This is a simple step-by-step guide on how to achieve the Powerhaul Prep Achievement in around thirty minutes.

Powerhaul Prep (Coupled to 1,000 Cars)

First you want to load a service. I selected the 'SD40-2 YN3b' locomotive and the 'U876 - B - Coal - Loading at Shaw Mine' service.

When the game has loaded, first sit in the Engineers Seat (if not already)

Next go to external camera mode. I personally chose camera three (number three on the keyboard)

Now using the arrow keys and mouse position the camera directly in front of a car.

Still in external camera mode locate the Coupler found between the Locomotive and the Car until the 'Coupler' prompt appears.

Simply keep left clicking switching between 'Coupler Locked' to 'Coupler Unlocked' and do this until the achievement unlocks. This process can be done in rapid succession if you time your clicks correctly.

If the locomotive or car gets widely separated simply move the loco back to the car.

While doing this, it is possible for the Car and Locomotive to derail prompting this message 'Service Failure - Vehicle Derailment'. Should this happen simply choose the 'Reply Service' option and repeat the process.

Make SURE that you are sitting in the locomotive as this will NOT work if your standing.