In response to a question about the use and purpose of the Fog Pressure Units that were deployed by the Chicago Fire Department in the early 1960s, Bill Post has provided the following historical commentary;
The purpose of the Fog Pressure was to be able to get an effective stream of water on the fire quickly before a conventional engine company could get hooked up to a hydrant and led out with a canvas line. They were also handy on expressways and in tight access areas such as alleys, near railroad embankments, and in areas with poor hydrant coverage and water supply problems.
When the Fog Pressure Units were purchased and put in service between 1961 and 1966, the Chicago Fire Department had only about 11 or 12 engine companies which had booster tanks. The CFD had gone literally for ten years (1955 to 1966) without purchasing any new engines. Only the last batch of engines that had been purchased which were ten 1956 B (cab model) pumpers were equipped with 200-gallon booster tanks. One or two older model engines had been modified by the shops and had similar booster tanks added, but they were exceptions to the rule.
The Fog Pressure Units were equipped with 300-gallon water tanks and two booster reels of narrow diameter hose. They had special fog (gun style) nozzles that produced fine misty streams of water at high pressures. This is why it was called “Fog”. With the exception of the first unit which was built on a “Willys” Jeep chassis with a John Bean pump, all of the other Fog Pressure Units were built on International Harvester chassis with Darley pumps and bodies.
While a few of the Fog Pressure Units were located near some expressways, most of them were located in your busy high fire volume districts on the west and south sides. Fog Pressure 2 was located at O’Hare Field using the original Willy’s Jeep apparatus.
Fog Pressure Units were also assigned as the second pieces to all three of our Snorkel Squad companies as they allowed the Snorkel Squad men some tactical flexibility. These were also used to carry additional men and equipment. In 1964/65, the CFD had purchased three Fog Pressure Units that had longer bodies than the previous Fog Pressure rigs. These were specifically for the use of the Snorkel Squad companies.
When the fire department started getting new engines put into service in 1967, most of which were equipped with 500-gallon booster tanks, the CFD started relocating some of the Fog Pressure Units away from stations that were getting the new engines assigned to them. They also started taking them out of service so that by 1970 all of the Fog Pressure companies were gone with two exceptions. Fog Pressure 2 remained at O’Hare Field and of course they kept the Fog Pressure (SS1A) which was assigned to Snorkel Squad 1. Most of the Fog Pressure units were taken out of service in 1968 and 1969 which includes the ones that were assigned to Snorkel Squads 2 and 3 as both of those companies were decommissioned in 1969 as well.
As described in the previous post, Fog Pressure 31A was temporarily put in service at Truck 31’s new house (at the time) for a little over a year as a stop gap measure until Engine 64 was relocated into the house.
At their height in 1966 and 1967, we had twelve Fog Pressure companies in service (not including the three assigned to the Snorkel Squads) but within 2 years nearly all of them were out of service with the above mentioned exceptions.
Bill Post
#1 by Phil Stenholm on May 7, 2012 - 10:32 AM
DAVID: Yes, the first fog pressure rig acquired by the Chicago Fire Department (the one that ended up at O’Hare as “Fog Presure 2”) was a John Bean demo built on a forward-control Willys Jeep chassis.
Fog Pressure 2 (at O’Hare) got a new rig in 1970 (a Dodge 4WD power-wagon) that was in service until about 1980.
#2 by Phil Stenholm on May 7, 2012 - 10:08 AM
There was also a fog pressure rig at Meigs Field in the mid-1970’s (442-A) that replaced Chemical 4 (634).
442-A was probably ex-SS1-A, because SS1 got a Pierce squad-engine (the new SS1-A) to replace its fog pressure in 1974 just before 442-A went into service at Meigs.
Fog Pressure 12 was rebuilt by the shops as Dry Chemical 6 (626) in 1969.
The fog pressure units normally ran with three-man crews, and back when they were in service they often had the pleasure of going (solo) on “Check the Box” runs back when Chicago had fire alarm boxes on street corners, so that engine companies & truck companies could be kept in service for legitimate still alarms. (This was also in the days before companies responded to “ambulance assists”).
BTW, the nozzles & hose lines on a CFD fog pressure rig were similar to what you would find at a gas station pump, except of course they usually used water rather than gasoline when attacking a blaze.
#3 by David on May 7, 2012 - 1:09 AM
Anybody got any more info (or even some photo) on the 1st fog pressure unit which should have been the only one on the Willys Jeep chassis?! Was that the same “Forward Control” Jeep like the rest of the CFD Jeeps?! I think I may have seen a pic of this rig once, but I’m not sure if it was the same rig which is discussed here. It was an FC with white over red paintjob (it was a b/w pic so I just guess that the dark parts were red) and a dome revolving light. Looked much like a demo to me as it wasn’t running in CFD colors.
#4 by Bill Post on May 6, 2012 - 11:54 PM
The triple stage High Pressure pumpers are at Engines 42, 98, 5 and Engine 60. When running in the third stage mode they can supply water at between 600 and 700 psi (pounds per square inch) to my understanding. They are meant to used for fires in the upper floors of high-rise buildings whose own internal pumps may be incapacitated.
The first one to go in service was at Engine 42 in 2005, Engine 98 was in 2006, Engine 5 was in 2009, and Engine 60 went in service in 2010.
New York City has been using “Triple-Stage” high-pressure pumpers on a few companies since 1983, and the last I heard Houston, Texas was running with two such pumpers.
#5 by Dan on May 6, 2012 - 4:42 PM
Thanks for the answer. Definitely an interesting read. I’m grateful you guys are willing to share your knowledge and stories.
Dan
#6 by scott on May 6, 2012 - 4:36 PM
They have 3-stage pumpers. I do not have the companies that have them; different than the old high pressure fog units.
#7 by Sebastian on May 6, 2012 - 3:17 PM
Does anyone know if the CFD currently has any high pressure engines on their fleet???