Track

Planimate® supports modelling of railway type networks with a set of related features collectively known as “Tracks”.

Tracks modelling capabilities are considered to be advanced uses of Planimate®, and require a good grounding in and familiarity with the concepts underlying the Planimate® Platform as a whole.

A “Track” is a Planimate® object, along which items can travel, taking a designated period of time.

Tracks are placed between Portal Objects (representing depots, terminals, crossing loops and junctions). Tracks connect together the subsystems of these Portals. An Item can leave a subsystem, travel across a Track object and some time later arrive in the subsystem at the other end.

Similar to Spatial Links, Tracks offer an opportunity to display and animate transport networks, where Portals represent nodes in these networks. However, Track Objects differ to Spatial Links because they impose limits on how items on them (trains) move.

Track Capacity & Roads

The capacity of a Track link is determined by the number of underlying lines, or "roads" that the track has. This is set by the "Type" option and can range from a single road up to 6 parallel roads.

A track's display shows the individual roads. Only one item can be on a given road at a time. Additionally a road can be unavailable (maintenance), speed restricted or temporarily held by a train using a mechanism called "loop hold'.

When a train enters a track, it gets allocated a road automatically by the track. This allocation depends on the type of the track. Advanced modellers can specify roads explicitly for a train.

Routes

Planimate® modellers are familiar with items moving along flows. These represent zero-time movement of an item from one point of capacity to another. Distinct to this, a track network is a spatial network where items take time to traverse between nodes. Simulation time passes and many items can be moving in parallel.

Every train (item) on a track network needs to have a route assigned. This route defines the order of the nodes that the train will visit. The route is important as Planimate uses it to manage congestion and avoid deadlocks.

Routes can be created up-front by a modeller using the Menu Bar / Track / Routes option. Each route is a list of locations that are visited in turn. Repetition of locations is allowed so a route can include full circuits, say mine to port and back to mine.

Routes can also be created dynamically by a model and assigned to an item.

Nodes, Loops and Junctions

Tracks always connect between Portal objects. In the context of a track model, these Portals are more generally referred to as Nodes.

Nodes at the end points of a track network might be mines or shipping ports. Typically trains there undergo a load/unload process delay before departing.

and ports but they also can bridge

Traffic Control in Tracks

When the links in a transport network (as well as the node points) have limited capacity and many items are moving along their routes across the transport network, traffic conflicts arise. This can become quite complicated to manage so Planimate® provides built-in supporting logic to assist with successfully managing traffic conflicts. This “Track Control Logic” logic provides “common-sense” checking that reduces (but cannot totally eliminate) the chance of traffic becoming ‘deadlocked’ and unable to move.

Broadly, before letting an item enter a track, Planimate® performs checks to ensure that the item is:

• free to move to its next point of capacity, which is often located in the subsystem at the other end of the track, but could in fact be a few subsystems and track sections ahead, and
• unlikely to cause trouble for other item movements elsewhere on the network if it moves along the track.

Planimate®’s built-in Track Control Logic is often all that is required to ensure that traffic movement is continuous and the movements collectively are “reasonable” in terms of the waiting times experienced by the individual items in making their way along their routes.

Sometimes however, special cases or particular circumstances in the system being modelled mean Planimate®’s built-in logic does not resolve traffic movements to the modeller’s satisfaction. In these cases, the modeller is able to ‘hook into’ the internal logic and inject conditional tests etc which will produce the desired outcome.

Track Articles

• Track Movement Sequencing Logic
• Route
• Network Details
• Track Section Type
• System Label Lists
• Train Graph View
• Immediate Messages in Track Lookahead
• Route Assignment Table
• Track Loop Delays
• Track Node Module
• Track-related System-Item Attributes
• Object Property Attributes of Tracks
• Track Options Choices
• Track Colour Change Threshholds
• Track Settings
• How to Set Section Types at Runtime
• How to Create a Planimate® Track Network
• When to Consider using Tracks
• Portal Exit
• Portal Entry
• Connecting to Track Objects
• Track Lookahead Separator
• Section Running Times
• UnblockTrain
• RegisterBlockedTrain
• Route Step Checking
• Route Options Choices