AC's and Sand

Well, yes and no. Sand is an FRA REQUIREMENT, however with modern high horsepower locomotives, ever since the EMD 50 series line and development of "Super Series" wheel adhesion control system, the wheels are ALLOWED to "creep". Under extremely high tractive effort and ideal rail conditions, sand actually acts as a lubricant and REDUCES adhesion. Thus on 50 Series, 60 Series, 70/70MAC Series units (plus the 80 and 90 Series units), the "Super Series" adhesion control system (computers now) actually control the wheel creep and when sand needs to be applied. The Engineer now no longer controls "manual sand", as in the old days.

 You can still use manual sand on all the NS locos that I've been on.There's a push button marked manual that you have to hold down,but not a manual lever that stays over.

 And trust me,especially when flood loading sand is needed for traction and when starting out a tonnage train.

mackb4,

Thrust me, even though you can push the manual sand button, and hold it, the onboard computer still controls WHEN the sand will actually be applied to the rail.

 Not trying to say who's wrong or who's right here Hot Water,but we sand the rail for 100 car lengths backing in reverse,towards the loadout before we start loading at the mine at East Lynn,WVa.And it is a manual application that apply's the sand because I have to manually hold the button down .Otherwise the rail would not be pre-sanded before we start loading,which makes the task of flood loading much easier.

mackb4,

What you described is of course possible, mainly because the computer knows that you are below the "manual sand cu-off" speed, plus you are very lightly loaded and would have no need for "Super Series" wheel creep anyway. Plus, you are reverse sanding.

After many years of continuous software development learned from the very first computer control systems on the 60 series units, things work MUCH better on todays newest computer controlled units from both EMD and GE.