No! It does not!
As often happens, the researching of this piece led in unexpected directions ...
Early Canadian passenger car cooling went through two phases.
- First, there was : Are you hot? Well, open the window! Enjoy some coal cinders from our hard-working locomotive!
- Second, there was: You know what's cold? Last winter's ice!
I read the following Trains magazine article from August 1951 and concluded there was a chapter in Canadian passenger car cooling which was unknown to me.
We begin with an advertisement from August 1951, mentioning that the C&NW 400 Fleet. 'Today air-conditioned cars are taken for granted.'
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| from: Trains; August 1951. |
I've added a brief contemporary overview of the Chicago & North Western, in case readers find it interesting.
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| from: Handbook of American Railroads; Robert G Lewis; 1951; Simmons-Boardman Publishing. |
The Trains article begins with a photo of a C&NW locomotive consist which is releasing steam.
Hoping for a slightly clearer explanation of all the elements of the system, I looked through CPR passenger car heating and cooling equipment instruction/rule books from the 1940s and 1950s. They provided instructions for ice air conditioning ... and Freon-based air conditioning in the era of the RDC (Dayliners) and the Budd-built cars for The Canadian. No other cooling system was mentioned.
During our summertime 1968 western trip over the CNR, we saw them loading the passenger car ice boxes at Capreol.
While some Canadian cars may well have had a 'steam jet refrigeration' system, my cursory research turned up no evidence that they did. On the first page of the article, it states that 30% more steam is needed to cool than heat the cars.
... Would penny-pinching Canadian railways choose to employ yet another cooling system (beyond: open windows, ice, Freon) which was that inefficient? Didn't they have all kinds of access to lakes and rivers all across Canada which froze every year? Didn't they have experienced casual labourers accustomed to working outdoors who were eager for employment during the winter months?
I finally checked From Abbey to Zorra via Bagdad; Dale Wilson; 1980; Nickel Belt Rails. In this book, he includes Official Register of Passenger Train Equipment pages from 1949 and 1960 for the CPR. Indeed, only Electro-Mechanical and Ice-System are indicated ... and Waukesha*(see bottom of this post) and Steam Ejector are mentioned in the footnotes as standard alternatives (on other railroads).
As you know, with a Freon system ...
- A compressor and a condensing coil create a high temperature, high pressure liquid (Freon).
- It is allowed to expand, passes through an evaporator (essentially it boils off) to become a low pressure, low temperature gas (Freon).
- The metal fins on the outside of the evaporator are cold and a fan blows the cold air to the area to be cooled.
It turns out that steam ejector or steam jet refrigeration is a classic thermodynamic technology which is used in many different types of 'process engineering'. If you want a gas, liquid or solid drawn into an area and cooled, you can do it with a steam jet. An oil refinery is/was probably one application where this technology would be useful.
Bernoulli's Principle, as you know, cautions us all against holding our smartphones at an open window on a single-engine aircraft to take that perfect photo - because the fast-moving air on the outside creates a low-pressure stream which will rip the phone from our grasp (see YouTube for examples).
A steam ejector uses Bernoulli's Principle, has no moving parts, and can be engineered to match the demands of the specific process, that is:
- The particular force needed to draw in the substance.
- The particular amount of cooling desired.
The train cooling schematic is reproduced and enlarged below. Only look at the top, right corner:
- Hot water emerges from the cooling coils - the coils/fins just have cooled a passenger area.
- It enters the evaporator where the steam jet creates an area of low pressure engineered to boil water at 50 degrees Fahrenheit - about 10 degrees Celsuis. The water becomes cold.
- The cold water is again pumped through the cooling coils to cool the passenger car space.
All the rest of that confusing diagram just explains how all the steam is handled and cycled into water after it leaves the jet. While it is great that it can create that 'jet' which results in water being cooled ... the post-jet steam still contains a lot of heat. So we're faced with the necessity of getting rid of the waste heat and not wasting copious amounts of water from the steam generator tanks on the locomotive - because then we must stop to refill them.
To sum up:
... If your railroad is hauling movie stars across a southern American desert on a prestigious train, I guess you won't mind spending extra on fuel for steam generators.
... If your Canadian railway is operating through relatively temperate summer weather most of the time, an ice system is still probably your best bet ... until Freon-type electro-mechanical cooling systems are available at a reasonable price after World War 2.
As one example of the Railway-Ice Industrial Complex ... the Wilson Ice Company of Hudson, Quebec had a large operation, cutting blocks of ice from the Ottawa River ... from the 1920s, until the loading and storage plant finally closed in 1960.
While it lasts, here's a link to a YouTube video of their operations in the 1940s.
(Steam fans: If you see similarities between steam ejector technology and the magic of the steam locomotive injector ... which takes boiler steam, raises tender water with it, and then briefly overcomes the boiler pressure to force water into the boiler ... Please award yourselves 10 bonus points. However, I don't want to confuse/frustrate/anger diesel fans and so I have meticulously avoided even mentioning steam injectors at all in this post. ... ... ... oops!)
* Waukesha: I found a Pullman (sleeping car) Company maintenance manual for Waukesha lighting and air conditioning equipment from 1944. Essentially, tanks of propane ran Freon compressors to provide air conditioning. Each car had a single propane tank - or a battery of them.
Propane tanks on a train?! On passenger equipment, Pintsch gas (you can search for an article on Pintsch gas on this blog) had been in use for illumination as it was less dangerous than having many reservoirs of liquid kerosene in passenger car lamps. In wrecks, the kerosene would splash all over the wooden coach interior and catch fire from the lamp's flame - which continued to burn atop a kerosene-soaked cotton wick. In a wreck, the wickless Pintsch gas flame would go out when the gas pipe broke ... and the Pintsch gas reservoir - if damaged - would probably safely and quickly vent below the car's steel, concrete or wood floor.
... So, for some time, the railways had already carried pressurized flammable gas under the floors of their passenger equipment.
Waukesha manufactured various products, including automobiles and small engines. Before rural electrification, some of their products would have been essential for cooling, refrigeration and ice-making when farming in a warmer climate in the USA.
... In Canada, however, cans of milk would often have been economically cooled in a cold water bath - pumped from the farm's well.
But, for the sunny and warm US farm, Waukesha produced small gasoline engines which could power Freon compressors for refrigerators and bulk milk tank cooling, and propane engines were available as well. Farms would already have their own bulk gasoline supplies for tractors so perhaps gasoline was more popular. We presume the gasoline/propane refrigerating equipment would have been installed outside the living spaces of a house!
If we look, I think we may find that Waukesha cooling systems were sometimes used in older freight refrigerator cars.
Unless, of course, you were a Canadian railway with abundant supplies of river/lake ice with which to fill the bunkers ...
