Date   

Re: Modeling A Hot Box

Craig Wilson
 

We do have a figure of a station agent modified such that he is holding his nose with one hand and pointing to the track with the other.  I've got a picture of him "in action" on the Atlantic Great Eastern.  I'll see if I can get it uploaded to the photos section.

Engineers are instructed to watch for the agent on the platform doing a roll-by inspection as they pass an open station.  Most of the time it is a figure giving a highball signal but every once in a while it's the guy indicating a hotbox.  In that case, the engineer had better well stop and have the train inspected.

Craig Wilson


Re: Solid Bearings vs. Roller Bearings

Todd Horton
 

Yes, I agree Dennis, the temperature of the oil has a big effect on the amount of drag a bearing has.  I have watched V8 engines on a dyno pick up 20-30 hp from the oil temperature going from 150 degs to 200 degs. 

 
Todd Horton



From: "destorzek@... [STMFC]"
To: STMFC@...
Sent: Friday, March 24, 2017 12:02 AM
Subject: Re: [STMFC] Solid Bearings vs. Roller Bearings

 



---In STMFC@..., wrote :


I'm not 100% convinced that a car with roller bearings takes less effort to start moving it but I can see a good argument for it.       At speed?      Well, that's another story.............

 
Todd Horton
=========================

It depends... If the car with plain bearings was moving, stopped briefly, and then restarted, likely not much difference. But... if the car with plain bearings sits for a while, say a day or so, the weight of the car squeezes the oil out, and the Babbitt bearing settles down on the journal. Now, you need to move the car to reestablish that film of oil between bearing and journal, and that is what causes the hard starting. The colder the ambient temperature is, the longer it takes to get the bearing floating on that wedge of oil.

I can attest, back in my railway museum days, that when we received our first roller bearing equipped passenger car, we found all sorts of places we thought the track was level, but wasn't. Places we'd set coaches while switching for years, the newcomer would silently start to drift away.

Dennis Storzek



Re: Solid Bearings vs. Roller Bearings

devansprr
 

Todd,

The roller bearings you are referring to are very different from the modern tapered roller bearings in freight cars. Each RR roller bearing is often carrying a load of over 30,000 pounds!

These loads, and speeds, are very different from engine bearing requirements. The lubricant used in RR RB's is for the dust seals and the roller cages (now plastic to further reduce parasitic friction and the need for grease.) RR RB's do NOT want grease on the surfaces of the rollers - it is not necessary and increases friction. There are advisories in the RR industry specifically to not over-lubricate RB's.

Adding oil into a roller bearing will significantly increase friction - effectively the rollers are pumping oil around the races, much as a gear driven pump is used to pump the oil out of the crankcase. So I can understand why RB's in a crankcase, or a machine tool spindle, might have higher drag than journal bearings, and even require cooling.

But that is an entirely different environment from freight car axles.

There are piles of railroad engineering documents about the MUCH lower starting friction for RB equipped freight cars vs. plain journal bearing equipped cars, and for most of the era of this list, the at speed frictions were similar, with a slight advantage to the RB's (the RB's were oil immersed in this era). But this was all before the later Timken tapered roller bearing designs (AP) that have rolling "friction" as low as one pound per ton of freight car - at all speeds, including starting. During the steam era (mandatory STFMC content), the minimum for plain/friction bearings was about 3 pounds per ton - typically at a speed between 15 and 20 mph. Starting friction could be as high as 25 pounds per ton - 35 if it was below freezing (source is 1999 AREMA manual on railway engineering.) Today the RB friction can be under 1 pound per ton of freight car. For a loaded car, friction from wheel flange rubbing the rail head, and poor roadbed (flexing of rails and absorption of energy by the truck's suspension) can be larger than the RB's. Today aero losses are by far the biggest consumer of fuel, especially for double stacks in cross winds.

This is a totally different set of challenges from motorcycle engines and high speed tools. Ball bearings have much higher friction than tapered roller bearings, since in a ball bearing some of the contact surface is actually sliding, unlike a tapered roller bearing where ALL load bearing surfaces are in rolling, not sliding, contact (hence the term "anti-friction" bearing.) There were some early roller and spherical RB's for railroad axles, but they have faded away - the opposed tapered roller bearings (Timken's patent, licensed to other manufacturers) are far superior, since they also handle the lateral thrust loads when going through curves.

Dave Evans



---In STMFC@..., <toddchorton@...> wrote :

Dave, all those Kawasaki KZ 900/1000/1100's  & Suzuki GS 1000/1100/1150's all used roller bearing cranks and rods. The Japanese started phasing them out in the late 80's. None of the new bikes today use them. Solid bearings make more power and they are cheaper to manufacture. 

In Nascar and Foumula 1 racing, money is not really a consideration, if roller bearings made more power they would use them in these applications. 

If you take a sealed grease packed roller bearing there's a lot of drag from grease, rollers and seals just to turn one. None of these will free spin unless you remove all the seals and grease. A dry bearing will spin freely but it won't last long. Roller bearing do generate considerable amounts friction even if being used in an application with a light air/ oil mist.  In the last 10 yrs or so ceramic balls and sometimes ceramic races are used in high speed applications where normal steel balls and races generate too much heat to survive. I'm in the machine tool industry and usually anything with over a 10,000 rpm spindle range requires ceramic balls to survive for extended periods of time. Machine tool builders use bearings in spindles to keep from having to having to add a closed loop oiling system.   Most high speed spindles use a spindle chiller to keep from overheating the bearings. 

Roller bearings absolutely have their place as we all know. Can you imagine going to get in your car and having to lube the wheels before you take a trip? This, In my opinion, was the main selling feature of roller bearings for freight car wheels. It eliminated a LOT of maintenance. 

I'm not 100% convinced that a car with roller bearings takes less effort to start moving it but I can see a good argument for it.       At speed?      Well, that's another story.............


 
Todd Horton



From: "devans1@... [STMFC]" <STMFC@...>
To: STMFC@...
Sent: Thursday, March 23, 2017 5:15 PM
Subject: Re: [STMFC] Solid Bearings vs. Roller Bearings

 
Todd,

"Solid bearings have less drag than roller bearings at speed."

Not true for freight cars. I can't comment on the HP difference for motorcycle engines, but the cost of a RB equipped motorcycle engine would go through the roof if all the connecting rod and crankshaft bearings were RB. I am skeptical HP goes up using journal bearings in place of RB's if the RB's could be kept DRY. But with the need for a motorcycle engine to oil lubricate the cylinder walls, I suspect it would be just about impossible to keep a motorcycle crankshaft RB dry - and oil in the RB's would increase there "friction" considerably.

Fortunately freight car wheel bearings are not inside a crankcase filled with oil and combustion products, so their RB's can remain dry.

I hate to fan this fire again, but roller bearings are properly called "anti-friction" bearings, because all load bearing surfaces are rolling contact surfaces, not sliding surfaces. (So the "friction" in the bearing is no different than the "friction" of the wheel rolling on the rail, when the wheel flange is not contacting the rail head. RB friction is LESS than the wheel friction if the wheel flange is sliding against the rail head (as happens when trucks are hunting and cars are in curves.))

Today, wheel flange friction and aerodynamic drag are bigger sources of friction/drag, compared to the RB's.

Dave Evans




---In STMFC@..., <toddchorton@...> wrote :

Solid bearings have less drag than roller bearings at speed. The initial start up from a dead stop might favor roller bearings but the  mechanical drag of metal against metal in a roller bearing causes more resistance at higher speeds,

Roller bearing are superior when it comes to minimal amounts of lubrication where as a solid bearing will quickly fail under the same conditions.

Internal combustion engines are a prefect example of this. In 70's and 80's a lot of motorcycle engines were built using roller bearings on the crankshafts and connecting rods, As the power in these engines continued to elevate to higher levels these engines went to solid bearings for cranks and rods because of mechanical drag and horsepower loss.

A  somewhat educated guess, but a 1000cc 4 cylinder engine at 10,000 rpms will probably make about 10 hp over a similar engine with roller bearings. 

Two cycle engines, with roller bearing cranks and rods with a slight amount of oil mixed in with the gas will live a long time. They could make more power if they used a closed loop pressurized oiling system but that presents another set of problems not for discussion on a  freight car related message board.

 
Todd Horton



From: "thecitrusbelt@... [STMFC]" <STMFC@...>
To: STMFC@...
Sent: Thursday, March 23, 2017 3:37 PM
Subject: [STMFC] Solid Bearings vs. Roller Bearings

 
I found this statement in Volume 72 of the Proceedings Of The American Railway Engineering Association:
 
"There is no appreciable difference between solid bearings and roller bearings above 35 mph, but other mechanical considerations heavily favor the use of all roller bearings."
 
I believe I have seen this same statement elsewhere.
 
So what other mechanical considerations favor the use of all roller bearings?
 
Thanks.
 
Bob Chaparro
Hemet, CA





Re: Solid Bearings vs. Roller Bearings

destorzek@...
 




---In STMFC@..., <toddchorton@...> wrote :


I'm not 100% convinced that a car with roller bearings takes less effort to start moving it but I can see a good argument for it.       At speed?      Well, that's another story.............

 
Todd Horton
=========================

It depends... If the car with plain bearings was moving, stopped briefly, and then restarted, likely not much difference. But... if the car with plain bearings sits for a while, say a day or so, the weight of the car squeezes the oil out, and the Babbitt bearing settles down on the journal. Now, you need to move the car to reestablish that film of oil between bearing and journal, and that is what causes the hard starting. The colder the ambient temperature is, the longer it takes to get the bearing floating on that wedge of oil.

I can attest, back in my railway museum days, that when we received our first roller bearing equipped passenger car, we found all sorts of places we thought the track was level, but wasn't. Places we'd set coaches while switching for years, the newcomer would silently start to drift away.

Dennis Storzek


Re: C&O "Lift to open"

radiodial868
 

That is way cool Gary, ask a question on ResinFreightCars and get an answer here! Vol 4 is the one volume I didn't have.
I was thinking it was the auto end doors with the "Open" stencil, and it is the side doors. Thanks for the help, I can continue decaling the F&C 1930 C&O 50' Automobile boxcar.
RJ Dial
Burlingame. CA


---In STMFC@..., <vasa0vasa@...> wrote :

Ted Culotta’s Focus on Freight Cars Volume Four at pages 32 and 33 shows 9380 a single door boxcar with the lettering “lift to open” on the left side of the middle of the door handle with an arrow pointing to the bar latch that is in the bottom middle of the door.

 

Gary Laakso

South of Mike Brock


SEEKING HELP ON UP B-50-20 50' BOXCAR BRAKE RIGGING

WILLIAM PARDIE
 

I am seeking clarification on the brake rigging for the Union Pacific B-50-20 boxcar. This is being done from a Westerfield kit. The underframe has a single center beam (Bettendorf I believe). A photo on page 78 of Volume One of the Focus On Freight Car series verifies that the brake levers passed through the center sill. This is in opposition to the arrangement on PFE refers using this underframe in which the brake levers were supported by stirrups under the centersill. The photo in the Focus On Freight Cafrs book is rather dark. I would suspect that the rod between the two levers is located on the same side of the centersill as the KC cylinder. I would like to confirm this prior to completing the car.

Thanks in advance for any assistance:

Bill Pardie


Re: Solid Bearings vs. Roller Bearings

Todd Horton
 

Dave, all those Kawasaki KZ 900/1000/1100's  & Suzuki GS 1000/1100/1150's all used roller bearing cranks and rods. The Japanese started phasing them out in the late 80's. None of the new bikes today use them. Solid bearings make more power and they are cheaper to manufacture. 

In Nascar and Foumula 1 racing, money is not really a consideration, if roller bearings made more power they would use them in these applications. 

If you take a sealed grease packed roller bearing there's a lot of drag from grease, rollers and seals just to turn one. None of these will free spin unless you remove all the seals and grease. A dry bearing will spin freely but it won't last long. Roller bearing do generate considerable amounts friction even if being used in an application with a light air/ oil mist.  In the last 10 yrs or so ceramic balls and sometimes ceramic races are used in high speed applications where normal steel balls and races generate too much heat to survive. I'm in the machine tool industry and usually anything with over a 10,000 rpm spindle range requires ceramic balls to survive for extended periods of time. Machine tool builders use bearings in spindles to keep from having to having to add a closed loop oiling system.   Most high speed spindles use a spindle chiller to keep from overheating the bearings. 

Roller bearings absolutely have their place as we all know. Can you imagine going to get in your car and having to lube the wheels before you take a trip? This, In my opinion, was the main selling feature of roller bearings for freight car wheels. It eliminated a LOT of maintenance. 

I'm not 100% convinced that a car with roller bearings takes less effort to start moving it but I can see a good argument for it.       At speed?      Well, that's another story.............


 
Todd Horton



From: "devans1@... [STMFC]"
To: STMFC@...
Sent: Thursday, March 23, 2017 5:15 PM
Subject: Re: [STMFC] Solid Bearings vs. Roller Bearings

 
Todd,

"Solid bearings have less drag than roller bearings at speed."

Not true for freight cars. I can't comment on the HP difference for motorcycle engines, but the cost of a RB equipped motorcycle engine would go through the roof if all the connecting rod and crankshaft bearings were RB. I am skeptical HP goes up using journal bearings in place of RB's if the RB's could be kept DRY. But with the need for a motorcycle engine to oil lubricate the cylinder walls, I suspect it would be just about impossible to keep a motorcycle crankshaft RB dry - and oil in the RB's would increase there "friction" considerably.

Fortunately freight car wheel bearings are not inside a crankcase filled with oil and combustion products, so their RB's can remain dry.

I hate to fan this fire again, but roller bearings are properly called "anti-friction" bearings, because all load bearing surfaces are rolling contact surfaces, not sliding surfaces. (So the "friction" in the bearing is no different than the "friction" of the wheel rolling on the rail, when the wheel flange is not contacting the rail head. RB friction is LESS than the wheel friction if the wheel flange is sliding against the rail head (as happens when trucks are hunting and cars are in curves.))

Today, wheel flange friction and aerodynamic drag are bigger sources of friction/drag, compared to the RB's.

Dave Evans




---In STMFC@..., wrote :

Solid bearings have less drag than roller bearings at speed. The initial start up from a dead stop might favor roller bearings but the  mechanical drag of metal against metal in a roller bearing causes more resistance at higher speeds,

Roller bearing are superior when it comes to minimal amounts of lubrication where as a solid bearing will quickly fail under the same conditions.

Internal combustion engines are a prefect example of this. In 70's and 80's a lot of motorcycle engines were built using roller bearings on the crankshafts and connecting rods, As the power in these engines continued to elevate to higher levels these engines went to solid bearings for cranks and rods because of mechanical drag and horsepower loss.

A  somewhat educated guess, but a 1000cc 4 cylinder engine at 10,000 rpms will probably make about 10 hp over a similar engine with roller bearings. 

Two cycle engines, with roller bearing cranks and rods with a slight amount of oil mixed in with the gas will live a long time. They could make more power if they used a closed loop pressurized oiling system but that presents another set of problems not for discussion on a  freight car related message board.

 
Todd Horton



From: "thecitrusbelt@... [STMFC]"
To: STMFC@...
Sent: Thursday, March 23, 2017 3:37 PM
Subject: [STMFC] Solid Bearings vs. Roller Bearings

 
I found this statement in Volume 72 of the Proceedings Of The American Railway Engineering Association:
 
"There is no appreciable difference between solid bearings and roller bearings above 35 mph, but other mechanical considerations heavily favor the use of all roller bearings."
 
I believe I have seen this same statement elsewhere.
 
So what other mechanical considerations favor the use of all roller bearings?
 
Thanks.
 
Bob Chaparro
Hemet, CA





Freight Cars Journal #8 help

lrkdbn
 

Dear group: I am looking for  the Reading USRA mill gondola drawings that were in Freight Cars Journal issue #8

I would be glad to pay for a scan of them.

Please reply to <lrkdbn@...>

Thank you

Laurance King


Re: Solid Bearings vs. Roller Bearings

np328
 

           Bob, you may have seen the same in a Railway Age article from the 1940 time span. It strikes a familiar note with me also. I cannot be certain however that is only 10 years and twenty large books to search. (Ah, for a supply of coffee and a pile of old Railway Age books to peruse some days.)  
         Of the second sentence of Todd Horton's comment about "initial startup". I seem to recall, however am not certain that there was something to this addressed in the Railway Age article that once there was a uniform coating of oil on the bearing surfaces, the advantages of the roller bearing - in so far as drag due to friction is concerned - were largely negated. Metal was not touching metal then, it was all riding on a thin film of oil.    Of course hot boxes are another matter.
        Of the advantages when starting, there can be no doubt roller bearings are advantageous. Many of us recall seeing the photos of this railroad or that railroad with three shapely office secretaries borrowed from the railroads offices pulling a boxcar (or even a locomotive) equipped with these (then) new roller bearings. And these photos can be found in the Railway Ages of that time.                                                                   Jim Dick, St. Paul, MN  
       


Solid Bearings vs. Roller Bearings

gary laakso
 

The industry had long time experience with roller bearings applied to passenger cars, both heavy weight and light weight and steam locomotives.  Great Northern, a paragon of thrift, started installing roller bearings on its 1937 Empire Builder and even started adding them to steam locomotives by 1940.  I wonder how much unit prices fell so that GN added them to its express boxcars?   GN waited until 1948 before ordering those newfangled all steel boxcars.

 

Gary Laakso

south of Mike Brock

 

 


Re: Solid Bearings vs. Roller Bearings

devansprr
 

Todd,

"Solid bearings have less drag than roller bearings at speed."

Not true for freight cars. I can't comment on the HP difference for motorcycle engines, but the cost of a RB equipped motorcycle engine would go through the roof if all the connecting rod and crankshaft bearings were RB. I am skeptical HP goes up using journal bearings in place of RB's if the RB's could be kept DRY. But with the need for a motorcycle engine to oil lubricate the cylinder walls, I suspect it would be just about impossible to keep a motorcycle crankshaft RB dry - and oil in the RB's would increase there "friction" considerably.

Fortunately freight car wheel bearings are not inside a crankcase filled with oil and combustion products, so their RB's can remain dry.

I hate to fan this fire again, but roller bearings are properly called "anti-friction" bearings, because all load bearing surfaces are rolling contact surfaces, not sliding surfaces. (So the "friction" in the bearing is no different than the "friction" of the wheel rolling on the rail, when the wheel flange is not contacting the rail head. RB friction is LESS than the wheel friction if the wheel flange is sliding against the rail head (as happens when trucks are hunting and cars are in curves.))

Today, wheel flange friction and aerodynamic drag are bigger sources of friction/drag, compared to the RB's.

Dave Evans




---In STMFC@..., <toddchorton@...> wrote :

Solid bearings have less drag than roller bearings at speed. The initial start up from a dead stop might favor roller bearings but the  mechanical drag of metal against metal in a roller bearing causes more resistance at higher speeds,

Roller bearing are superior when it comes to minimal amounts of lubrication where as a solid bearing will quickly fail under the same conditions.

Internal combustion engines are a prefect example of this. In 70's and 80's a lot of motorcycle engines were built using roller bearings on the crankshafts and connecting rods, As the power in these engines continued to elevate to higher levels these engines went to solid bearings for cranks and rods because of mechanical drag and horsepower loss.

A  somewhat educated guess, but a 1000cc 4 cylinder engine at 10,000 rpms will probably make about 10 hp over a similar engine with roller bearings. 

Two cycle engines, with roller bearing cranks and rods with a slight amount of oil mixed in with the gas will live a long time. They could make more power if they used a closed loop pressurized oiling system but that presents another set of problems not for discussion on a  freight car related message board.

 
Todd Horton



From: "thecitrusbelt@... [STMFC]" <STMFC@...>
To: STMFC@...
Sent: Thursday, March 23, 2017 3:37 PM
Subject: [STMFC] Solid Bearings vs. Roller Bearings

 
I found this statement in Volume 72 of the Proceedings Of The American Railway Engineering Association:
 
"There is no appreciable difference between solid bearings and roller bearings above 35 mph, but other mechanical considerations heavily favor the use of all roller bearings."
 
I believe I have seen this same statement elsewhere.
 
So what other mechanical considerations favor the use of all roller bearings?
 
Thanks.
 
Bob Chaparro
Hemet, CA



Re: Solid Bearings vs. Roller Bearings

earlyrail
 


Changing a brass in a solid bearing is rather more complex, since you have to jack up the truck frame, then maneuver the old brass (bearing) out, possibly install a new gasket at the back of the journal box, maneuver the new bearing into place, lower the truck frame, and then pack and lubricate the journal box.

Very close. but there is a wedge above the brass/babbate bearing that needs to be removed before the bearing can be removed.

Howard (son of a...carman) Garner


Re: Solid Bearings vs. Roller Bearings

devansprr
 

Bob,

What is the date of that volume?

Specific to the "over-35" claim - the early roller bearings were also oil filled - an appeasement to the old concept that oil immersion in bearings was critically important - but the oil also increased the drag forces, especially at higher speeds. Modern RB's are nearly dry and have small quantities of grease in them for the races that maintain roller position - but not on the bearing surfaces, which are best left dry and clean. Oil is long gone from RB's.

Timken and the PRR experimented with 100 hopper cars that were RB equipped in the 1930 time frame, and found that the "friction" at higher speeds was about the same (but much lower at low speeds, and longer trains could be started with RB's compared to friction bearings). That was even after the PRR insisted in using a higher viscosity oil during the RB tests than Timken preferred in the tapered roller bearings (a design more like some of today's passenger cars - the bearings were inboard of the wheels - there was no outboard truck frame on these test cars.)

The latest roller bearings have considerably less drag, at all speeds, compared to "plain"/"solid"/ "friction"/"journal" bearings, but much of the reduction in friction at higher speeds occurred late, and after, the era of this list.

Equipment reliability was a huge savings, but an ASME book on RR equipment development indicated that once plain bearings developed better oil distribution geometries, and sealed bearing cup caps in the 1950's, the incidence of hot boxes began to reduce dramatically, but that level was still well above the failure rate for tapered roller bearings. Note that the savings were from both reduced accidents and delays due to HB setouts - which benefited the operating RR, not the car owner, hence some of the resistance to RB deployment (much more expensive.) The setout rate was remarkably high prior to the early 50's.

I have a co-worker who grew up in Portage, PA, right along the PRR mainline, and he recalls playing ice hockey on a frozen creek adjacent to the main line as a child. There was a siding at that location that often had coal hoppers on it, and as young kids they did not think anything of taking the oil soaked rags out of the bearings and using them to start a fire to stay warm.... He had no idea - 40 years later he was buying the new DODX flat cars for the M1 Abrams tank when he learned about hot box failures.

Whoops...

Which recalls another cost of plain bearings - I think some on this list have posted links to photos of RR car men in hump yards checking bearing oil level as cars were humped. There were so many different forms of savings by going to RB's.

But MUCH higher reliability was the main mechanical benefit.  There are many posts on this topic from a few years back that include such data, IIRC.

Dave Evans


---In STMFC@..., <thecitrusbelt@...> wrote :

I found this statement in Volume 72 of the Proceedings Of The American Railway Engineering Association:

 

"There is no appreciable difference between solid bearings and roller bearings above 35 mph, but other mechanical considerations heavily favor the use of all roller bearings."

 

I believe I have seen this same statement elsewhere.

 

So what other mechanical considerations favor the use of all roller bearings?

 

Thanks.

 

Bob Chaparro

Hemet, CA


Re: Solid Bearings vs. Roller Bearings

Todd Horton
 

Solid bearings have less drag than roller bearings at speed. The initial start up from a dead stop might favor roller bearings but the  mechanical drag of metal against metal in a roller bearing causes more resistance at higher speeds,

Roller bearing are superior when it comes to minimal amounts of lubrication where as a solid bearing will quickly fail under the same conditions.

Internal combustion engines are a prefect example of this. In 70's and 80's a lot of motorcycle engines were built using roller bearings on the crankshafts and connecting rods, As the power in these engines continued to elevate to higher levels these engines went to solid bearings for cranks and rods because of mechanical drag and horsepower loss.

A  somewhat educated guess, but a 1000cc 4 cylinder engine at 10,000 rpms will probably make about 10 hp over a similar engine with roller bearings. 

Two cycle engines, with roller bearing cranks and rods with a slight amount of oil mixed in with the gas will live a long time. They could make more power if they used a closed loop pressurized oiling system but that presents another set of problems not for discussion on a  freight car related message board.

 
Todd Horton



From: "thecitrusbelt@... [STMFC]"
To: STMFC@...
Sent: Thursday, March 23, 2017 3:37 PM
Subject: [STMFC] Solid Bearings vs. Roller Bearings

 
I found this statement in Volume 72 of the Proceedings Of The American Railway Engineering Association:
 
"There is no appreciable difference between solid bearings and roller bearings above 35 mph, but other mechanical considerations heavily favor the use of all roller bearings."
 
I believe I have seen this same statement elsewhere.
 
So what other mechanical considerations favor the use of all roller bearings?
 
Thanks.
 
Bob Chaparro
Hemet, CA



Re: Solid Bearings vs. Roller Bearings

Garth Groff <sarahsan@...>
 

Bob,

This doesn't answer your question, but many railroads recognized the advantages of roller bearings on freight cars at least by the end of WWII. I have read that railroad management was slow to invest in roller bearing trucks on interchange cars because they saw them as mostly saving money on somebody else's railroad, and not at home.

The WP's first large order for roller bearing cars fit this philosophy. They were 29' mini-mill gondolas numbered 64001-6500, delivered by Greenville in 1953. These cars proudly carried the Timken "Roller Freight" herald when built. The short cars were only intended for U.S. Steel coil service between Geneva, Utah and Pittsburg, California. Cost savings and other benefits of roller bearings thus fell partly to the D&RGW, but mostly to the WP and their subsidiary Sacramento Northern.

The WP's next roller bearing plunge in 1956 was for ten PS-2 covered hoppers, 11201-11210, which were used for short distance limestone traffic to the Geneva furnaces. Curiously, 30 more PS-2 hoppers for the same service in 1958 numbered 11301-11330 had plain bearings. Go figure. These were apparently the last plain-bearing cars the WP ordered new.

In 1957, the WP bought 125 general purpose PS-1 50' double door boxcars numbered 35501-35625, and 100 more with auto loaders numbered 19601-19700. Both groups were equipped with roller bearings, though their truck frames had the usual hinged lids. The lids were painted bright yellow to mark the cars as roller bearing-equipped, a detail seen on some other roads about this time. From then on, except for the earlier mentioned PS-2s, all new WP cars came with roller bearings.

Yours Aye,


Garth Groff



On 3/23/17 3:37 PM, thecitrusbelt@... [STMFC] wrote:

 

I found this statement in Volume 72 of the Proceedings Of The American Railway Engineering Association:

 

"There is no appreciable difference between solid bearings and roller bearings above 35 mph, but other mechanical considerations heavily favor the use of all roller bearings."

 

I believe I have seen this same statement elsewhere.

 

So what other mechanical considerations favor the use of all roller bearings?

 

Thanks.

 

Bob Chaparro

Hemet, CA



Re: Chicago Great Western Caboose

Jason Kliewer
 

As a side bar, the under frame from caboose 354 was used for transfer caboose 176.



Jason


Re: Solid Bearings vs. Roller Bearings

Robert Heninger
 

Another important advantage to roller bearings is the markedly reduced initial resistance, meaning that roller bearings start rolling with much less effort than solid bearings. Up here in North Dakota, temperatures often go below zero, sometimes to -20 to -30, and can stay below zero for weeks at a time. In winter, tonnage ratings for steam locomotives dropped considerably because of the higher resistance due to cold bearings, in large part because the oil/grease would solidify in the cold.  I don't envy the steam era railroaders having to work through a North Dakota winter. There were all sorts of operational challenges they had to contend with which are now largely mitigated by technological advancements.


And yes, weeks of below zero weather is as awesome as it sounds. Ask me how I know.


Regards,

Bob Heninger

Minot, ND


Re: Chicago Great Western Caboose

Jason Kliewer
 

January 1960 Model Railroader has a drawing of 357.

Jason


Re: Solid Bearings vs. Roller Bearings

Todd Sullivan
 

Roller bearings don't get hot boxes; solid bearings do.  Roller bearings can fail, but I believe that happened much less frequently than hot boxes with solid bearings. 

Maintenance is easier because all you have to do to change out a roller bearing wheel set and its bearings is jack up or lift the truck frame.  The bearings and wheel set can be dropped out. 

Changing a brass in a solid bearing is rather more complex, since you have to jack up the truck frame, then maneuver the old brass (bearing) out, possibly install a new gasket at the back of the journal box, maneuver the new bearing into place, lower the truck frame, and then pack and lubricate the journal box.

Todd Sullivan


Re: Solid Bearings vs. Roller Bearings

destorzek@...
 

Reduced maintenance for sure. Roller bearings have gotten so reliable that they are essentially maintenance free for the life of the wheelsets, and are all (wheels, axles; and bearings) changed at once. Solid bearings required periodic repacking of the cotton "waste" that acted as an oil distribution wick, also more frequent topping off of oil, since the lubrication was a 'total loss' system with the oil escaping through the loose fitting 'dust guard' that acted as the rear seal of the journal box. Lubrication problems could result in 'hotboxes' which could burn the axle end off and lead to a derailment if not detected in time.

Lots of good reasons to get rid of plain bearings, which the railroads eventually did.

Dennis Storzek

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