Trimmers & setters/ switching lingo

[nbrodar]

An application and Release test would not be required if all you did was to cut the train (like for a crossing) and didn't change the brake pipe in any other way.  When you recouple all you have to know is that air pressure is being restored on the rear end.  This can be done by either having the EOT show a rise in pressure or having someone with a gauge showing the rise.  If there is no working gauge or EOT on the back end, than the brake pipe must be charged and the brakes must be seen to setup and release on the rear car by making a 20lb application and release.  (If the rear portion has been off air for longer than 4 hours, that portion needs a complete Initial terminal test.)

Jeff 

Jeff,

That's true, but it's still a good idea to do an apply and release anyway.  Some of the more restrictive Air Brake books I've seen require it.

Ed,

Most of our trains come in with a "relay" block or blocks that put on the next train without any switching, plus a block a local traffic.   We have a couple trains that come in with out any blocking at all.  If they relay block are put on ground air with-in four hours of arriving we don't have to do a Class I brake test.

Generally, any cars switched from the inbound local and unblocked trains, will be switched into a seperate class track, air tested, and then doubled to relay block.

Nick

[CShaveRR]

Hypothetical question, Nick, regarding your trains that come in without any blocking:

Are you at these trains' final terminal?  A train might look that way to you, but it's the result of what work was done earlier by yard and road crews.  In our example, the MPRCB may look like a dog's breakfast when it arrives at Council Bluffs South Yard, but that's because it's only carrying cars blocked for that destination, after setting out everything else en route.

On the other hand, our trains for North Platte carry just about anything that goes west, northwest, and southwest of that point.  I guess that fits your description of not being blocked, but it appears that any blocking we've ever attempted for North Platte proves inefficient or uneconomical at our end.

[nbrodar]

Carl,

For the trains we "switch", we are the final terminal. 

For example...Q301 comes in and is suppose to have relay blocks that go to Q405 and Q373 plus a mixed block of local cars.  Like wise, Q406 come in with a relay block for Q300 and a mixed local block.  Sometimes this relay blocking is called Pre-Blocking.  YPCA01, however, is always a dogs breakfast, with no pre-blocking.

We also have intermodal and trash trains, that simply pick up and drop blocks left by/for other trains.

Nick

[tree68]

Back on times: 

From the  Conrail EC-99 Brake Rules: (http://www.tree68.net/Railroad/EC99/)

6.6 APPROXIMATE CHARGING TIME TO 90 PSI

6.6.1	- Single Car	- 7 minutes
	- 50 cars	- 8-11 minutes
	- 100 cars	- 18-25 minutes
	- 150 cars	- 35-50 minutes

Times based on 50 ft. uncharged cars. Shorter times shown are for minimum brake pipe leakage, longer times are for maximum allowable brake pipe leakage.

6.6.2 - Pressure indicated at rear of train will determine state of charge.

We regularly do runarounds of our excursion trains at both ends of the trip.  We do set a handbrake or two and dump the air IAW rules and best practices, and even our longer trains (all 6 cars) take only a short period to reach acceptable brakepipe pressures for a Class 3/Road test.  A set and release, viewed at the tail end, and we're on our way.

[jeffhergert]

Carl/Jeff:

Thanks, great answers. 

Jeff, you mentioned that MPRCB gets to Boone and then is yarded and then leaves several hours later.  What is the purpose of the yarding?  Is it further classifying the cars?  In other words does Proviso simply make the three blocks and then Boone refines the blocks so the local yard can deliver the train's cars in sequence?

Hope that makes sense.

ed

In the current operational pattern, MPRCB is only yarded at Boone to hold it for Council Bluffs.  I'm guessing if they called it thru it would arrive at Council Bluffs at an inconvenient time for the CB yard to handle.  

Jeff 

  

 

[MP173]

Jeff:

That makes sense.  They want it out of Proviso by a certain time, but dont need/want it at CB before a certain time.  So, the logical question is...why not delay the departure time from Proviso to meet the arrival time.

I can think of several reasons why they leave at a certain time.

1.  To give a padding in the schedule for arrival at CB.  I would assume the arrival is timed for delivery by local crews.

2.  Perhaps the Proviso tracks are used to build another outbound train and is needed. 

Nick:

By "relay block" I would assume this term is similar to "block swapping" which is done out here at sidings, in which a block is dropped in a siding for a following train.

This stuff is interesting.  Hope you dont mind all the questions.

Can you imagine what it is like at FEDEX or UPS at midnight at Memphis or Louisville?

ed

[nbrodar]

Nick:

By "relay block" I would assume this term is similar to "block swapping" which is done out here at sidings, in which a block is dropped in a siding for a following train.

This stuff is interesting.  Hope you dont mind all the questions.

Can you imagine what it is like at FEDEX or UPS at midnight at Memphis or Louisville?

ed

Ed, it's similar, but not quite the same.  At least on my property, block swaping is where train A sets out cars for train B to pick up.  Train A and B continue on as A and B.

With Relay or Pre blocking.  Train A comes into the yard and terminates.  A's relay block is then put on a new train B, that originates at the yard. 

We preform both types of operation in my terminal.

The idea behind pre-blocking is to lessen the number of times a car needs to be classified.  Large, fast hump yards block the cars, so that a smalled flat yard simply has to move the block, rather then re-classifying the individual cars.   This can significantly reduce dwell time.

Nick

[Murphy Siding]

     Are hump yards going to become extinct?  The article makes it sound like West Colton does a lot less classifying than it used to do.  I've read in several places where a hump yard was taken out, or reduced in size.  Will there be a time where they are not needed, or not busy enough to justify the expense?