STEAM LOCO WATER TREATMENT?

Colorado-

  there are about as many different opinions about boiler water treatment as there are stars in the sky.  I've worked with 15" gauge railroads that religiously put in water treatment with every other tender full, and a low budget tourist line that basically used nothing. 

  In general the old CFR49 part 249 (Its been a while, I think I have that right)  covered steam locomotives rules in the US.  I believe it specified performing a boiler washer once every thirty days.  Now remember that stationary boilers, i.e. power generation, is covered under a whole different set of rules than Mobile boilers, and locomotives themselves were basically under the FRA.  (confused yet!?)

In boiler water treatment you are basically worried about keeping out oxygen and disolved solids.  There are a few different ways to do this but to removing oxygen in a power gen boiler generally involves feeding some type of caustic additive.  Boilers function well with a water ph of around 9.0 to 9.7 depending on the operating pressure. 

Removing solids out of the incoming water depends on the operating pressure.  For most locomotive applications, water softners similar to those used in residences are adequate.  For power generation you get into multiple cycle regenerative filters while counting the total dissolve solids (tds) count in micro-ohms of resistance in the water.  (remember water in its purest form doesn't count electricity - the dirt in the water causes it to become conductive)  For 600 psi boilers you are aiming for a tds generally under 50 but under 30 is better.  For large utility boilers like supercritical units if you get a reading over 3 micro-ohms you're in huge trouble.  In this case the water is usually filtered through a reverse osmosis membrane system.

When running really clean water you generally don't have to worry about foaming in the sight glass.  In relatively lower pressure operation like locomotive running mediocre water, sometimes an anti foam needs to be added.

As you stated there are multiple consequences to dirty boilers.

1. poor heat transfer efficiency

2. localized over heating leading to material failure ( i.e. leaks or blowouts)

3. clogging of the piping to the sight glasses, leading the crew to think the water level is higher or lower than it really is.

- Item #1 is just expensive, Items 2 & 3 can be deadly dangerous.

During normal operation a locomotive is "blown - down" once or twice a day to get rid of "boiler mud" that has accumulated around the fire box ring.  If you've never seen a blown down in person its a serious sight to behold - reminds you how much energy is inside that living, breathing, steam engine.  In power generation boilers that have steam drums ( the highest pressure units don't ), a small amount of water is continuous bled out just below the water line to help purge any solids that are floating on top of the water.  Aptly named continous blowdown system.

Sorry to go on and on.  This is some of what I do for a living.  ( And actually I haven't been involved in the operation side for about 4 years)  Something about your post just sent my brain into ovedrive this morning. 

Gotta go,

John Z

Accidently left out a whole paragraph on de-airator tanks to let get the gas out of the water after the caustic was added.  Oh well.

Believe it or not, I found that all interesting, and I think the answer is that, because of the frequent blow-downs, solids are largely removed, but to avoid things like blowing up an articulated at Hinton on the C&O, other measures are/were taken to make sure you got a good and clean water reading.  The bottom line is that they used whatever water was available and corrected the problem retroactively.  All that boiler maintenance,  blowdowns, boiler washing, etc. has lead to "the goose honk of the diesel being heard throughout the land".

The Stanley steam automobile used a piano wire wound boiler that was tested by the

Stanley brothers.  Since steam loco explosions were not unknown, they had to overcome those fears of prospective customers,  and tested their boiler by carrying one out into a vacant lot next to the factory.  They were unsuccessful in blowing it

up until they managed to develop pressure several times what the car could generate.

The blast is reported to have taken out the windows on that side of the factory.  They

didn't worry about it after that and I do not think anybody ever managed to blow up

a Stanley, White, or Doble steam car. I have not heard of piano wire wound loco boilers.  Steam cars, like steam locomotives, demand special skills and high maintenance.

Glad to help - although I'm sure some of my power plant contemporaries would rip me apart for the gaps in my notes, its a engineer thing....

Now there is one serious deviation in the thinking of boiler locomotive water treatment.  It is called Porta treatment; developed by I. Dante Porta.  Instead of running very clear water it involves running terribly ugly muddy looking water but reportedly it works well.  It just goes against my nature as a power plant guy. 

If you want to find out more about modern steam locomotive development a great place to start is http://www.martynbane.co.uk .  Martyn's page will give you more steam info than most brains can handle.

If you contact him, tell him the guy who was dreaming about building a 15" gague beyer-garrett says hi.

Remembering the READING RR Iron Horse Rambles in the early sixties, the Local Fire Company's were frequently called upon to provide water for the T1's. I remember them adding large tablets to the water Tender that were about 24 inches in diameter and 6 inches thick. Seems to me, one was blue and the other one white. They may have done a quick analysis to determine the number of each.

The water treatment for present day excursion steam locomotives is probably a lot more scientific and exact.

Do to our limited budget with 4449, we test and monitor the condition of the water in the boiler, at least once and sometimes twice a day. We can not afford to treat the water in both tenders, so our Nathan injector piping has been slightly modified so that we are able to simply squirt the required concentrated treatment chemicals directly into the boiler.

Continued use of the blowdowns throughout the day's operation, removes most of the solids suspended in the boiler water. 

More questions come to mind:  wooden water tanks with spouts at the bottom, would

seem to be easily blocked by the collection of sinking sediment from muddy creek water, or even gravity fed water from pipes off mountain streams.  I am guessing water tanks had to be periodically cleaned and had internal screens, probably, and filters?  Many of these water tanks have a central enclosure surrounded by all those supporting timbers.

Only a few mountain ones appear to be fed from the top, with sediment still sinking

to the bottom and collecting.  Probably the water was taken out a few feet above the

bottom of the tank, to allow for that sediment accumulation at the bottom? 

I am thinking about this because I planned to have an arsenic spring in my desert

mining camp, and was wondering if you could use that for loco water, while " piping

in town water to another tank from an up the hill and out of sight mountain stream."

And then I got to thinking about toxic heavy metals in the boiler water, in the tender,

and blown out into the air by the operation of the loco.  The EPA would go tilt, but

this is back in the good old days. However, I decided even then using that as a loco

water supply wouldn't fly.  (arsenic springs are found in certain desert regions, including Death Valley)  I have decided to pipe the water in to both tanks, fencing off

the spring.