Mid-June 2019 Boiler Progress

Chicago & North Western #1385’s boiler continues to see steady progress. Since the last update, the boiler has been moved across the Continental Fabricators shop floor and is now on the positioner.  With the boiler now on the positioner, it can be rotated to allow workers to put it into the best position for welding and assembly in areas that would otherwise be difficult to access.

C&NW #1385’s boiler on the positioner at Continental Fabricators. The positioner allows the boiler to be rotated. June 11, 2019. Photo courtesy Continental Fabricators.

Installation of the crown stays is also in process. Crown stays are the staybolts that connect the wrapper sheets – which wrap around the firebox – to the crown sheet (i.e. the top of the firebox). The crown sheet is directly above the fire and is the hottest part of the firebox.

crown sheet diagram

The crown stays (shown in green) support the crown sheet at the top of the firebox, preventing it from bowing inward from the immense pressures.


Late-May 2019 Boiler Progress

Work on Mid-Continent Railway Museum’s Chicago & North Western #1385 locomotive during the month of May has consisted of stay installation, stay installation, and more stay installation. With over 900 staybolts to be applied, this process represents one of the more time-intensive portions of the new boiler production. Each weld must be made with great care and precision to avoid leaks and ensure proper strength when the boiler is under operating pressure.

Continental Fabricator’s Tom G. peered into the belly of the beast on May 29th to take these photos of stay installation progress on the inside of 1385’s firebox.

Early-May 2019 Boiler Progress

Since we have a new month and new Monday we also have a new update! Tom G. from Continental Fabricators writes:

Here is the latest update..
All but 22 backhead stays are installed, most of them have the root pass in and  working on completing the welding.

The side sheet stays are also moving along.
Throat sheet flexible stay installation to start this week…

Included with the update was two photos.

Late-April 2019 Boiler Progress

Continental Fabricators’ Tom G. supplied Mid-Continent Railway Museum with another new photo and a brief progress update on April 29th. Continental Fabricators is the shop hired to construct a brand new welded boiler for Mid-Continent’s Chicago & North Western #1385 steam locomotive.

“Most of the backhead stays are fit as of this morning and they are beginning to weld. Stays in the sidesheets will be fit this week. The barrel is 60% welded.”

View of 1385 boiler backhead with most stays installed and ready for welding. The backhead is the portion of the boiler that extends into the locomotive cab. The large round hole in the center is where coal is shoveled into the firebox. Photo courtesy Continental Fabricators.

Flexible Staybolt Design and a Boiler Factory Tour

Photos and text by Pete Deets

Staybolt Update

No, this is not a fleet of UFO’s lined up at SPEC Machine. These are the caps for the latest batch of flexible staybolts being made for the 1385.


The caps and sleeves shown (above) and the staybolt itself is completed when a ball end (below left) is threaded onto the bolt and the bolt is placed into the sleeve (below right).

Below is a comparison of the two types.

You may wonder why we need 2 types of flexi’s. That is because we have to allow for support of curved as well as flat surfaces. This illustration from the 1938 Flannery Staybolt Catalog shows how the first batch of staybolts will be applied. This is the UW style and is designed to be used where the staybolt will be going through the supported sheet at close to a right angle and the inside and outside sheets are very close to parallel. The flexible staybolts on the throat sheet at the front corners of the firebox will utilize the UW style.

The latest batch is the WR style which is designed to be applied where the inside and outside sheets curve at different rates and do not run parallel. This is the situation near the top of the wrapper sheet and firebox. Because the top of the firebox (the crownsheet) is rolled in a tighter radius than the wrapper sheet and the rigid end of the staybolt needs to be square to the sheet it is attached to the flexible end goes through its’ sheet at some angle.

All these parts are coming together and will be forming a boiler very soon.

A Look Inside the Continental Fabricators Factory

I took a quick trip with Steve & Tyler Roudebush of SPEC Machine to deliver a palette of parts to Continental Fabricating in St. Louis as well as inspect the progress on the new boiler for 1385. More photos and details about the boiler will be posted later but I wanted to share a few shots of Continental’s shop. I hope this will give folks a feel for the size of operation building our vessel.