Steam & Excursion > Fan Trip Friday

N&W 611 performing a run-by at Dry Fork (VA) on the Danville District.  April 8, 2017, Brian Woodruff photo, my collection.

mike woodruff
anacortes wa

---

Awesome shot.

Waaay too much smoke.

It's a technical point : But why did N&W stick with "table grates" and 
the limited numbers of air holes, for so long after the better air-flow ptovided
by newer "finger-grates"?

There were two suppliers of 'finger grates'--- but, both provided much greater 
air flow and oxygen supply.

 Oxygen makes-up only 20% of air, by volume; 79% of air is inert nitrogen.
I've noticed that 611 black-smokes often and apparently very easily.

So, back in the day, testing affirmed that greater oxygen supply raised firebox
temperatures, ( Duhhh!), but it took railroads a long time after hand-firing
ceased to compete, before a lot of them went for finger-grate technology ).

But, I"m glad that 611 has a future on Virginia's state-owned rails.
And yes, that black smoke could be converted into additional miles between 
refueling...  Just that black cloud, if burned slower and brighter, could 
convert into about 2 miles-worth of fuel...

( And, yes, I could get increased firebox temperstures, and better coal-mileage
when I added additional air --- oxygen-- above the  [finger] grates of NKP 759,
by using the 'smoke consumers', at a very low amount of steam-jet boost...)

​W.
 



Edited 1 time(s). Last edit at 03/15/24 19:56 by wcamp1472.

wcamp1472 Wrote:
-------------------------------------------------------
> It's a technical point : But why did N&W stick
> with "table grates" and 
> the limited numbers of air holes, for so long
> after the better air-flow ptovided
> by newer "ginger-grates"?
>
> There were two suppliers of 'finger grates'---
> but, both provided much greater 
> air flow and oxygen supply.
>
>  Oxygen makes-up only 20% of air, by volume; 79%
> of air is inert nitrogen.
> I've noticed that 611 black-smokes often and
> apparently very easily.
>
> So, back in the day, testing affirmed that greater
> oxygen supply raised firebox
> temperatures, ( Duhhh!), but it took railroads a
> long time after hand-firing
> ceased to compete, before a lot of them went for
> finger-grate technology ).
>
> But, I"m glad that 611 has a future on Virginia's
> state-owned rails.
> And yes, that black smoke could be converted into
> additional miles between 
> refueling...  Just that black cloud, if burned
> slower and brighter, could 
> convert into about 2 miles-worth of fuel...
>
> ( And, yes, I could get increased firebox
> temperstures, and better coal-mileage
> when I added additional air --- oxygen-- above
> the   grates of NKP 759,
> by using the 'smoke consumers', at a very low
> amount of steam-jet boost...)
>
> ​W.

Wes,

Considering that the N&W "of the old days" used that VERY high BTU Pocahontas Region coal, maybe THAT is why they used those type of grates.

YES!

And on some HICO trips we burned the SAME coal...
Worked-out very well with the individual finger grates in NKP759.

Fan trip sized trains, once up to speed, provide very little rolling 
 drag; thus, relatively light drafts through the firebed ---- compared
to the drafts produced by 60+ freight cars...

The BEST performance I've witnessed with 759 was hauling WM's hot-shots 
Alpha-Jets 2 &1: unassisted: between Hagerstown and Cumberland, MD,
round-trip, in 1970, IIRC(?)..

That strong, continuous draft brought in great quantities of oxygen...and our 
coal was consumed at much higher temperatures, compared to typical fan trips!
The stoker did a good job of breaking-up the lumps; however, the stoker screw 
rotation speed was almost imperceptible.... it took very little coal to get white-hot
flame intensity!

As a consequence, we burned less coal hauling the freights, than we burned 
with low-draft excursions.  With excursions, the low-temperature 'volatiles' 
in the fuel provided quick heat in the modest draft conditions...

In the freight service, the volatiles burned very quickly, and the carbon content 
provided a greater proportion of the heat.  The gas velocity through the grates, and over 
the brick-arch was very rapid and coal particles were consumed, mid-air,
in little over 1-second, befrore diving into the flues surrounded by the colder boiler water.

Firebox temperatures reach 3000 F, flame temps; whereas, boiler water was near 
404F.... So, to the flames, the boiler water was very much "colder", than the fire!

You haven't seen a Berk perform, until you've watched them hauling freight,
at 50-per....!

Luckily, Ross and I got to see it in the 759's CAB... both directions!

W.



Edited 6 time(s). Last edit at 03/16/24 12:35 by wcamp1472.

Good thing they don't try that in CA.  Newsom and the gang in SAC would demand the engine be retired and scrapped like the Alco's of the Napa Valley Wine Train. 

ExStarlightHog Wrote:
-------------------------------------------------------
> Good thing they don't try that in CA.  Newsom and
> the gang in SAC would demand the engine be retired
> and scrapped like the Alco's of the Napa Valley
> Wine Train. 

Give it an effing rest.

Mary McPherson
Dongola, IL
Diverging Clear Productions