Trestle Tables: The Shape of a Tree And the Engineering of a Skyscraper
Trestle tables have always looked notoriously spindly and rickety to my eye. Compared to a traditional apron table, there’s just not much material there. Add to the fact that they are normally quite lengthy, and it seems like you have a recipe for a wobbly mealtime.
But after inspecting a fair number of historical examples from the mid-1800s at Pleasant Hill, Ky., I started to reconsider the form. In December, I built a fairly large example based on proportions from a Shaker version , though the form itself is much older.
I eschewed some of the more modern joinery available, such as incorporating bed bolts. And I built the base using Southern yellow pine, an inexpensive construction timber. The first surprise: There’s very little wood needed for the design. I built the base using only three 2 x 12 x 8′. And I had a good deal of wood left over. My bill for the wood: $33.
Since December, my spouse, two daughters and two cats have given the table a thorough workout. And though the table weighs very little, it’s remarkably stable and sturdy. After staring at the thing for hours now, two things are apparent: First, the whole thing works like an I-beam in a skyscraper. The top, ends, ribs and the stretcher beneath the top all tie together to provide remarkable rigidity. This I-beam form prevents the top from sagging and racking along the length of the table.
But what about racking forces across the width of the top , like when you push away from the dinner table? The end assemblies seem slight, as they’re made from 3″ x 3″ sections. It turns out that these ends are like the trees they came from. The foot is like the root structure. The leg is the trunk. The top brace is the branches. If you do a good enough job of tying these together in a tree-like fashion, the result is quite sturdy.
Yesterday I started building another trestle base for the autumn issue of Woodworking Magazine. After snooping around in some dusty books, we developed a clever way to build the base with a minimum of effort and the maximum strength.