[KS44]

Welcome to everyone who has stumbled upon this topic. I myself am not a professional expert on this subject, but rather an enthusiastic amateur. Bringing all this stuff to life and all the preparation that goes with it has pushed me significantly out of my comfort zone, which I am glad about, as it has given me an insight into something new. This topic was born to create a casual, polite, professional discussion between developers and people who know about Trello cards.

https://trello.com/c...s-across-europe

For the sake of repetition, I'll paste my idea here once again, so that those who don't follow the official OpenRails board on the Trello interface can read it:
In European rail transport (not including British conditions and specificities), the following types of brakes are used on freight wagons, passenger cars and locomotives:


The brakes genres in Europe
--------

G-P-R-R+Mg

In addition, there are sub-versions of the brakes:
G-P, P-R, G-P-R, G-P-R+Mg

"G" = slow-acting of the brakes
"P" = quick-acting braking
"R" = Rapid braking
"R+Mg"= Magnetic rail braking (Track brake)

Brake-related values differ for specific types of freight wagons / passenger cars, but wagon types with the same UIC mean have similar characteristics. In this context, the values given for each ORTS parameters are only valid for one specific wagon. For all other types, it is up to the individual to decide which braking values are given. Brake position "P" or brake position "G" is not only used for passenger and freight trains. Some freight trains run with passenger train P braking.

These parameter names are explained a little:

BrakeSectionG - Braking weight of the carriage in "G" brake mode
BrakeSectionP - Braking weight of the carriage in "P" brake mode
BrakeSectionR - Braking weight of the carriage in "R" brake mode
BrakeSectionR_Mg - Braking weight of magnetic rail braking for high speed rail (160km/h=99,42 mp/h or higher)

(The metal weight is determined individually for each wagon and locomotive. These values are sample values only.)

"P" mode brake cylinder charging time 3-5s
"G" mode brake cylinder charging time 9-20s
"R" mode brake cylinder charging time 5-9s

These values can be calculated in several ways:
1., Calculation from the ETCS* formula
2., Calculation in CZ-SK OpenRails formula

* European Train Control System

It is important to note that for the calculation of the braking force for a given wagon, the CZ-SK OR and the ETCS formulae give different values.

Example:
Given a passanger wagon of mass 51t, the braking of a passenger train in "P" mode is P=59t.
- with ETCS forumla: 0,75*59+0,076*51=48kN
- with CZ-SK OR's formula: 0,6 × 94 × 9,964016384 × 0,31 = 174 kN

The CZ-SK version uses this formula to determine the max braking force:
MaxBrakeForceN = Coef (a vehicle type dependent multiplier, locomotive: 0.84, wagon 0.60. If only two axles, 80% of these) * BrakeSystem.BrakeMassKG * 9.81* 0.31
The value 0.31 is the coefficient of slip.
And BrakeSystem.BrakeMassKG will get the G-P-R mass set in the wag, BUT if this is not set in the .wag file used by the particular freight/passanger wagons in that case the program will calculate based on the default setting. Rail freight wagon empty-loaded: 36-58%, passenger wagon in "P-R" mode : 105-149%, locomotive in G-P-R mode: 50-65-166%.

/////

Other new ORTS parameters:
- AutoLoadRegulatorCarriage - Activate automatic brake weight for passanger carriage
- AutoLoadRegulatorFreight - Activate automatic brake weight for freight carriage.
- BrakeDetalis (Oerlikon.inc or Stub brake.inc) - Describes the specific properties of the brake type family in an .inc file at the .wag / .eng files.
- RackingWeightShifter - A device that changes the gear ratio of the brake rod. This can be found on most older wagons makes of e.g. RÁBA Wagon, Poznan, etc. Has 2 positions: empty / loaded. On average, our Hungarian passanger wagons don't have racking weight shifter, but there are a few exceptions. Although it doesn't make much sense in my opinion.
- RackingWeightShifterEmpty - Indicates the value of the braking force exerted by the brake rod in the neutral position.
- RackingWeightShifterLoaded - Indicates the value of the braking force exerted by the brake rod when loaded.
- TrainTypeChanger - The setting of the position of the train couplers is not linked to the gender of the train.
- MagneticBrakeActivity - This parameter shows how active the magnets are during the braking of a magnetic rail brake. This would be on a scale of number 1-5.


The WagonEmptyWeight and FreightWeightWhenFull parameters already exist since stable OR 1.3, this is also related to the brake and chair shifters. FreightAnimContinuous is in block. So this is the part of the automatic load changer.

For example (Eas freight wagon):

WagonEmptyWeight ( 26.8t )
EmptyMaxBrakeForce ( 80kN )
EmptyMaxHandbrakeForce ( 16kN )

FreightWeightWhenFull ( 43.2t )
FullAtStart ( 0 )
FullMaxBrakeForce ( 158kN )
FullMaxHandbrakeForce ( 42kN )

//////////////////////


As you can see from the context, this is a set of ideas for a topic in outline form. I know it's perfect, but I believe that it will move forward through shared communication. This topic is strongly related to brake stuff, even the EP brake valve operation.

Most helpful to me on this topic has been the online blog RegionalBahn with its multi-part series on railway brakes, which have accurately compiled all the useful information on braking matters (based on railway road conditions), which applies not only to Hungarian rail conditions but also to pan-European ones. Yes, there is also a need to take care of European things, not for nothing many people from the neighboring countries have already turned to the official OpenRails. I recommend it to anyone who is a little interested in this subject and can help in the development of OR. The use of a translation program is recommended for those who do not speak Hungarian. :)

http://www.regionalb...ti-fekezes.html

Special thanks to Márton Paksi (@Marci), László Kovács (@Laci1959), Péter Gulyás (@pzgulyas), Szilárd Maron (special rail words translate & RegionalBahn's journalist & vagonWEB Hungarian section admin) and Péter Halász (RegionalBahn's journalist)

Thanks for reading. Have a nice day everyone!

Sincerely:

KS44

[Weter]

Hello.
Good start and nice idea.
There was variant with empty/loaded plain/mountain modes as well as auto-regime device, which automatically adjusts BC pressure in accordance with actual car's weight. As for mechanical regulators, here they are being most often used not to change brake rigging's gear ratio, but for automatic compensation of BC rod's travel, which increases with brake pads wear, so said system keeps it (and BC's volume) constant.

Here presents MAV engineer, nicknamed "Mozdonyos", so I would hope, he also could help with Your questions, by sine professional advices.

[darwins]

The article on http://www.regionalb...ti-fekezes.html is very informative. I am going to try to read through and comment on some matters as I find them.

Quote

Wooden brake blocks were used until 1870, and cast iron with different compositions only started to spread after that. It is interesting that in 1940 (!) the Deutsche Reichsbahn conducted experiments with impregnated beech wood brake blocks, and the experts determined that these had approx. Up to an axle load of 8 tons, its properties are extremely advantageous, even compared to gray cast iron: their friction factor - compared to cast iron - remained almost unchanged during the entire braking period.

Can anyone provide the coefficient of friction curves from the DR experiment?

Trams in UK continued to use brake blocks made of elm wood in the early twentieth century.

One railway still uses wooden brake blocks today. The Montreal Metro in Quebec, Canada, uses brake blocks made of cherry wood soaked in oil. These have a low CoF when fresh, but after first use become "carbonised" by the heat generated in braking. The carbonised oiled cherry wood is preferred to either cast iron or modern composite materials!


This is a CoF curve based on elm brake blocks

ORTSBrakeShoeFriction ( 0 0.489 4 0.487 8 0.486 12 0.487 16 0.490 24 0.493 32 0.490 40 0.481 48 0.465 56 0.443 64 0.415 72 0.381 80 0.340 88 0.294 96 0.241 104 0.182 112 0.116 )
Comment ( * Friction estimate for wood brake shoes based on elm blocks on tramcars * )

[darwins]

I have been waiting for the developers to release the new triple valve features. http://www.elvastowe...post__p__298916
These are needed to correctly model the UIC standard air brakes in use in Europe today. Section 8 tells us:

Quote

A fenti problémát az ún. csapolóberendezés oldja meg (de legalábbis teszi kezelhetové), mely a vonat elso kormányszelepének muködésbe lépésekor csekély mennyiségu levegot (néhány tized bar) csapol a fovezetékbol, azért, hogy az így keletkezo nyomáshullám a vonat kormányszelepeire csillapítás nélkül adódjon át. Ennek következtében a kormányszelepek egymás után viszonylag gyorsan és biztosan muködésbe lépnek. Azonban a csapolás nem jelenthet gyógyírt minden bajra, mert nyakló nélküli alkalmazása a fékezés fokozhatóságát veszélyeztetné: csapolóberendezés használatára csak a teljesen oldott fékkel való elso fékezés alkalmával van szükség, a fékhatás további fokozását követoen a kormányszelep már kelloen érzékeny (érzéketlensége pedig kelloen leromlott).

Quote

The above problem of [making small brake applications in long trains] is solved (or at least made manageable) by a quick service device , which releases a small amount of air (a few tenths of a bar) from the main line when the first triple valve of the train is activated, so that the resulting pressure wave is transmitted to the train's triple valves without damping. As a result, the triple valves operate relatively quickly and reliably one after the other. However, quick service cannot be a cure-all, because using it all the time would endanger the ability to increase braking: the use of a quick service device is only necessary during the first braking with the brakes fully released, after further increasing the braking effect, the triple valve is already sufficiently sensitive (and its insensitivity has deteriorated sufficiently).

We can now add this to OR using

ORTSQuickServiceLimit ( x )
ORTSQuickServiceVentRate ( y )

we just need to know the appropriate values for x bar and y bar/s!

ORTSQuickServiceLimit ( 0.4bar ) is probably sufficient for the first one, a "few tenths" suggests perhaps ( 0.3bar/s ) might work for the second parameter.

[darwins]

Quote

... self-acting, air-pressure braking devices had to be made suitable for two basic types of braking. These are:

fast-acting or passenger train (P) braking (the brake cylinder filling time is 3–5 s), and

slow-acting or goods train (G) braking (the brake cylinder filling time is 18-30 s).

In the case of slow-acting (G) braking, the so-called “inshot” is necessary so that the brake shoes come onto the wheels at almost the same time. The filling of the brake cylinders thus starts relatively quickly and continues slowly, thus congestion and jerks can be practically completely prevented.

Using the new parameters it should be possible to set up G type brakes now, as well as P type brakes. (R type brakes with cast iron brake shoes are not yet possible in OR.)

The "inshot" for the G type braking can be achieved with

ORTSQuickServiceApplicationRate ( 1.2bar/s )
ORTSQuickServiceLimit ( 0.6bar )
ORTSQuickServiceVentRate ( 0.3bar/s ) Comment ( guess - not confirmed )

The various UIC specifications are:

https://i.imgur.com/MI4ilOB.jpg

I am going to suggest that these might be represented as follows:

Passenger car ( Air_single_pipe )
MaxReleaseRate ( 0.26bar/s )
MaxApplicationRate ( 1.2bar/s )

Passenger car ( Air_twin_pipe )
MaxReleaseRate ( 0.26bar/s )
MaxApplicationRate ( 1.9bar/s )

Passenger car ( EP_brake )
MaxReleaseRate ( 0.84bar/s )
MaxApplicationRate ( 1.1bar/s )

Goods wagon
MaxReleaseRate ( 0.12bar/s )
MaxApplicationRate ( 0.20bar/s )
ORTSQuickServiceApplicationRate ( 1.2bar/s )

Locomotive ( Air_single_pipe – Passenger Braking Mode )
MaxReleaseRate ( 0.44bar/s )
MaxApplicationRate ( 1.2bar/s )

Locomotive ( Air_twin_pipe – Passenger Braking Mode )
MaxReleaseRate ( 0.44bar/s )
MaxApplicationRate ( 1.9bar/s )

Locomotive ( Goods Braking Mode )
MaxReleaseRate ( 0.12bar/s )
MaxApplicationRate ( 0.20bar/s )
ORTSQuickServiceApplicationRate ( 1.2bar/s )

For all of the above we might now add to the model:

ORTSQuickServiceLimit ( 0.6bar ) Comment ( 0.6bar to 0.8bar depending on specification )
ORTSQuickServiceVentRate ( 0.3bar/s ) Comment ( guess - not confirmed )
ORTSCylinderSpringPressure ( 0.3bar ) Comment ( guess - not confirmed )