While up at Steamtown yesterday I talked to the Mike about 3713. Work is progressing on the firebox but the engineers informed them that the outer crownsheet (sorry still learning parts) or the outer portion of the boiler above the firebox was repaired wrong way back when, the staybolts have beef up rings on the outside, and the whole topsheet will have to be replaced. More sheetmetal work for them.

B&M, Boston and Maine, correct?

Darn it! Yes Boston & Maine 3713

Shown here on her last Boston-Portland trip.

Thin crownsheets seem to be a recurring theme up there huh?

Please let this topic die a quick death, due to inaccuracies in the prior posts. I discussed a problem with Steve(aka Afboone), discovered while performing the boiler survey on this locomotive, I hardly call that a setback, it is a reality. There is no negative spin here, just items that must be brought into compliance with the CFRs. The boiler survey helps define the work scope for that locomotive's boiler restoration. The problem has to do with the outer wrapper sheet, not the crownsheet. It is not a problem with thinness per se, but with old undocumented(meaning we don't have access to the original designers to ask how they applied the various formulas to the boiler) design versus the formulas we are permitted to use to effect repairs under todays regulations (Perhaps a future topic for discussion) and undocumented alterations made by the operating railroad. Nothing unusual here, just something that every operator of steam locomotives is required by the CFRs to investigate and resolve. The Lackawanna & Wyoming Valley chapter of the NRHS is funding 2 contractors(myself & another individual)to further the restoration and are also paying for the Strasburg Railroad to complete the boiler survey and provide the form 4 for this joint venture with Steamtown National Historic Site. Anybody wishing to further the Chapters goal of returning this locomotive to service may send a donation to the chapter at:
Lackawanna & Wyoming Valley R.H.S
P.O. Box 3452
Scranton, PA 18505-0452

Steve and his crew are just starting out on their work on the 565, they have a lot of work ahead of them and I wish them great success. They will learn a lot of technical terms for railroad items in a short period of time. I do not mean to chastise him for his use of the term outer crownsheet, but instead wish to clarify the issue, because the mere mention of Steamtown at times on this board has caused problems in the past.

Mike Tillger

Thanks Mike. Still learning the tech terms. The thingy and the do hicky are slowly becoming parts we know by heart.

Mike and his partner are making great progress on the 3713. The mud ring is new and now they are working the issue we are talking about in this tread. Also Mike is my tech expert on 565 since he worked on her awhile ago.

I checked off the another part name to my long list. Still learning.,,,,,,,

I can understand how THREADED bushings in the outer wrapper can lead to issues in the calculations. However, various railroads once used bushings that were applied into a tapper fit in the sheet and then seal welded...A variation of this could be used where the bushings are welded in with full penitration restoring the hole opening to that of the staybolt diameter in the calculations.
One would have to do a cost benifit analysis to determin which is most effective.

No question about the work needing to be done, but how many more dollars and how many more years is this development going to add to the project?

Frederick G. Bailey