Crown Sheet Failure

That’s an interesting note in the Gettysburg report about CPR’s crown sheet design that would give a zipper-type collapse instead of sudden catastrophic failure. As horrible as the incident was, it might have been worse. 

Here’s a couple of crown sheet failure pics: just for reference the diagram shows the Medina OH steam tractor failure.

 

 

 

Kelly Anderson posted:

FORMER OGR CEO - RETIRED posted:

The steam locomotive fraternity is dealing with this blending of old and new tech with the advent of PTC (Positive Train Control.) The PTC rules specifically call for closing the throttle in case of a signal violation. On a modern diesel, that’s a couple lines of code in the computer program. But how do you do that on a throttle that consists of a long, ratcheted lever operating 6 big throttle valves via a bell crank 30 feet from the cab? Needless to say, the main line steam guys are working with the FRA to come up with a solution to this!

When operated by a competent crew, a steam locomotive is no more dangerous than any other big piece of machinery. 

Regarding PTC, the FRA has agreed to waive the requirement for closing the throttle on steam locomotives.

If the indication is for a STOP, is a throttle reduction, "A little too little too late?"

Kelly Anderson posted:

palallin posted:

Can anyone describe the operation of the Nicolson Thermic Syphon? 

As shown, Nicholson Thermic Syphons are roughly triangular shaped water legs supported by their own stay bolts, and fed water through a large tube connected to the throat sheet, bottom of the combustion chamber, or occasionally from the lower side sheets.  the water and steam heated inside the syphon is ejected out of the slot shaped opening in the crown sheet.

They add heating surface to the fire box, provide a support for the brick arch, and in the case of a low water event will keep portions of the crown sheet wet due to the water boiling out of them, even though the general water level is lower than the top of the crown sheet.  On the down side, they are a lot of work to make, install, and to maintain.  In later locomotives, I get the impression that "circulaters" were more popular than syphons, being somewhat less work all the way around, while performing the same functions.

Thank you!

I ask because I have read that the Frisco equipped almost all its locos with one or two of them and liked the performance so much that they deleted the low-water alarms as being superfluous.

Obviously, the locos still need attention, but this device apparently allows a larger margin of error (is that a fair way to put it?).

This is one of the reasons major railroads won't even touch a steam locomotive unless it has an experienced crew. They can be dangerous if not operated properly. Rich, so you retired from operating the 765 and now as CEO of the magazine? I probably will never see the 765 again in person because it probably won't go east of Ohio again, it only did a few years ago because of the NS sponsored excursions which are done. I'm glad I did the Horseshoe Curve and Lehigh Gorge trips because they were a one shot opportunity. From now on if we ride trains they will probably be shorter rides and closer to home. My mom has breathing issues and we can't travel very far much anymore.

Oh boy, look who’s back... 🙄

mlavender480 posted:

Oh boy, look who’s back... 🙄

Just ignore him and maybe he'll go away again.

Were you referring to me? Hot Water said Jim. But I don't see any Jim on this thread.

Robert K posted:

Were you referring to me? Hot Water said Jim. But I don't see any Jim on this thread.

Sorry, that was a spelling error. I meant to type "him", meaning you. I'll go back and correct that now.

Robert K posted:

They can be dangerous if not operated properly. 

Unlike every other form of transportation...

I have read about the Hinton, W.Va. C&O explosion, and about steam automobiles.  Am not familiar with boilers used in White or Doble, earliest Locomobile, etc., but the Stanley twins used a round hockey puck shaped boiler tightly wound in layers of piano wire.  They tested it once out behind the plant, had trouble getting it up to twice the operating pressure due to leaks in steam supply tubing, but finally succeeded in blowing windows out of that side of the plant when it let go, from location some distance away. They were satisfied they had a safe product. I think these were "flash" boilers.  There were two types used in autos.  I have fantasized a Mikado wrapped in piano wire.  Am sure there are all kinds of engineering reasons that can't be applied to locomotives, as probably completely different types of boilers, or would have been done. l suspect railroad accidents did not increase sales of steam cars.

 

Stanleys were fire tube boilers, nothing "Flash" about them, although Whites might be described as such. The Stanley boiler under test did not "explode" but the tubes collapsed, proving the effectiveness of their shell design. The reason for the piano wire was to allow for a thinner shell, saving a lot of weight. Dobles were basically water coils, and could be described better as a steam generator instead of a boiler. The advantage of the Stanley water tube boiler was the reserve capacity of steam, as automobiles can vary greatly in steam demand over a very short period of time (stop signs/lights, etc.), the steam generator type cars had to have the ability to very quickly provide maximum steam generation almost instantaneously because of their inherent lack of reserve steam capacity. Water level in a steam automobile boiler/generator had to be automatically controlled as the driver would be busy steering and avoiding obstacles such as other cars, pedestrians, etc. Little time to watch a water glass!

I read "Story of a Stanley Steamer" in highschool, back in geologic past, and couldn't find my copy to refresh knowledge, nor "Smogless Days", before posting, so shot from hip and missed the barn.  Apparently, besides controlled water level, water condensing was not used on steam locomotives? (as on steam cars to extend range) Neither are practical?

colorado hirailer posted:

Apparently, besides controlled water level, water condensing was not used on steam locomotives? (as on steam cars to extend range) Neither are practical?

I've only heard about that being done in Africa and other very dry regions. No real need to do that here.

Highrailer, I have both those books too! I also used to own a small steam car/buggy built of Locomobile and Stanley parts and a reproduction curved dash Oldsmobile chassis. Condensing steam was experimented with, but never worked out economically. With a railroad, the train goes where the tracks lead it, and stopping to replenish water was much more economical than maintaining a condensing unit and treatment of the reclaimed water (removing cylinder oil, etc. ) In a boat, you have all that water it is in to provide efficient cooling of the condensate, and cars are usually driven at speeds where the condenser (radiator) has enough air flow to function--no so with a slow drag freight! Some attempts were made at automatic water level control, but a fireman was much less expensive, and USUALLY more reliable!

Dominic Mazoch posted:

Kelly Anderson posted:

FORMER OGR CEO - RETIRED posted:

The steam locomotive fraternity is dealing with this blending of old and new tech with the advent of PTC (Positive Train Control.) The PTC rules specifically call for closing the throttle in case of a signal violation. On a modern diesel, that’s a couple lines of code in the computer program. But how do you do that on a throttle that consists of a long, ratcheted lever operating 6 big throttle valves via a bell crank 30 feet from the cab? Needless to say, the main line steam guys are working with the FRA to come up with a solution to this!

When operated by a competent crew, a steam locomotive is no more dangerous than any other big piece of machinery. 

Regarding PTC, the FRA has agreed to waive the requirement for closing the throttle on steam locomotives.

If the indication is for a STOP, is a throttle reduction, "A little too little too late?"

If it's close enough that the difference of manually closing the throttle vs. having the steam automatically shut off via a computer would make a difference, you are in a world of trouble that won't end well. 

Remember, you have thousands of tons of rolling resistance behind you that isn't going to stop on a dime regardless of what you do up in that cab.  That throttle is going to be shut immediately by the engineer once the indicator trips anyways, and a half-second difference isn't going to change much--if any--in the stopping distance.