A Block Group is two or more adjacent blocks that are tied together.
Block groups were originally defined for running manually in trackdriver systems like Dinamo. However, another very important use has been added that can help Rocrail avoid deadlocks when running locomotives automatically.
Block groups can be designated as critical sections, which means that a locomotive will reserve all the blocks in the group when it moves into any one of them, and will not move into any of the blocks in the group if all of them are not free.
See Critical Sections for more information.
For trackdriver systems, the first block is the Source Block. Additional blocks follow.
For Critical sections, all blocks must be reserved by a train before it can enter them if the flag “Critical section” is set on the General tab. After setting this flag the Source Block selection will be disabled to avoid confusion with the original purpose of Block Groups.
Note: To manually remove a loco from a block group the command Soft reset from the context menu of the relevant block has to be used (resetting locomotive assignment would only free the particular block but not the block group in total).
See Schedules Test Case for an example of using a Block Group as a Critical Section to prevent deadlocks. In this example, blocks A1 and A2 should be grouped to avoid a deadlock.
When a train is runs into a Block Group, it reserves all the Blocks in the Group. After leaving the Block Group (by running into a block not belonging to this group), the train will free up all the Blocks in the Block Group it just left.