We have been using a stationary boiler to preheat our locomotive boilers by bubbling steam through a pipe just above the mud ring. We have been able to raise steam up to 90# on house steam. Because there is no fire in the firebox it doesn't count as a service day. My question is; if one didn't have a stationary boiler for steam how could one prewarm the boiler without house steam to save conserve service days and reduce thermal stress on the boiler? Like a lot of tourist railroads we have a two a week schedule so it doesn't make sense to keep a fire in it all the time. Is anyone else doing anything like this?

Yes, the rack railroads in Austria and Switzerland!

https://dlm-ag.ch/wp-content/uploads/2020/06/Vorheiz-und-Vorw%C3%A4rmger%C3%A4te_d_e_2020-04-20.pdf

Mike

Swiss rebuilt 8055 carries this a step further. That boiler and firebox is heavily lagged, with high-R-value damper panels, and they found it possible to use about 35kW of 'electric water heater elements' not only to keep the locomotive warm over cold winter weekends but to maintain steam pressure -- meaning there are no differential pressure cycles as well as no thermal cycling. Modern nanoinsulation systems could accomplish a similar result...

If you used a Cunningham circulator, you could probably put a chamber with throttling heating elements in the line between the downcoming port in the convection section and the manifold at the water leg, and run a circulating pump a bit like sous vide to maintain desired temperature (or start heating from cold).

I am in too much discomfort to check CFR on a phone, but I believe there is part of the service-day determination that involves pressure above atmospheric due to heating the boiler. That would limit the ability to heat the boiler above 212F, but I think it would make sense to keep the thing "as hot as possible" even if you used nitrogen blanketing or a similar idea to keep air out of the system...

Swiss rebuilt 8055 carries this a step further. That boiler and firebox are heavily lagged, with high-R-value damper panels, and they found it possible to use about 35kW of 'electric water heater elements' not only to keep the locomotive warm over cold winter weekends but to maintain steam pressure -- meaning there are no differential pressure cycles as well as no thermal cycling. Modern nanoinsulation systems could accomplish a similar result...

If you used a Cunningham circulator, you could probably put a chamber with throttling heating elements in the line between the downcoming port in the convection section and the manifold at the water leg, and run a circulating pump a bit like sous vide to maintain desired temperature (or start heating from cold).

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I have been thinking of installing the equivalent of a home hot water heating system to keep 58 warm between runs. There would be a propane fired "boiler" and a low power draw circulating pump. The good thing about this setup is how common they are, meaning repair parts would be readily available. I would want to keep the temperature around 200 degrees which would start giving us steam pressure within about 15 minutes of starting the fire.

Why not simply use a gas or electric water heater commonly available at the hardware supply house? Connect the water column drain to the water heater intake, and connect the water heater output to the blowdown, all with quick fittings.

I agree with Rick Rowland's post.

Bob Krieger could give you the details, but for awhile they used one of the huge water heaters made for car washes.

Speaking of preheating, a solar water heater might do well...aka a long length of black hose laid up in back and forth folds over your dark-colored roof, most effective in already-hot weather but surprisingly usable in many climates most of the year. It sounds funny, but it can save a lot of fuel by supplying the tank with water that is already very warm to hot. If you’ve even used a camp shower bag, either in a spot without running water or during long outages, you’ll know what I mean.

In the early 1970's, Dan Ranger devised a layover system he used on Graham County Railroad Shay No. 1925. It consisted of a typical 50 gallon electric hot water heater that was connected to the locomotive by two hoses and depended solely on convection to circulate hot water through the boiler. This worked well on the engine, which was stored outside. He had a similar system on the GCRR's 70-ton GE.

In the 1980's. a railroad I worked for used hot water heater elements and hot tub pumps to keep EMD SW-style diesels warm, even down to in just above zero temperatures. The elements were enclosed in a section of 6 inch steel pipe.

Consider strongly the location of the heater relative to the height of the boiler. The preheat / maintenance system built at Golden Spike drained the boilers unintentionally into the heaters down in the pit.......

At Grand Canyon Railway, we devised a boiler preheater using a hot water heater that we recycled from a glycol heating system from a passenger car.

The heater runs off of 480V. We attached a circulating pump to it and fastened the whole thing to a 2 wheel 'dolly' for easy movement around the shop. Water is taken from the blowdown and enters the injector delivery pipe through a valve and pipe fitting we attached. That way the water follows normal circulation patterns - in through the boiler check on the front, out through the blowdown on the back.

The heater can bring the temperature up about 2 degrees an hour on a 4000 gallon boiler. We start 2 or 3 days before fire-up so that the water is just below boiling point when we light the fire. A thermostat on the heater allows us to control the temperature of the output water.

In theory, we could use this system to develop some amount of steam pressure. Once I came in on a weekend while the system was running, and the thermostat was a little too high. Apparently the water was boiling in the heater and creating steam bubbles, which were causing the boiler check to jump around and make a huge racket. To save wear on the boiler check, we stop around 195 degrees.

Works good to heat the water for hydro's too.

And as for the regulations in Part 230, A service day requires BOTH a fire in the firebox and pressure above atmospheric. So a water heater raising the pressure above 0 is not a service day, but a propane heater in the firebox is.

Eric

Kelly, it sounds like this is past tense i.e. SRC no longer uses it. Did they upgrade to something newer or do away with it all together?

If SRC got rid of it all together, what was the reasoning behind that?

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Bought a used tankless water heater today. Working on the install. Should be an interesting project.

So fair question here, but with most locomotives what type of boiler could you use that would cover the water pre-heating that isn't going to cost through the nose? When I look at something like J&L 58, the boiler that pops into my head as an option is one of the larger Buderus boilers that we deal with through work. But even if you just keep the boiler water at what, 180 degrees? You're still going to have the question of oxygen in the environment. What would that do to your preheating unit to help account for that? Oxygen equals corrosion, and corrosion eventually leads to any boiler failing. Could you somehow coat the interior of the preheat unit with something like the apexerior that I know is used in locomotive boilers? And if I'm getting the name wrong, my apologies. Whatever it is that the Valley has used on their locomotive boilers.