Atomic Systems

I've just noticed a very odd phenomenon - but it's one which rings a distant bell to me, and I wonder whether anyone can shed light on it.

I'm doing a 'timing run' down the EuropeanBahn East Coast Express ECML with a Deltic-plus-eight set, to work out for a planned activity just how much performance you can actually squeeze out of such a train within line speeds (but not necessarily within 100 mph).

Now, yous doubtless all know that KX to Peterborough is roughly 76 miles. As has been discussed in a recent post, the best current GNER timings are around 45-ish minutes; I recall 55019 doing it in about 53 a couple of years back on a DPS charter (also in fact 8 x Mk2!) despite a brief check. 45 minutes is obviously an average speed of just over 100 mph, and 53 is about 86 mph, if my arithmetic is right.

However, in my timing run, 55017 did it in just 40 minutes (would have been 39 but for my cautious run into Peterborough)! This just doesn't make sense: that is an average speed of 114mph!!!

Now, in accordance with the purpose of my timing run, I was on full thrash whenever line-speed allowed, but didn't exceed any line speed, including on departure from KX. I felt the performance of the Deltic itself to be pretty realistic: on 8 x Mk2c/d, the maximum reached was 117 mph, and most cruising was a mite over the 110 mph mark. Accordingly, I was expecting something like an average speed of 90-ish mph, which would be about 50 minutes-odd to Peterborough.

So you can see where this is going: that just ain't mathematically possible!

Now, as I say, this rings a distant bell: was there a discussion a couple of years ago where someone had discovered either that MSTS miles were actually less than real miles - or there was something about a "time-step solver" (?) or something which I never fully understood!

Can anyone shed any light on this phenomenon? If I can beat current GNER timings it sort of undermines the point of the activity I'm writing... (even if it confirms my prejudices as a Napier crank!).

What is causing it?

Is there anything I can do? (If there is, will I end-up with such a non-standard MSTS installation that my activities won't work as intended on other people's machines?)

As ever, thanks a lot in anticipation of all your input.

Cheers guys.

mick

Hello Mick

You're assuming three items, all of which need to be accurate for what you're trying to do.

- Is a MSTS mile a real mile?
- Is the Speedometer accurate (I've seen posts about how inaccurate it is)?
- Has the route been accurately measured and laid out?

The answer is probably no for more than one of these questions so the test you're trying should probably be done on a comparision with other MSTS equipment using the same route. You could then compare MSTS timings rather than comparing with real world timings.

GaryG

GaryG wrote: You're assuming three items, all of which need to be accurate for what you're trying to do.

- Is a MSTS mile a real mile?
- Is the Speedometer accurate (I've seen posts about how inaccurate it is)?
- Has the route been accurately measured and laid out?

Cheers Gary. Taking each of these in turn:

1. I don't know - that, to be honest, is the essence of my question. It should be, of course, but I have, as I say, a vague memory that it's been shown that they are not - even where the route has been correctly measured and laid out.

2. Speedometer isn't really relevant - I've done "76 miles" in 40 minutes start-to-stop. In any case, I was using track monitor rather than the loco's speedo (which is however accurate within a couple of mph) for the readings I gave above.

3. As above; I'm assuming it has been. I doubt whether EuropeanBahn would get if that far wrong (I think we're out by well over 10% - in fact nearer 20%).

Thanks for your thoughts though. You're right, however, in that it would be sensible to try it, say, with a 225 set and see if that will give an even more improbably fast timing (which I suspect it will).

mick

Also, the deltic physics may not be correct, there could be a tad too much power/acceleration, or the coaches may not have enough friction too them, or maybe even both.

What it all comes down too is that the chances of a route being 100% accurate lenght/gradient wise, along with accurate physics are pretty much impossible

i always always said they were the best of the best - seriously all my deltics are set to trip at 108 mph so that I can sustain 100 mph running without the overspeed waning. Mileages are a contentious issue with many threads relating to the MSTS short mile . Actual Mileages for ECML, that I used to use for logging in the '70s were to the nearest milepost, were:

Peterborough 76.25 - Grantham 105.25 - Newark 120 - Retford 138.5 and Doncaster 156

Can't remebmer the MSTS Mileages atm will have to run a stopper and see

Cheers

John

OK, well, just done the same run in a 225 set. Did it in 35 1/2 minutes - which is an average of 128.4 mph. Which is a tad odd as I didn't go over line speed by more than 1 mph at any point.

See what I mean? It just ain't possible.

No, I think the physics of the Deltic are surprisingly realistic: quite a slowish slog up the north London hills (not exceeding) 90 mph; after Peterborough I thought I'd see what Stoke looked like (largely in order to see if the physics were set up wrong), and, from 96 mph at Essendine, speed fell to a minimum of 86 mph, before recovering to 92 mph at the summit - pretty much realistic I would say. (As I say, it's a light train [8 Mk2c/d] so you wouldn't expect much more of a drop in speed than that.)

As I say, I've a feeling this is something within MSTS itself - I'm sure someone around here will remember the discussion a couple of years ago!

Cheers all

mick

PS By the way, John, for max. realism I would propose disabling the overspeed trip - the real thing never had it and you'll find, as I have, that the physics are set up such that you reach a fairly realistic 'balancing speed' which depends on the load. This is actually much better than many/most MSTS locos I've driven where you seem to end up bouncing off some sort of rev limiter at a particular speed. In any event, in 'real life' there've been many 110+ mph Deltic runs recorded, including a few in recent years (to be honest below 113-5 mph isn't really that remarkable unless it's a particularly heavy train!).

I should add by the way that my assumption that the EB mileages are correct (which you rightly question) is based purely on the milepost readings - but of course mileposts are just where the route author laid them (no disrespect whatever to the authors of ECE by the way).

I think it is, as you say, something to do with the MSTS 'short mile'.

In my post on York to London timings, it was noted in one of the replies that a 'MSTS' mile is about 0.9 - 0.93 miles long.

seern1 wrote:In my post on York to London timings, it was noted in one of the replies that a 'MSTS' mile is about 0.9 - 0.93 miles long.

Ah, thanks - sorry but I didn't see your post (to be honest I've been struggling to get my searches right!!).

Now we're getting somewhere - this affects all MSTS routes, doesn't it?

Cheers Mr Seern1

mick

I've always felt that this route was a bit short, based on 'next station' indicator (F10) - from memory, I think starting from Kings X running non-stop to York, next station is indicated as 160ish as against 'actual' 180ish (running on 'prototypical' schedules, rarely need to exceed 90mph); I think Peterborough shows as about 70 (correct me if i'm wrong!).

Regarding other routes, I've noticed that Thames-Mersey is also about 20 miles short, whereas Dorset Coast and Great Eastern are pretty much on the nail - could this be due to a scaling error between Route Editor and the game which has been corrected in the latter routes?

Tim

tialho wrote:I've always felt that this route was a bit short, based on 'next station' indicator (F10) - from memory, I think starting from Kings X running non-stop to York, next station is indicated as 160ish as against 'actual' 180ish (running on 'prototypical' schedules, rarely need to exceed 90mph); I think Peterborough shows as about 70 (correct me if i'm wrong!).
Tim

Now there's a thing - I don't think I even looked at the F10 (Duh!!!) indicator, having just trusted the mileposts shown in F4.

It's an MSTS problem If you run at exactley 40mph for 1 hour you will not have travelled 40 miles.

seriously all my deltics are set to trip at 108 mph

You'll need to change that for my activities on MEP. There you have to run at 110mph on one section to make all your traffic slots

Seriously, I read an article with timings which showed they did run at 110mph on some sections.

Being a bit of a Deltic crank in my dim and distant past I used to travel the ECML with stop watch in hand behind Deltics every free minute I had. Therefore, as someone who also drives Deltics along ECE trying hopelessly to recreate his youth, perhaps I could add my penny's worth. I believe the approx mileages are as follows;
KX to Peterborough - real 76.25ish, MSTS 74ish.
Peterborough to Grantham - real 29ish, MSTS 25.5ish
Grantham to Newark - real 14.5ish, MSTS 13ish
Newark to Retford - real 18.5ish, MSTS 17ish
Retford to Doncaster - real 17.5ish, MSTS 15.25ish
Doncaster to York - real 32.5ish, MSTS 32ish
That's about 12 miles missing throughout.

By the way, a Deltic with load 8 shouldn't really drop below 93ish climbing Stoke with 8 on. In fact, if it dropped below 95 I wasn't impressed. The top MSTS speed achieved of 117mph is typical of a really good thrash and was not outside the realms of possibility.
Just to finish, I did record a Deltic topping Stoke bank at 100mph on a couple of occasions. In those days there was a restriction of 90mph through the tunnel, so drivers usually eased as they approached the top.

Best wishes,

Paul

Lad491 wrote:

seriously all my deltics are set to trip at 108 mph

You'll need to change that for my activities on MEP. There you have to run at 110mph on one section to make all your traffic slots

Seriously, I read an article with timings which showed they did run at 110mph on some sections.

Looks like I'm gonna have to re-edit them all and increase the speed and remove the overspeed trip then

Thanks for the heads up Laurie

Paul - spent many a happy summer racing betweem Doncaster & Peterborough and on numerous occaisions wonder wher the little hillock Stoke had gone in the down direction - they were the days

Cheers

John