Sail Ribs and Tailbones
More than simply an ingenious water pump, the windmill remains an elegant memento of simpler times.
By E. Dan Klepper
The afternoon heat reaches 102 degrees as I recline beneath the shelter of my tent’s mesh awning. After a week on the edge of the Chihuahuan Desert, I have concluded that the only activity a living creature can endure in this place is motionless rest in shade. I hear the call of an anhinga, the water turkey, somewhere above me. But I don’t bother spotting it because to do so would require that I move. Instead, I remain in torpor and listen to the bird’s eerie call beat against the swelter.
Yesterday, thin clouds gathered in the northwestern sky and drew a veil across the sun. When I woke from my afternoon nap, the recurring boom I had heard in my dreams emanated from a storm cloud the size of Texas, as if the entire state had evaporated then condensed above the remains. However, its great distance from my camp muffled the thunder, and its lightning struck only the faraway horizon. I avoided preparing for the possible onslaught, confident it was moving very slowly or perhaps not in my direction at all.
But after reading a few chapters from a book on predators, I decided to go ahead and prepare the camp for turbulent weather in case I was wrong about the storm’s speed and direction. The sonic boom of earlier seemed to be growing progressively louder if not in real volume then at least in my imagination. I gathered my books and papers from inside my large and leaky tent and loaded the rain-sensitive paraphernalia into my truck. I covered the camp kitchen and my mountain bike with a silver tarp and anchored the corners with rocks. I secured the tent window flaps with their tie-downs and removed the poles holding the awning aloft and lowered the mesh to the ground. With my precautions complete, I sat down to continue reading just in time to hear a distant windmill’s bitter complaint as it turned achingly, and decisively, against the gale.
Wind is one of the most powerful and destructive forces in an arid environment. Often, the only windbreaks in the desert are man-made and hold up for just a few generations before submitting to the elements. Desert winds, clear of obstructions, strip soil and desiccate vegetation. The whirlwind, a frequent manifestation of this turbulence, relishes the hot and dry conditions of the desert and actually requires them in order to form. Despite its harmless appearance, a whirlwind can achieve winds up to 90 miles per hour; enough power to detach a roof, collapse a building and permanently damage the wheel of a windmill or even bring one down. But desert winds can also facilitate life, assisting the same windmill to pump precious water up from hundreds of feet underground and quench an otherwise parched country.
Texans have always expressed a particular fondness for old windmills like the one that began to keen above my campsite. Windmills are the desert’s handmaidens and signal the possibility of life in landscapes seemingly barren of comfort or overwhelmed by isolation. Their integration into the Texas profile is so complete that it is difficult to imagine the land having ever been without them. But windmills only arrived in the state around 150 years ago, introduced and made useful by good old German and Dutch ingenuity.
The first Texas windmills were employed by European immigrants to grind corn and other grains just as they were used in the old country. But the traditional gristmill was expensive to build and labor-intensive to manufacture and operate. Timbers had to be fashioned into shafts and gears, the blades needed to be stretched with large canvas sails, and it was necessary to wrestle the heavy grinding stones into place. Once engaged, the mill was in danger of running afoul, often reaching excessive speeds that damaged the wooden parts or caused them to catch fire from the friction created by their movements. In addition to a lack of speed control, the mill could not respond to changes in wind direction. Therefore, it was necessary for the miller to reposition the sails whenever the wind shifted.
But just as the gristmill was being introduced to Texas, ingenuity was hard at work elsewhere in the country. Connecticut mechanic Daniel Halladay was busy creating a simple and relatively labor-free solution to accessing water in the remote countryside. He modified the wheel of a gristmill by making it a true radiating wheel of slats, added a tail and then attached a basic engine comprised of a fly wheel and a shaft. The entire system was mounted on a tower with four legs so that it could be positioned directly over a water well.
The design was so simple and successful that it was to change very little over the following century, and Texas, above all states, became its biggest fan. Hundreds of windmills were installed by the railroads and Texas ranchers throughout the state by the late 1800s. Upon the turn of the 20th century, the famous XIT Ranch alone employed 335 windmills across its vast acreage. At one time, the ranch even boasted having the world’s tallest windmill, a wooden monster at 132 feet high. It was ultimately toppled and destroyed by, naturally, the wind.
Simplicity and ease of operation allow the windmill to work endless hours over the span of several human lifetimes. Sometimes a windmill will rest for a day, or remain dormant through a decade, then respond and perform with certainty when reenlisted. A windmill requires very little in return for this lifelong dedication.
The secret of a windmill’s success is its point-blank mechanism. Wind pushes against the tail, or vane, and positions the wheel so that it faces the prevailing winds. Wind power then turns a set of angled fan blades, or sails, that comprise the wheel. This spinning motion rotates a gear assembly and the rotary motion is converted to a reciprocating motion as it lifts and lowers sucker rods, connected end to end, that are attached to the assembly. The number of rod sections required is determined by the depth of the water well. The rods fit inside a pipe that runs down the vertical shaft, or pipe casing, of the well and the bottom end of this casing is submerged beneath the surface of the water table. Fitted inside the subterranean end of this pipe is a valve, often made of brass. Attached to the end of the final sucker rod is another valve just like it, and both valves open and close as the rods are forced down or tugged up the pipe by the reciprocating motion. The suction created in the valve exchange eventually draws the water up the pipe to the surface.
To hear a windmill’s valve system working, press an ear against the drop pipe and listen. The stutter of water through the brass on the upstroke recalls the sound of nostrils preparing to snore. The downstroke echoes the drone of August insects settling into memory. It is the song of sleep and dreams.
Sometimes it’s difficult to coax a windmill back into service after it has been allowed to stand in disrepair for long periods of time. However, a dormant windmill may be strong-armed into action with nothing more than a release of the brake lever or, if particularly stubborn, a fist-sized rock and a good pounding. If the brake (or windlass) of a windmill has been released and the blades are turning but no water appears, it is possible that debris has lodged in the valves, preventing them from functioning properly. Hammering the pipe just above the casing will cause the deep end of the pipe and rods to shudder, typically vibrating the obstruction loose, and allow the valves to open and close as designed.
Despite a windmill’s fortitude, something eventually gives up — the gaskets wither and tear, the check valve sticks or hobbles, the gear teeth wear smooth, or the wooden sucker rods split. Occasionally, the well simply runs dry. On this day, unlike any other when the rods would have been pulled or the valve retooled, the vaquero laments “papalote no está bueno,” and the windmill’s brake lever is engaged with purpose one last time.
The pulling of a windmill brake makes a lazy sound and often requires the body’s full weight to lower the lever, drawing the brake cable taut and folding the vane and its tailbone flush against the wheel. Without the aid of the vane to respond to wind direction or the blades to drive the mill, the rods and valves cease to upstroke water, and the windmill’s use comes to an end. But, unlike most simple machines, a windmill begins a life of its own once our dependence on it ceases. It luxuriates in periods of long, contemplative pauses or, if broken free of the brake cable, it explodes in whim-driven zeal. Relieved of its labor, with blades at rest or free to swing, a windmill will finally sing with the full voice of the wind.
Which is what I heard from this particular windmill as the storm overpowered the valley and swallowed my campsite. Sand shotgunned sideways and the temperature dropped 11 degrees. Lightning struck the ridges and split black willows in the limestone draws. Heavy rain and sluggish hail pelted the roof of my truck as I sheltered in its confines, hunkered down and helpless as I watched my tent blow away. I glanced out the windshield as lightning illuminated the windmill. The blades spun with dizzying speed, but the tailbone groaned routinely, turning the wheel callously and careworn into the maelstrom.