Essex Terminal #9 gets a new blast pipe

TrainDetainer · **Joined:** Wed Nov 23, 2016 7:05 pm **Posts:** 272

keepers - Thanks for straightening that out. I'll have to keep that source's info in the skeptic column. Glad to hear it wasn't right though.

E&N6004 · **Posted:** Sat Jun 02, 2018 12:16 pm

JJG Koopmans wrote:

E&N6004 wrote:

... This seems to go against the common idea of having the blast nozzle as low as possible making the entire exhaust system as tall (long) as possible....
Pat

Those common ideas have very little footing in fluid dynamics, which is the common problem with exhaust systems. Mostly they are simply fairy tales. The distance from the orifice to the throat of the chimney has an optimum. Larger or smaller distances give a diminished vacuum.
In #9 the 4 orifices are positioned at the optimal distance and use each 1/4 of the cross area. As a consequence this system acts as a system with 4 chimneys which is the equivalent of a double length chimney with 1 orifice.
You can verify this in Young's tests at Illinois University of 1933, his report is on the web these days: https://www.ideals.illinois.edu/handle/2142/4435
Look at fig. 28 Pepperbox vs double length
Kind regards
Jos Koopmans

Thank you Jos Koopmans: I also recently saw a photo of Talyllyn #3, which was recently rebuilt by the Vale of Rheidol shop, it also had a blast nozzle positioned surprisingly high, almost out of view up the chimney, is this also one of your designs? By the way enjoying your book, and the King sounds wonderful!
All the best: Pat Hosford

JJG Koopmans · **Joined:** Sat Oct 22, 2011 5:07 am **Posts:** 82

The Talyllyn#3 is not my design. They have some Lempors installed on other locomotives so #3 may have received one also.
Jos

k5ahudson · **Joined:** Tue Aug 24, 2004 6:30 am **Posts:** 758

TrainDetainer wrote:

RLK - I may be wrong (and someone please say so if I am), but IIRC Canada banned coal years ago and all engines are liquid fueled there now, so they wouldn't be concerned with coal.

You are wrong (you asked). ETR #9 is a coal burner and always has been. South Simcoe Railway #136, less than an hour away, is also a coal burner.

Essex Terminal #9 gets a new blast pipe

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