...and while I'm at it: You've another 47 seconds to finish up and get back here before I gotta throw her in reverse...
Acting Navvy on the Marube @63kph and ~4km distance from a forthcoming train
Welcome to a future. Mankind has brought doom upon themselves, their cities have been flattened by war and weather, and most of the northern hemisphere is radioactive badlands.
After having helped their planet to cool down a tad, humans start emerging from their underground retreats to once again make the surface theirs.
Patching and recommissioning pre-war trains engines they reconnect and spread along the old rail infrastructure. Settling the, now temperate, equatorial regions and scouring the desolate northern ones for technology.
Due to the vast expanse & unregulated nature of these rail-networks, and the size, state & character of these post-war communities, there is no single organisation or group that could realistically control more than a small section of the network - huge parts of it are thus wild.
As a result of that, most trains don't go above speeds at which they can safely break, if there is something wrong with the tracks or an oncoming train. Spoorcaneers (rail-pirates) actively make use of these circumstances by keeping their trains short and quick in order to catch-up with booty or even overtake it.
Pirate trains are usually made up of a single engine and a multi-purpose boxcar. Some compositions feature another boxcar or a flatcar offering additional space for e.g. gun emplacements or expected special cargo. There are seldom trains with two ore more engines, as a second engine is of much more use driving a second, independent, train instead.
When boarding, the more adventurous pirates pull their trains up in parallel to their bounty - akin to the buccaneers of old. This provides more area to transfer valuables between cars and even allows to transfer bigger things.
Just in case. The above diagram is obviously not to scale..
Due to the nature of their business though, pirates need to be able to turn on their heels at any moment. Be that to escape the possible artillery of a train they preyed upon unsuccessfully, or to clear the tracks before an oncoming train smashes theirs to bits.
An example of the latter would be two trains moving towards each other, both at ~60kph. The pirate train can spot the oncoming train at ~4km distance (curvature, horizon). As soon as they can see the oncoming train they will have to think about reversing, yet they still need some time, give some ~30-45s, to clear their crew off the bounty train.
Q: How could a system be designed to allow reversing a train at high speed over such a short distance?
A good solution:
- is sustainable, track infrastructure and trains suffer as little damage as possible
- can turn quickly:
- the less time between speed -> stop -> speed, the better
- the less distance it takes between a full break back to starting speed, the better
- does work for higher speeds, being able to do this at higher speeds means being able to prey on faster trains
- makes use of as little engines as possible, engines are valuable and two independent trains are worth much more than one slightly faster train
This question is NOT about:
- finding solutions to alternative situations; an example is given in the body, please do not start changing things to fit your idea
- finding a workaround; switching tracks is a great idea, but it's not a solution to the issue at hand