2 or 3 axle trucks on passenger cars

[Anonymous]

I am still working on a set of Con-Cor passenger cars I got off of eBay a few months ago. I want to upgrade to Micro-Trains couplers and that means changing the trucks. They were originaly equiped with two axle truks but most pictures I see seem to have three axles. They were called heavyweights but they were basicly big boxes of air with maybe 4,000 pounds of people in them. I guess both could be correct but which was the most common?

Personaly I think three axle trucks look better, but I want to keep it real.

[Anonymous]

Big boxes of air made of heavy steel plates, which is why Pullman and others put three axle trucks under them for better ride and lower axle loading so that they could be used over a wide range of main and branch lines. I think if you can find photos of similar cars you will see that two axle trucks were rare, and three axle the rule. And you are right they look better besides. The latter introduction of streamline cars used lighter weight materials that reduced the axle loads and caused the switch to two axle trucks.
Will

[orsonroy]

It depends on what the cars are. Yes, Pullman added three axle trucks to basically all of their cars for a better ride, but most heavyweight coaches, baggage cars, and about half the RPO fleet only got two axle trucks. The NYC and Pennsy had more coaches than most roads had freight cars (!), and virtually all their "cheap seat cars" got two axle trucks.

[Anonymous]

Thanks for the information. Using an extra axle to reduce to load on the rail makes sense. On a freight car if you are going onto substandard tracks you reduce the load. On a passenger car the car itself is the biggest part of the weight.

So my baggage car gets 2 axle trucks. The others can get 2 or 3 axle trucks and be realistic but with the three axle trucks they look better. Since my prototype went out of business in 1936 my freelance of them in the 1950's probably would not have had the best track. That is a very good rational for 3 axle trucks. Plus they look good.

[Eriediamond]

My 2 cents for what it's worth. Rail roads back in the 30's-40's competed pretty hard for passengers and strived for the fastest and smoothest ride. Trackage was not as smooth as today's standards. Speed was not a real problem, but the smooth ride was something else. To smooth out the ride, their answer was to add weight to the cars. This was in the form of concrete floors. These cars were called "heavey weights". Now with this added weight, they replaced the two axle trucks with three axle trucks to spread the added weight over the rails so the trackage could take that weight and not damage it. Baggage, mail, and express reefers kept their two axle trucks. Hope this little tidbit of history helps here. Ken

[UP Deano]

i am NO passenger car specialist, but i thought the "heavyweights"(old pullman types,steam era)had three axles, and the "streamliners"(bud built types,early desiel till 70s)had two axles. this is not the norm?

[markpierce]

As a general rule for the twentieth century, light weight (streamlined) passenger cars had two axles per truck, and for heavyweights, those with air conditioning had three axles per truck and two axles per truck without air conditioning. Cars around 80-foot in length usually had three axle trucks regardless.

[passengerfan]

Heavyweights generally had three axle trucks. All heavyweight Pullmans had three axle trucks. Heavyweight Coaches and head end cars could have either two axle or three trucks. Lightweights generally had two axle trucks. Exceptions to the two axle lightweight rule were some Budd built MP 10-6 sleepers that traveled up a branch line therefore needed the three axle trucks to spread the weight. Some railroads used lightweight articulated kitchen/dining cars that used a three axle truck where the articulation was and the full length domes from Pullman and Budd used three axle trucks to spread the weight of these cars over more axles. The UP also operated some steam generator lightweight baggage cars that used a six axle truck at the steam generator equipped end and a two axle truck on the baggage end. From memory I believe the Santa Fe operated several ballast cleaning cars converted from lightweight baggae cars that were equipped with steam genrators to clean the ballast and they were equipped with six axle trucks at one end as well. In both of the baggage car conversiuons the railroads changed the trucks themselves. The only other lightweights I can think of without looking them up that were delivered with six wheel trucks were some postwar Parlor and sleeping cars built for the GM&O but ordered by the Chicago & Alton. Don't hold me to this as it is all from memory and the older I get my memory sometimes plays tricks. But I think it is pretty accurate.

[passengerfan]

PS I just remembered one other thing regaring the heavyweights As a rule of thumb those with monitor roofs usually had two axle trucks and those with clerestory roofs generally were prone to have three axle trucks.

[orsonroy]

QUOTE: Originally posted by passengerfan

PS I just remembered one other thing regaring the heavyweights As a rule of thumb those with monitor roofs usually had two axle trucks and those with clerestory roofs generally were prone to have three axle trucks.

I wouldn't us this as any sort of rule of thumb. Like I said earlier, the NYC and Pennsy had THOUSANDS of celestory roof heavyweight cars with two-axle trucks.

[MidlandPacific]

A good source on this is John White's book, "The American Railroad Passenger Car." Prototype considerations aside, I've found that I like the look of two-axle trucks on shorter (i.e., sixty foot or less) cars, and three axle trucks on longer (seventy to eighty foot) cars. MDC's Harriman cars all come with two axle trucks, and the Rivarossi and Athearn heavyweights (which are longer, about seventy-two feet) come with three axle trucks.

[markpierce]

When the Southern Pacific airconditioned some of its 60' Harriman arch roof coaches, it exchanged the cars' two-axle trucks to three axles to take care of the extra weight of the ice evaporation system.

[Anonymous]

After a few hours on the Fallen Flags web site I think I have decided what trucks to use. Since I am painting these for a freelanced line that ran east out of Cincinnati I looked at the passenger equipment used by railroads that ran through the Cincinnati Union Terminal.

One smoothside baggage car pictured that belonged to the PRR definatly had 3 axle Buckeye trucks. The bearing caps are distinctive.

All the smoothside coaches, dinners, sleepers etc. had 3 axle Commonwealth trucks. The center axle is really hard to see in most of the photos but judging from the few that were clear it is there.

All the corragated side coaches where the trucks were in plain view appeared to be 2 axle Commonwealths. At least that is what I am ordering from the LHS. Thanks to everyone for the input.