Overhaul of a 9F

[don9f]

Hi, many years ago now I worked at a British Rail Intercity maintenance depot and if coaches were needing to be specially prepared for any reason, they were cleaned by hand, then wiped over with a 50/50 mix of diesel & engine oil....this gave a good temporary shine (although a bit smelly) onto the inevitably faded paintwork. The washing plants used Oxalic acid which fetched grime & brake block dust off but in time, faded the paint.

Cheers Don

[don9f]

Hello again, well after 16 months of inactivity on the 9F and having recently finished the 3F, today I took the cover off thats been over the engine all that time and spent a couple of hours, sussing out where I'd got to with the overhaul/reassembly!

I even managed to fit a couple of pipes...one from the cab to the leading brake cylinder and the one from the exhaust injector delivery to the boiler clack....major progress or what?

Anyway with luck and a fair wind, normal service might have resumed and I'm going to try and get 92167 ready for its 1.5 x hydraulic and steam tests....assuming we can get back to doing such things before too long!

I was further inspired just recently by Craig on his no23mk2 youtube channel, where he has now test mounted the boiler on his own immaculate model.

Also recently I assisted Bob on his thread with some details about 9F fireholes etc., so although not of my model, here is a photo of the cab of 92214, without its tender being in the way. It shows quite well the "Western" firedoor and flap arrangement, also the cab ATC equipment talked about on Roger's thread:-



I just need that new brake valve!!!!

Watch this space

Cheers Don

[Cro]

It's coming, honest!! I have a plan and I hope this month see's a lot of stuff done as I can't wait to see it in your cab!

Adam

[don9f]

Hi Adam, hope you’re ok....that would be really good if you can, because I would like to fit it before fitting the cab....not wanting to have to take the cab off again because it’s a fiddly operation with all the pipes, controls etc.

Cheers Don

[Cro]

Totally understand, doing my best to get loads done this month so it’s on the to do list.

Adam

[don9f]

Hello again, I've spent the last two days of workshop time fitting dummy snifter (or anti-vacuum) valves to the 9. When I built the model I created the cutouts in the valance over the cylinders, but like with so many things, never got round to fitting any actual valves!

One problem was that the cylinder castings which I had used (cast iron from Norman Spink in the 80's) had such an excess of metal around the main steam inlet, there was hardly any room for the snifters anyway. I don't know if the present day castings are the same or not, but having bought the valves relatively recently, I was determined to fit them somehow.

This photo of a real 9F shows how the valve bolts to a flange incorporated into the cylinder casting, just above the steam inlet to the steamchest:-




The Doug Hewson castings are in two parts and are maybe slightly overscale (not sure), but are a good representation of the real thing:-





The next photo will show why there's no way the valves would fit as they are....some butchery would be required!

You can see the totally non-scale arrangement of the steam inlet to the steamchest and the chunkiness of that part of the casting....of course this is normally partly hidden behind the valance:-



With great care to avoid damaging anything, I removed a lot of this unnecessary metal "in situ" with a junior hacksaw / grinder / files, until I had a fighting chance of getting things to fit. I knew that there was plenty of metal around the drilled holes for the steam inlets, so wasn't worried about breaking into them:-



I had to remove a fair bit off the back of the snifter castings (trial & error / eyeball engineering etc.) to be able to accommodate them in the spaces I'd created, but this isn't really of any consequence, as the major part of these valves on a 9F are hidden from view anyway, they're just visible through the aforementioned cutouts:-



To mount the valves, rather than fit them to the actual cylinders, I cheated and made use of two of the three screws that secure the covers over the main steam pipes in the sections of running boards above, the screws being conveniently in just the right place. On my engine, the front section of running board, smoke deflector, steam pipe cover and sundry other parts etc. are kept together as an assembly. Bits of brass to act as spacers, were milled to the appropriate thickness, drilled/tapped etc. and the valves (or what was left of them) secured to these bits with a single screw through the top part of them:-





The final photo shows one side completed and I'm quite pleased with how these turned out....it was well worth the effort, even though I got pulled up over the mess in the shower after residual cast iron grinding dust went rusty overnight (not the first time!):-



I think the next job might be to light a fire in it here at home and see if it all works, not sure when it could have a formal test though....

Hmmm, maybe I should build a "rolling road" for it?

Cheers   Don

[92220]

Hi Don.

Crafty way of doing it!! Looks good though. Yes you will need a rolling road to run the loco on air. If you just jack it up with the wheels hanging down, the coupling rods will bind in their bearings, at front and rear dead centres, around the crank pins. When I first tried mine, I couldn't work out why there was a tight spot when rotating the wheels. I assumed it was the coupling rod bearings being tight and somehow I had maybe made errors in measuring the axle centres, and opened them up until the wheels would rotate. You can't just push it along unless it's on rails because of the centre wheels not having flanges. When I realised what was going on I also realised that I had to remake all the bearings that I had opened out, as they had been made right in the first place!!

Bob.

[JonL]

A rolling road is a bigger proposition with 5 axles! It's really looking rather fantastic.

[don9f]

Hi all, just a bit of an update and photos from a few days ago....as mentioned last time it was time to light a fire, the first “proper” fire in its firebox since early 1996. The engine is still not fully reassembled, but has enough pipes and bits attached to be able to steam up and do some tests. I didn’t intend turning the wheels though, as I need to create a better, more stable setup with some Rolling Road units which I’ve ordered today. The reverser wasn’t connected and remained in mid gear!

Things went mostly ok with just a few minor snags to deal with. Amongst other things I particularly wanted to test my homemade gauge glass frames and although the frames themselves were ok, both blowdown valves were “blowing through” and subsequently needed better ptfe packings making as the first attempts obviously weren’t good enough!
Also, the live steam injector that I had taken apart for inspection / photographs nearly two years ago worked ok, just needing a bit of sealant adding to one of the joints to stop a leak.

I set the safety valves to 80psi, always finding that pressure more than adequate in the past. The boiler is actually designed and tested though for a 100psi safe working pressure.

I am making preparations to put the cab back on soon....a job that means removing some of the pipes again, as they and the various valve operating spindles all have to pass through the cab front, which makes it a bit of a fiddly job.

I still don’t know when it might get it’s 1.5 x hydraulic plus steam test....hopefully sometime soon but although some maintenance / grass cutting etc. has been done at our track recently, the site where we run officially remains closed until further notice, so no boiler testing at the present time.

I took a few photos to record this “momentous” steam up....not having waited quite as long as we did when restoring the real 92214, that engine waited 37 years for its next fire!







Cheers for now   Don

[JonL]

Amazing.

[JohnF]

This just popped up on my you tube watch list and I thought of you Don.

www.youtube.com/watch?v=3alISY7ADik

I thought it was very interesting.

John.

[don9f]

Thanks John, I’ve seen that video before.

I wonder if that’s the same “prototype” Evening Star that was on display at the Midlands Show a while ago?

Cheers Don

[don9f]

Sinice the recent “static” steam test, there’s been a short delay whilst one of the injector steam valves was sorted out (thanks to Adam), plus I was waiting for some Rolling Road units to arrive, so that I could setup a safe way to do some “dynamic” testing with the engine sitting on my hydraulic lifting table.
There are five individual units and when the supplier checked the suitability of their “fixed” design to a 5” 9F, I could see that these would interfere with those wheelsets fitted with sanding gear....so I went for the “adjustable” type of sideframe and these worked out well under the engine and could be set to miss the sandpipes.
Because a 9F has flangeless centre drivers, I drilled and tapped a few holes here and there, so that the unit under the centre driving wheels in particular, but the whole thing in general stayed put and wouldn’t wander about!





The top surface of this lifting table is not flat, but after a couple of tries, I got all five units to carry a share of the weight....you get a feel for this by trying to spin the rollers by hand under the wheels. I’ll probably add something at the front to support the pony truck wheels as well.

It was drizzling here most of the day, so no steam but I hooked up an air supply and took a short video of it in action outside (trying to avoid compressor noise) which can be seen here.

More soon....(7F permitting!)

Cheers   Don

[oldnorton]

It runs very nicely on air, Don. Looking forward to seeing the same on steam.

Interesting to see that the cab floor and pedestal are there whilst the rest of the cab is removable.

[don9f]

Yes, that’s like the real thing. One “drawback” with running it like this is I haven’t got the cab reverser mounted....it normally fits to a bracket that’s part of the cab side. I suppose I could make up a temporary support for it.

The cab is left off for now as I’m waiting for the new driver’s brake valve, which would be impossible for me to fit with the cab in place.

Cheers Don

[don9f]

Hi all, well it’s about 2 months since the last post in this thread and I’ve got no excuses now....look what arrived here today, the faithfully reproduced, working model of a Gresham & Craven Mk6 graduable steam brake valve, as should be fitted to 92167.

Its a fantastic achievement Adam, the detail is incredible so thank you very much for all the hard work and it’s been well worth the wait:-







The Mk6 was fitted to 9Fs, certainly later built ones (not sure if they all had them or not) and it was an updated version which used a diaphragm arrangement for the vacuum application section, as opposed to the cylinder/piston of the Mk4. The Mk4b was the same valve as a Mk4 but with the vacuum connections repositioned, so the pipework to them was clear of other equipment in the vicinity. Don’t know if there ever was a Mk5?

Enough rambling, I’ll get it fitted asap and try to get a steam test organised.

Cheers for now   Don

[Cro]

Glad you like it Don, Can't wait to see it fitted!

Adam

[JonL]

Astonishing craftsmanship.

[jon38r80]

I concur with Nobby, apart from the fingers for scale you would think its the real thing!.

[don9f]

Hi, had a short bit of workshop time today and managed to fit the brake valve in its rightful place. At my request, Adam had supplied the valve with coned connections for the main steam inlet and brake cylinder outlet....these were to suit my existing 1/8” pipework & nuts that were already on the engine. However due to restricted space, the exhaust connection was a bit smaller and suited a “flared” pipe of smaller diameter, which I had to make up for the new valve. This worked out well because 1/8” is reasonably scale for 1 1/4” pipe (nowadays I would have used 3mm) and 3/32” is close to scale for 1” pipe....these being the sizes of the real thing. I think after their introduction and realising problems of slow steam brake application response with three brake cylinders to fill, the pipe sizes of the main inlet and outlet were increased from 1” to 1 1/4” which improved the response time. The exhaust pipe remained at 1” dia.





As you can see, it gets a bit crowded behind the driver’s pedestal....there is a lot of pipework to get to fit in on the model...even more so on the real thing!

Cheers for now Don