Practical Carriage Building
Compiled by M.T. Richardson, Vol.1. 1891
That part of the carriage called the carriage part, Fig. 202, might with equal propriety be called the plebeian part, for it is that part which does the hard and dirty work, while the aristocratic body rides upon its willing shoulders. Like all plebeians, its first great need is strength—strength to bear the burdens and endure hardships; and this brings us at once to the consideration of the materials of which it is or should be composed—wood and iron. And allow me to say right here, in regard to wood, that the timber does not grow and never will grow too good for the running part of any vehicle, whether it is for business or pleasure, whether it has wheels or runners.
I include in the carriage part all the gearing which is back of, under, or in front of the body. Especially is good wood needed in whiffletrees, shafts, and poles.
Timber which is good in one part of a carriage may not be good in another. Poplar, or white wood, as it is called, makes good panels, but it would be good for nothing in the carriage part. There are certain qualities imperatively needed in the carriage part, namely, strength, stiffness, and durability. These are primary considerations. Timber must be found that is hard, that is stiff, that is strong. These terms are not interchangeable—they are not synonymous. Wood may be stiff, and yet be brittle and soft. This is the case with forest ash. It is stiff enough for the purpose, but it lacks hardness and strength. The best second growth ash and hickory, all things considered, is superior for this purpose, and it will not do to trust to the name alone. Hickory may" be good or may be poor; it may have the qualities which are needed, or it may lack them entirely.
There is nothing which equals American hickory for spokes, light felloes, whiffletrees, and neck yokes. The finest quality, when under great pressure, can be bent as shown by Fig. 203 (page 194), and even when cold will not break off.
When I said that all wood found under and in front of the body, I meant in all kinds of carriages, light and heavy. And certainly there is nothing, in my opinion, which equals our best hickory for light buggies. Ash will not take its place. Ash is excellent timber and has excellent qualities; but for light spokes, rims, perches, and axle beds we must have hickory.
For side bars I prefer other wood for the reason, or main reason, that while hickory is the hardest and the strongest, it is not the toughest. It has not that spring, that elasticity, that ash or locust or iron wood has. Iron wood seems to he very popular as timber for side bars, and I think justly so.
Soft wood will not do for a carriage part, no matter how stiff it may be. It will yield under the pressure of the bolt head and the clip. If it is a coach bar, and things are loose and shaky, it must be hard in order to hold the iron and the bolts. It must be stiff in order to keep its place, and it must be strong to sustain the strain that is placed upon it.
Twenty years ago hickory was almost exclusively used for side bars. The trouble with them was, not that they lacked toughness and strength, but that they would settle in hot weather.
I think the reason that they settled in hot weather was because they were used mostly in hot weather. Hot summer weather is very damp, and that dampness will affect wood, whether painted or not. I cannot really understand how it penetrates the paint; but it will. In the summer season we have a damp atmosphere, and it also affects the wood, making it more pliable or limber, the same as steam.
When you can find fine grained hickory of equal weight with coarse grain, it is better; and yet as a rule the coarser grained will be the heavier.
I would not recommend coarse grained hickory for spokes if the finer grained could be had. I should not reject a wood because it was coarser grained. If I was going to select the best piece that I possibly could get for exhibition, I should not take the coarse grained. I should take fine grained of good weight. I would, however, only be governed in part by weight. I would take the finer grained first for any purpose about a carriage.