Bending Steel Part 2: Forming the Throat Sheet

Gary Bensman and his team continued work flanging various sheets for the C&NW 1385’s firebox during the first half of April. Recent tasks included work on the 1385’s throat sheet and backhead.

This drawing of an Omaha Road Class I-1 boiler, a sister engine to the R-1 class #1385, identifies the location of the firebox, throat sheet and boiler barrel.

The backhead forms the rear end of the firebox and is located inside the cab. The fireman shovels coal into the firebox via a small door which will be cut into the backhead.

The already flanged (curved) sheet is the C&NW 1385’s new backhead. The backhead forms the end of the firebox inside the cab. Gary Bensman photo.

The throat sheet serves to connect the round boiler barrel with the firebox’s square-ish lower half. Such a transition requires the throat sheet to be a more complex shape. Where much of the bending of the steel sheets thus far could be accomplished via “cold flanging” by bending on a pneumatically-powered McCabe Flanger at room temperature, the throat sheet’s complex curves require a more hands-on approach. The “hot flanging” or “heat and beat” method involves heating the metal to make it more malleable and then using sledgehammers to pound it into the desired shape. The photo gallery below shows the throat sheet at various stages of progress.

Throat Sheet Backer Completed

“March 25 and 26 saw more progress in the shop. Shop forces included Doug Crary, Doug Klitzke, Don Angles, Jim Connor and Ed Ripp. We completed the throat sheet backer and bolted it to the throat sheet. Completed the rivet bolt tightening. Installed studs in the boiler. The DL&W 425 repairs moved along with work on the B-end truck. Also the center casting and new side bearings bolted and tack welded.”

Photos by Jim Connor.

Work Weekend of Rivet Holes and Back Plate

Mike Wahl reports:

“It was another great weekend in the shop. This was weekend Four in a row. Great progress has been made since Snow Train. There were many people in the shop throughout the weekend.

“The number one priority for the weekend was to finish the rivet holes between the barrel courses. Jim Connors started with a crew on Friday boring holes. On Friday, Jim, Doug Klitzkie, and Bryon Schumacher completed the second course. This work continued Saturday with the same crew working on the first course. We worked late into the evening to complete the boring but when we quit on Saturday the holes were all bored.

“The second priority was to make a new backer plate for the throat sheet. This work started on Friday evening with Pete Deets and Tennessee cutting the piece of material. On Saturday Pete, Mike Flood, Jim Gaiser, and Ed Ripp continued work on this. By the end of the day the backer was fitted and the rivet holes were drilled.

“While this transpired, Al Joyce and Dave Wantz were busy in the machine shop making studs for the throat sheet.

“On Saturday Mike Flood and I went out and measured up the tender. With the nice weather we were able to spend a good deal of time looking the tender over and also looking at how the 22’s tender was repaired. From this information a repair plan and drawings will be completed.

“Chris completed seal welding smokebox seams. There is a little welding left to complete on the front ring and a few bolt holes to weld-up that are misplaced.

“Saturday we were able to complete another task on the list. Ron Kokemuller was able to loan an auto feed magnetic drill to complete the boring of all 196 tube holes. Ron thank you for finding this equipment, it has sure made short work of the tube holes.

“On Saturday Jeff Bloohm and Kelly Bauman gave me a hand measuring the driver tires and lead truck wheels.

“On Sunday the work on the backer plate continued with Doug Crary drilling the pilot holes in the sheet for the staybolts and marking the centers of the holes for the backers. When I left on Sunday he was busy drilling the clearance holes for the staybolts and the stud holes for tapping. Doug how far did you get?

“Doug and I also went on a scouting mission looking for the inlet check so a new mounting plate to the boiler can be designed. After some looking we have found it.

“Bryon and Ed on Sunday worked on tightening the course seam bolts. The third course is tightened up. We need to finish the second and first.

“As you can see it was a great weekend with the highlight being Jim Busse and his family putting together a cook-out on Saturday night. It was beautiful evening and great food. Thanks to Jim and his family.

“Thanks to all!”

Pete Deets adds:

“At one point in time we had three magnetic base drills working at the same time. One was the demonstration machine obtained & operated by Ron K. drilling the front tubesheet. The second was the Fein drill inside the boiler barrel that Jim C. and company were using to core rivet holes. The third machine was the BIG drill on loan from Jim Baker that Ed, Goz and I were using to drill the rivet holes in the throat sheet backer plate. With the stud work, welding on the smokebox and work on coach 425 going on at the same time it was a real happening place! Smoke, metal chips and excitement were in the air.”

Jim Connor photos.

March 5-6, 2005 Work Weekend

This last weekend was most productive, also as we had a very nice crew hammering down staybolts and cleaning out holes in the throatsheet preparing them for welding. Betsy Zonnerville, Bob & Kevin Reihl, Mike Wahl, John Sorrel, Doug Crary, Dave & Bryon Schumacher, Al Hill, Chris Thompson and Kelly Bauman were there to lend a hand. Many staybolts were hammered down and the telltale holes were drilled clear to finish part of the firebox repairs. The staybolts are what hold the flat steel sheets of the firebox together against the pressure of the steam and water in the boiler. The throatsheet is the very front of the firebox that helps make the transition from the rectangular shape to the cylindrical shape of the barrel. The staybolt holes there are being filled with weld and will be drilled out to be threaded when the new rear tubesheet is fitted to the inside of the firebox/boiler. Once again, saying thanks doesn’t seem adequate but WE ARE DOING THIS!

Paul Swanson photos.