7 equi-spaced holes on a pcd - why?

I'm considering building a Double Tangye as my next project, in spite of a rather awful drawing on which I notice that the cylinder detail calls for 7 holes on the pcds of both ends. 7 holes seems to be deliberately awkward is there a reason for this due to a spacing clash that I've missed?

Tony M

Are the equally spaced or is it eight with one missing , possibly over the steam passage in the end of the cylinder ?

Roy ( The drawing would help )

Edited By roy entwistle on 03/02/2018 16:15:26

A bit of googling shows models made with 6 and a full size with 5 thanks to Jo on MEM. Scroll down a bit

The odd number usually means you don't have a stud where the steam passages are, if you used 6 to avoid the same clash then you would have problems with the drain cock positions at the bottom of the cylinder.

8 means having to leave out too many fixings at the crank end of the cylinder where the frame gets in the way as the flanges on the models are usually too thick for having the nuts on the cylinder side which the full size did

Edited By JasonB on 03/02/2018 16:33:51

Tony

Edgar T. Westbury's Double Tangye model has six studs on the cylinder covers. Detailed in ME Vol. 110 and pictured in Reeves catalog.

John

Westbury's 1954 article has 7 holes, you can clearly see why as I mentioned above they clear the steam passages and drain cocks. reeves also clearly shows 7 holes

Edited By JasonB on 03/02/2018 18:26:40

Built my Tangye with seven studs, not a problem, they arise when you fit to the standards at the rear, lol.

Why I wrote six holes instead of seven I have no idea, it's definitely 7 as Jason says, Sorry about the confusion.

John

A couple of pic’s

Smart looking engine Ian.

Emgee

There are some photos I took of a Vertical Tangye Engine here, very like a Stuart 10V. It has six studs

It's in the Black Country Museum in the room with examples of the products of the different Black Country Towns (ironically is has 'Tangye Birmingham' very prominently on the side of it).

Neil

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Your irony is rather lost upon me, Neil

(a) the photos show 'Tangyes Birmingham'

(b) that was a trademarked name for 'Tangyes Limited'

MichaelG.

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https://www.gracesguide.co.uk/File:Im18880106E-Tan.jpg

Edit:  Just realised that your irony probably relates to the purist view that Birmingham is outwith the Black Country. ... It's past my bedtime, I think.

Edited By Michael Gilligan on 03/02/2018 22:44:27

Just to confuse you more Michael, their factory was called the "Soho Works"

The Engine that Neil shows is quite a small one, as they went up in size the number of studs also increased, this is a 10" x 12" of similar style with 7 studs, you can also see the "thin" flange that allows the cylinder to attach to the standard from above that you don't often get on models due to their out of scale cylinder wall and flange thicknesses.

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No problem with that, Jason; I know that Soho is a district of Birmingham

... Allegedly derived from South Handsworth

Last night's nonsense [which I should probably have deleted] was triggered by me thinking that Neil was amused by Tangye/Tangyes on the castings.

MichaelG.

When I rebuilt a Stuart Turner S9, the original builder drilled the cylinder head stud holes in the wrong place, they coincided with the steam passages. Just a case of plugging the existing holes and drilling and tapping new ones.

Ian S C

Edited By Ian S C on 04/02/2018 11:05:31

The purist view is that Wolverhampton isn't in the Black Country! Birmingham certainly never has been

Neil

(Married to brummie with over 20 years working in Birmingham and the Black Country).

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... and Birmingham was once a small settlement near to Aston

MichaelG.

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[ Born in Winson Green Hospital ]

Ever come across the Centre of the Earth around the back?

Neil

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'fraid not, Neil ... but it looks rather fine !

We left that area when I was about 10 years old, and a few years later moved to Lancaster.

MichaelG.

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P.S. ... back to the Tangye[s] story: Grace's Guide mentions ...

"1881 The company was made into a private limited liability company Tangyes Ltd. The company was registered on 31 December, to acquire the businesses of Tangye Brothers, hydraulic engineers, and of Robert Price and Co, malleable ironfounders, of Winson Green, near Birmingham. ^[26] in which Tangyes had an interest. Richard and George Tangye held 19/20ths of the shares^[27]"

That 'Robert Price and Co.' was on Slough Lane, Winson Green

You will not find that on modern maps ... it is now Wellington Street.

I used to know one of the Tangyes

Neil