushes at the front of the valve rods originally had no lubrication. In the light of experienced wear, we modified ours with a grease nipple. However, you can’t use grease where there is rather hot steam, so steam oil has to be applied. Squeezing this thick oil in, forced water droplets out around the spindle.

Finally, the ‘nose’ goes back on over the end of the spindle.

We won’t fit the cladding around the cylinders or valves until after the steam test, otherwise you can’t see if and from where any steam might be leaking.

It is currently planned to light warming fires in all four locos on Wednesday, and to carry out initial steam testing on Thursday. That could give us Friday in which to tighten things (if necessary), but possibly not to fix things, because the loco will still be a tad warm.

At the end of the day, Loco Dept chaps began filling her up with water. A pump takes RO(1) water from the tank and pumps it up the injector overflow pipe. The water is forced through the injector and out along what is the ‘normal’ water flow path. So, it travels through the pipework, up around the boiler and into it via the clack valves on top.

There was no water level showing in the gauge glass at end of play. Filling may continue on Sunday.

I had put the shovel plate back in position on the floor of the tender ready for coaling-up on or before Wednesday.

Although the loco is in effect fit for a steam test, there is still one problem: the new brake blocks have not yet been delivered. So, there’s no chuffing up and down yet! I believe these are due to arrive on Wednesday, but if the worst comes to, we’ll fit the old ones back on temporarily.

(1) Reverse Osmosis (RO) is a water purification technology that uses a semi-permeable membrane to remove ions, molecules, and larger particles from the water, making it less damaging to the boiler.


Sunday, 19 February 2017

Maintenance Update (gadget, injector, felt, bracket)

Wednesday 15th
John T began the day by gluing insulation around the cylinder blocks. There are two layers, here, held in place temporarily using spray-on glue. John G and Gilbert subsequently assisted John T to get the cladding pieces fitted back on over the insulation. It looks easy enough, but lining up the bolt holes and persuading the bolts to go in straight is a challenge. Particularly fun are the bolts underneath! Gil (on his new pills) volunteered to crawl under the cylinders and fit those! After the large piece that wraps round the cylinder block, there are several small pieces to cover each end.

Gil fitted the timing gadget onto the two cylinder valves in readiness for David to play with the timing. I have a horrible suspicion that that involves pushing the loco up & down a bit! As the valve moves, a needle attached to the end of the valve rod slides two sleeves apart, thus marking the end positions of travel. I’m intrigued as to what happens then!

Bruce refitted the insides of the two injectors. A generous wrapping of PTFE is necessary round the end covers otherwise these tend to leak during use. It is critical to have two working injectors because of having to guarantee to maintain a sufficient water level in the boiler. If there was only one and it failed, you would be in deep do-dos.

Bruce & Gil examined the options and sizes for making a bracket to support the brake column. Amazingly, they couldn’t find a suitable bit of metal from which to construct the bracket.

As the weather forecast was dry in the morning and rain arriving at lunchtime, I began needle-gunning chairs, trying to build up stocks of boot scrapers for the beginning of the season. I managed five before rain did stop play. John G applied a top coat to the 6 in the production line after lunch, snugly tucked away in the warmth of the van!

After lunch I fitted the Mason’s Valve back in the cab (with assistance from Bruce); connected up the condensing coil, and then cleaned the sight glasses in the hydrostatic lubricator.

I was tempted to set you a quiz: How many of these components in the cab do you know? No prizes
for getting them all right.

Saturday 18th
On Friday I had an order for a boot scraper, so it was my first job to complete the lettering; fit
brushes and box up. After tea break, I spent the entire day inside the firebox.

Most of the stays are copper and are riveted over. Some are monel metal, which is a nickel alloy that is resistant to corrosion. These have nuts on the end. Those nuts that are in the fire bed, or close to it, can burn away in the intense heat. My job today was to clean these nuts by wire brush and then apply a heat-resistant (to 750°) paint.

The grate was not very clean of ash & clinker; the sides were covered in sooty deposits, and it is a tad cramped in there, especially down at the front end.

Gilbert started to fit one of the running boards and discovered how awkward (and heavy) they are!
Paul G [Loco dept] gave him a hand. Paul’s reward was two chocky biscuits plus a cup of tea.

John T finished fitting insulation around the cylinder blocks and refitted smaller cladding pieces.
Only the valve covers remain to be tackled - when the timing measurements are completed. John
then moved on to the brake column. He hoovered out the bottom of the box area and refitted the
top plate.

Gilbert subsequently got in John’s way, and then Bruce’s way; but he did fetch me a 100V lamp so that I could see what I was doing inside the firebox!

Gil, John and Bruce all had a play with the handbrake column, trying to work out how best to gain access to weld on a securing bracket. There are three metal discs and a bearing in the middle. The centre disc is the one to which we intend to weld the bracket. It would be nice if we could take it apart, but the handle is secured with a tapered pin which doesn’t look as though it wants to come out!

At the very least, it now needs some new nuts & bolts to hold them together!

Bruce spent much of the day making new felts for the piston rod lubricators.

He found a tin of almost the exact same diameter as the rods, which makes it handy for cutting out felt. The top felts have curved lower surfaces to fit round the rods. They are held in position by a metal cover.

The lower felt is just a strip that fits inside the bottom part. Here you can see the felts sitting in oil over lunchtime ready for fitting in the afternoon. As you can see, Bruce made two new top felts and only one for the bottom.

We didn’t get as much done as we had hoped, but every little bit is progress. We have to be available for service in 12 days time … that’s only three working days for the team.


Sunday, 12 February 2017

Maintenance Update (cylinder, chain, shaft, pin)

Wednesday 8th
Having been put on a new type of pill, Gilbert was back to his normal self, and was joining in everything again. However, he couldn’t get inside the cylinder to measure the internal bore, so John T did that. It appears that the cylinders have worn differently on each side - something that is not easily explained immediately.

Brian (with assistance from Gil) worked on the cylinder covers, starting with taking the RHS cover off (otherwise how could John climb inside?). All of the studs were cleaned and dies run down them; all of the nuts had a tap run through them. John T worked on the RHS, while Brian fitted PTFE seals to the two covers. At the very end of play, Gil, Brian, John and I fitted the cylinder covers back on. Gil manned the pulley; Brian applied the brawn. Alex gave encouragement.

John G was wielding his paintbrush once more. Beginning with the proverbial black bottoms (of the rail chairs that were cleaned last time) he moved on to applying a coat to the inside of the cylinder cladding.

The outside will get a coat later, as it is planned to repaint the black running boards and anything nearby. Hence the step that also holds the vacuum pump got a coating from John, too. Apparently it had been noticed (during the mechanical inspection by GWSR) that a rivet was loose. David fixed that so John painted it!

John T had completed the components of the gadget that he designed for guiding the loco/tender links into their correct holes. David welded it all together, even manufacturing a handle from a length of fencing that he found in the skip. Needless to say, John G painted it. Here it is standing upright inside our container.

Bruce had brought some chain from home. Two lengths of chain had suffered at the hands of footplate crews: there is a chain retaining a pin inside the smokebox which is used to secure the bar that is behind the smokebox door and into which the dart slots when closing the door; there are chains on the lids of the sandboxes, too, one of which had given up the ghost. So, David cut, fitted and welded new chain into place.

Bruce lapped the clack valves internal to the two injectors, so these are all ready to be reassembled and fitted.

John P [Loco Dept - performing mechanical checks] spotted that the brake column on the tender is not as secure as it might be. Bruce removed the cover plate and peering down, it became obvious that there are only two bolts holding the flange at the bottom of the column. There is no room for any more bolts down there! However, other tenders have got a bracket towards the top of the column, which holds it steady. John P said that the column could fracture and hence we should manufacture a retaining bracket.

Bruce’s homework this week is to ream the taper in the rocking shaft such that the new pin is a perfect fit.

Brian helped Bruce lift it into his car; I followed Bruce home and gave a hand lifting it out again.

Friday 10th
Bruce reported: “I have finished fitting the offset pin into the rock shaft. It was quite a long winded job as the removal of small amounts of metal from the diameter has a much greater effect on the amount the pin goes into the taper.”

Saturday 11th
Loco Dept wanted to fit new brake blocks to the loco, which meant being over a pit to undo the mechanism that connects all brakes together (so that individual ones can be removed and replaced). This meant coupling loco and tender … which meant an opportunity to test the connection jig that John T (in particular) designed. It did work, but some instructions will be necessary for those who are not familiar with it.

When the team from Loco Dept got to work and removed the old brake blocks, they discovered that the new ones wouldn’t fit! They are too wide at the pivot point, so a small amount needs to be machined off each one. So, the loco was pushed back into the shed.

A few minor tasks were carried out, such as: painting rail chairs, cleaning up the outside of the cylinder block, locating and acquiring some insulation to replace that between blocks and cladding.

However, the Big Task of the day took the whole team plus helpers from Loco Dept: this was replacing the LHS rocking shaft and connecting up the valve.

For a start, the rocking shaft is a two-man lift. Getting it up onto the running board was no mean feat. Bruce cleaned up and smeared oil on the brass shells. These two shells do not sit horizontally; they incline at perhaps 60°. The outer arm of the rocking shaft (black) has to pass down through a slot in the running board. Then the shells had to be clasped around the shaft (using Bruce’s fingers) while two chaps used a bar through the centre to manoeuvre the whole thing down into its saddle.

The top cover went on and was bolted down. At this point, Bruce rocked the whole thing to-and-fro to make certain that it was not too tight! With the oil pot fitted back on the top, this stage was complete.

The next step was to fit the valve link between the rocking shaft (outer black arm) and the valve spindle crosshead. That’s not too difficult apart from the fact that the taper pin is in the rocking shaft end, meaning that the link has to be rotated sufficient to get the pin into its hole.

Meanwhile, at the other end, the valve spindle crosshead was refitted and connected up to the valve spindle. Needless to say, the valve (and hence the crosshead) had to be pushed forwards before the link would engage with the crosshead. That done, the outside motion was complete.

Back inside the frames, the rocking shaft arm (red) needed to be connected to the intermediate valve rod that joins the rocking shaft to the die block in the expansion link. So, I volunteered to go in the frames this time; John T manned the reverser in the cab, and someone on the outside pushed the valve further forwards, sufficient for the rod and the arm to mate. Phew!

If you look it up in The Engine Driver’s Manual or the BR “Black Book” you find this diagram:


Sunday, 5 February 2017

Maintenance Update (bonnet, cladding, gauges, bore)

Tuesday 31st
Bruce’s homework for today was to take the tapered reamer to JB Toolgrinders Ltd at Tewkesbury for sharpening. We need it doing fairly urgently so that we can finish and refit the rocking shaft.

Wednesday 1st Feb
Bruce was up on top of the boiler again. Having machined the clack valves, Bruce refitted them. He is well pleased at how they remained steam tight after the previous machining, a couple of years back. Here he is fitting the brass bonnet back over the clacks.

He also measured the new pin for the rocking shaft and checked the dimensions of the taper within the rocking arm. The tapers must match exactly.

John T continued with the gadget for lining up the three drag links. This is very much a trial and error exercise. Having fitted the links back into the tender, the centre one is higher than we expected, which means another mod to the gadget’s design!

John G began by painting a couple of rail chairs and then intended touching up paintwork on the cab. However, there was so much condensation, that all he could do was clean and prepare the surfaces.

Brian began by refitting the two eccentric rods between the frames.

John then assisted Brian in removing the LHS front cylinder cover. This is so that we can check the internal condition for wear. To get the cylinder cover off means removing the cylinder cladding … which necessitates removing the rear section of cladding, too!

Luckily, it didn’t mean removing the valve cladding because that means having to remove the valve rod lubricator … Did Churchward ever work in the loco department, or just in the design shop???

You may spot that the piston head was right at the front of the cylinder, which meant you can’t measure the internal dimensions or check for wear! So, Brian found a pinch-bar; I found a length of wood, and together we pushed the loco backwards a couple of feet. It all looks very smart inside there (fortunately!).

John & Brian cleaned up the faces of the cylinder and its cover.

The gleaming gauges are another example of John’s handiwork with the polish.

Fitting these back on was a task allocated to me by the supervisor (Gilbert). Apart from that, I continued where John left off, painting rail chairs.

I had been advised that for the Wartime Weekend, there will be 2,000 campers in the field at Todders, so I should build up stocks of boot scrapers! Also, there is to be a Spitfire in the car park and for a fee you might get a chance to sit in it - but you have to pre-book. So, reserve April 22nd/23rd …

Saturday 4th
The sun shone (which meant I could work outside) so I prepared six rail chairs for boot scrapers. I also painted the gold lettering on those in the production line.

John T was busy: He began by measuring the cylinder bore on the LHS (under the supervision of Gilbert, who was in some pain during the day). John then checked the piston head diameters, and discovered that there has been no appreciable wear since last measured. John assisted Bruce in removing the cladding from around the RHS cylinder with a view to that cover being removed for inspection. The block & tackle was moved across and attached to the cylinder cover, but the decision was taken to leave it for Wednesday.

Bruce played with the new pin and the rocking shaft, ensuring that the parallel section of the pin is parallel and ditto the hole in the rocking shaft arm, which Bruce had to ream out a little. He can’t finish the pin/arm fit because the tapered reamer is away for sharpening. Bruce then cleaned up the injector innards ready to be fitted back in their bodies.

Pete [Loco Dept] replaced the packing in the LHS cylinder gland (photo right). He was also quite anxious to get in the firebox and remove/replace fire bars … but it was later than he thought!