I need to bump this to go with Prof. Milenkovic's, for the oh-so-Canadian-appropriate hat trick of Iron Highway posts. This one contains the truck design that was supposed to adapt the original independent-wheel single-steered-'axle' underfloor bogies to work in Australia, where lighter track standards dictated 'more wheels'...
This is an interesting solution, although I wish they had made more explicit reference to the braking arrangements.
A critical detail in this truck design is the arrangement that keeps the two sideframes aligned with the bolster, comparable to the wedges and shims in a three-piece truck. While I understand the computer-generated image may not be a 'structural' model, I note that the circumferential reinforcement of the bolster opening and springing in a three-piece truck is absent (there are no pedestal tie arrangements visible, either), and the frame opening at the top of the 'bolster pocket' has a relatively sharp radius. Since the frames are inside, it may be very difficult (as in the Allied Full Cushion) to keep the areas of potential cracking monitored in service.
One of the points of the original HPIT suspension in the Iron Highway was that any differential-loading-caused rotation of the truck frame was inherently accommodated by the bearing of the single axle. That is not true of the newer arrangement, and this will result in some rotation of the bolster relative to the sideframes. This combined with 'anti-lozenging' indicates that a very precise arrangement possible involving spherical bearing surfaces needs to be provided between sideframes and bolster, and again the installation and inspection of these may be difficult in practice.
The bearing discussion is an interesting one in principle. Presumably the inline narrow bearings have adequate grease sealing that they meet modern AP standards. It's well-recognized that AP bearings in many modern three-piece applications considerably outlast the practical wheel life of the sets they are installed on (effectively leading to 'wasted capacity' as the bearings must be removed and rebuilt any time the wheels have to be changed out). It should be possible for the wheels to be removed from these new sets without disturbing the bearings.
On the other hand, automated devices that scan for 'hot bearings' now have multiple layers of structure to attempt to 'see through', and I suspect the design would not be accepted in any context that required the ability to scan remotely for 'hotboxes'. Theoretically this might be gotten around by using heatpipes from the bearing boxes or seats 'inboard' to an IR-enhanced emitting surface at the bolster ends, visible past the "rubber" springing and endplates; that being a passive device tolerant of considerable vibration and impact damage, and in principle easily replaced if disabled.
I'm not convinced that the steering via links is comparable, though. It is required on the two-axle truck for obvious reasons; presumably those reasons are presumed to occur on a truck with narrowly-spaced axles (as here) but I have to wonder if links to the two sideframes, rather than to the bolster as the 'default' two-wheel version provides, is the best solution for truck steering in the presence of what (in Australia) may be a considerable level of line/surface defect and consequent differential sideframe pivoting accommodation (as in three-piece trucks). It would be interesting to consider the effect of leaving some of these links disconnected, as Prof. Milenkovic indicated might have been typical practice (see his post in this thread Aug 14 2006). I'd be particularly interested in what Dave Goding might have to say on this general subject, as his experience in what does and doesn't work well in guided-axle trucks is substantial. (He is also, as I recall, familiar with the stillborn attempt here in the latter '90s to accommodate some of the effect of heavier-axle-weight cars by using multiple-axle freight truck designs...)
I wonder whether a Taylor-type sideframe (with a circular 'bearing surface' in the center of each sideframe, with a bolted saddle to hold this firmly in the sideframe and act as a pedestal tie while allowing easy sideframe/wheel lift at servicing) would be a reasonable enhancement to the design.
I might also add that the redesigned sideframe arrangement appears to be relatively well suited to using disc brakes (with the calipers and mounts balanced either side of a bolster attachment, and the discs allowed to 'float' vertically with suspension accommodation between the pads). Since these wheelsets are already incompatible with 'general' wheelsets for conventional three-piece interchange trucks, adding a central 'seat' and perhaps keying arrangement for a suitable disc rotor seems relatively simple.
M636C & Paul Milenkovic discussed: "I have found the original CSX Iron Highway prototype! Are you all sitting comfortably? It was purchased by an AUSTRALIAN Road Transport company CRT ..."I'm resurrecting this 13+ year old thread to give you a link a webpage about the bogies on the Iron Highway platforms that ended up in Australia. On the Motive Power (formerly MK Rail) website, "New Truck Design for Iron Highway," undated, http://www.railmotive.net/22newtruckdesignfor.html. Those are two-axle bogies, to accommodate the lower allowable axle loads on Australian tracks compared to the U.S. where one axle was sufficient.
The "newest" CP Expressway cars added to the fleet are just old 55' flat cars from the 50's or 60's permantly coupled in groups. State of the art technoligy, same old cars in new paint.
So it went from CSX Iron Hiway to CP Iron Hiway to articulated Expressway cars back to ordinary pig flats sevice. That's the evolution.
greyhounds wrote: futuremodal wrote: nanaimo73 wrote: FM- How about an adjustable length multi-unit car where center sections could be dropped or added to suit demand ? Well, now you're opening up a whole 'nother can of ideas. It should be possible to develop an adjustable length railcar based on the slider chassis concept. If such is practical, then why not further apply the concept to multiple unit type cars? One other idea I had a while back involved current bi-modal equipment. What if, instead of having to have a loaded trailer for each bogie set, or having to load extra bogies on a flatcar if they are needed at the other end, we could just attach the bogies to the end of the consist with a hand held drawbar connecting each free wheeling bogie to the next? This would allow more flexibility of bi-modal operations. Why on Earth wold anyone want an adustable length railcar? Aside from being totally uneccessary in terms of use and expense - it would be very difficult to build. When I was at RoadRailer, we couldn't built an workable adustable length bimodal chassis because it was impossible to make it strong enough to stand the draft and buff forces in a train. The problem would be multiplied many times over in railcars. I suppose, with unlimited expsense you could built and adjustable length railcar - but again, why would you want to? As to dragging empty boggies behind a train - they're too light by temselves. They were at about 11,000 poiunds when I was with RoadRailer. That won't hold them on the rails. One good bounce and you've got a wreck.
futuremodal wrote: nanaimo73 wrote: FM- How about an adjustable length multi-unit car where center sections could be dropped or added to suit demand ? Well, now you're opening up a whole 'nother can of ideas. It should be possible to develop an adjustable length railcar based on the slider chassis concept. If such is practical, then why not further apply the concept to multiple unit type cars? One other idea I had a while back involved current bi-modal equipment. What if, instead of having to have a loaded trailer for each bogie set, or having to load extra bogies on a flatcar if they are needed at the other end, we could just attach the bogies to the end of the consist with a hand held drawbar connecting each free wheeling bogie to the next? This would allow more flexibility of bi-modal operations.
nanaimo73 wrote: FM- How about an adjustable length multi-unit car where center sections could be dropped or added to suit demand ?
FM-
How about an adjustable length multi-unit car where center sections could be dropped or added to suit demand ?
Well, now you're opening up a whole 'nother can of ideas. It should be possible to develop an adjustable length railcar based on the slider chassis concept. If such is practical, then why not further apply the concept to multiple unit type cars?
One other idea I had a while back involved current bi-modal equipment. What if, instead of having to have a loaded trailer for each bogie set, or having to load extra bogies on a flatcar if they are needed at the other end, we could just attach the bogies to the end of the consist with a hand held drawbar connecting each free wheeling bogie to the next? This would allow more flexibility of bi-modal operations.
Why on Earth wold anyone want an adustable length railcar? Aside from being totally uneccessary in terms of use and expense - it would be very difficult to build. When I was at RoadRailer, we couldn't built an workable adustable length bimodal chassis because it was impossible to make it strong enough to stand the draft and buff forces in a train. The problem would be multiplied many times over in railcars.
I suppose, with unlimited expsense you could built and adjustable length railcar - but again, why would you want to?
As to dragging empty boggies behind a train - they're too light by temselves. They were at about 11,000 poiunds when I was with RoadRailer. That won't hold them on the rails. One good bounce and you've got a wreck.
There is another idea that might work for an adjustable length spine car that uses the nut and bolt concept. It's basically a center sill that is round and bolt or screw shaped - turn it one way to lengthen the car, turn it in reverse to shorten the car. The center sill thus is the "bolt" and the end platforms/truck attachments are the "nuts". The platform itself would use the slider chassis mechanism to change it's length in conjunction with the center sill. The main benefit of this design is that all the longitudinal forces are taken up by the "bolt" in equal proportion regardless of car length, and the car itself can be configured for any length desired between the minumum and maximum. We have rotary drawbars, why not rotary center sills?
As for towing free wheeling RoadRailer or RailRunner bogies, if they are attached to each other using a light weight (for easy handling) slot-on-slot drawbar, the lack of vertical play in that type of connecting device should limit bounce, as the weight of the fore and aft bogies would counter the vertical tendencies. Of course, any such device would have to be tested prior to actual use.
I never made mention of All-Purpose well cars. Although, I do see them in the UPS trains on occation. I never really noticed if they were stand-alone or articulated.
We are a container only facility. We don't handle trailers. As such, we only use well cars. Occationally, we'll get an All-Purpose spine car, or flatcar with Interbox Connectors for containers.
You also may be interested to know, that some of the cars we use is trash service, are little more then frames on trucks, with IBCs to secure the trash containers.
Nick
Take a Ride on the Reading with the: Reading Company Technical & Historical Society http://www.readingrailroad.org/
nbrodar wrote: futuremodal wrote: Have you asked yourself why everything seems to move in sets of 6 and 12? Is that a rock solid axiom, not subject to the winds of change? What if sets of 5 and 10 come into favor? And why would anyone only load one UPS trailer on a 5-pack? Since intermodal equipment is mixed and matched, you can still use a 5-pack in conjunction with a singular car to hold the 6 set of trailers. Traffic does indeed change. I remember when we loaded almost exclusively 5 packs and 89' flats. We also used to actually switch out the cars to get them in proper order. Currently, traffic runs in sets of 6 and 12. Why? I don't know. Will it change again, undoubtedly. When I started, we loaded both trailers and containers. Now my terminal loads containers only. (A big mistake in my opinion) And because we double stack, I only handle well cars. Due to our traffic patterns and the flexiblity of loading 3 packs, that's what my people prefer. We load out for 6 destinations. The big advantage of 3 packs is that they don't need to be shifted around to get the proper number of platforms in the proper order. The UPS traffic is through traffic. I'm just responsible for inspecting the trailer's as they pass. Nick
futuremodal wrote: Have you asked yourself why everything seems to move in sets of 6 and 12? Is that a rock solid axiom, not subject to the winds of change? What if sets of 5 and 10 come into favor? And why would anyone only load one UPS trailer on a 5-pack? Since intermodal equipment is mixed and matched, you can still use a 5-pack in conjunction with a singular car to hold the 6 set of trailers.
Have you asked yourself why everything seems to move in sets of 6 and 12? Is that a rock solid axiom, not subject to the winds of change? What if sets of 5 and 10 come into favor? And why would anyone only load one UPS trailer on a 5-pack? Since intermodal equipment is mixed and matched, you can still use a 5-pack in conjunction with a singular car to hold the 6 set of trailers.
Traffic does indeed change. I remember when we loaded almost exclusively 5 packs and 89' flats. We also used to actually switch out the cars to get them in proper order. Currently, traffic runs in sets of 6 and 12. Why? I don't know. Will it change again, undoubtedly. When I started, we loaded both trailers and containers. Now my terminal loads containers only. (A big mistake in my opinion) And because we double stack, I only handle well cars.
Due to our traffic patterns and the flexiblity of loading 3 packs, that's what my people prefer. We load out for 6 destinations. The big advantage of 3 packs is that they don't need to be shifted around to get the proper number of platforms in the proper order.
The UPS traffic is through traffic. I'm just responsible for inspecting the trailer's as they pass.
The well car with the trailer hitches built in is probably the most versatile of the intermodal cars. I guess some railroads are operating under the "better to have it and not need it, rather than need it and not have it" axiom. What you lose in added tare weight for hauling a single trailer in a well car you make up for in ultimate flexibility. You can haul two UPS trailers in a single said well car, but aren't those well cars strictly stand alone or 3 pack drawbar connected, not in articulated 3 packs? I suppose the extra fuel use may not be as big a factor as one would suppose, but again that might change if fuel prices continue to increase.
nanaimo73 wrote:I was thinking more along the lines of 5 platforms on 6 trucks, that could be increased to 6 platforms on 7 trucks, or decreased to 4 platforms on 5 trucks.
Now I get it. So what you'd have is, say, a normal 3 pack spine car which is 3 platforms on 4 trucks. The two trucks on the coupler end would be a hybrid of articulation and a normal drawbar shaft. When in 3 pack mode, you just stick a coupler into the drawbar shaft, but when you want to add platforms you plug the additions into the articulation parts?
I'll just think as I go here. What if instead we have a 3-pack spine car, but with single axle bogies on the end units, thus a 1+2+2+1 set of trucks (with the 2's as normal articulated two axle trucks.) The additional units are all 1+1, but when you add the additions to the 3-pack (let's say we want a 5 pack), you make it so the two facing single axle trucks become a double articulated two axle truck. To do this, you need a way to lock the single axle truck inline with the car's spine body when in stand alone mode, but allow the two single axle trucks facing each other to become a functional two axle articulated truck when connected together. You'd do this by releasing the locking mechanism which holds the truck inline (there would be a centerplate directly over the truck to allow the truck to swing free when connected to the facing truck), and then directly lock the drawbars of the two facing trucks together so they'll act as a single two axle truck, albeit with a truck wheelbase that is longer than the normal two axle truck wheelbase. The corresponding car bodies would each pivot on the centerplate of the home axle set.
Or were you thinking more in the line of using bi-modal technology as a way of adding the extra platforms? Then you'd have a normal 3 pack in 2+2+2+2 configuration, but have extra Mark V type trucks and bi-modal platforms that are added as de facto car additions to make whatever type of slack free multiple unit car configurations as you like. Something like that?
nbrodar wrote: I never said it was a maintenance issue. It's an equipment utlitization issue. And I'm telling you what my intermodal people tell me. A five pack is not more efficient when you have 6 or 12 pieces to load to a destination (a common occurance in the I-95 corridor). With 3 packs you have no empty platforms. With 5 packs you have 4 empty platforms. And in my corridor, for UPS trailers it's about 75% 89' flats and 25% spine cars. You can't say I'm wrong. I can count the cars as they pass my tower. Nick
I never said it was a maintenance issue. It's an equipment utlitization issue. And I'm telling you what my intermodal people tell me.
A five pack is not more efficient when you have 6 or 12 pieces to load to a destination (a common occurance in the I-95 corridor). With 3 packs you have no empty platforms. With 5 packs you have 4 empty platforms. And in my corridor, for UPS trailers it's about 75% 89' flats and 25% spine cars.
You can't say I'm wrong. I can count the cars as they pass my tower.
No one is saying you're wrong. But you're using anecdotal evidence to support a counterintuitive theory. Things can change over time.
The problem with the current 5-pack spine cars is that they are a "tweener" with the 48' platforms, too short for 53' trailers and containers, too long for 28' combo trailers. If a railcar manufacturer was to build new spine cars today, they could just as easily build a 6-pack with 53' platforms if the 5-pack is out of kilter with the 6 and 12 *rule*.
Since UPS favors the 28' trailer, it is logical that those would be loaded onto 89's rather than 53' 3 - pack spines or 48' 5-pack spines. Spine cars typically have one hitch per platform, so if you're hauling mostly 28' trailers, you're wasting alot of space with the longer platforms even though there's a trailer on each platform. 89's have three hitchs per car, so it's a nice fit for the 28' trailers.
A while back Trinity offered a 3-pack spine car with 57' platforms, probably in anticipation of wider acceptance of the 57' trailer, before finally throwing in the towell all together on spine car manufacturing. This car, if any even exist today, would be easily convertable to handle 2 x 28' trailers per platform, and would be the "perfect" car for hauling UPS trailers.
nbrodar wrote: And actually, 5 platform cars are losing favor (at least in the I-95 corridor) to 3 platform cars. The number of destinations, and volume of trailers/containers makes the 3 platform sets more effecient.
And actually, 5 platform cars are losing favor (at least in the I-95 corridor) to 3 platform cars. The number of destinations, and volume of trailers/containers makes the 3 platform sets more effecient.
The 5-pack vs 3-pack arguement isn't about the maintenance issue, rather the 5 pack w/40' wells is the favored configuration for ISO containers, but the 3 pack is favored for 53' domestics. Since spine cars are primarily meant for hauling trailers, and since single unit trailers are mostly 53', we get the 3 pack spine car. UPS trailers are still 28', so it is more efficient to haul them with the older 48' per platform 5 pack spine cars.
But whatever the case, 5 packs will always be more "efficient" than 3 packs.
futuremodal wrote: TomDiehl wrote: futuremodal wrote: (1) there is an inherent problem with long consist type cars, in that if one wheelset needs to be replaced, the whole unit has to be taken off line. Since coal cars are prone to suffer abuse, it's easier to keep them as single cars, so that if one needs a mechanical fix, you only lose that one, not 12 others at the same time. That's why we'll never see spine cars and well cars coming in 10 packs and 20 packs. Whether the Trough Train concept would have as much load factor value if it came in a more operationally flexible 4 pack (like the Southern 100) as opposed to it's originally designed 13 pack I can't say. Exactly the problem with the Iron Highway car. It was a 20 (or more) platform car. To be totally accurate about "why we'll never see spine cars coming in 10 packs" you'd have to add the statement "any more." The original Fuel Foilers on the AT&SF were ten packs (ten trailer platforms). They were changed to 5 platform size for this, and operational reasons. If you had 12 trailers to carry, you'd have to run two 10-pack cars with 8 empty platforms. Regular operations like this would throw the railroad's slim advantage right out the window. So the original concept was 20 or so platforms per unit. There is an inherent problem with long consist type units. Ergo, we completely ditch all aspects of the innovation. Isn't that akin to throwing the baby out with the bathwater? The question to ask is whether the Iron Highway could have been modified into shorter sections and still retain the core advantages of the concept. In this case, it appears the answer would be yes, e.g. shortening the units does not detract from the core concept.
TomDiehl wrote: futuremodal wrote: (1) there is an inherent problem with long consist type cars, in that if one wheelset needs to be replaced, the whole unit has to be taken off line. Since coal cars are prone to suffer abuse, it's easier to keep them as single cars, so that if one needs a mechanical fix, you only lose that one, not 12 others at the same time. That's why we'll never see spine cars and well cars coming in 10 packs and 20 packs. Whether the Trough Train concept would have as much load factor value if it came in a more operationally flexible 4 pack (like the Southern 100) as opposed to it's originally designed 13 pack I can't say. Exactly the problem with the Iron Highway car. It was a 20 (or more) platform car. To be totally accurate about "why we'll never see spine cars coming in 10 packs" you'd have to add the statement "any more." The original Fuel Foilers on the AT&SF were ten packs (ten trailer platforms). They were changed to 5 platform size for this, and operational reasons. If you had 12 trailers to carry, you'd have to run two 10-pack cars with 8 empty platforms. Regular operations like this would throw the railroad's slim advantage right out the window.
futuremodal wrote: (1) there is an inherent problem with long consist type cars, in that if one wheelset needs to be replaced, the whole unit has to be taken off line. Since coal cars are prone to suffer abuse, it's easier to keep them as single cars, so that if one needs a mechanical fix, you only lose that one, not 12 others at the same time. That's why we'll never see spine cars and well cars coming in 10 packs and 20 packs. Whether the Trough Train concept would have as much load factor value if it came in a more operationally flexible 4 pack (like the Southern 100) as opposed to it's originally designed 13 pack I can't say.
(1) there is an inherent problem with long consist type cars, in that if one wheelset needs to be replaced, the whole unit has to be taken off line. Since coal cars are prone to suffer abuse, it's easier to keep them as single cars, so that if one needs a mechanical fix, you only lose that one, not 12 others at the same time. That's why we'll never see spine cars and well cars coming in 10 packs and 20 packs. Whether the Trough Train concept would have as much load factor value if it came in a more operationally flexible 4 pack (like the Southern 100) as opposed to it's originally designed 13 pack I can't say.
Exactly the problem with the Iron Highway car. It was a 20 (or more) platform car.
To be totally accurate about "why we'll never see spine cars coming in 10 packs" you'd have to add the statement "any more." The original Fuel Foilers on the AT&SF were ten packs (ten trailer platforms). They were changed to 5 platform size for this, and operational reasons. If you had 12 trailers to carry, you'd have to run two 10-pack cars with 8 empty platforms. Regular operations like this would throw the railroad's slim advantage right out the window.
So the original concept was 20 or so platforms per unit. There is an inherent problem with long consist type units. Ergo, we completely ditch all aspects of the innovation.
Isn't that akin to throwing the baby out with the bathwater?
The question to ask is whether the Iron Highway could have been modified into shorter sections and still retain the core advantages of the concept. In this case, it appears the answer would be yes, e.g. shortening the units does not detract from the core concept.
The other aspects of the "innovation" that didn't work added together to shelve the idea. Nick covered them pretty well. When so many aspects of an idea combine to cause problems, what was thought to be just a simple concept can become unworkable as we see here. You're focusing on a few aspects that did work in limited situations. The now-standard spine cars have become the best of both worlds.
TomDiehl wrote: futuremodal wrote: (1) there is an inherent problem with long consist type cars, in that if one wheelset needs to be replaced, the whole unit has to be taken off line. Since coal cars are prone to suffer abuse, it's easier to keep them as single cars, so that if one needs a mechanical fix, you only lose that one, not 12 others at the same time. That's why we'll never see spine cars and well cars coming in 10 packs and 20 packs. Whether the Trough Train concept would have as much load factor value if it came in a more operationally flexible 4 pack (like the Southern 100) as opposed to it's originally designed 13 pack I can't say. Exactly the problem with the Iron Highway car. It was a 20 (or more) platform car.
David in Opelika wrote:Trucks all go at the same speed (not really, but hang with me) because all trucks have to obey federally mandated speed limits AND federally mandated weight limits. Say you have a semi-tractor trailer combo. It's maximum weight is limited to 80,000. For a typical tractor hp rating of 400hp, its ratio between weight to power is 200 lbs/hp.Now take a coal train at 15,000 tons, or 30,000,000 lbs. For a typical set of 4 locomotives rated at 4000 hp, its ratio will be 1875 lbs/hp. In order to match the power ratio of a simple truck, the railroad needs 36 locomotives per coal train!Or they can limit total train weight to 1600 tons.So trucks can travel faster than trains because they are so much overpowered than trains that they hit the mandated speed limit before they run out of power. Heavy trains travel slower than lighter trains because the weight difference between the light train and the heavy train is vastly greater than that between an empty truck and a loaded truck.
Exactly! Empty that coal train may only weigh 5000 tons. That's a big difference. As a result, even the slightest grade greatly effects train speed. And don't forget the added rolling resistence, called Equivilent Grade, curve introduce.
nanaimo73 wrote: FM- How familiar are you with BN's Trough Train ? I believe arbfbe posted that one of it's main reasons for failure was all of the special parts and fittings it had.
How familiar are you with BN's Trough Train ? I believe arbfbe posted that one of it's main reasons for failure was all of the special parts and fittings it had.
Well, I have an artist's rendering of the Trough Train in action, autographed by the inventor himself.
I'm not aware of the possible problems related to specialized parts, but if there is validity to that then it fits in with all the other innovations which inherently have non-standard parts (otherwise it wouldn't be an innovation). What I remember from my conversations with the Trough Train's inventor is two main operational problems that cropped up over time-
(2) there is a preference these days for rotary coupled coal gons as opposed to bottom dump hoppers for use in unit coal trains. The Trough Train concept would be nearly impossible to modify into a rotary dump version.
And no, despite the similiarities the Southern 100 was not the inspiration for the Trough Train, according to the inventor.
futuremodal wrote: Again, this speed differential based on premium pricing occurs only on railroads. Those same intermodal customers are paying that same premium on over the road trucks and on barges, but that doesn't translate into a given speed differential for those two modes based on that package premium or lack thereof. That coal truck and coal barge are moving at the same speed respectively as the intermodal truck and the container barge.
Again, this speed differential based on premium pricing occurs only on railroads. Those same intermodal customers are paying that same premium on over the road trucks and on barges, but that doesn't translate into a given speed differential for those two modes based on that package premium or lack thereof. That coal truck and coal barge are moving at the same speed respectively as the intermodal truck and the container barge.
But you don't see Next Day packages moving by trailer or 5 Day packages moving by air. If this isn't speed difference, I don't what is? I'm not talking about the speed difference between the UPS truck and the coal truck. I'm talking about the difference in final delivery time between a Next Day and a 5 Day package.
BTW, out here, those UPS guys move much faster then gravel or coal trucks.
In this example, speed of travel is irrelevent. The only time that counts is the TOTAL time between that package being picked up and that package being delivered delivered.
Do you work for or have ever worked for a railroad? Are you familar with the operational requirements of railroading? Have you ever been on the throttle and taken 13,000 tons of coal up and down a mountain? Have ever had to weave 8, 10 or 12 trains through a space designed for 4?
I have. Sit at my desk and do my job for a day, and you'll probably run screaming to your mommy.
Everything is easy on paper. Thing are little tougher, when it's 0 degrees and snowing, or 100 degrees with 100%humdity, or (what I hate the most) when it's 3am, 36 degrees, and pouring down rain.
nbrodar wrote: Hmm... Let's try this example...Stop looking at railroads as cars and trucks on a highway, look at the railroads like UPS or FED EX. And each car as a package to be shipped. UPS and FED EX charge more for Next Day then they do for 5 Day. So the Next Day package recieves preference over the 5 Day package. Intermodal customers pay premium prices so thier packages of trailers move faster then the packages of coal. BTW... In asking about your commuting time, I was trying to illistrate the fact that as traffic increases, overall speed decreases. A point you apparently missed. And I have been on numberous highways that have different speed limits for cars and trucks. Nick
Hmm...
Let's try this example...Stop looking at railroads as cars and trucks on a highway, look at the railroads like UPS or FED EX. And each car as a package to be shipped.
UPS and FED EX charge more for Next Day then they do for 5 Day. So the Next Day package recieves preference over the 5 Day package.
Intermodal customers pay premium prices so thier packages of trailers move faster then the packages of coal.
BTW... In asking about your commuting time, I was trying to illistrate the fact that as traffic increases, overall speed decreases. A point you apparently missed. And I have been on numberous highways that have different speed limits for cars and trucks.
Nick,
I'm not missing your point, but you do seem to be missing the points I'm making in regard to the odd way traffic is diseminated on railroads compared to all other modes. Take this statement you made:
"Intermodal customers pay premium prices so thier packages of trailers move faster then the packages of coal."
Regarding the seeming overall speed decrease associated with an increase in traffic, that is not a function of the traffic increase per se, but rather a function of the statistical likelyhood that anomolies to traffic flow will occur on an increasing basis with an increase in traffic. The most common anomoly is not the stalled car, etc., but rather backup on off ramps. This is one of the inherent flaws in the mindset of highway planners - they design the roads for the expected average traffic flow, not for the expected maximum traffic flow.
nbrodar wrote: As I have said before....the problem with the Front/Four runnings was NOT THE DRAWBARS. The problem was the long rigid wheelbase of EACH INDIVIDUAL PLATFORM. I had more operational problems with the single cars using standard couplers.
As I have said before....the problem with the Front/Four runnings was NOT THE DRAWBARS. The problem was the long rigid wheelbase of EACH INDIVIDUAL PLATFORM. I had more operational problems with the single cars using standard couplers.
Yes, the rigid wheelbase was problem #1, but the way the drawbars on the Four Runners (and the couplers on the single cars) were designed may have contributed to tracking problems. The drawbars ran from striker to striker, but there was about 7 feet between the striker and the truck center at the ends, so when negotiating a tight S curve, you'd get the problem of the lead car pulling the trailing car right off the tracks. This problem is less apparent in cars using standard three piece trucks, but for single axle cars with the rigid wheelbase, it became more animated. If the drawbars on the Four Runners (and for that matter the couplers on the single cars) could have been run from truck center to truck center instead of striker to striker, the pull would better follow the longitudinal forces. But you still have the rigid wheelbase, which for 36' is rather long, and for that articulating AC and DB ends together with a standard three piece truck (leaving the CD drawbar connection in place) would alleviate the problem.
Traffic, even on the highway does not move at all the same speed. Dave, you seem perfectly willing to discount passenger cars from your highway arguement. Why? You say we're not talking about passenger traffic. It doesn't matter. Passengers are simply a commodity. Just like gravel, coal, or anything else. You can only put so much traffic in a given space, before speed suffers.
The point of the analogy is that there is no implicit speed differential on highways et al based on commodity type, this seems to only happen on railroads. You will always be able to see a UPS truck and a logging truck travel at the same relative speed on highways. Check any posted truck speed limit sign on any US highway, you will not see discrimination based on what that truck is hauling, it is all posted for the same speed.
The reason we discount passengers from the example is that passenger trains are for the most part a non-existent anomoly on US railroads, so they do not provide a counter example to average railroad speeds.
How long is your commute to work? Does it take longer at Rush Hour? I'll be it does. My commute is 45 mintues, at Rush Hour, it's 1 hour 15 minutes or more.
Currently my commute is 15 minutes both ways. A few months ago it was 1 hour 15 minutes both ways. Remember, I live out here in the sticks. It's a choice afforded by quasi self employment.
Not sure what any of this has to do with the topic though.
Are your highways dead flat and arrow straight? Mine sure aren't. Grade and curvature greatly effects speeds. Traffic around here always bunches up around hills and curves.
The UPS truck can't take that curve any faster than the gravel truck or the tanker. Only on the grades is there an apparent difference in commodity types as it relates to speed, and this is due to the relative hp/t ratios.
On railroads, you would think the relatively unstable center of gravity would force the TOFC to slow down through curves more so than the unit train of coal gons. But it seems to work the other way around, soley based on commodity type.
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