More on the Uncoupling Bug

bigvern · Post by **bigvern** » Fri Aug 30, 2002 4:44 pm

During Alpha testing of the Mallaig line, I've uncovered what appears to be further evidence as to why the uncoupling bug occurs. It seems either due to a bug in the code, or deliberately built in feature, that the programme progressively weakens the couplings according to the strain placed upon them as you proceed along the route.

Example: I've been using the Flying Scotsmam and Load 8 to test the route. Arriving in Glenfinnan from Mallaig - a distance of 25 miles involving extreme gradients and curvature - the coupling broke away between the loco and tender. I moved the point 50m to the rear in case it was an issue with the reverse curve, however same thing happened again.

I set up another activity with the same consist but this time starting about 2 miles out of Glenfinnan. Coasted down the hill, applied the brake for the 15 MPH speed restriction and the whole train passed smoothly over the points without incident.

The only logical explanation I can think of is, as I say, that the stress on the coupler is acculmulated until you reach the point at which further strain causes a terminal break. This would explain why routes such as LTV with its rather exaggerated gradients had such serious problems with coupler breaks. (Or indeed the problem as originally manifested on Marias Pass).

Possibly this is not a new revelation but it does have serious implications for the development of long heavily graded routes. The next step is to try a diesel hauled train, then to "beef up" the break value on FS loco and tender to see if that at least allows the train to make it over the entire 41 mile section. What chance though of getting a complete train from Fort William to Glasgow?

I now publicly urge Kuju and Microsoft to get to grips with the problem. If just one bug is fixed in V1.5 then please make it this one. The development of long, challenging routes is essential for the ongoing and sustained success of the product and this issue poses a serious threat.

bjdick · Post by **bjdick** » Fri Aug 30, 2002 6:28 pm

Probably something in what you say.The only other thing I've noticed is that the more frequently you accelerate,and brake hastens the onset of a break.It doesn't break due to harsh acceleration,but often when you're trundling along at a steady speed.
You start again,with less throttle brake frequency,and can complete ok.
Personally,it was ruining my enjoyment doing activities,(in sight of the finish-break),that I altered coupler break values to stop it completely.
I suspect the majority have too.

bigvern · Post by **bigvern** » Fri Aug 30, 2002 7:13 pm

The West Highland is a constant round of hard acceleration followed by equally hard braking - there's no other way to get across a route which is more akin to a rollercoaster than a rail line!

I've now done the run with Paul Mitchell's Class 27 and Ian Morgan's Mark One's and got to Glenfinnan without a hitch. However with a diesel it's a bit easier to control the aceleration and braking, also I may have previously doctored the coupler break value on the coaches.

At least that proves it's not my track laying and the route is sound. However, I can see when it does go out it's going to be very difficult to create activities using default MS rolling stock, without advising users to up the coupling strength on FS and the tender.

saddletank · Post by **saddletank** » Fri Aug 30, 2002 7:26 pm

Increasing coupling strength is what most people in the know seem to be doing these days anyway and in the notes you issue with the route I'd suggest you advise the user does so.

The silly thing is the couplings aren't breaking, they are just coming unhooked. If they actually broke it would be activity over. But you can stop your engine, back up, collect you train and carry on. On very long trains (60+ wagons) I have had 8 or 9 consecutive wagons part their couplings, then 3 or 4 more about once every half-dozen or so. If I reverse up and reconnect each 'break' I can carry on.

Now if they were breaking I could understand the logic, but the fact that the links are popping off the hooks is just daft and so it must be a bug.

bigvern · Post by **bigvern** » Fri Aug 30, 2002 8:07 pm

They are definitely breaking in this case as the "Coupler broken - activity ended" message comes up.

However good news is the 27 and Mark Ones has now got successfully from Mallaig to Fort William.

micksasse · Post by **micksasse** » Fri Aug 30, 2002 8:48 pm

Can't wait to see the route, Vern, if it's anything like as good as your Far North Line! I'd be more than happy to change my break values for that!

dforrest · Post by **dforrest** » Fri Aug 30, 2002 11:39 pm

bjdick wrote: ............ I altered coupler break values to stop it completely.........

Coulld you point me in the right direction on finding out how to do this!?

bjdick · Post by **bjdick** » Sat Aug 31, 2002 9:11 am

Go into your Eng or Wag file,of rolling stock you want to change.
Find line with Coupler Break value,say original is "1.1e7N 1.1e7N",and change,using wordpad to say "3.6e7N 3.6e7N"
Alternatively,download utility EngMod14 I think,and you can investigate\rewrite most eng\wag parameters.

asalmon · Post by **asalmon** » Sat Aug 31, 2002 10:53 am

That doesn't completely stop it breaking; and sometimes if you make the strength too much, instead of coupler breaking the train derails!

bjdick · Post by **bjdick** » Sat Aug 31, 2002 11:37 am

I've only seen derail with strong couplings in an "S" bend scenario.IE where inward pull on train length round bends(in effect trying to straighten out curve) will cause derailment.Can happen for real life too.Physics is marvellous isn't it?

bigvern · Post by **bigvern** » Sat Aug 31, 2002 12:32 pm

AFAIK it's the second figure next to the "N" you need to change - make it 9 instead of 6 or 7 as shown.

dforrest · Post by **dforrest** » Sat Aug 31, 2002 1:16 pm

bigvern wrote:AFAIK it's the second figure next to the "N" you need to change - make it 9 instead of 6 or 7 as shown.

Now I am completely confused again!

Timcourt1 · Post by **Timcourt1** » Sat Aug 31, 2002 2:46 pm

Ok,

Here's my six pennys worth, I have changed values to 8 on Mideast, I have had numenrous derail problems, what happens is (i refer to it as "the slinky effect) the trains telescopes in and out like a accordion, if you experience a break run it again, this time go to View 2 and watch the train, the loco will be fine, the train will expand and collapse as it crosses the point.

If you just change the loco value of the second number to 8 as a first shot then this more often than not corrects the problem, the norm is for the 1st coupling to go first so changing tha value on the loco only does fix the problem, only go for the stock if you still get the problem or get stock breakages further down the train.

Adjusting the coupling tesion can also have an effect on this too.

Believe me over the past 6 weeks Me and a couple of other people have done a fair bit on trying to correct this problem

bjdick · Post by **bjdick** » Sat Aug 31, 2002 3:19 pm

Right,in order to dispel some of the confusion,try to follow this explanation.
1.0e6N is "one" times "ten to the power of six" Newtons.IE 1,000,000 Newtons.
3.6 (or any other figure)e6N is three point six(or the figure chosen) times "ten to the power of six" Newtons IE 3,600,000 Newtons.That means they are of both within the same order of magnitude,as far as the mathematics\physics are concerned.It has increased mathematically by 3.6 times
Altering from 6N to 7N increases the order of magnitude,by one,to "ten to the power of seven".IE 1.0e7N is 10,000,000 Newtons.IE it has increased by ten times.If you altered the first figures as well,you will get a multiple of the two.IE 3.6e7N is 36,000,000 Newtons.Thirty six times greater than 1.0e6N
If you change 6N to 9N the result for 1.0e9N is 1,000,000,000 Newtons.IE one thousand times greater than 1.0e6N
I'll let you decide which is the better way to adjust coupler break settings for better realism.

dforrest · Post by **dforrest** » Sat Aug 31, 2002 3:32 pm

Timcourt1 wrote:If you just change the loco value of the second number to 8 as a first shot

Just to be absoloutely clear, are you recommending changing, for example, "1.1e7N 1.1e7N" to "1.1e8N 1.1e7N"?

Thanks for the help.