How To Fly Shunt

Overview

Introduction to railway braking and shunting methods, and detailed guide to fly shunting in Derail Valley.

Introduction

In this guide I would like to share my knowledge and perspective about a method which can be used to shunt efficiently.
You are obtaining more and more licences and the bonus times are getting shorter. It can mean a lot if you can perform your shunting duties as quick as possible.

This is my first guide ever on Steam, so feel free to share your thoughts with me.

Update: I changed some words which was censored out, but what should I do if this is the name of the part?

Momentum of Vehicles

The railway vehicles are rolling quite efficiently, because their mass are high compared to their rolling resistance. We are using this to haul hundreds of tons only with a shunter locomotive with few hundred kW power.
We can use this benefit for our own good during shunting too, which I will explain below. But first, let’s see some generic railway knowledge.

The Train Brake

The trains are heavy and require long distances to be stopped. But that’s not enough, we like to have them working any time.
The railway brakes are intended to be fail safe. This means that the train shall be stopped when there is a break in the coupling, e.g. the coupling screw tears apart due to overloading, or there is any failure in the system, e.g. the air is lost somewhere.
To monitor these events, the railways implemented continuous brakes. This means that the brake system is acting as one system through the whole train.
There are two basic types of continuous brakes used around the world:

• Vacuum brakes: Nowadays less common around the world, there are some railway operators with special requirements still using this type.
• High-pressure brakes: The standard principle in today’s railways.

There are several variants of high-pressure brakes, and there are slight differences between them. The main principle is always that the high pressure corresponds to the released state, while the atmospheric pressure corresponds to the emergency braking state, providing a fail-safe operation.
The common elements of the brake system are the following:

• Compressor: Produces the pressurized air.
• Main reservoir: Holds the pressurized air, because when releasing the brake, the demand is usually higher than the capacity of the compressor.
• Brake valve: This is the device which controls the pressure in the main pipe, releases air to the outdoor and doses pressurised air from the main reservoir.
• Main pipe: Goes through the whole train, feeds the distributed elements of the system with air and relays the pressure changes controlled by the brake valve. The continuity is established by the hoses, which can be disconnected easily in case of an incident, while at each end of the train it is shut by the coque.
• Brake cylinder: This is the actuator of the system, it pushes the brake calipers against the wheel or a brake disc.
• Distributor valve and auxilliary reservoir: Located in each wagon and their job is to provide air for the cylinders when the pressure is dropped. The auxilliary reservoir is refilled from the main pipe.

In Derail Valley
The game works in a simplified manner. It looks like to me that the main reservoir has no role in the braking (at least I never observed its gauge moving), and the compressor is working directly for the brake valve. Also, the system looks non-exhaustable, therefore I assume there are no distribution valves and auxilliary reservoirs implemented. That would require auxilliary release handles too though.
The operation of the system is similar to a spring brake system, which in real life are used for parking purposes only. In this case, the high pressure releases the brake against a spring, and as the pressure decreases, the more force of the spring pushes the calipers, so the higher will be the effect.
Even if it’s simplified, the principles are the same, so it’s okay for us. We can use this system to shunt creatively.

Methods of Shunting

In the real life, there are three basic methods of shunting:

• Flat shunting: The locomotive is always attached to the wagons, and applies its brakes. This is the basic and safest method of shunting, although it takes more time to achieve the same results.
• Fly shunting: The locomotive pushes the wagons, which are then rolling freely, until they are stopped.
• Gravity shunting or hump shunting: The locomotive pushes the wagons on a hill, which are rolling down on the other side. It requires a specially designed hump yard.

Fly shunting

During fly shunting, the vehicles are pushed by a shunter locomotive. The wagons can be disconnected from each other beforehand or during the process. In real life, the wagons are stopped with drag shoes, or less frequently there are built in rail brakes (beam retarders, jaw rail brakes, Dowty retarders)
Here is a video from the internet how does a drag shoe works:
There are three method of the fly shunting.

• Fly shunting with stopping: The shunter loco is stopped after each push.
• Fly shunting with pushing impulses: The shunter loco is not stopped, just slows down. It requires the couplers to be opened while the wagons are moving.
• Fly shunting with pulling: Very dangerous method of shunting. The shunter loco pulls the wagons, and when the coupler is opened, the locomotive speeds up. The switches are set between the loco and the wagons, directing the wagons into another track. Requires a lot of experience and teamwork.

In the game we are alone, therefore we can use the first method safely. Fortunately the teleport function help us making these movements possible.
Pro Derailers may try to use the other methods too, good luck for them.

How To Use The Train Brake During Shunting

We don’t have drag shoes in this game to stop the wagons in pre-defined locations, therefore we should use something else. We can use stationary wagons (which get damaged if the pushed wagon arrives too fast), which are properly braked in standing position, or we can use the train brake.
The advantage of the train brake is that it’s continuous. Therefore if the pipe is broken anywhere, or you let the pressurized air out, the brakes will be applied along the train, or at least on the segment which is connected together with the main pipe and the brake hoses.
You can even separate some the train into air segments, braking only parts of the train. In this case you may observe a warning light over the main pipe gauge indicating that there’s a problem with the coupling. (You get this too when you loosen the couplers but not disconnect them.)
In the game, you can use this approach to stop the wagons any time from basically anywhere on the train.
For example I use the brake coque of the last wagon (usually standing on it, if there is a place), to stop the train if it clears the switch, especially if I shunt with long consists, and I would be too far on the loco to see exactly the position of the last wagon.
The more air you release, the more braking force will be applied. If the locomotive is attached to the train, and you left the brake valve in released position, it will fill back the main pipe releasing the brakes. If you don’t have a locomotive attached, you should be careful because you don’t have air supply, so if you release the air, you won’t be able to release the brakes anymore, unless you connect it to a locomotive again.

How to fly shunt in Derail Valley

You can fly shunt the wagons in this game, as it allows each wagon to behave individually.
Fortunately in your area, everything, every switch, brake valve and coque and loco throttler remains in the same position as you left it. So you can just move around places and operate them one by one. (Useful for multi-headed hauling too.) The wagons will roll, so you can even observe the multiple stacks are rolling on the siding tracks next to each other.
During fly shunting you should push the wagons in stacks. You don’t have to push them one by one, it takes more time and doesn’t make sense since the wagons destination is the same track.

As I mentioned earlier, you can either let the standing wagons stop the pushed stacks, but there’s a risk of collosion if the speed is not reduced properly. If you don’t push it enough, you can have them stranded in the middle of the switch area, blocking the track.

I present two methods of fly shunting I usually use.

Method one: Decouple beforehand
You want to go for sure, and decouple the wagons before you push them.

• Decouple the wagons and separate the brake hoses. Make sure that you close the coques on the wagons you’d like to push before you disconnect the hoses, else the air will go away and the brake will be applied.
• Get into your loco, and start pushing the wagons. Gain quickly a sufficient speed, use sand if necessary. 20-25 km/h is usually enough, but it depends on the distance.
• Turn off traction and apply your train brake or individual brake on the locomotive, to make it stop with the rest of the wagons you’d like to push later.
• Quickly teleport to the first wagon. Enjoy the ride without the locomotive.
• When you are close to your target (end of track or standing wagons), start applying the brake. Note, that the more air you release the more brake force you will apply. You are not connected to a loco anymore, so use the air wisely to not stop too early, and try not hit the standing wagons too hard.

Method two: Decouple on the go!
You like the adventures, so you decide to decouple the wagons when they are already moving.

• Get into your loco, and start pushing the wagons. Gain quickly a sufficient speed, use sand if necessary. 20-25 km/h is usually enough, but it depends on the distance. Turn off traction before you go away.
• Teleport to the coupling where you’d like to divide the wagons. I recommend to stand on the wagon you want to roll to the siding. Close the brake ONLY coque on the wagon you’d like to have rolling. Loosen the coupler and disconnect the hoses.
• As you haven’t closed the coque on the loco side, the air will escape from there, stopping the locomotive and the rest of the wagons. You can enjoy the ride on the still rolling wagons though.
• When you are close to your target, apply the brakes similarly to method one.

Setting the route to the destination track is up to you, I usually do it before the push to make sure the stack goes to the right siding, it’s quite convenient with teleport. But you can set the points on the go too.

You can help yourself if you are able to stop the loco with the rest of the wagons before the switch selecting the destination of the next stack, so you don’t have to pull back for the next push. But it’s not too effective if you are too far, as you take too much time riding the wagons or you risk the stack to slow down and get stranded in the middle of the switch area.

At the end of the movements, especially if you have plans with the wagons, you may visit each track to push the wagons together. Although since the wagons are on their destination tracks, you can claim your salary for the job, and do this afterwards.

I hope you will enjoy trying out these methods.
Have a safe operation.