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.


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