Lifting Injector Search : Please Help!

Hi,
The Ffestiniog Railway is currently appealing for anyone who can possibly help to take a few minutes of their time to try and help towards searching for information on the Holden & Brooke Sirrus or S pattern injectors fitted to Merddin Emrys.

Further details here:
www.merddin-emrys.co.uk/Pages/Injectors/merddin_and_the_injectors.html

 

Surely it is not beyond the wit of man to work out what the required cone tapers and relative diameters should be?

There are a number of individuals who both make small scale new injectors and repair old ones commercially. Strikes me that they either do this from first principles, or have the empirical design data required.

I would point you in the first instance to Terry Baxter, he advertises 3, 4 and 6 inch scale McLaren traction engine models in the road steam press.

Perhaps also it may be worth a shout to Richard Metcalfe, given the former family firm used to make such things, you never know what he may have. I believe Mr Riley may know how to get hold of him, but you may need to go to another forum for that. Failing that I do have his phone number.

 

Having spent some time searching on-line last night, I then followed the link in the OP and found they were already way ahead of me. So I strongly recommend anyone read all the info in the link first to understand how far the search has already progressed :doh:

 

LMS injectors all had the same tapers to the cones, no matter what the size and I think that these will essentially work for small injectors but only experiment would prove it. The Sirius injector is quite a bit different from the LMS in many ways but the delivery cone half angle of 2° 23' would probably be a good starting point as all delivery cones are fairly simple and similar. The combining cone is the difficult one as the LMS is the moving cone type. However, it essentially has three tapers. Starting at the inlet end, the half angles are: 24° 26', 6° 42' and 2° 51'. The LMS steam cone is a nozzle with an inlet half angle of 2° 23' and an exit half angle of 7° 7' but the Sirius is a simple diverging cone. As most steam cones are converging, I doubt that this is critical. The BR standard injectors were also all similar in cone angles throughout the range but I don't have exact details of these.

My gut feeling is that any simple injector with similar angles will work and there is little in the way of scientific calculation in any of the early injector designs, of which there were many, usually to overcome patent rights.

You've got a lot of information on the dimensions of the injector and, if you draw the thing out, I'm sure that the missing dimensions can be reasonably guessed, using the angles I've given as a starting point.

In terms of lifting injector problems, the usual one is sucking air in which prevents the injector from creating the necessary vacuum. Such air leakage may be difficult to find as there may be no corresponding water leakage when the pipework is flooded. It can also be internal and wear in the moving cone of this injector might be a starting point. However, I'm probably teaching you to suck eggs with this.

HTH.

 

I have a nasty feeling that Richard Metcalfe died a couple of years back at a relatively young age. Happy to to be proved wrong on this, of course.

 

It would appear that the word 'Sirius' is more of a trade name, rather than describing a particular type, and is thus something of a red herring. Taking things to the extreme. even the totally different design 3 mm hot water injector used by Sentinel on steam road waggons, locos, railcars, etc., are described by them as being the Holden & Brooke 'Sirius' injector. In these the second half of the combining cone is fitted in, slides and spins, in the front of the delivery cone.

Accordingly, I would expect that the H & B injectors of 1958 to be somewhat different to the Ffestiniog supplied ones of 1890.

 

It is his son Richard who I am referring to.

He is very much alive, he will be machining my Fowler second shaft once I liberate it out of the shed.

 

I presume you have contacted Armstrong Holden Brooke, to see if you can identify their drawing / reamers.

Injectors are fussy anyway. Did you check that it's still properly set up, and clean?

I mean, injectors are much more likely to build up a crust of scale which prevents them wearing.

And anyway.... Aren't the lengths more important than the specific angles of taper..... The drawing you have (more or less) gives you the lengths. The rest is down to setup.... No?

 

Thanks William for starting this in this forum. I wasn't aware of it or a member until this evening.

Just to do a little update on progress.....

No need to assume that we have contacted Holden & Brooke as I have cleary documented this on the web page. They have no records beyond the few brochures which I have also added to the web page.

Sirius was a "trade" name and referred to a lot of their products probably as a result of their address being based at Sirius Works, Manchester. The documentation we have over the ages suggests that the spelling of Sirius varied over the years.

The injector we are discussing is clearly identified as the "Pattern S" single action injector. The brochures and engravings we do have support the view that it changed little over the years right up to the end. In support of this, as well as the pictures we have the statement in one of the documents which says "they just worked" So why change them if they just worked.

Thanks for the info on cone angles. If all else fails we will be designing replacements from a combination of the drawings we do have and from first principles. I have been put in touch with someone who has a barely used one we may be able to measure the only hiccup is that it is in New Zealand.

I have plans to do more detailed investigations of the injectors we have but there is currently a slight logistical problem to that, I'm in York and they're fastened to an in service steam engine that keeps moving and will certainly miss them at the moment. Hence the current paper quest.

My quest is to find enough information to return them to as close to "as built" condition and to remove the incremental changes made over all the years of service repairs. Part of the problem is that whilst we do have a spare for each of the ones in use on the engine they were professionally overhauled by Davis and Metcalfe and haven't work properly since. Then in trying to correct that Hugh Philips beggard them up further so the steam valves also leak.

On the positive side I have been promised a drawing of another Holden & Brooke injectors and have started a discussion regarding pattern making for making new cones as the combing and delivery cones are a one piece casting.

There is one point this forum may be able to clarify for me that i could sort for myself if I had a set of cones here but I don't so I'll ask. One injector I know for sure is described as having a 6mm cone. Is the 6mm the smallest diameter in the cone? ie at the tail end of the combining cone in the detail on the drawing on my web page.

Thanks for all your comments and suggestions

Paul Martin

 

Correct. Injectors are normally 'sized' by the smallest diameter of the delivery cone which sets the output of the whole device.

 

As Eightpot says, injectors are described and sized on the smallest diameter of the delivery cone and always in millimeters - the only true metric dimension on British steam locomotives!

 

Because the injector was invented by a Frenchman, M. Giffard. . The early development of ic engines was also continental, hence why car and motorcycle engines had their bore and strokes in mm, even in the old imperial days ( with oversizes in thous!)

Rob

 

On the other hand the pneumatic tyre was invented in this country and so the world over they are measured in Imperial units. True that recent low-profile ones have the cross-section in metric, but the rim sizes are still in inches.

A curiosity is so-called 35 mm film. It is actually closer to 1-3/8" wide and the sprocket holes 7/64" x 9/64". Try metricating the latter dimensions!