Propane & Propane Accessories

[Montell305]

Ok, sorry about the "King of the Hill" subject line, but I couldn't resist.:cool: Anyway, I am a bus fan from Toledo, Ohio and very much enjoy visiting Chicago and riding the CTA. Being only four hours away the windy city provides a great weekend getaway with some A+ bus watching. So here is what I was wondering, what were the CTA Flxible Propane buses like to watch/ride/drive? What did they sound like? I have always thought that CTA's propane fleet was a very interesting operation that was abandoned too soon. Being that the last propane buses were retired in 1976, two years before I was born, I never had the opportunity to see or ride them in person. IMHO, I feel that the virtues of the propane bus are still greater than the diesel buses in terms of maintenance cost, emissions and longevity. I think this is especially true with respect to today’s technology as it pertains to starting and fuel metering. I also feel that the propane unit is a better option than the CNG bus. CNG has a shorter range then propane and while propane is heavier than air, Chicago proved that it could be handled in large volumes safely during their 26-year tenure with the fuel. CNG buses also require a more complicated fueling station than propane. Anyhow, just curious, if anyone has anything to contribute I would like to hear it. Thanks!!

-Brian:shy:

[westing]

I was never able to experience the buses either, being born in 1986. Yet, from the book "CTA at 45" I found some information about CTA propane buses.

"Propane, with an octane rating of 125 (compared to modern unleaded gasoline at 87), was used in a high-compression engine. This resulted in a smoother performing engine than the diesels of the day, with higher power output at low and high speeds"

Accidents occurred North Park, Kedzie, and 69th garages, reducing enthusiasm for the buses. CTA apparently favored the double-stream exit doors, only made by Flxible at the time. Later GM came out with a diesel buses with single-stream doors and the CTA’s "test" procurement of GM’s buses started a phase out of the propane era.

All I know about the propane buses is from books. I am curious myself how they sounded and handled. Maybe someone else had the chance to ride them will post

Ryan

[Busjack]

I did ride the propane buses on 55th Street from about 1969 to 1974, both the "Big Greens" (5500 series Twin Coach) and the "New Looks" (8800 series Flxibles). They seemed like normal buses, except, by then, the suspensions were gone on the Big Greens, and their interior paint jobs, with all the dark green, seemed oppressive. The run was out of the 69 Garage, which I learned later was late in receiving new equipment because it was all propane until it was converted to all diesel in 1974, upon receiving some buses in the 7540s to 7620s range (pine and lime GMs). The 8800s were replaced by some GM 100 series diesels, which smelled a lot worse, and seemed noisier.

[geneking7320]

Hi All;

I'm a native Chicagoan born in 1954. I lived in Woodlawn until my family moved to Chatham in the late 1950's. I have ridden the 5500s, 8800s and Mack 7200s from the 69th/Ashland and 78th/Vincinnes garages. When I attended Lindblom HS (1968-1972) I found that on some winter days the Flxible 5500s could be colder inside than it was outside.

Also don't forget the Twin Coach 5000's from the North and West sides.

[Montell305]

Did the propane buses basically sound like a gasoline/propane school bus?

[geneking7320]

IMHO the CTA's propane buses (Flxes and Macks) did NOT sound like gasoline school buses and they did NOT sound like diesels. When I visited San Diego in 1996 I think they had some CNG buses (New Flyers) which I thought sounded like the Flxible 8700s.

[trainman8119]

I remember riding the old Propanes. The 8700 series new looks were very quiet. The best way I could describe the sound would be to imagine the sound of a locust in the trees in the distance with a slight hum in the engine. I know that may sound a little weird, but if I had to describe it, that was it. I remember liking the new looks as a kid because the windows were easier for me to look out of, they were much lower than the old Flxible propanes and Twins which had higher windows, both on the side and in the front. I always felt like I was looking up in the sky when I was on one of those. The old look (5500 series) Flxibles were a little bit nosier, more of a whine with a hard and/or delayed transmission shift in them. Maybe that was from age, as I rode those in the later years of their lives. The new looks seemed much brighter, and I guess the flourescent lighting on those was newer, but definitely much better. The old looks were very dark and dingy...but then if there was a new look Flxible or GM out there now, it would seem the same way in comparison to what we have today.

I was a north sider, so the new looks I rode on were at North Park in their later days...I got the old Flxibles and Twins from North Avenue and Forest Glen.

I agree that the "CTA at 45" book gave some good info on the 8700's. Their main comment was that the buses were sluggish and really didn't perform too well, and that is part of the reason why they did away with them and went to diesel.

[buslist]

I did ride the propane buses on 55th Street from about 1969 to 1974, both the "Big Greens" (5500 series Twin Coach) and the "New Looks" (8800 series Flxibles). They seemed like normal buses, except, by then, the suspensions were gone on the Big Greens,

Please remember that the suspension (ride ) differences were probably due to the fact that the 5500s had steel spring suspension while the 8700s had air ride, a huge difference not at all due to the suspension being "gone" . Of the "old look" Flex's all from 8200 on had air bag suspension and rode quite well.

[buslist]

The 8700 series new looks were very quiet.  

The old look (5500 series) Flxibles were a little bit noisiermore of a whine with a hard and/or delayed transmission shift in them. Maybe that was from age, as I rode those in the later years of their lives.

Please remember that the "old look" Flxibles had underfloor engines and were therefore much morre noisey inside than an 8700 which was rear engined.  But I never found the noise from the under floor beast objectionable. And yes the 8700s were slow, But still very lovelable (Understand that CTA had a potential plan to re engine them with 6-71s {one tired} but didn't follow through)

[CTAFAN8000]

I'm also a native Chicagoan, born in 1957. I rode these buses every day for almost eight years between home and school. They had some distinct sounds to them, as I recall.

The engine sound was noticeable and there was some vibration present inside. They'd start off slow, and at a certain point there was a delay in acceleration and engine noise while the transmission switched gears. This was punctuated with something that sounded like "Pa-tuck"! The engine noise would then return. As the bus slowed down, the transmission would then downshift with the same "Pa-tuck" sound. Then you'd hear the airbrakes kick in with a swishing sound.

The transmission sound would also be present when the bus was put into gear. I recall drivers shifting into drive with a loud buzzing sound which ended in the "pa-tuck" noise.

These buses could be cold in the winter, and were hot in summer as they had no air conditioning.

It was sad to see the state of one of these buses in a recent photo. Hopefully, this bus can be protected and restored

[geneking7320]

I'm also a native Chicagoan, born in 1957. I rode these buses every day for almost eight years between home and school. They had some distinct sounds to them, as I recall.

The engine sound was noticeable and there was some vibration present inside. They'd start off slow, and at a certain point there was a delay in acceleration and engine noise while the transmission switched gears. This was punctuated with something that sounded like "Pa-tuck"! The engine noise would then return. As the bus slowed down, the transmission would then downshift with the same "Pa-tuck" sound. Then you'd hear the airbrakes kick in with a swishing sound.

The transmission sound would also be present when the bus was put into gear. I recall drivers shifting into drive with a loud buzzing sound which ended in the "pa-tuck" noise.

These buses could be cold in the winter, and were hot in summer as they had no air conditioning.

It was sad to see the state of one of these buses in a recent photo. Hopefully, this bus can be protected and restored

I was born in 1954 and I know of what you speak.

I have ridden Twin Coach [old look], Flxible/Twin Coach [old look] and Flxible [new look] CTA propane buses. I can recall going to Lindblom H.S. in the late 1960s and board a #50A South Damen bus at 87th and Damen one morning in the winter. It was warmer outside than it was on the Flxible/Twin Coach bus [which probably just started it's run from being stored outside at the 69th/Ashland barn.

Gene King

[CTAFAN8000]

Yes, seeing that photo of #8281 really brought back a lot of memories for me. I was always curious about the strange transmission sounds. I knew they were associated with the transmission, but have always wondered, from a mechanical standpoinpoint, what the source of these sounds were and why they were necessary. They could be quite loud outside the bus. Wish I could find a diagram of the tranmission sometime, but information on the old look Flxible busses is hard to come by.

Some 8000 series busses just hissed a little during upshift and downshift. I believe the 5000 series did this as well.