Oxford SX 09-24-2021

Welcome to Oxford!

Movements in this timetable are slightly different than in real life, as Oxford was resignaled and featured a newer layout starting in Summer 2018. Some services have been adapted to accommodate any discrepancies between eras.

The simulation lacks the now-existing high speed DRL from Oxford P4 towards Wolvercote Jnc. Accordingly, fast trains must be signaled onto the ML at Oxford. Some freight trains have been programmed to recess on this slow speed loop, rather than on the high speed mainline.

There is no crossover from Oxford P4 to UML, so the occasional modern-day movement in this direction is not possible. Trains with such movements are routed to terminate and reverse at Oxford P3.

Oxford Engineer's Sidings have been moved to the north side of the station.
Oxford Turnback Lane is Oxford Down Carriage Sidings #1 in this simulation.

Why are DMU top speeds not quite 75/100mph?

Why are most freights only 65mph? Including class 6 (60mph)

Why is 6V25 800m?

Re: speeds of DMUs. This is to reflect that they don't run constantly at the fixed top maximum speed. They're set a few mph less, which makes their running times much closer to reality.

I'm sorry but are you able to prove it was an HOBC on this day? I've never known the HOBC to run on this train during my time of living in the area - I wonder also whether Hinksey would be able to accommodate it let alone Kennington.

wellgroomed in post 146187 said:

Re: speeds of DMUs. This is to reflect that they don't run constantly at the fixed top maximum speed. They're set a few mph less, which makes their running times much closer to reality.

First point is that most passenger trains in SimSig TTs should gain time. This is because most WTT paths include allowances for pathing, engineering works etc. These allowances will include an element of contingency time to help a train get back to schedule if there has been any operational perturbation. The best indication as to whether a train is actually running to schedule is to validate the actual running time for a sector against the timing in the TT nett of allowances. Artificially adjusting the characteristics of a particular train type is subverting the whole principle behind the writing of the real world WTT. It also reduces the ability of the signaller to get things back to schedule after an incident. If you do feel the need to create an artificial TT another approach would be to change the acceleration and weight settings in the train type rather than changing the maximum speed.

In the actual operation there will be some instances where the driver continues at line speed even though there are allowances in hand so running early because the driver is aware of a problem which will lose some time further down the line and other cases where a driver will reduce speed and run to time as the train may create a conflicting move if it arrives early at a junction and so would be held until the conflicting move was cleared. Adjusting speeds for those situations while running a simulation is something far beyond the remit of the SimSig core code.

They are adjusted to match how it runs in reality and consequently why it was done in the first place. This was done quite deliberately and with 'Chiltern' driving style to reflect ATP intervention.

wellgroomed in post 146196 said:

They are adjusted to match how it runs in reality and consequently why it was done in the first place. This was done quite deliberately and with 'Chiltern' driving style to reflect ATP intervention.

You could do this without entering adjusted data by using the Class of Service and Defensive Driving rules to reflect the Chiltern driving styles. We all want to see things running as realistically as possible but if there are ways to do it within the capabilities of the SimSig code then it is preferable to use those capabilities and real data in my view.

Are you citing "reality" driving styles as the reason why freights are 65mph?

peterb in post 146188 said:

I'm sorry but are you able to prove it was an HOBC on this day? I've never known the HOBC to run on this train during my time of living in the area - I wonder also whether Hinksey would be able to accommodate it let alone Kennington.

6V25 is a mixed engineers train and can vary from day to day. confusion with HOBC easily done but its a Colas job, normally bogie boxes, hoppers or side tipplers(HQAs) I have seen it formed as 2 axle MHA spoil types as well.

6M50 is the opposite working IIRC at Water Orton 26/5/21 formed below

70805 w 15.09 6m50 westbury-bescot

29520 29344 705892026 29546 503014 29408 29461 29115 705892004 29108 705892009 29212 29409 29276 29079 29236 29411 29507

HTH

wellgroomed in post 146196 said:

They are adjusted to match how it runs in reality and consequently why it was done in the first place. This was done quite deliberately and with 'Chiltern' driving style to reflect ATP intervention.

You could do this without entering adjusted data by using the Class of Service and Defensive Driving rules to reflect the Chiltern driving styles. We all want to see things running as realistically as possible but if there are ways to do it within the capabilities of the SimSig code then it is preferable to use those capabilities and real data in my view.

I'm sorry but are you able to prove it was an HOBC on this day? I've never known the HOBC to run on this train during my time of living in the area - I wonder also whether Hinksey would be able to accommodate it let alone Kennington.

Are you citing "reality" driving styles as the reason why freights are 65mph?

Thank you for the suggestion. For a defensive driving ruleset to achieve the same result, would it be appropriate/make sense to use the following:



If not, what would you suggest otherwise? :)

First point is that most passenger trains in SimSig TTs should gain time. This is because most WTT paths include allowances for pathing, engineering works etc. These allowances will include an element of contingency time to help a train get back to schedule if there has been any operational perturbation. The best indication as to whether a train is actually running to schedule is to validate the actual running time for a sector against the timing in the TT nett of allowances. Artificially adjusting the characteristics of a particular train type is subverting the whole principle behind the writing of the real world WTT. It also reduces the ability of the signaller to get things back to schedule after an incident. If you do feel the need to create an artificial TT another approach would be to change the acceleration and weight settings in the train type rather than changing the maximum speed.

In the actual operation there will be some instances where the driver continues at line speed even though there are allowances in hand so running early because the driver is aware of a problem which will lose some time further down the line and other cases where a driver will reduce speed and run to time as the train may create a conflicting move if it arrives early at a junction and so would be held until the conflicting move was cleared. Adjusting speeds for those situations while running a simulation is something far beyond the remit of the SimSig core code.

Wellgroomed is probably the best one to ask about the defensive driving rules that Chiltern apply. However, the suggestion you have put forward is basically the same as putting in an artificial maximum speed in the train type as you are setting the maximum speed when running under greens to 98% of the actual capability.

I have been thinking over the past day how to make this work, because I'm genuinely interested in making this even better.

The question I have at this point is: Is there a way to have a train type run 1 or 2mph below the linespeed in "normal-running good times" and a way for a train to run at linespeed when there is trouble or delays? I assume from what Wellgroomed has posted here that the intention of putting the train type max speed at 74 (for example) was to replicate the defensive driving rules of Chiltern. That train type could be amended and a new defensive driving rule set could be implemented to have a train run at 98-99% of linespeed...But again, this would be in effect whether a train was delayed or not. Am I mistaken in thinking that a train in Simsig is unable to detect how late it is and then consequently speed itself up or "ditch" a defensive driving rule set in favour of making up time?

I've always seen the pathing and engineering allowances on the WTT and Simsig. Is the key to use these fields and that would enable a train type to detect between "good times" and "bad times"?

Help.

While it would be easy enough to run at X% lower than top speed if early, and nearly at top speed if late, it's difficult to work out whether a train is delayed between two timing points. Yes, a real life driver would have a good idea, but doing that in code is more tricky. A faster train could depart a station on time, then get stuck behind a slower train for a few minutes, which then moves out of the way to give greens to the faster train, until it reaches the next timing point (by now late).

GeoffM in post 146231 said:

While it would be easy enough to run at X% lower than top speed if early, and nearly at top speed if late, it's difficult to work out whether a train is delayed between two timing points. Yes, a real life driver would have a good idea, but doing that in code is more tricky. A faster train could depart a station on time, then get stuck behind a slower train for a few minutes, which then moves out of the way to give greens to the faster train, until it reaches the next timing point (by now late).

And that does make sense.

Geoff, do you have an opinion or suggestion on the matter?

Not really. One could perhaps have a flag that gets set if the train passes somewhere early or on time, and then gets unset if a restrictive aspect is encountered, or if it passes the next location late. But that's not going to work if a train was timed on a 125mph fast line and is actually running on a 75mph slow line. There is no information in the timetable that can be linked to simulation data to identify what the speed the train was timed at. You can't use the train's maximum speed because it may have actually been scheduled and timed on the slow line.

[Edit] If people think it's worth a try anyway, I guess I could look into it. It would be opt-in though, by timetable writers, probably under Defensive Driving Rules.

Not really. One could perhaps have a flag that gets set if the train passes somewhere early or on time, and then gets unset if a restrictive aspect is encountered, or if it passes the next location late.