40 foot boxcar rebuild

[nachoman]

Depending on the locale, many 40' cars were still in use long after they were impractical for most applications - the lightly-built branch lines on the Canadian prairies are an example of this: with track too light to support 100 ton covered hoppers, shippers continued to use 40' boxcars well into the '80s.

Interesting. So what did they eventually do, upgrade the rail, or start shipping by other means?

[Puddlejumper]

As for braking, my understanding of the procedure is to use dynamic braking (where available) in conjunction with both the locomotive's independent brake and the automatic air brakes on the cars. Hopefully, someone with practical experience can expand on this.

Wayne

Well from what I remember from my time as a trainman on CSX, the independent brake was rarely used during train handling, it was primarily for the locomotives when moving around in terminals and switching and such. The automatic brake was used in all other instances. Of course the automatic brake also applied the brakes on the locomotives, which during normal train handling was "baled off" to keep the slack stretched. The use of dynamics and automatic brake depended on the result desired from the engineer, and the terrain, etc. as the dynamic would get the train all bunched up, while application of the automatic would keep the train somewhat stretched out, especially when the lokies were bailed off and allowed to keep pulling.

I know when stopping in bad areas we always used automatic and pulled against it to keep the slack stretched to make it impossible for thieves and vandals to uncouple the train. Also when placed into emergency the locos go to idle and the brakes come on full. You want to bail off real quick to keep the locos moving, as the weight of the train slamming into the locomotives can throw you right out of your seat onto the floor.

[Gary S]

Great-looking results on that car, Gary. I especially like the open door and your technique for modelling the inside face of the closed door.

Thanks for the compliments and the info, Wayne. Even though the back of a real door doesn't look quite like the corrugated plastic I used, it serves the purpose.

One of the advantages I see about a shelf layout is that a car with an open door can still be used for loading during operations. Just turn the car around and now it has a closed door. Can't see the other side, no matter where it is on the layout. Which brings up an interesting thought... A single car could be used to represent two different cars... different road numbers, even different roads.

[Gary S]

Everyone:

I appreciate the discussion on brakes! I am a bit astonished that I didn't have a clue about braking and how a train stops. Thanks to everyone for enlightening me.

As I am thinking, it seems that the brakes on the locomotive would not be all that effective in stopping a train. Just like in pulling, the limiting factor would be the friction of the locomotive wheels on the track. With a heavily loaded train, if we could jam the locomotive brakes on, locking up the wheels, I am sure that the inertia of the rest of the train would simply push the loco down the rails, squealing and grinding.

[doctorwayne]

Gary, you're right about being able to letter each side of a car with either a different number or a completely different roadname. If I'm not mistaken, there was even a large display layout somewhere that did just that.

The locomotives in the steel plant where I worked seldom used train brakes, even when moving interchange cars, unless the car, for some reason, needed special handling.


On in-plant cars, which had no brakes whatsoever, all braking was done with the independent brake - this included long drags of loaded ingot buggies, often at weights approaching 100 tons per buggy and 3,000 tons or more per drag. And some hoggers would really hustle once they got 'em rolling.

Wayne

[Puddlejumper]

Indeed, when switching cars in the yard, the locomotive brakes are the only brakes used. The cars brakes are all bled off to facilitate shifting and kicking cars.

[Triplex]

Depending on the locale, many 40' cars were still in use long after they were impractical for most applications - the lightly-built branch lines on the Canadian prairies are an example of this: with track too light to support 100 ton covered hoppers, shippers continued to use 40' boxcars well into the '80s.

Interesting. So what did they eventually do, upgrade the rail, or start shipping by other means?

Both CN and CP actually used 40' boxcars for grain until around 1997. In the case of CN, I believe they eventually decided that the track could support large covered hoppers, and they'd just been overcautious.

[Lester Perry]

I believe that there was a time when the car brakes had to be set before descending a grade. A high brake wheel would be useful if you were walking the roof of a moving train. A low wheel would be a problem in this case unless the brakeman could run fast and a good distance. I may be wrong here.

[Triplex]

They certainly did that in Britain, anyway, up to at least the end of the steam era - they were very slow about adopting any sort of continuous brake.

[Puddlejumper]

Sorry this turned into a brake discussion... the bottom line though is that boxcar is fantastic!

[Gary S]

Sorry this turned into a brake discussion... the bottom line though is that boxcar is fantastic!

Hey, no problem for me! I'm a lot smarter now than before this thread started. And thanks for the compliments on the boxcar. Again, it isn't a museum piece, but will serve well and look decent when being moved around on my layout. This weekend I hope to find the time to build a short length of ballasted "display" trackage on a board so I can take some nice photos of my completed rolling stock and upload them to the Gallery here.

DocWayne: Thanks for the info about the steel mill railroad using only the loco brakes for braking. I'm sure that at some point though, a long, heavy train would have to rely on the car brakes to help stop.

Considering a heavily loaded freight, I wonder if the brakes were locked up on the locomotive, but the cars were left free rolling, if that could actually cause a derailment with the cars slamming into each other....

[Lester Perry]

I am guilty of going on a siding with the brake wheel thing. I am sorry, I agree with Puddle jumper, nice work. I do have a question. It appears to be humped up in the middle, it could be an illusion or I might be seeing things,
Les

[Gary S]

The close-up function on my camera has a bit of distortion in it. I need to center the subject better. I had the boxcar at the top of the photo and cropped the bottom off to post the image.

[doctorwayne]

I'm sure that at some point though, a long, heavy train would have to rely on the car brakes to help stop.

Considering a heavily loaded freight, I wonder if the brakes were locked up on the locomotive, but the cars were left free rolling, if that could actually cause a derailment with the cars slamming into each other....

Yes, a train relies on the car brakes for stopping, as well as the locos' dynamic brakes: after all, not all locos are equipped with dynamic brakes.

Slack run-in can be a source of problems, including derailments - there's about a foot of slack (or more) in the draught gear of most freight cars. Part of the problem is that the brakes on the cars don't all apply at the same time - the signal from the locomotive is via a pressure reduction in the brake pipe, which can take some time to make its way to the end of a 100 car train. There are electro-pneumatic systems in use which send the signal electronically, while the air pressure, already available on each car in the train, is used only to apply the cars' brakes. Response is almost immediate. However, as far as I know, this system is not in use in North America, at least for freight trains.

I am guilty of going on a siding with the brake wheel thing. I am sorry, I agree with Puddle jumper, nice work. I do have a question. It appears to be humped up in the middle, it could be an illusion or I might be seeing things,
Les

These little side trips can often add a lot of useful information to the main topic and/or to viewers' general knowledge.

I think that the "hump" is due to the camera's lense. The 36' boxcar shown below was photographed using the camera's "close-up" setting, and was shot through the lense of my Optivisor, too. (I'm pretty sure, though, that the prototype was equipped with Camel door hardware, a perfect excuse for that "hump".)


Wayne

[Gary S]

So let's talk about dynamic brakes. I assume that pre-dynamic brake locos simply used friction brakes. And the dynamic brake is a process whereby the electric motors that are driving the wheels are actually operating as a generator which feeds a heavy amperage into a resistor load bank. And of course, the more amperage we pull from a generator, the harder it is to turn. This results in a braking action on the train without the issues of friction brakes which I suppose would get burned up pretty quickly under heavy braking loads, plus all the heat that would be placed on the braking components. With the dynamic brake, the heat is transferred to the resistor bank and a fan blows the heat out of the loco. Nothing to wear out like with the friction brakes.

But as for braking "power," regardless of the braking method, the limiting factor in stopping is going to be the friction between the rails and wheels.

Does that sound right?