Tag Archives: backhead

C&NW #1385: The Looking Glass

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What are those 3 most important things about a boiler? Water! Right Again! How can you tell where it is at? Peer through the looking glass although it is more commonly known as the water glass, sight glass or gauge glass.

The 3-dimensional chess continues with placing the water glasses on the backhead of the boiler. The board clamped in place served not only as a way to locate both FRA-required water glasses correctly but to facilitate checking for enough clearance around and under the other appurtenances already in place.

Water glass mockup.

The metal plate clamped to the backhead serves as a nice flat baseplate for the magnetic based drill used to drill the holes for the appurtenances and studs.

Baseplate mounted to assist drilling water glass hole.

The plate is lined up for drilling of the hole for the first glass. The result is seen here. And like the bottom try-cock the lowest indication of the water glass is 4” above the highest point of the crownsheet per C&NW practice.

First water glass installed.

The plate was then moved to the fireman’s side where the single glass had been mounted on the original boiler and X marks the spot.

Water glass hole location marking.

After drilling and tapping in the threads the second glass is seen here.

Second water glass installed.

With both glasses mounted the backhead is looking more like a locomotive all the time.

Both water glasses installed on backhead.

A volunteer session is being held on September 17 and 18 to work on the the C&NW #1385 locomotive tender. Tasks planned include filling the tender with water to check the truck spring compression and making any necessary adjustments. Additional work planned includes brake pipe fabrication. Persons with experience heating/bending pipe are highly encouraged to participate in this session. If there is sufficient help, other tasks in the Engine House will be tackled. Sign up by contacting project lead Ed Ripp or using the form on our Volunteering page.

C&NW #1385: Mounting Achievements

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The next item to be mounted to the backhead of the 1385 is the hydrostatic lubricator.  That is merely a complicated name for the device that delivers steam cylinder oil to the valves and pistons as well as to the steam end of the engine’s air compressors.  Steam cylinder oil is specially compounded to mix with and then be carried by the steam to all the internal moving parts.

The lubricator lives in the cab of the engine within reach of the engineer so he or she can keep a constant eye on this vital function.  If the oiling stops the engine will begin to make some really ugly noises in a very short time and if not immediately corrected those noises become quite expensive. 

Once again the 3-D chessboard is set to mock up the placement of several pieces at once and the lubricator is hanging from the chain hoist.  The bracket for the lubricator is mounted using 2 studs and its position is being verified between the try-cocks, throttle and one of the two required water gauge glasses.

A chain hoist is used to hold the lubricator in place during test-fitting.
Placement of the lubricator bracket between the try-cocks and water glass.

Here is the lubricator mounted in its final position showing how it is studded to the boiler.  Our parting shot shows the upper right corner of the backhead and the top of the boiler with the body of the throttle peeking up out of the steam dome area.  The dome was made to be removable to better facilitate maintenance work in the future.

Hydrostatic lubricator installed.
Hydrostatic lubricator with top of boiler and throttle in view.

C&NW 1385: Giving it a Try

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The latest accomplishment on the 1385 boiler has been the installation of the Try-Cocks.  That is the proper name of an important set of monitoring and safety devices.  In previous posts the question “What’s the first 3 things to know about any boiler?”, was asked and the answer is still “Where’s your water?“, times three.  It was also shown the highest point of the crown sheet was measured and marked. We are additionally required to install water level indicating devices whose lowest reading shall not be less than 3 inches above the highest point of the crown sheet.          

Close study of the locomotive drawings has shown (Thanks, Ed) that the C&NW standard was to install the indicating devices to show not less than 4 inches of water, giving us an extra inch of safety margin. One of the types of indicating devices is a set of three Try-Cocks, so named because they allow the operator to “Try” the level of the water in the boiler.

Punch marks indicating location of crown sheet are visible just above the blue tape.
Steve R. of SPEC Machine adds punch marks for use with locating the Try-Cock.

In the first picture the punch marks showing the water side of the crown sheet can be seen just above the blue tape.  Steve R. of SPEC Machine works so quickly it is sometimes hard to catch a clear picture as evidenced by the photo of him placing a punch mark to locate the center of one of the Try-Cocks.  A hole is then drilled and threaded to accept the base or “spud” of each Try-Cock. 

Checking the placement and clearance of the throttle and try-cocks.

The above shot shows all three in place along with a temporary placing of the throttle handle to check clearances.  This is part of the 3-D chess necessary to make sure all the components will fit before they are installed.  In the circle is a marking of the water side of the crown sheet so we can be sure the lowest Try-Cock is at the proper level.

C&NW 1385 Try-Cocks. Bonnet and stems (left) are original. Spuds (right) are new.

The Try-Cocks themselves are a mixture of new and old.  As seen here, the bonnets and stems are original to the 1385 but the spuds were machined from a new piece of code-compliant material.  This was necessary because the new boiler has a reinforcing plate applied to the inside of the backhead in order to meet with the strength requirements of the current construction code.  This means the steel in that area is much thicker than the original boiler and in order to properly reach far enough into the water space the spuds needed to be longer.

Each Try-Cock has a drain tube installed in the valve stem to direct the steam and water into the drain cup when the valve is operated to “Try” the water level.  Below is how they look after final installation of the spuds, stems and drain cup.  The drain cup will have a pipe that extends through the cab floor to drain the water out onto the right-of-way.

Final installation of 1385’s Try-Cocks, stems, and drain cup.

In Upcoming Updates: The throttle handle and rod as well as the engine lubricator.

Early August 2019 Boiler Progress

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August has arrived and with it is a new update on 1385’s boiler as it progresses toward becoming a finished vessel.

The fire door ring has been fitted to the firebox and backhead sheets and will be welded in place.  The firemans’ shovel will pass through this opening many, many times feeding the fire that will keep 1385 running.

fire door

Looking at the other end of the firebox we can see where the rear tubesheet braces will be installed.  Those are the wider-spaced holes below the field of closely spaced 2” tube holes.  The braces are necessary because the holes in the tubesheet are above the top of the throat sheet so the braces are welded to the inside of the belly of the boiler.  The braces are shaped like an elongated and squished “Z” so they can enter the hole in the tubesheet at a right angle and also lay flat on the boiler shell belly as they are welded in place.

The shot of the top of the boiler shows that just a ‘few’ stays need finish welding.  You can also see that the steam dome base has been finished. The holes that do not have stays inserted are going to be some of the flexible stays and are awaiting the installation of the sleeves on the outside of the shell before the bolt itself can be applied and welded in place.

We do not have an anticipated return-to-service date for the 1385 but every weld is one step closer. Stay tuned to this webpage or our official Facebook and Instagram pages to keep up with most up-to-date information on 1385’s progress.

We appreciate the public’s enthusiasm to see the 1385’s progress first-hand; however, the contractor shops where the #1385 work is taking place are not open to the public. Anyone showing up at our contractor’s locations requesting to see the locomotive will be turned away. Please help #1385 return to operation as expeditiously as possible by respecting our contractors’ wishes.

Early-May 2019 Boiler Progress

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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.