>So if the coach weighed 48 tons and there were 200 coaches, does this mean that each loco was pulling a quarter of a ton?
Not if the coach is on level ground. The weight of the coach will act in a line running at 90 degrees to the rail on which the coach rests. The locos pulling the coach have to overcome the rolling resistance of the coach along the rail. This is determined by the coefficient of friction between the wheel and the rail and that is where my memory of applied mathematics runs out..... but I'm sure there is at least one member who can pick up the baton and run with it. I for one would welcome a "refresher" on this.
David
Not if the coach is on level ground. The weight of the coach will act in a line running at 90 degrees to the rail on which the coach rests. The locos pulling the coach have to overcome the rolling resistance of the coach along the rail. This is determined by the coefficient of friction between the wheel and the rail and that is where my memory of applied mathematics runs out..... but I'm sure there is at least one member who can pick up the baton and run with it. I for one would welcome a "refresher" on this.
David