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.
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.
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.
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.
In Upcoming Updates: The throttle handle and rod as well as the engine lubricator.
On April 23, 2022, a team of volunteers consisting of Kyle G., Ross S., Perry A. Richard P., and led by Ed Ripp, Mid-Continent’s newly named General Foreman of Steam Power, worked on jacking up the front of the tender and rolling out the tender’s front truck. While the truck was out from under the tender, the wheelsets were removed from the truck to facilitate inspection of the roller bearings.
The inspection was necessary due to flooding at Mid-Continent Railway Museum in 2018. The bearings were potentially reached by the floodwaters which could have led to corrosion on the bearing surfaces. To make sure no water damage had occurred, it was necessary to remove the wheelsets to allow for a full, detailed inspection. Fortunately, the inspection of the front truck wheelsets found no evidence of corrosion.
The volunteers also made an adjustment to one of the shim plates so the plate will sit correctly against the tender frame. This work was able to be completed by evening.
Another volunteer work session will be forthcoming to inspect the roller bearings of the rear truck and possibly start installing fittings on the water ports of the cistern.
Our update of November ’21 covered what was going on with the grate installation inside the firebox. Here we will tie things up and cover the shaker mechanism & linkages. The shaker fulcrums are attached low on the backhead of the boiler near the mud ring. The cardboard over the firedoor hole is a mock-up for a needed spacer to allow mounting the firedoor over the staybolt ends. Detail on why is included below.
The shaker handle is slipped over the short stub controlling the section of grates to be shaken and the latch is released to allow the work to begin. The shaker rods reach under the boiler and connect to the tabs on the bottom of the grates in groups.
Because we are dealing with a new boiler of welded construction modifications are having to be developed and implemented. In the new boiler the welded staybolts stand out from the surface where the original construction used threaded stays which were hammered over during installation and resulted in an almost smooth backhead as seen in this shot from 2004.
A spacer plate has been machined in order to give a smooth mounting surface for the fulcrums and you can also see new pins and latches have been fabricated. In the last shot we can see the grate shaker system fully installed and ready for the first fire.
What are the first three things an operator must know on any boiler? 1) Where’s your water?, 2) Where’s your water?, And 3) Where’s your water?
A steam locomotive’s water level is so important the Federal Railroad Administration includes an entire section dealing with water gauges in the CFR Title 49 Part 230 Steam Locomotive Inspection and Maintenance Standards. Part of 230.51 states that “…The lowest reading of the water glasses shall not be less than 3 inches above the highest part of the crownsheet. …”. What’s the crownsheet? It is the ‘roof’ of the firebox so it will have the heat of the fire on one side and the water of the boiler on the other.
The water is constantly absorbing the heat transferred through the crownsheet and keeping the steel relatively ‘cool’. If the water were allowed to get low enough to let the crownsheet become dry then the heat of the fire from the underside could quickly damage the steel or worse.
How do we prevent this situation? By constantly being aware of the water level in the boiler. But first we must know how low is too low by knowing where the top of the crownsheet is. This was done at SPEC Machine in January by first confirming the engine was setting level. Front to back level was first checked and then side to side.
The next task was to use clear plastic tubing to create a “U” shaped tube open at both ends. One end of the tube was placed against the highest point of the crownsheet inside the firebox but with a small notch in the end to allow air and excess water to escape.
The other end of the tube was brought out through the firedoor and tied to the throttle gland so the outside end would be higher than the end inside the firebox and a funnel was used to fill it with water. Once the water quit running out of the end of tube in the firebox the level of the water shown at the outside end is equal to the level of the bottom or inside/fireside surface of the crownsheet.
To locate the top of the crownsheet and mark it per FRA requirements we had to add the thickness of the welds and the crownsheet itself. Now that we’ve found the top of the crownsheet the water glasses and try cocks can be laid out for installation so the lowest water indication is no less than 3 inches above it. Generally speaking as long as we can see water in the gauges we’ll have at least 3 inches of water over the crownsheet if we’re on level track.
Once finished playing in the water, other layout and installation steps have been made. Locating and installation of the sand dome base has been finished and this task includes another milestone in the 1385 project; the first studs to be applied to the boiler since its delivery to SPEC Machine are used to hold the sand dome base in place. You can even see the glint of one of the new studs at the top of the boiler and just under the edge of the base here.
Another fixture on the backhead is the throttle lever and the pivot point that is studded to the boiler. Here Steve has rigged a temporary way to support the pivot to facilitate this layout. The throttle rod reaches through the packing gland attached to the backhead and through the boiler to connect with the bell crank and levers that will allow the engineer to open and close the throttle which resides in the steam dome.
The Wisconsin State Journal writer Barry Adams paid a visit to SPEC Machine to take a look at the latest progress on Mid-Continent’s Chicago & North Western #1385 steam locomotive and interviews shop owner Steve Roudebush.
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