Injectors - hidden behind footsteps!

[barhamd]

I'm trying to work out the shape and plumbing routes for the injectors on ex-GER J17. Trouble is that they always hide in the murky bits of photographs behind the cab foot steps and photos from the rear extremely rare.

injector.jpg

I can roughly see the shape on the GERS drawing but don't really understand where the pipes go in and out, particularly at the rear.

Can anyone point me at a diagram or photograph which will help?

Thanks
David Barham

[davebradwell]

By saying ex-GER you presumably want the LNER arrangement which wasn't necessarily the same as on the GA. It looks very similar to the arrangement used on ex-NER engines and may even be the same injector.

The top front pipe is the delivery and it goes to the boiler. LNER preferred a single large fitting each side of the backhead with steam supply and clack for delivery in one piece. Ex-NER locos were brought into line when fitted with LNER style boilers. Original NER boilers retained the injectors on the backhead.

The pipe below it is the overflow which ends under the rear of the step so that the fireman can see it.

Sometimes, to avoid having LH and RH injectors, one of them was turned round so there'll be a bit of a tangle of pipes on one side so they all end up going the right way. Dodge used on ex-NER engines was to cast a mounting brkt on each side of injector so it wasn't handed. I can't see the 2 fixing bolts on the step, though. Perhaps it just needs a sharper photo.

At the rear end of injector was water feed from tender and steam supply from that fitting on backhead. A further NER variation involved water valves which were on the tender so you'll need to check these, too. Later style was a pull up bar that worked a valve on front of well tank via cranks. Finally there's the question of whether the flexible hose went above or below the brake shaft!

If this matches I can dig out photos of current J27 and Q6 arrangements. I even have castings!

DaveB

[Will L]

I'm trying to work out the shape and plumbing routes for the injectors on ex-GER J17. Trouble is that they always hide in the murky bits of photographs behind the cab foot steps and photos from the rear extremely rare.

injector.jpg

I can roughly see the shape on the GERS drawing but don't really understand where the pipes go in and out, particularly at the rear.

Can anyone point me at a diagram or photograph which will help?

David
This drawing from the GER society full set of loco drawings. Well worth it if you don't already have it.

You have 4 pipes
A - the boiler feed water pipe, from the front of the injector routed up to the footplate then along to the clack valves on the boiler
B is the steam input pipe, from the injector valve on the back head
C water from the tender
D the injector drain pipe clipped to the bottom of the cab steps

The other side is a mirror image.

J17 injector 2.jpg

Ive had a go at GER injectors before for a J69 but beware these are mounted facing backward for some reason viewtopic.php?f=96&t=2932&start=100#p80411

Dave I think the the LNER, at Stratford anyway, stuck with later the GER arrangements which this is.

[barhamd]

Thanks for the responses.

I have the GERS drawings which are most useful. Having an understanding of which pipe is what though is very helpful. One question I have is that the drawings appear to show two tubes that form the injector casting, on the drawing these appear to be one behind the other. The photograph from the front though seems to show two tubes, one above the other. Am I misinterpreting the drawing?

David

[DougN]

David, I think Iain Rice in one of his books had a sketch of an injector. Which might help with an idea to fabricate one. I cant remember which one but it involved some wire, tube, 12BA nuts and other bits.

[barhamd]

David, I think Iain Rice in one of his books had a sketch of an injector. Which might help with an idea to fabricate one. I cant remember which one but it involved some wire, tube, 12BA nuts and other bits.

Thanks for the pointer. Just found it in 'White Metal Locos' page 30.
This one seems to just have a single tube and not be quite the shape of the GERS drawing or the photos.

David

[Will L]

David, I think Iain Rice in one of his books had a sketch of an injector. Which might help with an idea to fabricate one. I cant remember which one but it involved some wire, tube, 12BA nuts and other bits.

Thanks for the pointer. Just found it in 'White Metal Locos' page 30.
This one seems to just have a single tube and not be quite the shape of the GERS drawing or the photos.

If you follow that link in my post you can see my effort, and the one Mr Rice (may his memory be long cherished) provided for the J69 which just isn't right. I don't think the body shape on mine is entirely right either but it does provide the two parallel pipes in one out layout required. At least the questionable bit hides behind the footstep. Lets not be shy here's the pic. Mine on the left the kit offering on the right.

[davebradwell]

I suggest the drain comes out of the inside face here, probably with moveable elbow to avoid injector being handed. Drg shows it a bit further forward than on yours, Will. Drain pipe is very useful for attaching fitting as soldered joint to bottom of step is accessible. Steam and possibly water feed pipe probably a size smaller than others - it'll be on GA.

Nothing like my casting, which is a shame! You could visit the preserved one, of course!

It's worth looking at injectors on model engineering sites to get an idea of the bits.

The GE does seem to have escaped the LNER standardisation largely unscathed.

DaveB

[Will L]

I suggest the drain comes out of the inside face here, probably with moveable elbow to avoid injector being handed.

I rather suspected my drain pipe don't quite come from the right place i.e. it should come from the side on the same side as the water in pipe. This comes from bastardising the original kit casting. However Stratford did make them handed or certainly drew them like that. What I remain unclear about, apart from the exact shape of the injector body casting is whether they were entirely suspended from the pipework or if there was some other support.

[davebradwell]

I hadn't intended to comment on your fitting Will, I just looked at the drg. and was being relative. The round body is a good start, too.

Injectors were a substantial lump of brass and had a cast-on bracket for attachment. The NE Region type were bolted to the vertical plate supporting the steps and the bolts were visible - it's likely a similar fixing was used here. It's possible the bolts also held the step in place, although I would expect one bolt to be above the other for access. This fixing also works when same injector is used on other side. Of course the bracket can be missed off the model as it can't be seen.

I see the preserved engine has a different overflow fitting at the front and a suggestion of a mounting bracket is visible - it looks handed!

DaveB

[Will L]

...I see the preserved engine has a different overflow fitting at the front and a suggestion of a mounting bracket is visible - it looks handed!

The restored J69 was taken to an earlier congratulation with the injector fitted close under the footplate and happily from a modellers point of view more or less invisible. I have yet to find a photo of what's under the J15.

[barhamd]

I had looked at the photo on Will's link but couldn't quite match the image with the drawing or the prototype photo. I think I now understand it better so I will have a go at assembling something and then post some pictures.

On the plus side the model injector is hidden behind the footplate to just the same degree as the prototype!

David

[Will L]

../
On the plus side the model injector is hidden behind the footplate to just the same degree as the prototype!

Absolutely, so its getting the pipe runs in is the bit that really matters, which off course is where this conversation started.

[Will L]

I suggest the drain comes out of the inside face here, probably with moveable elbow to avoid injector being handed...

Ah yes, Ive eventually realised exactly what you meant. That could well be true

[barhamd]

Thanks to everyone for their help. I've had an enjoyable evening bending brass rod, sawing little bits of tube, soldering bits together, making bits fall off and having to solder them on again - you know the stuff.

In the end I'm pretty happy with the result. They seem to match the photos and once covered in traditional Stratford grime will be well hidden behind the footsteps.

aIMG_9805.jpg

aIMG_9808.jpg

The loco itself is coming along nicely.

aIMG_9807.jpg

Getting pretty close to a coat of primer.

David

[DougN]

Very nice David. By the sound of it you have enjoyed the above discussion and the interest in building the injector.

This to me shows the importance of this society as everyones modelling improves.

[Will L]

I agreed with Doug. Your clearly a man who enjoys doing the plumbing David. I can but sympathise.

[zebedeesknees]

Thanks to everyone for their help. I've had an enjoyable evening bending brass rod, sawing little bits of tube, soldering bits together, making bits fall off and having to solder them on again - you know the stuff.

Step soldering - use 240° or whatever first, soldering as much as possible without heating other joints. Then let the job and the iron cool, and use 145° for the next bits. If necessary, repeat with 70°for the final touches. Couldn't have made Masokits wagon brakes work otherwise!

Ted.