Blocking Trains .....
Blocking of trains refers to how multi destination cars are grouped together and assembled or incorporated into a train. Basically blocking is done to simplify
the task of downline YMs who may need to take cars off or add cars to the train. Blocks can consist of any number of cars (subject to the HP/Ton and maximum
Train Length requirements). Correct blocking is fairly straighforward, however, you do need to know some things about the trains you will build or add blocks of cars to.
Things like what car type they carry, which intermediate yards do they work. This information can be found from the TSARs.
1. Intermodal, Autorack, Roadrailer, Coal, Grain, etc
These train types are the easiest to Block. They will have a limited number of car destinations (Maximum 5 in FYM).
Each block consists of cars for a single yard only.
If the train is to set off cars at Stations between it's source and destination, then the blocks should be assembled in the order of set off.
Blocks can either be assembled starting at the Head End or the Rear End of the train. In the examples below Block A is the first block to be set off at some
intermediate Station, then Block B. Blocks C and D will continue on the train to it's destination.
The graphic above shows the cars blocked at the Head End, for Block A and then Block B removal.
The graphic above shows the cars blocked at the Rear End, for BLock A and then Block B removal.
If the train is to pick up cars at intermediate Stations then, they should also be blocked and each picked up block should be added to an existing block
for the same yard. Or if a block for a new destination then it should be added in such a way as not to hinder any set offs at Stations down the line.
New Block C is to be added to the train, after Block A has been set off. Because the new block is for a yard for which a block already exists on the train,
then it must be added to the existing block. Correct positions for this block are indicated in GREEN - D-C-C-B, while
incorrect positions are indicated in RED - D-C-B-C or C-D-C-B. (Only the Rear End set off example for Block A is shown).
New Block E is to be added to the train, after Block A has been set off.
Because this new block is not for the same destination as any others on the train and assuming it is not to be set off before Block B then the correct positions for this block
are indicated in GREEN - E-D-C-B, D-E-C-B, D-C-E-B, the incorrect position is indicated in RED - D-C-B-E.
However, if this new Block is to be set off before Block B then the correct positions for this block are shown above in GREEN - E-D-C-B, D-C-B-E,
while incorrect positions are indicated in RED - D-E-C-B, D-C-E-B.
These trains are slightly more difficult to block, simply because the blocks (unlike the single destination blocks above) can contain just about anything.
There can be a number of blocks on the train, with each block's composition being different to the others. However, the same basic principles described above still apply.
Some notes for Manifest Trains:
a. Trains bound for a Hump Yard or other Classification Yard and which do not set off at intermediate Stations do not need to be blocked (unless there are explicit instructions in the TSAR
for this train).
b. Trains in a. above which pick up cars at intermediate Stations, do not need these cars blocked i.e. they can be added anywhere on the train.
c. It is very important that you know what trains you dispatch or set off cars from or add cars to. The composition of such trains, whether they work intermediate yards or not,
How the destination yard will handle the cars.
d. If you are unsure about any of these things then ask the relevant TSAR owner - See the Contacts Page for details.
e. You should add a pop-up note to the train at specific Stations, giving the YM there information about a block or blocks he may need to deal with. If this information always
applies to this train, then see the TSAR owner to have it included within the TSAR.
f. When you add cars to a blocked manifest, then the cars shoule be added to the correct block (in exactly the same way as described above for Intermodal trains).
g. When you build a train make sure that you don't have blocks scattered throughout the train. This is a common fault on trains from Hump Yards, where a bowl (Block A) siding
fills quickly and the cars are pulled from the bowl and placed in the departure yard. Sometime later additional blocks (B and C) are added to the 1st block
- so far so good. But then another Block A is added giving Blocks A-B-C-A, which unless it satisfies a. above is incorrectly blocked.
h. Strings of cars pulled from the Hump sidings with the same set of car assignments for humping, will always go into the same block on the train.