Here are some detail shots of the 642. Basically the whole design is a flat
car with a nose plow and four side blades added. A cabin at the back of the car
provides protection for the crew and an operating station.
|Front blade and small side blade.|
|The front and small side blades are interlocked and controlled by these two pneumatic cylinders. Here they are locked in the raised position with the cylinders lowered.|
There are two main blades. The blades appear to be solid iron but are made with a wood core and metal sheathing. The wood has some rot and eventually will require the blades to be torn apart and rebuilt.
|There is more control over the main blades. The various poles and cables allow adjustment of the angle of the nose and heel of the blade, plus how far it swings out.|
|This cylinder and the one on the other side control the nose of the blade.|
|The two pneumatic cylinders under the cab control the heel of the blade. The two small cables go to pins that lock the blade in place. Note the decking over the angle beams is missing and needs replacement.|
Northern Pacific Railway Museum NP 642 NP 642 Photo Pg 2