Injecting water into working steam eng. boiler....

[Modelcar]

.......Would someone talk a bit of the mechanics of injecting water into a working steam engine boiler while under say...250 - 300 PSI. Sounds like a difficult task and of course it had to be done all the time to continue to produce steam.

[sooblue]

Hey there Modelcar,
As complicated, as it might seem it really wasn't. In engines that ran at 250 to 300 psi and above there were two ways to inject water. The main way used a pump that forced the water from the tender through a preheater to raise the temp. of the water going into the boiler so it would be closer to the temp of the boiler water so as not to shock the boiler and or cause a drop in the temp of the boiler water. Turn a steam valve on in the cab and the pump started to inject the water.
The other way was the "classic" water injector. First the fireman or the engineer would turn on a water valve to get water to the steam valve just before the boiler, then the steam valve was turned on and the steam pressure equalized the piping from the valve to the boiler. Once equalized the water velocity carried the water from the tender into the boiler. The steam itself only equalized the pressure in the piping.
One of the drawbacks to this method was that the water didn't get preheated enough before it entered the boiler.
In operation the fireman would do what he could to balance water use and water injection. Adding a lot of water all at once dropped the boiler temp down enough to cause a loss of pressure. A sure way to get cursed at by the engineer[:D][:D]
Stay cool[8D]
Sooblue

[Modelcar]

....Thanks, Sooblue for providing some technical data for us on the subject...Have another question....When steam was turned on to equalize pressure, what kept that pressure from backtracking back into the temder...? And I assume the injector pump[s], were powered by steam....Almost seems like one pulling himself up by his own bootstraps....

[Saxman]

Good simple and concice explination Sooblue to Modelcar on how water was injected into a boiler of a steam locomotive. I would like to offer one correction. It is the steam that imparts the volociety to move the water through the piping from the combing chamber of the injector to the boiler. It is the weight of the water and the volociety of the steam that forces the check valve open to admit water to the boiler. As a rule, boiler check valves are placed at the smoke box end of the boiler. Since water is circulating through the boiler, this water is closest to the temperature of the being injected to minimize pressure drop trhrough adding "cold" water.

As Sooblue stated, it really is a fairly simple process to inject water into a boiler of a working steam locomotive.

Saxman

[Modelcar]

....Again, thanks Saxman, for adding to the explaination of above subject....I'm trying to sort out these forces involved to make this happen...that is to make water flow from the supply in the tender [under normal atmosphere press.] to the hostlle forces of press. in the boiler. Are there check valves involved to the piping when the equalizing pressure comes to play so the water doesn't back track back to the tender...?

[Saxman]

Modelcar,

The answer to your second question is the boiler check valves. I breifly mentiond these in my first response. These prevent the problem you are talking about. It was not uncommon for a boiler check to get a steam cut that would allow steam and water to flow back. When this happens, it makes it difficult to inject water into the boiler. If a locomotive crew encountered this on their trip, it would be reported on the engine work report and corrected. The last thing one wants on a steam locomotive is to not be able to put water into a boiler.

Steam locomotives were/are required to have periodic boiler washes. This is were the boiler is drained and washed out to remove any scale build up from the impurities in the water. During this process the boiler check valves and injectors would be removed and inspected for steam cuts. If any were present, they would be corrected using lapping compound and grinding them smooth again. At the steam tourist railroad I worked at this was done by hand.


Saxman

[Modelcar]

....Thanks for the additional data Saxman...and I can very well see this info is coming from someone that is into it first hand....This has been a subject that has had me wondering for some time. Steam engines sure seem to have been so reliant on much maintenance. Perhaps the diesel / electric really made some of these things much more simple. That is, producing power to move the train over the division for longer distances and without as much required attention.

[Saxman]

The injector usually stops the flow of steam and /or water from the boiler checks back to the tender if a boiler check is leaking. This in turn makes the injector get too "hot" to "pick up" the water from the tender. There is a device on an injector that allows a fireman to "blow " steam back into the tender during cold weather to prevent the water from freezing in the lines between the locomotive and the tender. So, steam can be your friend or your enemy depending on what the circumstance are

Yes the steam locomotive WAS reliant on a great deal of daily maintenance! At the steam railroad I worked at, we put in about 1 and 1/2 hours of maintenance for every hour we operated each day. This was from when the fireman reported to start the day at 6:00am and the shop foreman left to end the day at 9:00pm. Actual operation was from 11:00am to 5:00pm. Most of today's large terminals are loctaed where there at due to the steam locomotive and its need for maintenace. As an example: On CSX start at Willard, OH and go west. Where is the next large yard? Garrett, IN. How many miles is this? About 100. On the NS (ex Wabash) out of Detroit, MI to Fort Wayne, IN? Montpelier, OH. Distance? About 100 miles. Try this with most any railroad and the formula will pretty much hold true with a few exceptions. There is a saying about the differance between steam and diesels locomotives that goes like this: On steam locomotives it took five minutes to find the problem and three days to fix it. On diesels locomotives it takes three days to find the problem and 5 minutes to fix it.

Steam is neat but man it is a lot of work that IS well worth the time!

[Modelcar]

Terry....Thanks for all the good stuff regarding steam engine mechanicals. I have never done any work on any steam engine but am old enough to have been around them in the past including some when they were the main source of power. I understand very well they required a lot of work and your point of the spacing in miles of the large terminals is very interesting.

My first thought on hearing of "blowing" steam back into the tender to free the lines of ice, etc....sounds like something the Fireman would have to be careful doing. If there was some ice wouldn't it be possible to blow off a hose incoming from the tender if he got too aggressive with it....All interesting stuff. I can understand the Fireman and Engineer really have to understand what is going on to be successful running their engine.

[sooblue]

Thanks Saxman for adding to the discussion.
I would say though that if the steam in the piping were to stay in the steam state it would only be able to equalize the pipe and boiler because both would be the same pressure. It was the action of the steam condensing back to water that made an increase in the pressure that overcame the boiler pressure. That act of condensation preheated the tender water too. Isn't it interesting what you can do with the laws of physics. I think it's amazing, and there is so much we don't know. What's just around the corner?
Sooblue

[Modelcar]

...When the inventors of steam power first got started....I wonder if they bumped up against the problem of "how do we get water into the boiler while under pressure..." Surely, that created some problems.

[sooblue]

I think it's mind boggling thinking about how the steam engine came together.
Getting water into a pressure vessel under pressure was probably the beginning but just.
The physics involved is astounding.
Just the differences between a cold boiler and a hot one are amazing.
Sooblue

QUOTE: Originally posted by Modelcar

...When the inventors of steam power first got started....I wonder if they bumped up against the problem of "how do we get water into the boiler while under pressure..." Surely, that created some problems.

[Saxman]

What is really amazing about the development of the use of steam and boilers, is that the individuals involved did not have advanced degrees from universities! These guys degress came from the University of Hard Work, Trail and Error. Their calculations were not done on some super computer nor did they have the advantage of CADCAM to design their pressure vessel either. One has to asked could it be done today!

[sooblue]

Hi Saxman,
You are so right. I can't tell you how many times I've looked at some invention and wondered how the heck they had that Idea?
Most of the really complicated inventions that we see today, like the most modern steam engines, are really inventions that are progressivly built or refined.
But some things just come out of the blue and you wonder what made a person think about that?[8)]
Sooblue

QUOTE: Originally posted by Saxman

What is really amazing about the development of the use of steam and boilers, is that the individuals involved did not have advanced degrees from universities! These guys degress came from the University of Hard Work, Trail and Error. Their calculations were not done on some super computer nor did they have the advantage of CADCAM to design their pressure vessel either. One has to asked could it be done today!

[Modelcar]

....Experimenting with what kind of vessel it took to stand the working pressures of their first crude steam engines would have been on the dangerous side for sure. Not knowing the limitations of it without trail and error it makes one wonder how they survived to make a suitable working model.

[sooblue]

I think Leonardo Davinci made the first working steam vessel.
If I am remembering rightly, It was a round dome like vessel that had two jets opposite from each other. The vessel was filled with water and heated from below and when it made steam it spun.
Between that time and the first true steam engine was a few hundred years of experimentation. But you’re right none the less. Every time the envelope was pushed disaster was right there too.
Just today one of my men pumped 55 gal. of hydraulic oil out of a barrel without loosening the vent plug so the barrel collapsed. I popped it out with an airline connected to the vent. I considered setting the barrel out side and seeing if it could withstand 150 psi but the thought of it rocketing up and over the building and then down onto my new truck stopped me just in time. [:D][:D][:D]
Have you ever seen the aftermath of a blown boiler?
I read the report on the steam tractor that blew up in Ohio last year. It went airborne.
The policeman and the tractor owner never heard the explosion.
Sooblue

QUOTE: Originally posted by Modelcar

....Experimenting with what kind of vessel it took to stand the working pressures of their first crude steam engines would have been on the dangerous side for sure. Not knowing the limitations of it without trail and error it makes one wonder how they survived to make a suitable working model.

[Modelcar]

.....Sooblue: Yes, the vessel in the early steam experiment you describe is one I've seen in school books somewhere along the line....Sure had some thinking minds when trying to invent some of the stuff that is now used everyday.

For your 55 gal drum...It's easy to understand why it collapsed...That approx. 14 psi. has plenty of power.

And I can answer with a "yes" on the blown boiler....In about 1944 a large steam engine on the Somerset and Cambria B&O branch in Pennsylvania...did blow up and several of us kids rode on our bikes to see what was left. There was nothing above the frame and driving wheels and steam cylinders, etc.... All of the structure above was blown away. I don't remember how far the bulk of the structure blasted away but I don't remember it being anyway near what was left of the locomotive that was still sitting on the tracks...!!

[Modelcar]

....One more tale of sorts....You [Sooblue], mention of being afraid of hitting your brand new truck with the 55 gal drum airborne, etc.....Don't think it can't happen. A few years ago a fellow [in Florida], was on night shift and running a large machine...an earth moving drag line. On break, he had moved his pickup truck and then forgot about doing so and a little later at work on the drag line he was swinging it around with a large load of ground and was dumping it where it was out of sight to him.....and....yes, that's right, it landed right on top of his pickup and crushed it to about 2 ft. high....so, such strange things can happen.