A Quick look at the Polar Express Berkshire
 An inside view

A Great Smoker and Great runner!

Click on Images for larger view

Here is the Berk opened up.
Note the mounting screw locations

The loco has a clean look inside.

The motor has an optical tach controlled feedback for the cruise feature

The electronics for the motor driver, sound and smoke are all on this mother board assembly.
It has a clever plastic shield held on with locking tabs.

o remove the smoke unit you must remove the mounting bracket with these 4 screws.

Once the bracket is removed you can drop down the smoke unit to clear the smokestack and remove the unit towards the rear.
The smoke unit is the same design as one used in the AF Y-3. The only difference is the smoke exit ring on the top of the PC board and the mounting bossed have been milled off for clearance. Also two mounting bracket holes have been added to the bottom.
The motor appears to be the exact same one used on the Y-3. Part number 610-1154-130.

I recommend occasional lubrication of the fan motor by pulling off the impeller and using a drop of sewing machine oil on the upper shaft bearing.

The element is also the same 16 ohm as used in the Y-3 .