Operating a Steamship Whistle on Air
Operating a Steamship Whistle on Air
(OP)
Hello all,
For those that don't know, I volunteer on a retired "museum" steamship [ see www.sskeewatin.com ] as part of the
Engineering Group.
Among many of our projects, we are working on ways to get the ship's whistle operating again. Up to now, we have been working on piping up an air receiver to the whistle, planning to sound the whistle on high-pressure air [we're not overly concerned that the whistle would be operating on a denser medium and therefore have a lower pitch than when it operated on steam].
However!
One of our number was recently conversing with a fellow steamboat type about our plans, and the other fellow suggested we could accomplish the same thing by threading the sound bell on the whistle way down, meaning the labium would be in very close proximity to the languid, and we could use a [leaf?] blower to develop the necessary wind.
I have my concerns, among them:
How much pressure drop could we expect across the whistle valve itself? I'll have to ask the guys that overhauled it if the valve is of the 'pilot' type, meaning there wouldn't be enough air pressure available to operate it, in which case we'd have to replace it with a quick-acting butterfly valve or equivalent.
Does anyone have any idea how much wind pressure and volume of air we would realistically have to have available / develop to enable the whistle to sound, and could anyone recommend a name brand, make, model and the power rating / consumption of a blower that would be suitable for this service?
Please be advised we have only a 120/240V single phase AC supply on board.
Any advice / recommendations?
For those that don't know, I volunteer on a retired "museum" steamship [ see www.sskeewatin.com ] as part of the
Engineering Group.
Among many of our projects, we are working on ways to get the ship's whistle operating again. Up to now, we have been working on piping up an air receiver to the whistle, planning to sound the whistle on high-pressure air [we're not overly concerned that the whistle would be operating on a denser medium and therefore have a lower pitch than when it operated on steam].
However!
One of our number was recently conversing with a fellow steamboat type about our plans, and the other fellow suggested we could accomplish the same thing by threading the sound bell on the whistle way down, meaning the labium would be in very close proximity to the languid, and we could use a [leaf?] blower to develop the necessary wind.
I have my concerns, among them:
How much pressure drop could we expect across the whistle valve itself? I'll have to ask the guys that overhauled it if the valve is of the 'pilot' type, meaning there wouldn't be enough air pressure available to operate it, in which case we'd have to replace it with a quick-acting butterfly valve or equivalent.
Does anyone have any idea how much wind pressure and volume of air we would realistically have to have available / develop to enable the whistle to sound, and could anyone recommend a name brand, make, model and the power rating / consumption of a blower that would be suitable for this service?
Please be advised we have only a 120/240V single phase AC supply on board.
Any advice / recommendations?
CR
"As iron sharpens iron, so one person sharpens another." [Proverbs 27:17, NIV]





RE: Operating a Steamship Whistle on Air
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RE: Operating a Steamship Whistle on Air
For the locomotive horns he had a large 240VAC air compressor and several (very) large air storage tanks to deliver the volume. It would take some time for the compressor to charge the tanks and of course, tank volume would limit how long the horn could be blown.
Should be a matter of calculation of flow rate @ required pressure to determine how long a give size tank will blow the whistle.
I would wonder whether a leaf blower can meet the psi requirement. Any ships records to how, where the whistle was connected into the steam plant? at what pressure?
RE: Operating a Steamship Whistle on Air
Look at ref 39 and 40.
Most of these would be off of med steam pressure, say 100-300psi.
But many would have choked flow, so the actual pressure and flow at the whistle is another matter.
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P.E. Metallurgy, Plymouth Tube
RE: Operating a Steamship Whistle on Air
I really don't think the leaf blower will work. Try compressed air from a shop compressor (~120 psi) to start with, because it's easy and cheap to try. Are there compressed air sources on the boat?
STF
RE: Operating a Steamship Whistle on Air
RE: Operating a Steamship Whistle on Air
B.E.
You are judged not by what you know, but by what you can do.
RE: Operating a Steamship Whistle on Air
Here is a link to a steam engine and traction engine discussion group, talking about the same problem you are having, and the bell type whistles you are using.
B.E.
You are judged not by what you know, but by what you can do.
RE: Operating a Steamship Whistle on Air
Thanks for that link; useful stuff there.
Sparweb,
The only source of compressed air we have on board at this time is a tow-behind Diesel-engine-driven air compressor that we have more or less permanently installed; it works, but is intended more as an emergency air supply only, and that almost exclusively for the operation of the original steam-driven warping winches. In my view use of this compressor on an ongoing basis would be unsustainable, and I'm hoping that the rumours of an electrically-driven air compressor still in a warehouse near the ship's former home that may yet be made available for our acquisition become a reality...but at this point that remains naught but a rumour.
As I stated in the OP, based on what I've read on line, the expectation is that the whistle would sound at a lower pitch due to operating on a denser medium. One poster in the thread that berkshire provided suggested the pitch would be higher since "steam is a denser medium," but if my thinking is correct both air and steam would be expanding to atmospheric pressure as their internal energy was translated into kinetic energy during transit through the languid...and at atmosperic pressure steam is less dense than air [hence the recommendation in the old stationary engineering books that as steam begins to be produced the try cocks immediately above the surface of the boiler water level sould be opened in order that as steam collects against the crown of the boiler drum the air within will be displaced downward and expelled via the try cocks].
CR
"As iron sharpens iron, so one person sharpens another." [Proverbs 27:17, NIV]
RE: Operating a Steamship Whistle on Air
Perhaps whistle blows would be done on a fairly infrequent basis, e.g. once a day at noon. Not on demand, constantly. Lest the neighbours get cranky.
So a pressure tank might be used, and re-pressurized with a relatively small compressor.
RE: Operating a Steamship Whistle on Air
Also rent a good microphone and recording equipment.
Blow the whistle a few times & record it.
Install a good PA system.
Play back the recording as required.
Or... I guess that misses the point of refurbishing a real steam ship.
What is Engineering anyway: FAQ1088-1484: In layman terms, what is "engineering"?
RE: Operating a Steamship Whistle on Air
All rely on a combined diaphragm/valve that is stretched tight over a seat ring at the small end of a trumpet. Compressed gas is applied to an annulus around that seat ring. The pressure integrated over the annulus' area deforms the diaphragm and lifts it off the seat ring. The gas then flows into the trumpet for a brief period, the pressure within the annulus and within the central circle both decline to a value that cannot hold the diaphragm/valve open, the diaphragm reseats itself, and pressure builds in the annulus until it is once more sufficient to open the gap between the diaphragm and seat, in a cyclical fashion, until the inlet pressure is shut off by other means. The dynamics (and part sizes) appear to be tuned to a particular frequency, as is the horn. It basically works like a relaxation oscillator. It requires a relatively high pressure to open the diaphragm/valve, but consumes relatively little gas. A modest air compressor, a reservoir, and a relatively large operating valve complete the ensemble.
I suspect a big whistle will require less pressure than a big horn, and a lot more flow.
A leaf blower is worth a try, but I'd guess you'll need a Roots blower.
Mike Halloran
Pembroke Pines, FL, USA
RE: Operating a Steamship Whistle on Air
Forget KENAT's idea of the recordings; much better to spend 23 hours and 58 or 59 minutes a day charging a receiver tank for one noon blast as suggested by VE1BLL.
Again, from a locomotive perspective, steam was used for whistles, not for horns. The former SP4449 has both a steam whistle and an air horn, very different devices, different working media. If it's truly a whistle, MikeHalloran's interesting description of horn function won't be of much help.
RE: Operating a Steamship Whistle on Air
Your recommendation is what we were already well on the way to implementing; we have a fairly large [used] air receiver that we've cleaned up, visually inspected, and re-painted, and will soon test hydrostatically. The plan, as I understand it to this point, was to prove the feasibility of the scheme using our Diesel-engine-driven air compressor. Once we had that confirmed there'd be a greater incentive to acquire an electrically driven compressor for normal service.
And as you suggest, there would not be any sounding of the whistle on demand, but only on a schedule of, say, at noon, one PM, and five PM.
KENAT: Playing a recording on a PA system? Not quite criceket, in my view...
The idea of using a Roots blower [thanks, MikeHalloran!] may well be a viable alternative; we'll have to check into that.
The "whistle" in this case is definitely of the stopped flue pipe variety, and employs neither reed, nor diaphragm, nor slotted cylinder à la Hope-Jones diaphone.
CR
"As iron sharpens iron, so one person sharpens another." [Proverbs 27:17, NIV]
RE: Operating a Steamship Whistle on Air
However, I deal with a lot of customer 'requirements' where they jump to a solution without letting us know the problem. Sometimes when we get to the bottom of the real problem our solution is somewhat different from what they thought of. So, good habit or ill, I often carry that over into my Eng-Tips posts.
What is Engineering anyway: FAQ1088-1484: In layman terms, what is "engineering"?
RE: Operating a Steamship Whistle on Air
I also carry my work with me wherever I go...
CR
"As iron sharpens iron, so one person sharpens another." [Proverbs 27:17, NIV]
RE: Operating a Steamship Whistle on Air
RE: Operating a Steamship Whistle on Air
IIRC from those days the blower division of Spencer Turbine used to manufacture a unit capable of some 200" water column [almost six PSI] at considerable volume for the esoteric voices/ranks that need such extraordinary wind pressure to function.
As an aside, I just last night learned that the hand-operated foghorn a friend and I once got to sound [many years ago now] within the confines of the small building where it was stored was in fact a "Powers Brothers hand horn" [if you Google the term you can find pictures of one or two].
CR
"As iron sharpens iron, so one person sharpens another." [Proverbs 27:17, NIV]
RE: Operating a Steamship Whistle on Air
RE: Operating a Steamship Whistle on Air
Not sure how well dry ice or similar will work though, and titanium tetrachloride has some issues.
What is Engineering anyway: FAQ1088-1484: In layman terms, what is "engineering"?
RE: Operating a Steamship Whistle on Air
RE: Operating a Steamship Whistle on Air
The flames would be cool! :<)
RE: Operating a Steamship Whistle on Air
I doubt that these were fed with superheated steam, but still there is a lot of difference.
You might look at regenerative blowers (Gast, Spencer), good volume at fairly low pressure, and good efficiency.
= = = = = = = = = = = = = = = = = = = =
P.E. Metallurgy, Plymouth Tube
RE: Operating a Steamship Whistle on Air
And as for your propane jokers, no, we won't be doing that on a ship with wooden superstructure
CR
"As iron sharpens iron, so one person sharpens another." [Proverbs 27:17, NIV]
RE: Operating a Steamship Whistle on Air
RE: Operating a Steamship Whistle on Air
B.E.
You are judged not by what you know, but by what you can do.
RE: Operating a Steamship Whistle on Air
CR
"As iron sharpens iron, so one person sharpens another." [Proverbs 27:17, NIV]