Be careful, boilers can be lethal.

[oldboatguy]

Back in a former career, I worked for a company called Leitelt Iron Works. They used to build and repair boilers as well as mill engines in the distant past. In the course of our boiler service work, we were contracted by an insurance company to forensically dismantle and remove from the property, a heating boiler which had exploded. By forensically, I mean we had to work with the State inspectors and insurance adjusters to identify the reasons for failure and preserve the affected materials as evidence for the ensuing lawsuits.

The heating boiler in question was a "Scotch" type horizontal firetube boiler which was oil fired. The boiler pressure vessel was riveted plate and was approx. 7' in diameter by 16' long. There were approx. 120 2" diameter firetubes reaching from the firebox to the smokebox.

The reason the boiler failed is as follows: The low water cut-off switch had been tampered with by the building superintendant because it had been "nuisance tripping". With the switch jumpered, the boiler continued to fire well after the water level had dropped below the crownsheet level. This caused failure of most of the crownsheet stay bolts and allowed the crownsheet to rupture. This also allowed the firebox tubesheet to rupture into the firebox end of the boiler. The steam violently exhausted from the upper portion of the boiler thru the firebox end, causing the entire boiler to literally become a horizontal rocket.

The boiler was located in the basement of a 70 year old storefront building in Detroit. When it uprooted itself and began to move, it went entirely accross that basement and did not stop moving until it had penetrated thruogh five masonry walls each about 18" thick and fetched up in the basement of the sixth building to the south. The other basements were being used for various shops so numerous people were present when the boiler went.

Sadly, there were 5 fatalities and over 20 serious injuries due to scalding and crushing. We arrived to work on the scene a day after the explosion happened. That was over 30 years ago, but I will never forget looking through those 5 holes in the walls and seeing that crumpled boiler about 160 feet away from where it had started.

The point of the lesson to me is that boilers contain awesome amounts of latent energy! Even little bitty ones! This hobby is meant to be fun so if you are going to work with steam. PLEASE OBEY THE RULES & be safe.

 

[Mcgyver]

thanks for the interesting account OBG

 

[Cliff]

I will say amen to that. A few years ago I worked as a maintenance mechanic for the Goodrich Corp here in Pueblo, Colo. and in the almost eleven years that I worked there we had no accidents as far as the boilers because safety was number one the list. There was seven boilers ranging from fifteen hp to eight hundred hp. Cliff.

 

[rawblacksmith]

when i worked on modern steam engines and boilers we called those non-monotube "blowupandkillyou" kind!

i had a burn injury once during the period i worked on steampower...
it was from a barn fire during horse rescue mission, not while at work with steam.

 

[fdew]

I took a course in operating a Steam traction engine. Great fun

The first question before the hello my name is.... was what is the most important thing to check on a steam traction engine. Water level.

We must have heard water level at least twice a hour all day. I am now in the habit of looking at the water gauge first when ever I walk up to one of these great machines.

Frank

 

[cfellows]

I don't completely understand why water levels getting too low are a problem. I believe it, but I don't understand it.

Can anyone offer a good explanation on what happens in a boiler that causes it to fail when the water level gets too low?

Chuck

 

[fdew]

The short answer is that boilers are water cooled! The water may be at 260 deg but it is still cooling the metal inside the boiler. The fire box is actually INSIDE the boiler and it is heating a wall and ceiling (crown plate) with water on the other side. If the metal is not covered with water it will fail (bend, and seems let go.

Once this happens most of the rest of the water leaves and there is a lot of metal to quickly turn the little remaining water to steam. Steam expands over 1000 times it's water volume and that is what blows up the boiler.

Even a antique steam tractor has a lot of safety features. There is a soft plug in the crown sheet that will melt, this allows the steam to get out, and it puts out the fire. Also steam tractors in most states in the US are required to have two pumps to add water to the boiler. (A good trick because you are pumping water into a pressurized boiler.

There is a pressure relief valve to let the steam out if the pressure gets to high, and in traction engines, you can literally pull a lever and drop the fire on the ground.

If all of these devices are in good order, and the boiler is not rusted out and the operator knows what he is doing, then the boiler is safe.

http://www.herculesengines.com/Steam/Boiler Construction/index.htm

Check your area but in most places club rules, and state laws insure that you are safe.

I would not even be allowed to drive one of these engines let alone maintain it until I had compleated school and a test.

Frank

 

[Noitoen]

A nice experiment I do at barbecue parties to impress the guests, scratch.gif is to drive a plastic or paper cup into the red hot embers to boil some water. You can literally surround it with embers without melting the plastic as long as the water level is kept to the top. ;D

 

[itowbig]

very interesting. the more i read the more i learn''''

 

[stevehuckss396]

Remember what happened at the Ford Rouge Plant when natural gas leaked into the combustion chamber ignited while the boiler was still hot. I think 4 men died in that explosion.