Yes.

Might want to have a discussion with our Canadian Pacific brothers who placed the burner under the firedoor and a brick arch over the firepan.

Just look at those chevrons.

Take THAT 787!

Am I the only one confused by this reference?

As Ed Dickens explained it to me, the Canadan oil firing system was developed to allow the easy conversion back and forth between oil and coal fuel to take advantage of the changes in relative fuel costs. When using oil, the flash wall is built over the throat sheet, with the burner pointed at the center of it. The flame path reverses, going back toward the door underneath the arches, then it reverses again going over them and through the tubes. This makes three passes through the firebox. Never tried it myself, but he tells me it works pretty well, and that they considered it for #4014, but decided to stay with UP practice in the interest of historic authenticity.

The chevrons at the end of the blast pipe extension serve to reduce the turbulent flow at the interface. This can be commonly seen on the 787 Dreamliner aircraft engine fan housings where it is used to quiet jet engine noise. It has been a life time since I took Mass, Heat, and Fluid Transfer and Statistical Thermodynamics, but I think it makes the velocity differential gradient between the steam coming out of the blast pipe and the combustion gases coming out of the tubes/flues more gradual. So now instead of gases with differing velocities shearing each other at the point of contact and tearing at each other and creating turbulence, the chevrons create a mixing layer so the transition from one velocity to another is not as abrupt.

So it should make the exhaust noise a bit quieter but I'm not sure how it impacts efficiency. Does the mixing induced by the chevrons increase or decrease the uptake of combustion gases by the blast pipe steam as compared to the mixing that occurs in a more typical design when the two flows meet and mix in the turbulence created?

This is an interesting idea. These guys really have MIND POWER!

Thank you from the back of the room in Blast Pipe 101.

Wesley

Yes, but the sound of the exhaust beats is part of what makes steam an experience instead of just something pulling up there. Not in any way unappreciative of the brain power involved in the engineering..... sustainable steam is something I've been tinkering with for a while now.

In thinking about this a bit further, my unverified inclination is that the chevrons will increase the mixing of the combustion gas from the tubes/flues into the blast pipe steam stream at the slight expense of a modest increase in blast pipe back pressure. I'd love to hear from someone with a better more recent grasp of this. Thanks.

Now if I could only remember the name of the Lone Ranger's nephew's horse!

Maybe they're still tinkering with their setup. I notice they hadn't installed a blower yet. Wonder what the smokebox interior will look like in a few months...

.

I posted something back in December on this (Oil burner design thread) citing the Morris County Central engines, each of which had, at one time, two burners. Glad to see that Everett 11 got a very conventional installation, should work well.

We had 16 Krupp 2-8-2s in Guatemala, originally equiped with three burners, placed at the front of the firebox and aimed at the flash wall. The oldtimers said that system worked very well, but they eventually replaced it with components salvaged from retired Baldwins due to the lack of any spares from Krupp.

Hopefully they'll have the time and money to do some before and after testing. This crown like nozzle is definitely a departure from the Porta type nozzles. It is interesting that people are still inventing new steam locomotive exhaust nozzle designs.