Classic cars forum & vehicle restoration.

[Peter_L]

Stumbled across this page and a photo of 1950's U.S cars with "desert water bags"

http://theoldmotor.com/?p=148942

I had seen modern vehicles in U.S desert areas, with bags hung on the front, never though much about it but there is more to this than just a supply of water.

Back in the 1920's crossing the deserts by motor vehicle was not easy on the primitive cooling system. Flax bags, the Flax coming from Scotland, were filled with water and often hung in front of the radiator. The water slowly seeps through the flax and evaporates, cooling the contents of the bag and also the air passing over the bag. It would appear that the cooler air reaching the radiator did more than compensate for the reduction in air flow caused by the bag. As cooling improved, bags were hung from the bumpers and served solely as a water supply for the vehicle and its occupants.

Looking back further, it may be that the early pioneers, often from Europe, used old flour bags to store and cool water.

Look up "Flax cooling bags" for lots of images

[peter scott]

I can see the sense of bags on the roof but a bit skeptical about bags in front of the radiator.

Peter


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http://www.nostalgiatech.co.uk
1939 SS Jaguar 2 1/2 litre saloon

[colwyn500]

[Peter_L]

Hello Peter S and Colwyn. Your comments about the airflow are similar to my original thoughts, i.e restricted airflow. However, from what I read and having driven "moderns" in the California deserts, where temps can reach 120 °F (49 °C), the thinking and science behind hanging the bags applies to these conditions rather than the more normal.

At 40+C, the hot air doesn't cool the engine coolant sufficient to prevent boiling and therefore water loss. Although the bag reduces the volume of air, the air that does reach the radiator has a cooling effect that could not be achieved by the hot air and higher air flow volume.

This link https://physics.stackexchange.com/questions/97959/how-does-a-canvas-water-bag-cool-water and others explain the science behind it.

I gather that when cooling systems improved, the bags were hung from the bumper or wings/fenders and were there just as a supply of water and not an aid to cooling.

[Penman]

Hi
I haven't noticed this on the LRDG vehicles.
http://tinyurl.com/y972ghpj
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Bristols should always come in pairs.

Any 2 from:-
Straight 6
V8 V10

[Peter_L]

[roverdriver]

Water bags are still popular in Australia, although growing less in recent times. As far as I understand, the plan was simply to cool the water in the bag, and had no intention to cool the engine.

The water bag dates back long before the motor era. Early settlers and explorers would hang theirs on a handy gum tree, in the shade, and where it could catch a breeze.

Using the same science, a popular home device was the Coolgardie Drip Safe for storing perishables.
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Dane- roverdriver but not a Viking.

[Peter_L]

At the moment, it looks as if the "jury is out" on whether or not the bags were hung on the radiator of older vehicles (1910-1920 ish).

I found this article from a California museum, a Model T complete with bag.
However, this only goes to further muddy the waters, as it may be a result of something that is in fact an urban legend.

There was a TV show "Mythbusaters", now ended, they could have a taken a Model T into the desert and tested it.


https://emilyzell.com/2015/05/19/we-find-ourselves-dias-de-los-muertos/

I have yet to find a period photo of the aforesaid bags in position on the radiator.

There were so many bags made by several companies, most with the opening top to allow cleaning, which confirms their primary use was potable water, but, what if one morning John or Jane Doe forgot to take the bag off the front of the radiator where it had hung for use in the camp.

Off they went on their merry jaunt in the 120 F heat on;y to find that they got further before the steam started to rise from the radiator ? ?

[Da Tow'd]

The old canvas water bag had " a cool drink on a hot day" printed on it
water tasted nasty
but the radiator never complained
Hank