Thank You.
Well I do not think the device caught on very well despite the claims and data shown. Seems photo's of it are rare. Perhaps other roads tried it out but the fact we had a heck of a time tracking this thing down as to it's function indicates very limited acceptance. Some very smart and experienced people here were stumped.
Wonder what other appliances for steam locomotives were put forth that we may have difficulty figuring out what it is and does.
There are so so many variables with steam ...driver diameter, steam pressure, valve gear, drive mechanism and options all around, and on and on it goes.
It begs the question...is there a perfect optimum? ,...not a one size fits all solution but rather the best application and use of learned principles and applied mechanics and construction that would unquestionably produce the finest steam locomotive possible for it's intended use.
Seems like they were getting closer and closer to that goal but never got there. Maybe half-way.
Would there be today a button ( a program ok), we could push that would give us without a doubt the optimum. Laser cuts, advancements in metallurgy, welding advancements, boiler design, computer aided design, and so on were simply not available to Roanoke, Juniata, Baldwin, MLW. Can we derive and build a perfect steam locomotive?
Thanks wanswheel. I was hoping that you might find that description. That confirms what I concluded in my preceding post. The device is intended to limit firebox draft to only what is needed, rather than let it rise higher than what is needed, as it naturally would without the device.
http://www.ebay.ie/itm/1941-Railroad-Article-Locomotive-Operation-Improved-by-Automatic-Draft-Control-/311608421944?hash=item488d4f2e38:g:bbgAAOSw0OJXL2Rj
I know that steam locomotive designers are always looking for ways to reduce backpressure in the cylinders with the objective being the production of more power.
But I do not believe that is what this invention on the Lehigh Valley locomotives is intended to accomplish. I do not believe it is a device for limiting cylinder backpressure because the descriptive text says the device is a “Locomotive Automatic Draft Control.”
That does not sound like it is related to the common objective of limiting cylinder backpressure. Instead, it sounds like a draft control. The manufacturer claims: “the device limits the exhaust backpressure and therefore [limits] the draft by allowing exhaust steam to bypass the nozzle and stack when the backpressure exceeds a pre-set value.”
The phrase, “and therefore the draft” indicates to me that this is the objective, i.e. limiting the draft. The method of achieving that objective is the sensing of exhaust backpressure. Exhaust backpressure is related to cylinder backpressure, but I do not think limiting cylinder backpressure is the objective to this invention.
Indeed, there is another steam locomotive design objective that is directed to reducing the firing draft entering the firebox when the full draft is not needed. It has nothing to do with reducing cylinder backpressure. The firebox draft is produced either by steaming the engine under power, or somewhat just by convection up the stack when not steaming.
There are several inventions with this objective of reducing the natural running-induced draft when the full amount of this draft is not needed. Their objective is described as saving fuel because reducing the firing draft reduces the fire, and therefore reduces fuel consumption. Their objective also describes the benefit of reducing firing draft to prevent the incoming firebox draft from tearing holes in the firebed by lifting coal off the grate.
This objective has been cited for giving particular advantage to anthracite burning locomotives using a Wooten Firebox with a relatively wide grate and thin firebed. Note that the description of this Lehigh Valley engine device does mention that it allows larger draft inlet holes under the firebed, thereby reinforcing that the objective is to control firebox draft.
Not all of these draft control devices used the same method to accomplish their common objective of limiting firing draft. Some were manually operated by the engineer moving levers and mechanical linkage leading to the smokebox where the controlling mechanism was placed. So they were manual draft controls devices. The device under consideration with the LV engines is an automatic draft control that automatically responds to the need for draft limiting by sensing locomotive exhaust backpressure being produced by the restriction of the blast nozzle.
Since this accessory on the LV engines is an automatic draft control, I suspect that there is a spring loaded diaphragm valve in that cylindrical feature of the device that will lift and open when the locomotive is working hard, and allow some of the exhaust flow to bypass the blast nozzle. This bypassing limits the ability of the engine to produce firebox draft, which is the point of the device.
The precision of this spring loaded diaphragm valve would allow it to seat and seal when not needed. This is important because when there is no need for draft limiting, you want the smoke box to be tightly sealed except for the open stack. Some earlier manual draft control devices were probably incapable of providing a perfect seal when closed.
RME There is a picture of one of these devices in action, on a Wyoming 4-8-4, from an overhead vantage point. It's in Bert Pennypacker's book on Eastern Steam (published by Daphne Carleton back in the day). What the device permits is a larger volume of steam mass flow through the cylinders (to produce power) without requiring all the mass to pass through the restrictions of the (single, relatively primitive) draft arrangements. Something of potential interest is that it strongly appears there is combustion gas coming through the large port on the top of the device, in addition to steam flows (the colors and "detail" appear different in the shot) There are a number of good shots of the device in the 1975 PFM book on prototype Northerns, in particular the one on p.137 which shows one on 4-8-4 5106 in 1934, only a couple of years after that locomotive was built. You can get a clear view of how the device is put together, without any applied external insulation: its top and bottom 'rings' are bolted flanges, and there is an additional bolted joint below the 'drum'. PM me if you want a 'snapshot' of the detail in question (taken with a phone camera). There might be some interesting commonalty between the back-pressure-sensing approach here and the one used for automatic cutoff in the early 1920s.
There is a picture of one of these devices in action, on a Wyoming 4-8-4, from an overhead vantage point. It's in Bert Pennypacker's book on Eastern Steam (published by Daphne Carleton back in the day).
What the device permits is a larger volume of steam mass flow through the cylinders (to produce power) without requiring all the mass to pass through the restrictions of the (single, relatively primitive) draft arrangements. Something of potential interest is that it strongly appears there is combustion gas coming through the large port on the top of the device, in addition to steam flows (the colors and "detail" appear different in the shot)
There are a number of good shots of the device in the 1975 PFM book on prototype Northerns, in particular the one on p.137 which shows one on 4-8-4 5106 in 1934, only a couple of years after that locomotive was built. You can get a clear view of how the device is put together, without any applied external insulation: its top and bottom 'rings' are bolted flanges, and there is an additional bolted joint below the 'drum'. PM me if you want a 'snapshot' of the detail in question (taken with a phone camera).
There might be some interesting commonalty between the back-pressure-sensing approach here and the one used for automatic cutoff in the early 1920s.
Johnny
RME- Any thoughts on Paul North's suggestion of similarity with the Geisl Ejector?
I'm not a Mechanical Engineer, only ring I wear is for Mining, and your input is always very thorough and valuable.
That issue of Trains featuring the Giesl January '68 was one of my all time favourites, must have read through it a half dozen times over the years.
AnthonyV From http://www.rypn.org/forums/viewtopic.php?f=1&t=32143 "It's a "Locomotive Automatic Draft Control" device. You can find an advertisement for it on page 335 of the 1941 Locomotive Cyclopedia. The locomotive in the advertisement also appears to be an LV 4-8-2.The manufacturer claims the device limits the exhaust backpressure and therefore the draft by allowing exhaust steam to bypass the nozzle and stack when the backpressure exceeds a pre-set value. The manufacturer claims it functioned in the high power output ranges and reduced waste of fuel and allowed grates with larger air openings.I have no idea how well the things worked but I don't recall seeing them on photos of any other locomotives."
From http://www.rypn.org/forums/viewtopic.php?f=1&t=32143
"It's a "Locomotive Automatic Draft Control" device. You can find an advertisement for it on page 335 of the 1941 Locomotive Cyclopedia. The locomotive in the advertisement also appears to be an LV 4-8-2.The manufacturer claims the device limits the exhaust backpressure and therefore the draft by allowing exhaust steam to bypass the nozzle and stack when the backpressure exceeds a pre-set value. The manufacturer claims it functioned in the high power output ranges and reduced waste of fuel and allowed grates with larger air openings.I have no idea how well the things worked but I don't recall seeing them on photos of any other locomotives."
Anthony V,
Thanks for that information. I take it that the device is intended to limit firebox draft where it is generated by exhaust through the smokebox. If so, the purpose would be to reduce the potential to tear holes in the fire bed, and to save fuel by reducing the fire when steam production demand falls below production rate.
It would be nice to see the patent to understand the function. In this case, the phrase, “reducing exhaust backpressure” is the method, but not the objective.
By the total description, I conclude that the objective is not to reduce backpressure, but that is just a consequence of how it works. Actually, I believe that it vents steam directly to atmosphere by diverting the exhaust flow to bypass the exhaust nozzle and stack petticoat whenever the backpressure of those features exceeds a predetermined limit. So the device operates by measuring exhaust backpressure ahead of the exhaust nozzle.
So, when the exhaust backpressure exceeds a predetermined limit, the device opens like a safety valve, and allows excess exhaust to vent directly to atmosphere. This limiting of exhaust flow through the nozzle and stack limit the production of firebox draft, which is the ultimate point.
Thank You!, Too!
Would that device have the same function - reducing back pressure - as the Giesl ejector ?
Which twin has the Giesl?
Bingo! Thank you Anthony V. Terrific stuff.
Euclid I assume that a flow passes through the body, and that the discharge is the presumably open pipe standing just ahead of the stack. If so, the flow comes up the pipe from inside the smokebox. With that flow entering the center of the cylindrical body and exiting the circumference, it does remind me of a cyclone separator. I do not know what it might be separating. But the larger question relates to the fact that if there is a separation of flow, there should be an inlet and two outlets.
I assume that a flow passes through the body, and that the discharge is the presumably open pipe standing just ahead of the stack. If so, the flow comes up the pipe from inside the smokebox. With that flow entering the center of the cylindrical body and exiting the circumference, it does remind me of a cyclone separator. I do not know what it might be separating. But the larger question relates to the fact that if there is a separation of flow, there should be an inlet and two outlets.
Quoting RME: "Why did you have to go to court to get access to them? Simple permission with a waiver of liability usually works... " And I thought I proofread my post:
I see what looks like a wire leading from the device to the headlight. Could it be a turbogenerator?
DeggestyIt reminds me somewhat of the ventilators that I sued to see on roofs. But--what could it be ventilating?
Why did you have to go to court to get access to them? Simple permission with a waiver of liability usually works...
Seriously, a "logical" thing this might be is a centrifugal separator for steam and water in the feedwater-heater circuit, perhaps to remove entrained air in place of the simple air vent that wastes a certain amount of steam on an open-type exchanger. But that doesn't explain the exponential folded horn in front of the stack, which is the sort of thing used as a plenum to reduce turbine back pressure for better running efficiency. If I didn't have my '47 and '52 Cycs packaged up and completely out of reach, I'd page through the auxiliaries section to see if I could find this device.
As a cockamamie idea, it might be a substitute for blower in providing 'ashless' draft at low speeds or standing, driven off a small amount of exhaust steam via the visible line. The ash is centrifugally separated and falls down from the cyclone into the front end (where it would be ejected via self-cleaning action under running draft) while the small amount of steam and gas goes through the duct.
Deggesty- sort of like one of those whirlybird's ,,,may be a cyclone sizer for large cinders, or very fine ones.
It reminds me somewhat of the ventilators that I used to see on roofs. But--what could it be ventilating?
Euclid- Yes, very good..got your message. If RME and NDG don't know what it is then we need more detectives on this mystery. The shape does seem to indicate what it does...we have identified 3 locomotives with this appliance but no others. It is a fairly large thing-a-ma-jig.
I do not see any steam or exhaust of any kind coming from it.
Euclid Miningman If you go to the Steam and Preservation and scroll down to "Looking for Lehigh Valley steam info" thread, the last 3 or so postings, there is a discussion about an appliance near the stack on some Lehigh Valley steam locomotives. No one has been able to identify what it is. Any thoughts? Can you post a link to that thread? I recall seeing a thread about Lehigh Valley RR locomotives, but can't find it there now.
Miningman If you go to the Steam and Preservation and scroll down to "Looking for Lehigh Valley steam info" thread, the last 3 or so postings, there is a discussion about an appliance near the stack on some Lehigh Valley steam locomotives. No one has been able to identify what it is. Any thoughts?
Can you post a link to that thread? I recall seeing a thread about Lehigh Valley RR locomotives, but can't find it there now.
Link to that thread:
http://cs.trains.com/trn/f/740/p/260524/2935406.aspx#2935406
Euclid- The photo's showing the appliance in question is further down the thread.
I am helping a writer friend on a mystery novel he is working on. It takes place in 1945 and the plot has the characters riding from Philadelphia to Buffalo on the Lehigh Valley's Maple Leaf. I know that LV had some streamlined Pacifics pulling the John Wilkes, did they use streamlined Pacifics on the Maple Leaf as well? Also I know the Philadelphia section ran over the Reading to Bethlehem. Was this run as a Reading train or did the LV have trackage rights over the Reading? Where were crew change points on the LV main line? I appreciate any help.
Charlie
NDG- yes it's a mystery that's for sure. Maybe its an air raid siren!
Turbogenerator? Some kind of lubricator? Cinder device? Some LV guy knows.
NDG- Very good descriptions and accounts of working on and along the boiler. These are things that many of us do not know. With all the hazards you describe it would seem you took a tumble on more than one occasion.
How on earth does an acorn nut get atop an actuating cylinder? Chipmunks? I guess so!
Things have sure changed since those times. No hard hats, gloves "sometimes", no high visibility vests, no lanyards, D-Rings, and everyone and their dog smoked anywhere and everywhere. Yet we survived, a lot of us anyway. Self preservation is a good motivating factor.
I spent decades working underground in several hard rock mines. There has been tremendous advancements in safety equipment and procedures to the point where fatalities are pretty rare, at least in North America. If you were a haywire kind of guy back in the day...well not so good likely.
You have very good knowledge of steam locomotives. Wondering if you could shed some light on a question. If you go to the Steam and Preservation and scroll down to "Looking for Lehigh Valley steam info" thread, the last 3 or so postings, there is a discussion about an appliance near the stack on some Lehigh Valley steam locomotives. No one has been able to identify what it is. Any thoughts?
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