Water Tube Boiler Casings -Advice welcomed

[PeteThePen1]

Hi Folks

I have just got around to starting work on the "final" casing drawing for the WT boiler. However, whilst chewing the end of my pencil and seeking inspiration, my mind wandered off to the topic of funnels.

The resulting question is:

What degree of slope/cant from vertical is "right" for a launch funnel?

As ever, you views and suggestions would be appreciated.

Regards


Pete

[farmerden]

Hi Pete I went searching my archives and came up with this photo.I am positive that you MUST use this angle As you can see over here it's a personal thing! I suggest you mock it up ,drag it out in the driveway and have a look-sometimes a visual is better than theory. I notice alot of boilers over here are using a heavy flange at the base of the funnel which is hinged allowing the steamer to lower the funnel for transport and not use any guys.Again personal opinion again. So there ask a simple question and you end up with more questions Den

[PeteThePen1]

Dear Den

Thanks for the picture and advice but, being a pen pusher, I would like some numbers!

Just to place a marker, I am doing my drawings with 4 degrees cant off the vertical. It looks OK on paper, but I wondered what other people's actual measurments are.

Regards to all


Pete

[dhic001]

The rake on the funnel depends on how racey you want the boat to look. Do an internet search for photos of P.S. Wakatere, her funnel was 7 degrees rake, which is probably about the maximum you'd want.
Daniel

[Edward]

Dear P the P ,

I more or less agree with Daniel . A rake of 5 1/2 degrees is more or less standard and quite respectable , 5 1/2 to 7 1/2 a bit sporty/racy ; more than that is definitely the mark of a cad or bounder and is likely to lead you into trouble with both the ethics and aesthetics committees of the SBA .

Best regards Edward .

[artemis]

Dear P the P ,

I more or less agree with Daniel . A rake of 5 1/2 degrees is more or less standard and quite respectable , 5 1/2 to 7 1/2 a bit sporty/racy ; more than that is definitely the mark of a cad or bounder and is likely to lead you into trouble with both the ethics and aesthetics committees of the SBA .

Best regards Edward .

Andrew VanLuenen designed the funnel on Flyer to have a rake of 7 degrees. It is one of the few hobby steamboats I have seen that looks like it's going 10 knots when tied to the dock.

[stevey_frac]

Andrew VanLuenen designed the funnel on Flyer to have a rake of 7 degrees. It is one of the few hobby steamboats I have seen that looks like it's going 10 knots when tied to the dock.

I do love the banter in this forum. Very light hearted.

But this comment left me laughing for a good 5 minutes, and I couldn't catch my breath enough to explain it to my wife!

[PeteThePen1]

Dear Everybody

Thanks for all you inputs and I laughed too. So for all you Cads and Bounders, how about this? I think it is about 12 degrees!

Fairy Queen



This is taken from:

Pattinson G.H. (1981) The Great Age of Steam on Windermere, Windermere Nautical Trust, Windermere, p. 49.

The book is a treasure of stories and pictures, though few are good enough for measuring funnel angles. It is still available from the Lakeland Arts Trust.

Regards

Pete

[artemis]

And for all those who simply want a "hot" looking steamboat, Check out this pic of Flyer mentioned in my earlier post:
Note that the rake of the flagstaff aft matches that of the funnel!

[PeteThePen1]

Thanks for that photo Ron

That funnel and flagstaff are really well chosen.

Looking at the pictures leads me to another thought - is there a ratio between funnel diameter and funnel length (probably a range) for which the structure looks "right"? Fairy Quen and Flyer seem to have it just right, whereas some of the Victorian and Edwardian fast/racing launches seem to have short fat funnels that look unappealing (to me at least). (See back issues of Funnel or SBMSL).

The figures for Fairy Queen and Flyer appear to be 6.5 to 1 length to diameter. Thus for a 200mm funnel on would need a length of 1300mm which is not impossible.

As ever your observations would be welcome.

Regards

Pete