Derail Valley
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About this mod

Significant changes to better track with reality. Affects diesel locomotive traction, overheating, resource consumption, and more.

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Accurate throttle

The DE6 locomotives now have 8 throttle notches plus the idle setting, to better match the real EMD G16 prototype. Notch 1 engages the main generator, sending power to the traction motors, but does not increase engine RPM. Engine RPM as displayed on the DE6 tachometer now matches the actual EMD 567C prime mover.

It is no longer possible to use power settings "between" notches when using the keyboard for throttle control.

The idle position on the throttle levers is all the way forward. In reality this is so in an emergency the engineer can mash every lever forward to stop the train. Similarly, with this mod you can roll the mouse wheel up while passing around the control panel to set brakes and cut throttle.

Improved traction model

Diesel locomotives are constant power machines. As speed increases the amount of force delivered by the electric motors to the rail decreases proportionally.

It is substantially easier to overpower adhesion and slip the wheels at a standstill or low speeds. Using more than notch 2 when starting is almost guaranteed to lead to heavy wheelslip unless using sand, or running without a train attached.

Conversely, you will need much more throttle to accelerate at higher speeds. With a heavy load, don't be surprised to find your train barely accelerating above 40 kph even at full throttle.

Accurate resource consumption

Fuel and oil consumption can be adjusted via mod settings to suit the player's taste. A setting of "1" matches real fuel consumption figures for EMD locomotives.
Sand capacity now matches the 2 tons actually carried by SD locomotives.

Sander consumption and capacities reflects real equipment.

Accurate cooling

Diesel engine cooling is affected by the current temperature. You will see temperatures stabilize at a fixed point for a given load, instead of climbing steadily into the overheating range. DE6 fans engage and disengage at correct EMD specified temperatures.

The DE2 shunter is equipped with a thermostatically-controlled electric fan. The fan switch overrides the thermostat to force the fan to run at full speed, even when the engine is at colder temperatures. This can help keep temperatures down when approaching a steep climb.

Traction motor transition modeling

The DE6 will reconfigure its traction motors at moderate speeds to avoid overloading the main generator. This will cause a momentary loss of power while the motors are reconfigured.

Working ammeter

The DE6 ammeter has been reconnected to indicate the current flowing through traction motor #2. This is closely tied to the tractive effort exerted by the locomotive. Observing this meter closely will help optimize throttle settings to exert maximum traction while still avoiding wheelslip.

Improved junction switch handling

Running through a switch from the diverging side while the switch is set to the opposite branch will not automatically toggle the switch. Instead, this has a chance to damage the switch, which will make a loud sound shared with derailment. When damaged, a switch cannot be toggled manually, but instead has a chance to toggle on its own when cars pass over the junction. Take due caution to avoid switch splits and possible derailment!

Damaged switches can be repaired by paying a fee at the Career Manager.

The chance for switches to take damage, the chance for a damaged switch to change on its own, and whether to play the derailment sound when a switch is damaged is controllable from the mod options. Turning the chance to 0% will disable this feature.

Improved coupler handling (disabled by default)

Some of the curves on the DV map are too tight to be safely traversed by long cars, especially flatcars. Adjacent cars can bind, clipping into each other, and forcing each other off the tracks. This mod can disable collisions between coupled cars, reducing or eliminating the chance of damage or derailment.

This feature is disabled by default, but may be turned on in the mod options. It is experimental and may cause other issues. There is also an option to change the strength of couplers to adjust the forces needed to break a train in two.


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