Note: The following letter is one of the few surviving bits of my previous website. Originally it was a post to Karl Peterson's excellent Lightsteam list. Thanks to GB Gilbert for saving it and digging it up from his files.

Subject: Freezeproof Steam Car
Date: Thu, 23 Sep 1999 02:26:15 -0700
From: Peter Brow
Reply-To: LIGHTSTEAM
To: LIGHTSTEAM@MAELSTROM.STJOHNS.EDU

Hi All,

Matt from Canada wrote me about freezeproofing a steam car. If you are on the list, Matt, I tried sending a reply to the return address on your email, but it was returned with a "user unknown" error message. So I decided to post some of my ideas on this to the list.

I will also post this to my website. An updated description of my current steam powerplant concept is now there:

http://sony.inergy.com/inventor

Here is the reply I wrote to Matt. I am not sure if he is on the list or was simply replying from my website.

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Thanks for your interest and question. I live in southern California, where freezing weather is extremely rare, but have done quite a bit of design work on preventing freezing in steam cars.

Stanley steamers, interestingly, were most common in the northeast US, where freezing winters are the norm. Their boilers, like most steam car boilers, were so tough that no damage occurred when they froze. However, usually they were simply left with the pilot light on, and if set right, this would not only prevent freezing but keep up full steam pressure for days. Freezing was never a problem. The exhaust flue from the boiler let out right next to the water tank, and the slight flow of hot gases from the boiler kept the tank from freezing, too.

The water tank was designed to freeze without splitting; its sides were sloped like the sides of a compartment in an ice cube tray. If the tank froze, it would quickly defrost after a couple minutes of driving, due to hot water coming in from the condenser and hot boiler exhaust flowing over the outside of the tank. Hot air from the radiator at the front of the car also helped.

I plan to use a similar approach, with some changes and improvements. The water line and pump (the hardest parts to freeze-proof) would be encased in a small insulated flue-gas duct to conduct heat from the boiler to these parts for preventing freezing or for defrosting. The pump and water line are very short and small in diameter, and will take minimal heat to defrost. Whenever the burner or pilot are running, heat would flow to these parts to warm them. A similar warm-exhaust duct would be put down the middle of the feed water heater to keep that from freezing on standby; both of these would thermostatically shut off warm gas flow once the system is warmed up.

If a sensor indicates the water system is frozen (flexible high-pressure tubes prevent bursting), the throttle will automatically lock and a "wait" light will come on until defrost is completed. Then everything will come on line. Boiler exhaust will keep the tank liquid. The pilot light will keep the boiler at full steam full time. With ~1" of modern ceramic fiber insulation on the boiler, the pilot light needed for this will be the size of a few bic cigarette lighter flames, and by my calculations will only take a few cupfuls of fuel a week, not much more than would be consumed firing up the system from cold every morning.

I am looking into insulating the water tank and running boiler exhaust through a metal flue lying against or surrounding the tank. The flue could be open or shut with a simple and reliable thermostatic flap, to maintain tank at optimum temperature under any conditions. This would increase short-trip fuel economy also, by warming up the tank quickly.

I would prefer an anti-freeze water additive, but have researched this, and nothing seems to be available which will take 700°F steam temperatures without breaking down or reacting with boiler tubes or oil in the system. If I find something like that, I may use that instead of the above tricks. However, even then a system like the above, which isn't too complex and would add a couple hundred dollars at most to the cost of the car, might still be preferable as people wouldn't need to mess with special additives or end up with a frozen car if they forgot.

If the car is to be left in freezing weather for an extended time, a "shutdown" switch is pressed, and the pilot light turns off. This could be a special shutoff position for the steering column key. The boiler will siphon full from the water tank as it cools down and forms a vacuum inside, and boiler and car can then freeze. With high-pressure steel tubing, no problems will arise. To start up again, just turn on the main burner. This defrosts and then steams up the boiler, and the hot water and steam automatically blown off from the boiler during warmup will blow through the valves and cylinders, warming them up, and will defrost the feed water heater, condenser, and water tank. While this is happening, hot gas from the burner flows through the duct mentioned above and defrosts the water line and pump. In a minute or two, the entire powerplant is ready to run.

It would be more convenient to just leave the pilot on, so you could take off immediately without waiting 1-2 minutes, but this may not be practical if the car is to be left for, say, several weeks in freezing weather.

Unlike gas cars in very cold areas, no electric block heater is needed.

There are lots of ways to freeze-proof steam cars. These are a few possibilities. Many were used back in classic steam car times, before 1930, and are used with antique steam cars today. Some sound a bit crazy or complicated, but they work with minimal extra equipment, and I think complete automatic freeze-proofing in a modern steam car would be pretty easy and affordable. It is not a killer problem, despite occasional claims by steam car critics. This system would not require any special attention or adjustments from the driver; even in severe freezing conditions, running the car would be "turn the key and go".

My plan is to make built-in freezeproofing standard equipment no matter where the cars are to be sold. Even cars in tropical areas are sometimes driven to mountain altitudes where freezing can occur. In my area, it rarely freezes on the coast, but freezing areas in the mountains are less than an hour's drive away and many people make the trip.

I apologize for the length of this reply, but hope you will find the details interesting. As you can see, I have given this issue some thought. Your comments and suggestions are welcome and would be interesting and useful due to your experience with freezing conditions.

Steamcerely,

Peter Brow
San Diego, California