Steam Whistles and Safety Valves

[Brian Rupnow]

Don't shoot me for asking a possibly "dumb" question, but-----I missed the great age of steam by about 10 years. The local sawmill was powered by a steam traction engine off the prairies, and the local train that come thru my village was steam powered, but I was just a little kid then, and I don't remember too much about it. I know that the steam engine at the sawmill had a VERY loud whistle that was blown every morning at 7:00 AM to signal "Time to go to work" and if it was blown in 3 sharp blasts it filled everyones heart with dread because it meant "Man injured in the mill!!!" There was an old man who lived in a "free" house at one corner of the millyard, and he got his little house free because he was responsible for getting up every morning at 4:00 AM and stoking the firebox so the boiler would have a good head of steam to start work at 7:00 AM. It burned the waste slabs and edgings off the logs that were sawn. However, I digress----I'm sure that old Arthur didn't set and watch the pressure valve on the boiler untill he had a full head of steam. I THINK that the pressure valve was tied into the steam whistle so that when the boiler got up to pressure it would begin to "blow off" and sound the whistle, providing an audible alarm to bank the fires a bit before everything blew up.--Or maybe the safety valve blew off anything in excess of the boiler pressure rating so that it didn't matter. I don't know if the steam whistle that sounded "Go to work" was the same one that blew when the boiler got up to pressure or not. I'm not even sure that the whistle blew when the safety valve began to 'blow off" or if I'm making that part up. Who can shed some light on this issue???---Brian

 

[PTsideshow]

Unless he had Rube Goldberg something the answers to your question is no they are tied in to each other in any way on a full size boiler. After 34 years of operating, coal and gas fired boilers. After a little while you known what the boiler will do and how long under assorted conditions and firing rates.

I use to freak people out, by getting up and going out to check the stoker hopper level. It sounded different when it got down to the going to run out. It sort of thing that you learn like when you are driving a car or truck and a different sound. you know it at once.

There is a low water, high water whistle on the water column which is controlled by floats. If the whistle was blown at the same time each day it was the foreman yanking the cord/chain on it each morning.

They safety valves are to be piped unobstructed to the atmosphere after the discharge of the valve and only one 90' elbow up and out.

 

[bearcar1]

My Grandfather was a steam operator and owned his own Russell engine as well as a Keck Gonnerman separator. Anyway, when he was out and about on a job, every morning when he got pressure built up in his boiler, he would sound the whistle. Now this was sort of a tradition but it allowed the other operators in the area know that that rig was set to go to work. Every operator in the area did this ritual and it was sort of like 'bragging rights' of a sort when an operator got started ahead of another on any given day. Perhaps the old timer that ran that engine was in the same 'habit' of sounding the whistle to alert the countryside that the engine was ready to go to work. Old traditions/habits from those days gone by are hard to break.

BC1
Jim

 

[Brian Rupnow]

PTsideshow---Thank you. So how about that song "The wreck of old 97"---"He was going down grade, making 90 miles an hour, when the whistle began to scream---He was found in the wreck with his hand on the throttle, and scalded to death by the steam." Somehow I always thought that "The whistle began to scream" had something to do with a boiler about to explode from too much pressure.

 

[Tin Falcon]

I think some operators will blow the whistle to blow off steam. To help release extra steam faster in addition to the safety.
If the safety valve fails then to warn of impending danger.
Not an expert just my opinion for what it is worth.
Tin

 

[steamer]

PTsideshow---Thank you. So how about that song "The wreck of old 97"---"He was going down grade, making 90 miles an hour, when the whistle began to scream---He was found in the wreck with his hand on the throttle, and scalded to death by the steam." Somehow I always thought that "The whistle began to scream" had something to do with a boiler about to explode from too much pressure.

Nope more to do with a crash. The safety valve is connected to nothing by boiler and nothing else is "supposed" to be connected to it.

NO whistles on the safety outlet! When they lift, their plenty loud enough to get your attention.....PT speaks wisdom here.

If the boiler exploded....trust me ....he wouldn't be anywhere near the throttle when they found him....unless that part of cab followed him after the explosion.... 8)

To PT's point, machines will "speak" to you if you pay attention and listen. It is amazing what you can determine and understand just by the change in tone or timing of the usual "song" of a machine. This all sounds very much like so much rhetoric, but start paying attention to what your lathe or engine sounds like...pretty soon, you hear a change immediately if something is not right.

Dave

 

[Maryak]

I think some operators will blow the whistle to blow off steam. To help release extra steam faster in addition to the safety.
If the safety valve fails then to warn of impending danger.
Not an expert just my opinion for what it is worth.
Tin

Tin, some safety valves do have a whistle fitted to the pilot valve which if you are lucky enough to hear it gives you a few extra seconds to reduce the firing rate, ( really only works on oil fired watertube boilers where the firing rates and consumption rates are able to change, be changed, very rapidly). Lift safeties on a firetube boiler and they're lifted, no hiding your mistake.

In tugs of yore when coal was king, if the master was a mad whistle tooter it was not unknown for the stoker, (fireman), to visit the wheelhouse and plant one on said master for wasting his coal and steam. 3 furnaces at 3 14lb shovels per minute not to mention raking out, disposing of the ash and trimming the coal bunkers did not make for a happy camper if steam so hard earned was frittered away by an anchor clanker.

Best Regards
Bob

 

[Jared]

I think some operators will blow the whistle to blow off steam. To help release extra steam faster in addition to the safety.

I've heard that it was a source of pride for an engineer on tugs and steamers in the Pacific Northwest (and probably anywhere) to never lift a safety, so blowing the whistle might have been him cheating a little.

Thanks, Maryak, I like those kinds of stories.

 

[PTsideshow]

In the USA, nothing no pilot whistle, nothing can be connected to the safety valve or piping.

PTsideshow---Thank you. So how about that song "The wreck of old 97"---"He was going down grade, making 90 miles an hour, when the whistle began to scream---He was found in the wreck with his hand on the throttle, and scalded to death by the steam." Somehow I always thought that "The whistle began to scream" had something to do with a boiler about to explode from too much pressure.

There are stories told from the old timers and when the trains are about to crash or other problems in the locomotive. That the engineer or fireman/brakeman would either tie down the chain or hold the whistle open as a signal to the rear end crew, or passenger conductors.

If you like the old stories a magazine I suggest you hunt up is called Railroad magazine, it was a pulp paper magazine in the olden times, 70's and older in the traditions of the Men's magazines of the drugstore rack days of bright painted covers of fighting the war,Flame belching steam trains roaring down the track to their impeding doom. Along with the things of the day. To entice young boys and men, to drop the .25¢/.35¢ on the counter for the latest issue. Have to look and see if I have any around. Most of the stories were first person I was there when ole 999 went through the roundhouse, up the street and into the old folks home! kid of story.

And yes depending on the size of the whistle, they generally are steam hogs. And will use steam up fast. The safeties are supposed to be sized and in number of to unload the steam faster than the boiler can generate it.

One of the biggest problems with lifting safeties during the safety valve testing is that some times they don't reset correctly and will then leak.

Also the weighted arm style of safety valves was outlawed in the USA in favor of the spring/return spring operated safety valves. Much harder to tie down so they wouldn't lift slightly and or leak constantly. As now or then they are expansive to have adjusted or repaired by an certified shop.

Two low water whistles on cheap and quick air valves

More than most people would ever what to know about steam whistles. More theory and how its done than any where else in a recent book. This is destined to become the standard book on whistles that all others shall be judged.
ISBN#1-931626-01-4 ©2001

The same thing on full size gauges
ISBN 1-931626-13-8

The publishers web store they also have a lot of other books that may be of interest. Reprints of steam stationary, traction, and rail

I'm just a satisfied customer

 

[PTsideshow]

A couple more important things is there are different safety valve for boilers and superheated steam boilers. the super heated steam valves have what is called nozzle shaped passage.
More than one safety valve can be connected to a single outlet at the boiler.

Also the discharge piping can not be connected to the safety valve. You must use a slip fit connection this is to remove any stress from the weight and attachment of the piping from the safety valve mount.

This is generally a wider lipped fitting that the discharge piping hangs in the center of there is an air gap of anywhere from a ½" to 1". I have been told that under certain conditions, and the edge of the discharge pipe at this junction can cause a high pitched whistle. At the very start of the discharge.

Normally the sound is a lower pitched roar as with lower pressure boilers, under 600 lbs. As the steam immediately starts condensing into visible water vapor, and that is what people see.

It is what the steampunk genre, the general public usually call steam! It is not! It is condensate.
As all steam is invisible. Everything coming off a boiler or engine or other equipment is water vapor condensate., It may be at 210'F, the general rule is if you can see it, it is water vapor. Its the stuff that you can't see that can harm or kill you.

 

[shred]

Tim Cahill does a good number making fun of the "A Jaguar is Gnawing my Leg!"/"There I was, Train on Fire, Damsel in Distress!" Ripping Yarns type pulps.. Very funny books.

I wonder if dumping the whistle on a locomotive you know is heading for doom might also be a last-ditch attempt to get some pressure out of the boiler that's about to explode.

I'm idly considering making the safety a whistle on the toy roller I'm working on, just to see what happens. In that case the whistle should have no problem exceeding the boiler generation capacity.

 

[steamboatmodel]

I'm idly considering making the safety a whistle on the toy roller I'm working on, just to see what happens. In that case the whistle should have no problem exceeding the boiler generation capacity.

Put in two Safety Valves one set lower than the other and play around with the lower set one.
Regards,
Gerald.

 

[itowbig]

very informitive i enjoyed this reading and will persue more of same thanks

 

[shred]

Put in two Safety Valves one set lower than the other and play around with the lower set one.
Regards,
Gerald.

With a 30 PSI boiler and a wobbler that will lift off the spring if it gets too much pressure, I'm not thinking 2 safeties right now. I was just going to cut the vents in a traditional safety design with drilled holes in the form of a whistle instead. Is there something bad I'm not thinking of with that arrangement?

 

[JMI]

I can speak only to US marine applications. Having worked aboard steam ships from 1973 till the mid-90's I can say the discharge piping is definitely connected to the safety valves via bolted flanges. Most of the steamships had operating pressures of 900 - 970 psi at the superheater outlet with a higher drum pressure, 1050 or so. These powered a cross compound turbine arrangement, with a HP turbine which exhausts to a LP turbine that also has astern turbine blades.
The superheater had its own safety valve which is set to lift prior to the drum safeties (2) to ensure flow through the superheater and avoid overheating it. A feature that differentiates a safety valve from a relief valve is the safety has a "blow down" pressure that re-seats at somewhat lower pressure then what it lifts at.

Jim

 

[steamer]

JMI,

Your right about the safetys on marine applications, The connection is usually a loop (180 degree bend) or some such to keep the stress off the valve as much as possible, but PT's comments do jive with the boiler code.....The boiler code and the USCG don't always agree in the particulars...., and there is some leeway in both applications due to physical realitys ......All "scape" pipes do need a drain though!

Dave

 

[steamer]

I've heard that it was a source of pride for an engineer on tugs and steamers in the Pacific Northwest (and probably anywhere) to never lift a safety, so blowing the whistle might have been him cheating a little.

Thanks, Maryak, I like those kinds of stories.

In my experience Jared your right. Though a normal event, its generally considered bad form on a boat as it gets the passengers nervous...

On a boat with a condenser, you usually plumb a bypass. Steam is dumped from in front of the throttle right to the condenser. Good for a minute or two if you have a full glass and can't use an injector.

Filling the glass with the Injector is my favorite trick to dump pressure...at least put it to work!

Dave

 

[PTsideshow]

I have no knowledge of marine or USCG rules as I only hold a Unlimited pressure and horse power license for stationary applications 1st class city of Detroit license (32 issues). And a state of Michigan registered 1st class engineers license.
The A.S.M.E code is very clear on the connection its in section 67 of the code book.

As there is little to no movement on board most of the boilers rooms in buildings unless the earth is moving, or the coal truck trailer flips when a half load of frozen coal slides down as a one block. And comes thruogh the roof and wall

Besides I was an electrician in the Navy.

 

[steamboatmodel]

With a 30 PSI boiler and a wobbler that will lift off the spring if it gets too much pressure, I'm not thinking 2 safeties right now. I was just going to cut the vents in a traditional safety design with drilled holes in the form of a whistle instead. Is there something bad I'm not thinking of with that arrangement?

As long as you are not restricting the flow from the Safety you should be OK, especially as its a Wobbler which is almost like having an extra Safety. I have a Midwest Boiler that if built according to instructions does not have a safety. It was intended to be soft soldered together, I silver (Hard) soldered it and added a safety bushing.
Regards,
Gerald.

 

[steamer]

Hi PT,

We agree...You are correct, the code is very specific.

But with every bureaucratic agency.....well...case in point

Here's a picture of "Sabino's " boiler...a 960 sq foot Almy

http://i164.photobucket.com/albums/u27/mcandrew1894/Img18.jpg
and some others
http://i164.photobucket.com/albums/u27/mcandrew1894/Img10.jpg
http://i164.photobucket.com/albums/u27/mcandrew1894/Img15.jpg

She has 2" copper 180 returns of about 10" radius leading to the "scape" pipes ( 2 safeties per boiler code for anything over 500 square feet, at least here in the US. Bob, Aussie may be different 8))

A problem you have with an installation of this nature is the passengers are standing next to the boiler. If the safety lifts , it causes much concern among the uneducated masses.and they tend to not know a damn thing about boilers other than they ALL explode....they would tell me that every trip...They think you either a genius or an idiot, either way they always look at you , the engineer, covered in coal dust, oil and sweat, with pity....

Its all 1908 automatic...The engineer does it all automatically.
I polished those returns, and ran the engine, answered the bells, shoveled coal,maintained water , ran the pumps, and the turbo generator, and otherwise made myself useful for 12 years as a part time volunteer engineer.

Now that's a far cry from an unlimited license...I know what that is PT and I have great respect for that...they don't give those away...
but I know that boat....and she is Coast Guard Certified for 100 passengers on the Mystic River. And trust me , they go over her every year with a fine tooth comb. They hate wooden boats...especially steam powered wooden boats with coal bunkers and large fires on board.

Now, what any of this has to do with wobblers....well beats me. :

Now Gerald made some good points regarding practical safety. Don't block the safety! Two safeties is not a bad thing on any boiler.

Make sure the outlets are not blocked...and don't be leaning over it when it blows....well don't do it twice anyway ;D : They call that "Experience" :big:

Dave