I'd like to add a pair of photos that will hopefully help clarify some parts of the braces under discussion. This shot is from inside the firebox of C&NW 1385 and you can see that the firebox doorsheet knuckle has been removed so you can see inside the water space. In the shot you can see 8 clevis's (sp) riveted to the backhead. I've circled a 4 rivet clevis and a 2 rivet clevis.

In this shot I've circled a pair of the 4 rivet and the same 2 rivet from the outside. Using a bit of imagination you should be able to see the pattern of the bases and get a handle on how many braces have been applied to this section of the boiler.

The surgery applied to the boiler took place in the late 90's (prior to current Part 230) while the vessel was under the jurisdiction of the state and we were working to satisfy the State Inspector.

mld

In answer to Chris regarding the lack of Form 4 documentation of the brace end attachments, it was not an oversight. The Form 4 does not pretend to be a record of every possible calculation needed in analyzing a boiler. The intent was to substantially increase the information required over the historical form but only address the issues where problems were typically found. It is pretty rare that problems exist with brace attachment since the geometry is very specifically called out in the 1952 Loco Code and up to 1971 Section I (applicable rivet code until the 2013 edition which brought back PR). This geometry was called out pretty early in the code world, though I can't recall the exact first appearance. The only issues I have encountered are with the old forged-end strap-like clevises that pre-date code requirements which are sometimes undersize. These older locomotives also often contain other unique construction methods that sometimes do not fit within the more standardized methods of later construction. There is no doubt that this information is very important which is why it will be included in the new ASME locomotive boiler construction code.

The current Form 4 attempted to get the majority of information that would lead people to consider other items not specifically called out. Additionally, the new form was the result of a public process where anyone could comment and all comments were required to be addressed. It was a political process as well as a technical one, where the new form needed to be "sold" to the industry. Yours is the first comment I have seen that indicated the form might be too short. There were plenty in the other direction. It is my opinion that we probably would not have gotten the new form had we included the information you spoke of in such a way as to align with existing codes at the time, along with other information the committee considered.