Off and racing

[xcrosswitch]

Hi Everyone,
I didn't know whether to put this in scenario creation or problems. It's definitely a problem. Anyway, I have created a Free Roam scenario on the Trona route out at the Mitsubishi cement works. I have 3 locos in a lash up and a heap of cement trucks to build a consist. I have the 3 locos parked ready for work, but when I start the scenario they are racing away at top speed with the brakes on full. They eventually pull up and I can get on board and get going but I was wondering how to prevent this from happening. I made a Standard scenario based on the same set up and the loco lash up waits patiently where I set it up.
Any advice is greatly appreciated.

Cheers Rob K