 |
Re: SP P-8 #2467
Author: watchman
Date: 12-24-2019 - 12:18
From Trainorders:
Date: 03/26/12 19:40
Re: SP P-8 #2467 Story
Author: speeder3
kilroydiver Wrote:
-------------------------------------------------------
> Is it still in operating condition, sitting over
> at the CSRM?
>
> Dave
Technically, yes, it is in operating condition. To be operated, however, the boiler would require a full FRA 1472-day inspection. Compounding that, the #2467 suffers from an overheated crown brass in one of its driving boxes.
Brian
Date: 03/26/12 21:01
Re: SP P-8 #2467 Story
Author: speeder3
john1082 Wrote:
> A 1472 inspection I can understand and I bet it
> would do well there as it has so little time on
> the boiler since leaving the park.
>
> But what is the story on the 'crown brass'?
> First, what is a crown brass? Second, what damage
> does overheating do to it? I would guess that it
> softens the piece. Third, how tough is it to make
> a new crown brass?
True, the boiler accumulated very few service days since the locomotive left the park, but overall the boiler has had considerable wear. A full UT inspection of the barrel and firebox sheets would probably reveal some work to be done. I don't know if anyone knows for sure just when the tubes and flues were installed by the SP, but it stands to reason that new tubes would be necessary. The flues could be UT'd to determine if they could be used. Again, it's unknown just how many service days the tubes and flues actually have on them.
The "crown brass" is the arched shaped bearing that supports the locomotive on the driving axles. Within the frame, there are two driving boxes on each driving axle. Each driving box has a crown brass. I've attached a photo taken when we removed the #4 driving wheel set from our Baldwin 2-8-2, the ex-Polson Logging #70. You can see one of the driving boxes sitting on the floor just to the left of the wheel. The arched shape of the bearing can be seen. In the case of the #2467, it's a long story but while the locomotive was being stored at Oakland, it was parked beside a concrete recycling plant (the Oakland Army Base's yard tracks had been torn out) that was set up during the reconstruction of the I-80 approaches to the Oakland-San Francisco Bay Bridge. It is believed that concrete dust managed to get in between one of the crown brasses and the axle. The #2467 was later allowed to operate over the mainline on its way to Oakdale, CA to participate in a steam "round up" on the Sierra Railroad. At some point during the trip, one of the bearings began running very hot and the trip was scrubbed. The #2467 was then hauled to the Golden Gate Railroad Museum's facility near San Francisco where it was stored for some time before eventually going to CSRM for display. But I digress. To answer your question, if for some reason the driving box bearing were to lose lubrication, or in the case of the #2467 become fouled by something abrasive like concrete dust, the thin film of lubricant between the bearing and the axle will be compromised resulting in increased friction. Several things can occur, including scoring of the axle's journal surface, scoring of the bearing brass, and overheating of both the bearing and the axle. In extreme cases, the overheated bearing can ignite the lubricant causing all sorts of swearing and flailing of the arms. Just one reason why the Class 1 railroad's don't much care for steam locomotives running around. They can really tie up the system if things don't go just right.
As for replacing a crown brass, it's really not that difficult as long as you have the right tools. First, you have to drop the offending driving wheel set, so a drop table is pretty handy. Next comes a lot of inspecting to see what can be saved, and what needs to go. Sometimes the bearing and the axle's journal surface can be re-machined and placed back into service. If the crown brass is really bad off, then it has to be pressed out of the driving box and replaced. A new bearing brass is poured and machined to fit the box, then bored to the proper diameter to fit the axle. That's about it.
Brian
Complete thread is here: [www.trainorders.com]
Date: 03/26/12 19:40
Re: SP P-8 #2467 Story
Author: speeder3
kilroydiver Wrote:
-------------------------------------------------------
> Is it still in operating condition, sitting over
> at the CSRM?
>
> Dave
Technically, yes, it is in operating condition. To be operated, however, the boiler would require a full FRA 1472-day inspection. Compounding that, the #2467 suffers from an overheated crown brass in one of its driving boxes.
Brian
Date: 03/26/12 21:01
Re: SP P-8 #2467 Story
Author: speeder3
john1082 Wrote:
> A 1472 inspection I can understand and I bet it
> would do well there as it has so little time on
> the boiler since leaving the park.
>
> But what is the story on the 'crown brass'?
> First, what is a crown brass? Second, what damage
> does overheating do to it? I would guess that it
> softens the piece. Third, how tough is it to make
> a new crown brass?
True, the boiler accumulated very few service days since the locomotive left the park, but overall the boiler has had considerable wear. A full UT inspection of the barrel and firebox sheets would probably reveal some work to be done. I don't know if anyone knows for sure just when the tubes and flues were installed by the SP, but it stands to reason that new tubes would be necessary. The flues could be UT'd to determine if they could be used. Again, it's unknown just how many service days the tubes and flues actually have on them.
The "crown brass" is the arched shaped bearing that supports the locomotive on the driving axles. Within the frame, there are two driving boxes on each driving axle. Each driving box has a crown brass. I've attached a photo taken when we removed the #4 driving wheel set from our Baldwin 2-8-2, the ex-Polson Logging #70. You can see one of the driving boxes sitting on the floor just to the left of the wheel. The arched shape of the bearing can be seen. In the case of the #2467, it's a long story but while the locomotive was being stored at Oakland, it was parked beside a concrete recycling plant (the Oakland Army Base's yard tracks had been torn out) that was set up during the reconstruction of the I-80 approaches to the Oakland-San Francisco Bay Bridge. It is believed that concrete dust managed to get in between one of the crown brasses and the axle. The #2467 was later allowed to operate over the mainline on its way to Oakdale, CA to participate in a steam "round up" on the Sierra Railroad. At some point during the trip, one of the bearings began running very hot and the trip was scrubbed. The #2467 was then hauled to the Golden Gate Railroad Museum's facility near San Francisco where it was stored for some time before eventually going to CSRM for display. But I digress. To answer your question, if for some reason the driving box bearing were to lose lubrication, or in the case of the #2467 become fouled by something abrasive like concrete dust, the thin film of lubricant between the bearing and the axle will be compromised resulting in increased friction. Several things can occur, including scoring of the axle's journal surface, scoring of the bearing brass, and overheating of both the bearing and the axle. In extreme cases, the overheated bearing can ignite the lubricant causing all sorts of swearing and flailing of the arms. Just one reason why the Class 1 railroad's don't much care for steam locomotives running around. They can really tie up the system if things don't go just right.
As for replacing a crown brass, it's really not that difficult as long as you have the right tools. First, you have to drop the offending driving wheel set, so a drop table is pretty handy. Next comes a lot of inspecting to see what can be saved, and what needs to go. Sometimes the bearing and the axle's journal surface can be re-machined and placed back into service. If the crown brass is really bad off, then it has to be pressed out of the driving box and replaced. A new bearing brass is poured and machined to fit the box, then bored to the proper diameter to fit the axle. That's about it.
Brian
Complete thread is here: [www.trainorders.com]
