Near Williams Town to Oxford

This page describes how web•TrainSim worked through the steps to create the Near Williams Town to Oxford on Modern England activity, from the first inkling of an idea to the final outcome (which is far from being achieved at the time of writing).

The first job was to create a path (drivable) from Manchester to Oxford via Williams Town, Moorewood and Oxford Junction. The switch at 119 MP was the exit point from the main line but when the path was driven, it was found that this switch is not automatic. Hence, the drivable path for the activity was altered to begin on the branch line to Williams Town, just off the main line at 112MP.

As part of the activity, a local service would begin at Oxford and travel in the opposite direction to the driver train. There are two passing sidings just past Oxford Junction and the drivable path had both these sidings marked as "Begin passing path" from the right-click menu.

From the shot above, however, you can see that at Moorewood station, web•TrainSim is blocked. In the distance behind web•TrainSim's train, after picking up and dropping passengers at the platform, the traffic train has stopped at points that are still switched for web•TrainSim's train. It's back to the drawing board because it's a situation pointed out by Rich Garber in Step by Step Guide to Train Sim Activities.

Bright idea 1

First fix&test: Change driver train path through Moorewood to pick up at platform 2 on the mainline. Also, for this path through Moorewood, set a Begin passing point at the approach points and an End passing point at the exit points to get any opposing traffic to use the siding which passes through platform 1. For the traffic train path, we change it to pass through the platform 1 siding.

Result: We come into Moorewood at platform 2, stop to pick up/drop off passengers, depart station and are stopped at a red before the points that switch to the platform 1 siding - this is to be expected because somewhere between our train and Oxford is the traffic train. After a few minutes the traffic train approaches Moorewood, and takes the platform 1 passing siding, just as we expect because we've used the Begin passing siding - End passing siding property. The traffic train stops and departs the platform, continuing through the points back onto the main. But we remain stuck at that red signal! By the way, in case you were wondering if web•TrainSim had tried, when the oncoming traffic train from Oxford is removed from the activity, we get a clear.

Second fix&test: Set the traffic train's path through Moorewood to the main and check this section as being an Optional Path Section in the Path editor.

Result: The traffic train keeps to the main and drives right through our train (we're waiting at the red). Clunk! So the traffic train's path is changed back to take the siding through platform 1.

Third fix&test: Adjust the traffic train's departure time from 1600 (our start time) to 1615 to give us time to get through Moorewood and perhaps have a meet at one of the sidings just east of Oxford Junction

Result: Our train still waits at the red signal.

Fourth fix&test: Put everything back to the way it was when we first started, run the activity in MSTS and check if the points change at each end of platform siding 1 when the traffic train stops at platform 1, departs and goes back onto the main line. We're doing this to check the points are actually automatic and the dispatcher/controller moves them accordingly.

Result: With the F8 display showing in the cab in MSTS, web•TrainSim observes that the dispatcher/controller changes the points to allow the traffic train into platform siding 1, and after it leaves siding 1, the points are set back for a straight run along the main through platform 2. So what's the reason for the red light not changing to give us a clear to Oxford Junction? As an aside, the driver timetable won't recalculate past Oxford Junction - uh??

Fifth fix&test: At Moorewood, take out the Begin & end passing point markers, don't have any path sections set as an Optional path section, and check that the paths look ok.

Result: Well, you can't remove a Begin passing point nor a End passing point in AE! So the path has to be re-done! A tip: just do enough of the path to get started - you can get confused with AE showing the old path, the traffic path, the old start and end points, etc. Leave the path editor so AE returns to the Player service window then choose to Edit the path again. The display will be less cluttered. Without passing points allocated to the two passing sidings east of Oxford Junction, the player's timetable recalculates without getting stuck.

Sixth fix&test: Move the start point of our train east of Moorewood. Mark the first passing loop on our way to Oxford Junction as Begin passing point and End passing point. For the opposing traffic, mark each section in the loop as Optional Path Section. You do this in the Path editor - choose Highlight and click ..next until AE highlights the desired section in red.

Result: No luck. Our train stops at the first red it meets. Setting its departure time as 1610 (our train starts at 1600), the traffic train from Oxford stops at the first red on its jounrey, not long after leaving the station. Ummm...

Bright idea 2

Seventh fix&test: One trial was to move the traffic's start point further along the track and delay its start time. A Play in AE resulted in both trains facing each other just outside Oxford. So the traffic path was changed from beginning at Oxford Platform 1 to the other siding line (the line that connects to the main Oxford-King's Cross).

Result-1: A Play in AE had both trains running, and, by sheer luck, they cross at Moorewood, without any problems (the traffic's path is into Moorewood platform 2 siding).How's that, eh? Now, let's see what happens in MSTS...

Result-1: Just as ordered. We have a red at Moorewood (as before) because the traffic is coming along the single from Oxford - that's to be expected. When the traffic meets us at Moorewood and it goes into platform siding 2, we get a green to continue to Oxford. This wasn't happening before... it's all due to starting the traffic on a siding that's different from our path at Oxford. We might test our luck and send off a second traffic train from Oxford and try to time it so we have to cross on one of those passing sidings past Oxford Junction... hmmm...

Isn't amazing how we observe? web•TrainSim has just noticed that, in Play mode, the AE shows the signals changing aspect.

Theory: the logic of passing sidings

The logic which web•TrainSim is following to set up the driver and traffic paths for Williams Town to Oxford comes from a discussion on the Trainsim.com Activities Message Forum. Here's what John, Oldrailfan concluded from his testing:

• 1) I have to designate the passing path on my player consist first.
• 2) Both the player and the AI paths have to go past the first switch beyond the passing siding.
• 3) Start time for the AI is critical. If I get two trains banging heads, I can go into the Activity Editor and adjust the traffic's start time by a minute or two (in either direction!) and they'll pass.
• 4) If I designate neither train as path optional, or if I designate both trains optional, HAL has some internal coin tosser to determine who stays on the main and who takes the siding - no apparent rhyme or reason. If only one train is designated optional, it takes the siding.

Signalling

When trying to set up traffic trains in the AE, bear in mind that MSTS works much the same way as a real railway. Traffic is controlled by assigning one piece of traffic only to a section or block. Each section or block is begins with a signal set and ends with a signal set. As you know, before you get a red, you are warned with a yellow (it could be flashing, depending on the country and route), another yellow (solid in most cases) then the red, unless the traffic ahead has cleared its current section. In other words, the MSTS dispatcher/controller is looking ahead at least three sections, i.e., three sets of signals.

Also bear in mind is that MSTS routes usually consist of two types of points/switches: manual or automatic. The MSTS dispatcher can change the latter according to your traffic patterns, but not the manual type. Thus, if you're unaware that a set of points is of the manual type, your activity will not work out as expected.

The original intention of this Williams Town - Oxford activity was to begin the run at Manchester - that was until web•TrainSim drove the train from Manchester to test the path he'd set up and discovered the points didn't automatically change to take his train from the main line to the branch line to Williams Town. Now the activity is named Near Williams Town....

If you're a route builder, as Rich Garber explains in Step by Step Guide to Train Sim Activities, you have to be careful how you place points/switches. For those of us creating activities on someone else's route, we have to work with the way the route was originally constructed and sometimes find alternative methods of making an activity as realistic as possible.