The other day I found this bit of info about the use of cooper ferules in my "Two Foot Cyclopedia" Volume 2, on the SR&RL #23 2-6-2.

This is the order form that was created by the customer (SR&RL) and the Builder. It states that the locomotive was to be delivered new with copper ferrules when delivered new, here it is;

Tubes;
Worth Brothers "Charcoal iron", 2" diameter, 12' 10" long,
set with copper ferrules at the firebox end of its tubes , 2" dia #12 B.W.G

If a tube sheet was drilled to use copper ferules you should use them or stand a chance of over rolling a tube & splitting it.
Ferules are used to get a good seal between the tube & sheet. They also protect from over rolling the tube & disforming the tube sheet. I am sure there are more reasons to use copper ferules but these are off the top of my head.

Dave Huffman

To give a bit more history, they were originally utilized for many years pre-welding technology as a method of improving the seal between the tube and the sheet. Copper expands more than steel after all. Following the availability of seal welding the use of copper ferrules continued because "that's the way it's always been done", there in fact was and is no need as long as welding is utilized. Furthermore, some smaller locomotives were built in the later years without any type of ferule.
As previously stated, ferules can be used to compensate for an oversized tube hole preventing damage (destruction really) caused by over rolling. However, while copper can be used a number of railroads transitioned into the use of steel (as did the stationary/industrial steam generation industry, almost exclusively) in the late 40's through the 50's. After all, the point in the era of welding is to simply fill a gap.
A number of locomotives are running in this country with new sheets and no ferules of any kind. They had there purpose, technology negated the need to use copper, steel is perfectly functional but at the end of the day if your holes are not oversized nothing is really needed.

Cheers, Jason

Copper is used commonly on steam locomotives for it's ability to expand and seal a joint while still holding pressure. Staybolt caps have a copper seal, the steam dome cap has a copper tube ring which crushes down when the plate is wrenched down. If you had a new sheet with perfectly round holes for the flues they wouldn't provide as much function, but it does add some protection to maintain a seal. I've also been told that a seal weld can help protect against cinder cutting, especially on a coal burning engine and if the locomotive is being used in rigorous service. The continued use may primarily depend on just what kind of money the railroad chose to invest in maintenance and the experience of the foremen who made the decisions. If you had seamless flues a copper ferrule may not see as much abuse as maybe an engine that has seamed flues and perhaps a well worn flue sheet.

At any rate, today you'll find some engines that get beat to death everyday and others that run three or four times a year. Each situation is unique.

The main point I want to make is that if a boiler was built to have ferules. The tube holes were drilled around 1/8" to 1/4" larger than the tube diameter. If ferules either copper or steel aren't put back in, the tubes will be over expanded causing cracking & leaking. I know of a boiler where this very thing happened. Also having the soft copper ferule helps prevent damage to the tube sheet from over expansion from improper installing of the tubes.
I guess the point I want to make is if it had ferules, it needs ferules of some sort.

Dave Huffman

Mr. Hillier,

Please refer to my first post for the history on the use of copper. In the late 30's it became standard practice to seal weld ALL tubes on the firebox end. The seal weld seals the tubes as does the expanded fit to the sheet. The act of seal welding does not do much if anything to protect the tubes from cinder cutting, what it does do is thermally bond the tube to the sheet.
The end of the tube (even when beaded over) will get burned over time, more rapidly on an oil burning locomotive. The tube heating up somewhat independently of the tubesheet is what results in leaking tubes. Copper does not "add" to maintaining a seal, it was a means of making a seal under conditions that occured prior to thermal bonding by weld.
A ferule /tube sheet does not know if a tube is seamless or ERW, if there are any surface imperfections to suggest there is a notable difference the tubes should be rejected from the supplier and replacements sought.
The other objects you mentioned using copper use it as the only method by which a seal is made. It is a crush gasket no different than the rings used on the brake systems of some automobiles or the stainless/graphite composite ring gaskets on modern day piping systems and some boiler manholes. Stainless does not expand much compared to copper and yet they still keep seals quite satisfactorily for many years and through countless thermal cycles.

DBH,

Tube holes were generally reamed 1/16" larger to accommodate a 1/32" ferule on 2" or 2.25" tubes. This is assuming that the tubes were not (from the manufacturer) swaged as are all flues. Any tube hole in excess of this is larger from multiple retubings and possibly over rolling. If ferules are not put in on sheets with oversized holes they will be damaged.
Copper should not be viewed as a means to protect a tubesheet. If a tube is over rolled to the point damage may occur to the tubesheet then the tube itself has been damaged and it's full service life may well not be obtained, depending upon operating conditions. "One doesn't know what they don't know until they know it"....unskilled/knowledgeable individuals should not be installing tubes into nor doing any other type of work to a locomotive boiler.

A tubesheet does need ferules if it utilized them(because the holes from the factory were oversized) or if the tube holes are oversized from wear/damage. Beyond that, the use of ferules would be an act of not recognizing the learning curve experienced by the railroads and industrial steam generation industry over half a century ago. This accomplishing nothing more than adding unneeded expense and an extra step to the retubing.

Cheers, Jason

I mentioned an engine getting beat to death for a reason. In a perfect world all flue sheets would be even and consistent, but when an egg shaped hole and wear come into play, that is one of several cost factors that come with steam maintenance, including a fairly consistent employee turnover that you will find at most if not all steam operations today.

I understand that beading over a tube end was a newer method, however it still is done on engines that were built after the 1930's. Cinder cutting well still wear out a seal weld, I've seen it myself. The ferrule does not extend beyond the sheet end but does act to help seal the surface between the inside of the sheet and the outside of the tube. I agree that oil firing may see an increased fluctuation in heat and in a shorter period of time than coal, however there are still outside stresses to consider such as cinder cutting and fireman/hostler training and experience.

Jason your last paragraph said what I have been saying all along. I have installed tubes on both fire tube & water tube boilers & the rule I have went by is use what you have to work with. If the tube sheet was sized for ferules use them.

Dave H

DBH,

I guess I could have stated it more clearly....I was agreeing with you save the size of the tube holes from the manufacturer.

Mr. Hillier,

The practice of beading is not that new of a practice, I have several books published pre-1900 that detail this as standard practice. The seal welding is the new practice. While I do not doubt that you have witnessed cinder cutting of seal welds(as you were there and no doubt saw what you saw) it is simply something I have never witnessed nor do I have any documentation regarding it being a common issue. In fact, it was and is a common occurrence for debris, soot, carbon, clay, etc. to build up on the surface of the tube sheet and tube ends. This occurs as the exhaust gasses diverge as they enter the tube leaving a "dead" area amongst all of ligaments...Mr. Austin, any thoughts on this?
If a hole is egg shaped and is not repaired, copper would help. It would be appropriate, by one method or another, to true the hole back into round. There is a callout for the maximum allowable out of round of a tube hole but my mind fails me, my library is two hours away and I am not going to guess as to the correct dimension.
In regards to crews, well....An inexperienced person should not be allowed to abuse the boiler just because he is the only one that can be scheduled or because "he has put in his time towards being qualified". I am perhaps to much of an idealist as I know this is a regular issue.

Jason

Yes you are correct about the hole sizes. My bad. Been over 20 years since I have replaced a tube.

Dave Huffman

It may be of interest to note that in removing tubes from SP locomotives I have found strips of sheet metal (iron or steel ) between the outside of the tube and the inside diameter of the tube sheet hole. These are only found on the smoke box end. The edges of the strips come close together but don’t actually touch. Often the ends are cut at an angle not square. It would appear that a strip of sheet metal was cut and bent into a ring and placed in the hole to act as a ferrule. I haven’t cut tubes out of an old SP locomotive in maybe 30 years but I have just now been reminded of this and so have searched through my copy of “Southern Pacific Boiler Repair Manual” copyright 1982 Charles Hoyle.
From section 6, Instructions governing the resetting, safe ending and maintenance of tubes and flues, issued January 21st, 1935, Rule 3, paragraph (h),

“When tube holes in the front tube sheet are found slightly enlarged, the tube shall be shimmed with black iron or jacket iron shims (not galvanized) of proper thickness. Tubes should then be rolled in the sheet with the proper diameter rolls. Care must be taken to prevent rolling too severely, as this will thin out the tube walls, and may result in tube failure.”

I have seen these shims and they look out of place. Some ever project past the tube sheet and you can see them sticking out.
Elsewhere it states that if the hole is 1/8” or larger than the tube outside diameter the sheet is to be renewed.