Oil Trains Cause Track Defects?

[schlimm]

In your need to defend every practice, you miss the point completely.   Heavy trains are much harder on track, leading to derailments and making higher speeds difficult and more expensive.   Bulk shipments of oil and coal are not seen as a growth area for the future.  The salad days of easy coal shipments to utilities are fading fast.  International containers may decline as well.   Buffett and BNSF have sufficient vision to see this and also see the way to grow is to take back some of the lost truck traffic.

[dehusman]

schlimm

In your need to defend every practice, you miss the point completely.  

In your need to disagree with anybody who has any practical experience, you tend to restate the obvious and miss points yourself.

 Heavy trains are much harder on track, leading to derailments and making higher speeds difficult and more expensive.

Mixed bag of yes, no and maybe.

Yes. Heavy trains are harder on track.  Gravity sucks.

No, heavier trains don't necessarily mean more derailments.  Heavier trains mean more infrastructure and more maintenances.  Lack of maintenance or inadequate infrastructure means more derailments.

Maybe. Any time you mix trains of different speeds you get an overall lower speed.  Higher speed track ALSO means more maintenance and more infrastructure.  Higher speed requires more infrastructure and maintenance than heavy trains does.   Running shorter trains faster and handling the same traffic becomes prohibitively expensive with little or no return.  Coal and grain companies really don't need productes delivered at 110 mph. Its a huge waste of fuel, running bulk trains at high speed causes geometrically more damage to track and is hugely maintenance intensive.  Speed is way more expensive to buy than size.

Bulk shipments of oil and coal are not seen as a growth area for the future.  The salad days of easy coal shipments to utilities are fading fast.

Common knowledge.

 International containers may decline as well.   Buffett and BNSF have sufficient vision to see this and also see the way to grow is to take back some of the lost truck traffic.

As has pretty much every railroad in the US.  That's been a strategy since the 1980's.  That's why both the UP and BNSF have CTC'd and double tracked their E-W lines across the US. (P.S.  The BNSF started upgrading their Trancon and the UP their Sunset way before Buffett had anything to do with the BNSF). 

[Murphy Siding]

schlimm

In your need to defend every practice, you miss the point completely.   Heavy trains are much harder on track, leading to derailments and making higher speeds difficult and more expensive.   Bulk shipments of oil and coal are not seen as a growth area for the future.  The salad days of easy coal shipments to utilities are fading fast.  International containers may decline as well.   Buffett and BNSF have sufficient vision to see this and also see the way to grow is to take back some of the lost truck traffic.

 

  Come on now.  Why so combative?  This is a discussion about something we all have an interest in, not a game where we're keeping score.

[schlimm]

Murphy Siding

 

 

schlimm

In your need to defend every practice, you miss the point completely.   Heavy trains are much harder on track, leading to derailments and making higher speeds difficult and more expensive.   Bulk shipments of oil and coal are not seen as a growth area for the future.  The salad days of easy coal shipments to utilities are fading fast.  International containers may decline as well.   Buffett and BNSF have sufficient vision to see this and also see the way to grow is to take back some of the lost truck traffic.

 

 

 

 

  Come on now.  Why so combative?  This is a discussion about something we all have an interest in, not a game where we're keeping score.

 

 

Says the scorekeeper-in-chief with dripping irony.

[edblysard]

schlimm

 

edblysard

To add to Dave's analogy,

Imagine all those rush hour cars having to use just two lanes, one in each direction, and all of them trying to get into the same two or three parking lots at the same time. 

Why do folks insist on comparing the European model of railroading to the American model, when they face two completely different geographic obstacles/ regions, and vastly different distances, and two different political models?

 

 

 

 

The politics are irrelevant.   The terrain in Europe is as rugged as here and only transcontinental runs are really essentially different.   

 

 Oh yes, politics are relevant, state funded and nationalized railroads have the resources and legal power to do things American railroads can't.

And some of the terrain in Europe is much more rugged that in the US, hence shorter trains are the only way to get over the road.

But you just go on ignoring facts and pretend they are the same, if that's what floats your boat.

[Murphy Siding]

schlimm

 

 

Murphy Siding

 

 

schlimm

In your need to defend every practice, you miss the point completely.   Heavy trains are much harder on track, leading to derailments and making higher speeds difficult and more expensive.   Bulk shipments of oil and coal are not seen as a growth area for the future.  The salad days of easy coal shipments to utilities are fading fast.  International containers may decline as well.   Buffett and BNSF have sufficient vision to see this and also see the way to grow is to take back some of the lost truck traffic.

 

 

 

 

  Come on now.  Why so combative?  This is a discussion about something we all have an interest in, not a game where we're keeping score.

 

 

 

 

 

Says the scorekeeper-in-chief with dripping irony.

 

+1  

Seriously, you do seem to have some interest other than your agenda-no?

[edblysard]

schlimm

Not sure that 20 years at Conrail is much of a recommendation. 

 

I don't know...take a bunch of railroads that are both financially and physically bankrupt, and out of that mess create a successful and profitable railroad, one that was so profitable and strategic that, when offered for sale, had two of the largest Class 1 roads in a bidding war...

Not a bad thing to have on your resume.

[Paul_D_North_Jr]

Buslist

schlimm

dehusman

schlimm

Try that one on CSX and NS RoW and operating personnel who were there after the takeover.

Since the CSX is one of the roads having some of the track related derailments we are discussing, aren't you living in a glass house?

Not sure what you are saying.  I am saying Conrail was a mess and the track and equipment CSX and NS inherited needed a lot of work.  Hence derailments today.  

And those CSX derailments att on former CR track right? And almost 19 years later. And CSX was so upset at CR's operating practices that the appointed CR's VPO, Ron Conway, as their VPO after the purchase.

19 years is about 3 T&S cycles (Tie & Surfacing = add ballast, tamp & line, etc.), and 1 or 2 rail replacement cycles (depends mainly on the curvature, grade, and on the annual gross tonnage).  So there wouldn't be much that was there in the beginning. which is still there 19 years later - just the subgrade and R-O-W, in general - and there would have been plenty of time to work out the defects.

[CShaveRR]

Going to put my two cents' in here (don't spend it all in one place):  

Most of the crude-by-rail incidents in the US have occurred on two railroads:  BNSF and CSX.  One eastern railroad and one western railroad. Why not UP?  Because they handle less crude traffic than BNSF (If I see a crude train on our line--the Overland Route--here, it's noteworthy).

In the east, you have two railroads receiving crude shopments from the west--CSX and NS.  I don't know the proportions here, but I don't think I've heard of a major crude disaster on NS.  CSX gets wrecks.  They don't have inferior trains running over their lines.

I'll submit for your consideration that CSX tries to maintain its track (as well as do anything else, it seems) on the cheap.  Conrail was doing a dared good job of bringing its track into shape before the breakup, and that could be seen, and felt.  CSX has had predecessors with a known bean-counter mentality that has hurt their lines considerably.  I remember my first long-distance train trip over the C&O in 1972--smooth as glass, a fascinating operation over two-track CTC that made me proud of that railroad (I was on the C&OHS Board about then).  It didn't take long before things went downhill--that two-track main line started losing track, and the ride became much less smooth, with hard bumps that felt like broken rail.  The C&OHS newsletter quit mentioning the derailments because they became too numerous.  The first line to fave problems with Amtrak's SDP4F was--you guessed it--C&O.  Those engines could find a weak spot in the track and exploit it.  Now, take come of the other railroads that C&O merged with to form CSX:  SBD roadbed standards (narrow sub-roadbeds, for example) were inferor to those of NS and the western railroads.  Hence the sun-kinks that derailed Amtrak a time or two.  I also remember the pictures showing a side-by-side comparison of CSX and NS lines, both of which handled Amtrak trains (still do, except CSX spun its line off). CSX did upgrade its ex-B&O main line in preparation for the Conrail break-up, but again, it didn't take long for the track to be worn out, in spite of the fact that it wasn't getting nearly the business they anticipated.  Their profit margins are impressive, fueled by such weird measures as 28-hour days, cannibalizing their mainline network, laying off employees, and on and on.  You don't hear about that too much on the other railroads.

Why don't people on the outside understand this?  Sorry about the rant; tomorrow I'll be older and wiser.

[Electroliner 1935]

I've never forgotten riding west from Belvue Ohio behind 611 on a NS Independence Limited train doing 70 mph and looking forward from the observation cars dutch door and being impressed by seeing  NO motion between the cars. The train could have been standing in a station, so smooth was the track. In other areas, the track was just as good. The NS impressed me in their track maintenance. Convinced me to buy stock. Defered maintenance may make the bottom line look good this quarter but it will cost you later. They are a railroad, not a holding company. I do fear for what the decline in coal traffic will do to the NS. We already see the CSX shutting down the Clinchfield, and the NS has rerouted coal trains away from p/o its ex'Virginian route. 

[schlimm]

edblysard

 

 

schlimm

 

edblysard

To add to Dave's analogy,

Imagine all those rush hour cars having to use just two lanes, one in each direction, and all of them trying to get into the same two or three parking lots at the same time. 

Why do folks insist on comparing the European model of railroading to the American model, when they face two completely different geographic obstacles/ regions, and vastly different distances, and two different political models?

 

 

 

 

The politics are irrelevant.   The terrain in Europe is as rugged as here and only transcontinental runs are really essentially different.   

 

 

 

 

 Oh yes, politics are relevant, state funded and nationalized railroads have the resources and legal power to do things American railroads can't.

And some of the terrain in Europe is much more rugged that in the US, hence shorter trains are the only way to get over the road.

But you just go on ignoring facts and pretend they are the same, if that's what floats your boat.

 

I am not ignoring facts or have some agenda.  Simply trying to expand the range of possibilities.  The rail expert ignores several important bits of information in his piece on DB.  

1.  The engineers' (or as they are called everywhere but in the US, "train drivers") strikes over the last two years cost Schenker Rail (freight division of DB) 8-10% of their customers who have not returned.  

2. Slow progess in cutting excess freight stations and delivery points.  20% of all of them generate only 1% of revenue.  

3. Some on here think having a government connection is some sort of advantage.  Maybe, but politics reduces the flexibility of any cuts of stations or labor force.  Think Amtrak.

 

It is possible to learn from the some of the experiences of foreign rails, rather than a knee-jerk reaction of rejection.

[cefinkjr]

If a new automobile manufacturer came along or an existing manufacturer suddenly increased its sales, would you blame highways for an increase in the number of that manufacturer's vehicles being involved in crashes? 

[zugmann]

 

If the highways were responsible, then yeah.  If a road gets busier, then it gets widened, traffic lights added, or bypasses built.  The road needs to be upgraded to handle the increased load.

 

Track defects are track defects.  If maintenance isn't being done to handle the freight that runs on them, that's a problem that needs addressed.

 

 

 

cefinkjr

If a new automobile manufacturer came along or an existing manufacturer suddenly increased its sales, would you blame highways for an increase in the number of that manufacturer's vehicles being involved in crashes? 

 

[Euclid]

The premise of the article in the first post is not that more oil trains are derailing because the number of oil trains is increasing.  The premise is that more oil train derailments are caused by track defects than is the case with other types of trains.

[BaltACD]

I would imagine reading and interperting the data that is generated by rail inspection is somewhat analogous to Doctors or X-ray technicians reading a X-ray.  If you have not been trained it what you are looking for, you have very little idea of what it is that you are seeing - unless the problem is manifestly self evident.

With the FRA saying that both Sperry and CSX 'overlooked' the defect - I would suspect it was far from self evident.  It is a whole lot easier to pinpoint the defect after the failure and then relate it to the data that was gathered prior to the failure.

[Euclid]

I have no idea whether the article is drawing a valid conclusion.  It is a major challenge to just understand what its conclusion is.  Here is what I think the article concludes:

If you compare a number of oil train derailments to an identical number of derailments of other types of trains such as grain unit trains, coal unit trains, or mixed freight trains; you will find that track defects caused twice as many of the oil train derailments compared to how many of the derailments of the other types of trains were caused by track defects. 

I cannot see why oil trains would encounter more derailment causing track defects than other trains; or why oil trains would challenge a track defect more than other types of unit trains. 

So that leaves this possibility:  Oil trains that derail are causing track defects which then derail that same train before it passes the defect. That is the only conclusion that can explain what the article observes from the statistics.   

[edblysard]

schlimm

 

edblysard

 

 

schlimm

 

edblysard

To add to Dave's analogy,

Imagine all those rush hour cars having to use just two lanes, one in each direction, and all of them trying to get into the same two or three parking lots at the same time. 

Why do folks insist on comparing the European model of railroading to the American model, when they face two completely different geographic obstacles/ regions, and vastly different distances, and two different political models?

 

 

 

 

The politics are irrelevant.   The terrain in Europe is as rugged as here and only transcontinental runs are really essentially different.   

 

 

 

 

 Oh yes, politics are relevant, state funded and nationalized railroads have the resources and legal power to do things American railroads can't.

And some of the terrain in Europe is much more rugged that in the US, hence shorter trains are the only way to get over the road.

But you just go on ignoring facts and pretend they are the same, if that's what floats your boat.

 

 

 

 

I am not ignoring facts or have some agenda.  Simply trying to expand the range of possibilities.  The rail expert ignores several important bits of information in his piece on DB.  

1.  The engineers' (or as they are called everywhere but in the US, "train drivers") strikes over the last two years cost Schenker Rail (freight division of DB) 8-10% of their customers who have not returned.  

2. Slow progess in cutting excess freight stations and delivery points.  20% of all of them generate only 1% of revenue.  

3. Some on here think having a government connection is some sort of advantage.  Maybe, but politics reduces the flexibility of any cuts of stations or labor force.  Think Amtrak.

 

It is possible to learn from the some of the experiences of foreign rails, rather than a knee-jerk reaction of rejection.

 

No "knee jerk reaction", which is what you often say in an attempt to divert the conversation into a war of sorts...

Short fast trains have been tried here, SP'S Blue Streak Merchandiser blew across east Texas at 79 mph with short trains all the time, but it almost never made money.

Santa Fe had a hotshot intermodal service, specialized service, and it too almost never broke even, which is the crux of it all.

Nationalized and state subsidized carriers don't have to make money.

They can of course, and some do, but it is not the driving impetus behind their operating plan.

Most North American railroads on the other hand, do have to make money, they are businesses, not public utilities.

Know who the worlds largest employer is?  

India Railroads...nationalized way back, they employee more people than the top 5 largest business in the world combined.

Not just in the railroad industry, not just in Asia, but the world.

They can hire track walkers whose sole job is to walk miles of track, every day, tightening joint bolts and doing minor repair.

They have flagmen/gate guards at rural road crossings, and they carry 6 million passengers every day...6 million people daily

Commuters pay something like 5 rupees to ride...that's what, a dollar American?

If you work for them in the operating department, you get subsidized housing, health care, and have a job for life.

For them, it makes perfect sense, trains are the major mode of transportation for both people and freight there, and always have been since the British laid the first rail.

Your short fast train idea makes perfect sense in Europe, it is what that/those systems were designed from the beginning.

I mean, come on, the Swiss are digging a tunnel under the Alps to speed up their trains and get trucks off their massively overcrowded roads, their real estate is so limited they can't build more roads. 

America railroads were designed the exact opposite, to haul as much stuff, and people as possible at once, because the manufacturing of goods here was so much larger, and we had vast western lands to settle, Europe on the other hand,, was crowded even back then.

We still move more goods farther by rail, with less trains than a before, than any other country.

Compare ton miles revenue of the smallest American Class 1 to any European carriers.

Do I think nationalization is a good thing?

For freight carriers no, they are profitable businesses who pay dividends to stockholders, and they pay their employees pretty darn good, I earn in a day what the engineers on Indian railroads are paid in a week.

Of course, my cost of living is vastly different than theirs.

I have to pay for my own transportation to and from work, my own housing, healthcare, so forth and so on.

Your typical German railroad worker most likely lives in some form of government subsidized housing and has socialized healthcare, and likely has a job for life...I can get fired if I screw up. 

So yes, politics and form of government do play a important part in the difference between the two models of railroading.

Do I think passenger trains can make a profit here?

Nope.

I know the romantics/rail fans would love if their favorite carrier brought back its premier trains, but it can't happen, passenger trains quit making money after WWII, even the Santa Fe, who ran the most recognized train in the world, gave it up when they could.

The private automobile, which everyone here could afford, and which was a luxury in Europe, along with the Interstate Highway system, killed the passenger train quite nicely, and I don't know of too many rail fans who would give up either their car, or the interstate, just to see passenger trains run here, our entire economy includes both, and would collapse if either one went away.

Do think Amtrak should be nationalized?

You betcha!

Hire the top West Point graduate from the logistics division of the Army Corp of Engineers, and put him/her in charge.

Fine the crap out of any freight railroad that delays any Amtrak movement, period.

Put a penny a gallon tax on all gasoline and diesel fuel sold and you could build a world class rail transportation system, one that would stand against the TGV, the Bullet trains in Japan, any train in Europe.

You could pay the train crews the same wage they earn now, and have money left over.

[schlimm]

OK, not a knee-jerk rejection.  Instead it is a rejection o anything outside your frame of reference with a laundry list of either irrelevancies (India Rail) and mis- or disinformation so long that I will just leave it with you to ponder.

[Murphy Siding]

schlimm

OK, not a knee-jerk rejection.  Instead it is a rejection o anything outside your frame of reference with a laundry list of either irrelevancies (India Rail) and mis- or disinformation so long that I will just leave it with you to ponder.

 

 That was well put.  Probably one of the most soft core apologies I've seen in a while.

[Deggesty]

As to short, fast, trains, many moons ago (more than forty-three years; I do not remember just when) there was an article in Trains which described the then practice of the Rio Grande of running such. When my bride and I rode the Rio Grande Zephyr from Denver to Salt Lake City in July of 1972, I expected to see many of them along the way--and I saw none.

Apparently the Rio Grande determined that the practice was uneconomical.

[Electroliner 1935]

edblysard

Do think Amtrak should be nationalized? You betcha! Hire the top West Point graduate from the logistics division of the Army Corp of Engineers, and put him/her in charge. Fine the crap out of any freight railroad that delays any Amtrak movement, period. Put a penny a gallon tax on all gasoline and diesel fuel sold and you could build a world class rail transportation system, one that would stand against the TGV, the Bullet trains in Japan, any train in Europe. You could pay the train crews the same wage they earn now, and have money left over.

Well said Ed.

[Euclid]

I don’t think that it is as cut and dry as short, fast, frequent trains versus getting the greatest number of cars into one train as possible.  I doubt that either approach is always better in any given country or even with any given train on a particular railroad.  If they run shorter, faster trains in Europe in general, I would not conclude that they are choosing the less profitable method, but they don’t care because they are nationalized and don’t have to make money.  And even in this county, trains do not seem to always max out at the greatest possible number of cars.  You see lots of trains under 100 cars when they could just as well have 250 cars.  I think the debate needs a lot more detail to have any meaning.

[Dakguy201]

edblysard

Do think Amtrak should be nationalized?

You betcha!

Hire the top West Point graduate from the logistics division of the Army Corp of Engineers, and put him/her in charge.

I was following your logic nicely until I got to that.  I don't understand which of Amtrak's major problems have much to do with logistics, other than passengers being self loading cargo.  Nor do I understand why the military would be a superior source of upper management talent for Amtrak.        

 

[edblysard]

Your right, it is not cut and dried.

Correct too not all American trains run maxed out....while we don't run on a timetable schedule, most trains have to leave their start terminals within a routine time window.

If there are enough cars to max it out, then that's how it runs, sometimes there are more than that, and the leftovers go the next days train, there are set limits on each carrier on train lengths and weight.

Often there is no where near the max number of cars, and it runs like that.

UP runs a yard to yard train to us every shift, even though they could hold it all and run it as one big train, they choose not to, because they would have to use a big track to start it from, it would be hard to manage, and by running short, 50 to 60 car trains three times a day instead of one big 150 car train, they can keep that part of their yard fairly liquid.

It works for us too, as we only have to worry about a 60 car switch instead of a 150 car switch.

Schlimm, my point with India railways is they run short, fast passenger trains, often with a five minute headway.

Massive amounts of people moved on short, fast trains, that model works for them, and they run a lot of freight in the same manner.

The "European" model works great for one of the worlds biggest railroads.

That still does not mean it will work here on our railroads.

Keep in mind European yards tend to be smaller than ours, they run a lot of point to point trains, where our interchange system requires trains to be switched into forwarding blocks and added into new trains going on to the final destination.

Distances tend to be shorter there also.

Yes, there are some massive yards there, they do forward or interchange cars, but no where near the amount we do.

[BaltACD]

When it comes to freight in the US, the carriers and their customers work in concert with each other.  For the most part, customers desire their plant to be switched one time a day, most of the time when plant production personnel are not on the clock.  Therefore, the ability to deliver multiple switches a day by short, fast, frequent service is a service the customer is not able to use and won't pay for.  Even unit train customers have 'preferred' service times that the carriers must satisfy.

No matter what each carriers operating plan is, it must fit the physical capabilities of it's terminals.  Pumping 5K cars a day toward a terminal that can only handle 3K is a quick way to bring the carrier to gridlock.  Pumping 3200 cars a day to that same terminal will also result in gridlock - it will just take longer to happen.

European operating plans satisfy the needs of their customers; US carrier's oprating plans satisfy the needs of their customers.

[greyhounds]

edblysard

Hire the top West Point graduate from the logistics division of the Army Corp of Engineers, and put him/her in charge.

The Quartermasters and Transporation Corps generally handle logistics.  Army engineers build things (i.e. put a bridge across a river in one hour while being shot at) and destroy things (clear minefields, blow up a bridge so the enemy can't use it.)

 

[cefinkjr]

Short, fast, frequent or long, slow, and occasionally don't matter as much to the most important piece of the puzzle --- the customer, the guy paying the bills.

The customer wants, above all else, reliability.  If you tell the customer that his shipment will leave Podunk at 7:00 pm and arrive at Elsewhere by 9:00 am on the 2nd day, the dust needs to be settling behind it at 7:01 and he wants to see his people opening the door to unload the car at 9:01.  Anything else is unacceptable because he is unable to schedule the rest of his operation and, worse, he is unable to make good on his promises to his customers.

[dehusman]

cefinkjr

Short, fast, frequent or long, slow, and occasionally don't matter as much to the most important piece of the puzzle --- the customer, the guy paying the bills. The customer wants, above all else, reliability. If you tell the customer that his shipment will leave Podunk at 7:00 pm and arrive at Elsewhere by 9:00 am on the 2nd day, the dust needs to be settling behind it at 7:01 and he wants to see his people opening the door to unload the car at 9:01. Anything else is unacceptable because he is unable to schedule the rest of his operation and, worse, he is unable to make good on his promises to his customers.

The wrinkle in this is that different customers want different things.  Bulk customers want a consistent flow.  Some customers want a consistent departure, some want a consistent arrival, some want to hit the same time every day, some don't care what the time is, but just hit the time you say.  For some which car is more important than the time.

European railroads are designed as passenger railroads, they are designed to handle a lot of short fast trains.  Therefore the freight trains have to fit in with those flows.  The biggest impediment to dispatching is not slow trains but mixing fast and slow trains.  Consistency of speeds is most efficient, whether than speed is fast or slow.

What most people don't understand is that when you run Amtrak on a single track freight line, it has a footprint that can be 100-150 miles long.  When Amtrak is leaving one crew change there may be freight trains held 125 miles away at the next crew change to make a meet with Amtrak, because all the sidings on the subs are or will be filled with trains that have to be met or passed by Amtrak.

[schlimm]

dehusman

European railroads are designed as passenger railroads, they are designed to handle a lot of short fast trains.

Let's set the record straight.  Most of the German Rail components were largely designed to move heavy military trains.   The same is true of those in many other European countries, though not the UK.   Passenger trains were mostly slow, with the exception of a few lines until the last 40 years.  Some very fast trains ran in the UK, and some lines in France and Germany in the 1930s.  Freight trains in Germany run fast to meet customer needs for scheduled, quick delivery primarily ("just-in-time" inventory control), since most of the important lines are multitrack.  They don't just run fast to keep out of the way of fast passenger trains.  And true HSR stretches (> 225 kmh) have their own track or even RoW.

Of course different countries have differing needs, but as an advanced country, our needs are not so radically different from Europe and elsewhere.   And apparently BNSF and Buffett agree.

Why change?  Adaptation to changing markets.  The US rails have prospered from the low-hanging fruit for years, unit trains of commodities: coal, grain, and later ethanol and oil.  Several of those are becoming a smaller revenue stream already or in the near future.

[Paul_D_North_Jr]

edblysard

[snipped - PDN.] . . . Often there is no where near the max number of cars, and it runs like that.

UP runs a yard to yard train to us every shift, even though they could hold it all and run it as one big train, they choose not to, because they would have to use a big track to start it from, it would be hard to manage, and by running short, 50 to 60 car trains three times a day instead of one big 150 car train, they can keep that part of their yard fairly liquid. . . .

   And of course, as soon as a train is held to fill it out to the max number of cars, then even more cars will show up unexpectedly, overflow that train and the following trains, clog up the yard, and then operations deteriorate until the traffic flow decreases enough to get things back to normal.