Re: Reading Baldwin Drawings

This is a standard way of laying out sections on erecting drawings. The draftsman is assuming that the person looking at the drawing is quite familiar with locomotives, and is looking at these drawings all the time. Actually, you are looking at seven different sections of the locomotive.

On the far left is a front view of the locomotive. You are looking at the end beam and coupler pocket. The right side of that first pair is the section through the mid point of the cylinder block and exhaust nozzle.

Second from the left, the left side of that pair is a section at the front axle (the crankpin cap is counterbored to clear the crosshead guides), looking to the rear (you are looking into the socket in the crosshead for the piston rod). The right side of that pair is a section at the second axle (the crankpin has a nut sticking out of its end), looking to the rear (you are looking at the reverse shaft behind the Walschaerts link).

Third from the left is a section at the main driver, looking forward at the frame cross brace that is just in front of the third driving box.

The left side of the right hand section view is a section at various depths. It shows the inside of the front cab wall, the profile of the firebox at the front of the crown sheet, the burner sticking through a hole in the throat sheet, the oil valve on the backhead, the frame at the equalizer fulcrum for the trailing truck, and the trailing truck pivot pin support.

The extreme right hand section is a rear view of the locomotive.

These drawings were only used to show the relationship between the various components when erecting (or assembling) the locomotive, so there is little need for dimensioning. The blueprint package would also include hundreds of detail drawings of the various parts and were used to actually make those parts, and they would be extensively dimensioned, though even they would lack any tolerances or fits between parts. Again, the person making the parts was expected to be familiar with them and know what tolerances were needed.