Walking around the rim of Indian Gulch (aka Trestle Glen), I poked my head up St. James Circle, ’cause that’s what I do. And there was the weirdest looking utility-hole lid: a square contraption made of two steel triangles, forged in Oakland by Phoenix Iron Works.
This odd access cover (to use the British term) was invented by William W. Taylor, of Cincinnati, in 1959. The idea was to avoid the noisy rattling when vehicles drive over warped or clogged lids. The U.S. Tax Court described it well in 1970:
The invention was advertised as “Silent Knight — The Modern Manhole Cover. The first and only truly progressive development in manhole covers in years.” A notable feature of the device was its square shape. The frame, which was to be installed at the mouth of the manhole and upon which the manhole lid was to rest, was square, and the lid was formed by two triangular halves, which were joined by iron rods to form a square. The sides of the lid were longer than the diameter of the manhole (to ensure that the lid could not fall through the manhole). As suggested by its name, Silent Knight was advertised as “silent and safe,” as well as economical. An advertising leaflet proclaimed: “Silent Knight products are made by foundries, North, South, East and West and sell at freely competitive prices.”
Here’s a closer look at the trademark.
In 1960 the National Noise Abatement Council gave Taylor its Achievement Award for the invention. Licensees in Canada and the UK produced them, and the design still has fans in places like St. John’s, Newfoundland.
I wish there were some outside my place.