A few questions reguarding diesel locos

A few questions reguarding diesel locos.

Does the roof mount exhaust have a cover to keep water from flooding the engine? I always wonder this. If the engine is running does rail or snow present a problem?

About the dynamic brake grid, does that have a device separating it from the compartment below or does the compartment get soak when it rains?


How about other locos like the F40 and P42

I have another question to add. Why are the DM30AC's so much quieter in electric mode then P32AC-DM's? The P32's are almost deafining to stand next to.

The only time rain and snow could present a problem is when the engine is shut down. In a perfect world, the engine before it is started would have the cylinder flash cocks opened and the engine turned over a few revolutions to blow and water or oil out of the cylinders. Newer EMD engines have a feature called "Engine Purge" and instead of blowing the engine out prior to starting, the engine rolls over on one starter motor for one or two revolutions and the second starter picks up. If there is water in the cylinder to such an extent that it fills the combustion chamber, one starter motor will not be able to turn the engine over and it stops cranking before damage is done to the conecting rod.
Before you ask, if you have low batteries, there is a switch called "EP 11" or (depending on model) EPB (eng purge bypass switch0. Both do the same function in bypassing the engine purge function and rolls the engine over on both starter motors.
On the dynamic brake grids, there is a shroud (sp) that protects the grids and blower from the manifold heat.

Emfinite the Genesis has more inverters to cool than a DE30 or DM30.
A DM/DE unit has 3 main inverters and a Auxiliary
A Genesis has 5 min inverters and an Auxiliary

the dynamic brake grids are mounted in airducts and drain to the sides of engine. the grids are not visible from inside the engine.

DRN: I like your avatar. What is that sphere thingy in the background? BTY, I snagged a Hancock air whistle from the rear of one of those FL9s that were being sent for rebuild to AC traction.

The sphere is some sort of gas storage tank (Natural gas???). The shape works really nicely under high pressure...