Dynamic Load Variation and Refuelling
Aim - This page aims to describe how to define the parameters for animation of loads, the loading/unloading of trains, such as tender coal in a steam locomotive, grain and coal wagons, as well as the types of tests that can be undertaken to ensure that it is operating within realistic bounds. It also describes the ways of refuelling the locomotive.
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Index
Locomotive and Tender Definition
Picking Up Water from Track Trough or Pan
Key Parameters Used in Open Rails
Introduction
Open rails supports the functionality to load and unload trains, as well as the ability to refuel the locomotives with either coal, water or diesel. This functionality can be further enhanced with moving animations, so that for example, the coal loads in a tender can rise and fall depending upon normal usage, as well as refueling.
Additionally locomotives, will have their weight and related physics charisteristics change as they use consumables such as coal, water, diesel, etc, and wagons physics characteristics will also change as their load varies. The key physics parameters that will change with load are BrakeForces, Friction (Resistance), Weight, Centre of Gravity, and Drive Wheel weight on locomotives. Variation of wagon physics with load relies on having two known points of reference, ie the conditions when the stock is empty, and the conditions when the stock is full (loaded).
When looking at laod animation configuration, a modeller needs to consider the following two elements:
- Visual Effects - This is the actual movement of a load due to the load changing.
- Physics Effects - This is the adjustment of the physics, such as weigh, friction, etc as the load changes.
- Static - in this mode the freight animation is only loaded at the commencement of Open Rails and does not change during the game. Whilst multiple freight animations can be added to a vehicle, it is suggested that only one has "loaded" physics parameters associated with it.
- Dynamic (continuous) - this allows wagons to load and unload during the game. In this mode there maybe a linked freight animation shape which moves as the load rises and falls, such as the case where an open wagon is filled or emptied. In the case of, say a covered van, there maybe no freight animation shape file used. It should be noted that locomotives and tenders only use the continuous freight animations for defining physics parameters,
IntakePoints are defined instead in the generalENG file, and not as part of the freight animation. - Step 1 - Create relevant pickup points within the route,
- Step 2 - Configure the relevant wagons to allow loading and unloading at relevant pickup points on the route, define loaded and unloaded physics characteristics.
- The line before the include statement must be blank
FreightWeight - weight of freight load. This will be added to theWagonEmptyWeight to calculate the loaded weight of the stock- Empty physics characteristics read from base
WAG file Full..... - loaded or full physics characteristics- The line before the include statement must be blank
FreightWeightWhenFull - weight of freight load. This will be added to theWagonEmptyWeight to calculate the total loaded weight of the stockIntakePoint - includes location information for intakepoint, and the OR name of the type of intake point (see above for names)Shape - if stock does not have visible moving freight when loading, such as a box car, tanker, etc then the Shape, Maxheight and MinHeight parameters can be left outEmpty..... - unloaded or empty physics characteristicsFull..... - loaded or full physics characteristics- The line before the include statement must be blank
WagonEmptyWeight - weight of locomotive or tender without coal and water fuel. To calculate empty weight of locomotive or tender it maybe necessary to subtract the coal and water allowances from the full weight of the stockFreightWeightWhenFull - this value will be added to theWagonEmptyWeight to calculate the total current loaded weight of the stock. For a tank locomotive, "Freight Weight = Coal Mass + Water Mass + Boiler Mass + Fire Mass", whereas for a tender locomotive, "Freight Weight = Boiler Mass + Fire Mass". The Fire and Boiler Mass can be determined by running OR, and finding out what value(s) are displayed at start up.IntakePoint - not included in FreightAnimation code for locomotive or tender, instead in rootENG orWAG file Shape - not included in FreightAnimation code for locomotive or tender, instead in rootENG orWAG file Empty..... - unloaded or empty physics characteristicsFull..... - loaded or full physics characteristics- Unless the shape of the locomotive or the tender changes between the full and empty states, then no wind resistance changes need to be included in the parameters.
ORTSWaterScoopFillElevation - Height of water scoop in metres.ORTSWaterScoopDepth - Depth of water scoop dipped into the trough.ORTSWaterScoopWidth - Width of water scoop were it is dipped into the trough.
Whilst these two elements have a loose linkage they need to be considered two different elements. For example a diesel, and some steam locomotives do not have moving visual loads, and hence in this instance it is unlikely that a visual effect will apply. They can however still have the Physics Effects configured. Naturally some other locomotives will support the use of both effects. Typically when setting the Visual Effect it will be necessary to also have the Physics Effect configured.
Wagons can be set up for one of the following modes of load operation:
To successfully set up load variation and animation functionality it is necessary to:
The test the loading/unloading process a demonstration activity has been created to show how a route, and stock can be set up to load and unload, with in this example, a coal train.
Whilst this page has been developed specifically for steam locomotives, a diesel locomotive could be substituted for the steam locomotive to test fuel diesel refueling and load variation, etc.
The following sections provide a "worked example" of setting up the load/unloading feature within OR. Also refer to the Open Rails manual.
Route Pickup Points
Open Rails currently supports the following pickup points for loading/unloading, and refueling:
Load Type |
Type # |
OR Name |
Comments |
|---|---|---|---|
Null |
0 |
|
|
Freight - Grain |
1 |
FreightGrain |
|
Freight - Coal |
2 |
FreightCoal |
|
Freight - Gravel |
3 |
FreightGrvel |
|
Freight - Sand |
4 |
FreightSand |
|
Fuel - Water |
5 |
FuelWater |
|
Fuel - Coal |
6 |
FuelCoal |
|
Fuel - Diesel |
7 |
FuelDiesel |
|
Fuel - Wood |
8 |
FuelWood |
|
Fuel - Sand |
9 |
FuelSand |
This is not an option in MSTS |
Freight - General |
10 |
FreightGeneral |
This is not an option in MSTS |
Freight - Livestock |
11 |
FreightLivestock |
This is not an option in MSTS |
Freight - Fuel |
12 |
FreightFuel |
This is not an option in MSTS |
Freight - Milk |
13 |
FreightMilk |
This is not an option in MSTS |
Special - Mail |
14 |
SpecialMail |
This is not an option in MSTS |
As indicated above some of the load types are not supported generically by MSTS Route Editor, and therefore some text file editing may be required to support the inclusion of the non-MSTS load types into OR.
For a detailed description and example of how to add Loading/Unloading and Refueling points to a route see the section titled, Pickup Points for Loads and Refueling.
For a working example of Loading/Unloading and Refueling points see the section below, Load Variation Demonstration.
Key Parameters Used in Open Rails
The key parameters that define load animation in Open Rails are described on the following web page.
Standard Load Animation Parameters for WAG Files (updated June 2019)Wagon Definition
Whilst the
A static and dynamic worked example are provided in the animated test stock.
Static Load
As indicated above a static load will only be loaded when OR initially starts. OR will use the base
include ( ../ctn_test_static_animation_wagon.wag )
Wagon (
ORTSFreightAnims
(
MSTSFreightAnimEnabled (0)
WagonEmptyWeight(6.5t-uk)
FreightAnimStatic
(
SubType(Default)
Shape( ..\\common.Loads\\15ft_open\\15ft_3p_HumpSheet2.s )
Offset( 0, 0, 0)
FreightWeight( 9.0t-uk )
Comment ( No load compensation fitted - assume same braking force as empty)
FullMaxBrakeForce ( 19.43kN )
FullMaxHandbrakeForce ( 6.477kN )
Comment( Assumptions - speed - 60mph (100.0km/h), Friction Bearing, 2 axles, frontal area - 6.0m2, Wagon Weight - 15.75 ton (metric))
FullORTSDavis_A ( 358.37 )
FullORTSDavis_B ( 7.7739 )
FullORTSDavis_C ( 0.718740 )
FullCentreOfGravity_Y ( 1.8 )
)
)
)
Code Notes:
Dynamic Load
As indicated above a dynamic load will cna be load/unloaded at appropriately defined pickup points throughout a route. The known full and empty physics information is all obtained from the
include ( ../ctn_test_animation_wagon_coal.wag )
Wagon (
ORTSFreightAnims
(
MSTSFreightAnimEnabled (0)
WagonEmptyWeight(10.0t-uk)
EmptyMaxBrakeForce ( 29.892kN )
EmptyMaxHandbrakeForce ( 9.964kN )
Comment( Assumptions - speed - 60mph (100.0km/h), Friction Bearing, 4 axles, frontal area - 5.8m2, Wagon Weight - 10.16 ton (metric))
EmptyORTSDavis_A ( 580.71 )
EmptyORTSDavis_B ( 5.0148 )
EmptyORTSDavis_C ( 0.694782 )
EmptyCentreOfGravity_Y ( 1.41 )
EmptyORTSDavisDragConstant ( 0.0012 )
EmptyORTSWagonFrontalArea ( 62.5ft^2 )
IsGondola(0)
UnloadingStartDelay (5)
FreightAnimContinuous
(
IntakePoint ( 0.0 6.0 FreightCoal )
Shape(H_Coal.s)
MaxHeight(0.1)
MinHeight(-0.85)
FreightWeightWhenFull(26.0t-uk)
FullAtStart( 0 )
FullMaxBrakeForce ( 89.676kN )
FullMaxHandbrakeForce ( 9.964kN )
Comment( Assumptions - speed - 60mph (100.0km/h), Friction Bearing, 4 axles, frontal area - 6.2m2, Wagon Weight - 36.57 ton (metric))
FullORTSDavis_A ( 748.61 )
FullORTSDavis_B ( 18.0157 )
FullORTSDavis_C ( 0.838530 )
FullCentreOfGravity_Y ( 1.8 )
FullORTSDavisDragConstant ( 0.0005 )
FullORTSWagonFrontalArea ( 62.5ft^2 )
)
)
)
Code Notes:
Locomotive and Tender Definition
Locomotives and tenders are treated slightly differently to wagons. The main difference is that
To add dynamic load visual effects, such as coal load going up and down, firstly the coal load needs to be separately modelled for the tender, and the following paramter needs to be included in the tender
Where:
x = animation shape file,
y = maximum height of animation shape file,
z = minimum height of animation shape file.
It maybe necesary to set up an activity so that the fuel levels can be set at 0 and 100% in order to get the correct animation heights. Typically for a coal load this parameter will be included in the tender file, however for a Tank locomotive it will be included in the wagon section of the
The example locomotive setup for a locomotive and tender fitted with load variation is H6a Consolidation - #1499. Relevant specification information used for defining this locomotive can also be found by clicking on the link.
The following code block provides an example of the physics effects used for a locomotive or tender:
include ( ../USRA-Tender.wag )
Wagon (
ORTSFreightAnims
(
WagonEmptyWeight( 28.75t ) Comment( 57500lbs )
EmptyMaxBrakeForce ( 29.892kN ) Comment (Assume empty weight of 62.41t us)
EmptyMaxHandbrakeForce ( 9.964kN )
Comment( Assumptions - speed - 60mph (100km/h), Friction Bearing, 4 axles, frontal area - 12.075m2, Wagon Weight - 26.08 ton (metric))
EmptyORTSDavis_A ( 682.19 )
EmptyORTSDavis_B ( 12.8726 )
EmptyORTSDavis_C ( 1.446464 )
EmptyCentreOfGravity_Y ( 1.41 )
FreightAnimContinuous
(
FreightWeightWhenFull( 42.725t )
FullMaxBrakeForce ( 190.771kN ) Comment (Assume full weight of 71.475t us)
FullMaxHandbrakeForce ( 9.964kN )
Comment( Assumptions - speed - 60mph (100km/h), Friction Bearing, 4 axles, frontal area - 12.075m2, Wagon Weight - 64.841 ton (metric))
FullORTSDavis_A ( 929.27 )
FullORTSDavis_B ( 32.0042 )
FullORTSDavis_C ( 1.446464 )
FullCentreOfGravity_Y ( 1.8 )
)
)
)
Code Notes:
Picking Up Water from Track Trough or Pan
Typically the early steam locomotives had tenders attached that gave them an approximate range of 40 miles before they needed to stop to replenish their water supplies. These stops added to the overall journey times of the train. and as pressure was put on railways to speed up trains operations and reduce journey times, the idea of picking up water whilst on the move was developed in the UK, USA and France. This eliminated the need to use tenders with bigger water capacities on them. Hence the use of track water troughs, or water pans as they were know in the US was born. For a more detailed description of water troughs refer to this article.
Tender Water ScoopIn regards to the operation of the water scoop the train crew lowered the scoop whenever the train was over the trough, and provided the train was traveling at a sufficient speed (Usually in excess of 15 mph) water was forced up the scoop into the tender. The above diagram provides a representation of the arrangement of a typical water scoop.
The minimum speed was typically determined by the height of the water scoop above the pickup point ( the distance h shown on the above diagram). The amount of water picked up by the scoop was determined by the area of the scoop immersed in the water trough, and the length of time that it was lowered into the trough.
OR models this functionality using a default set of dimensions. If the modeller knows the dimensions of the locomotive that they are modelling they can enter the following parameters into the
The locomotive also needs to have a controller defined using the parameter
The table below indicates some of the typical dimensions for water sccops and troughs on different railway companies. These figures can be used as a guide if it is desired to customise the sccop dimensions in OR. Note that the water scoops used in the US were typically larger then those used in the UK. OR defaults to a medium sized scoop (somewhere between a US and Uk sized one). (Default - Width = 1ft, Depth = 3.5ins, Height = 9ft)
Railway |
Scoop Width (ins) |
Scoop depth below rail level (ins) |
Trough water surface above rail level (ins) |
Scoop depth in water (ins) |
|---|---|---|---|---|
London and North Western Railway (LNWR) |
10.0 |
1.0 |
2.0 |
3.0 |
Lancashire and Yorkshire Railway (LYR) |
10.0 |
1.0 |
2.0 (steel) |
3.0 |
Midland Railway (MR) |
10.0 - Approx 9in @ base and 11in at water surface |
0.75 |
1.5 (steel) |
2.25 |
London, Midland and Scottish Railway (LMS) |
10.0 |
1.0 |
2.0 / 1.5 |
3.0 / 2.5 |
Great Northern Railway (GNR) |
10.875 |
1.5 |
1.0 @ Werrington, Muskham (wood), 2 @ Scrooby (steel) |
2.5 / 3.5 |
North Eastern Railway (NER) |
11.0 |
1.0 |
1.25 / 2 |
2.25 / 3.0 |
Great Eastern Railway (GER) |
10.0 |
? |
? |
? |
Great Central Railway (GCR) |
10 |
0.5 |
? |
? |
London North Eastern Railway (LNER) |
10.875 |
1.5 |
As per GNR / NER / GER / GCR |
? |
Great Western Railway (GWR) |
11.875 |
1.0 |
1.5 (steel) |
2.5 |
BR Standard (inc Diesels) |
10.0 |
1.0 |
As per LMS / LNER / GWR |
? |
New York Central (NYC) |
14.0 |
6.5 |
-2.0 |
4.5 |
Pennsylvania Railroad (PRR) Atlantic (4-4-2) Locomotive |
12.5 |
? |
? |
3.5 |
Ouest / Etat / SNCF |
? |
? |
? |
? |
Water effects are also able to be configured in the wagon section of either the
A demonstration activty shows how this feature works, and the relevant pieces of stock used in this activity provide an example of how to set up this feature.