A November 13 online talk will reveal details of a novel water wheel that harnessed tidal power 130 years ago in Maine. The wheel, resembling a huge windmill fan, powered a grist mill and fertilizer factory in the little village of Bowdoinham in the late 1800s. This 27-foot-diameter wooden wheel designed by J. M. Kendall was submerged in the tidal Cathance River and drew energy from tidal flow, similar to the way tidal stream generators work today. The associated power train used reversible gearing to operate on both incoming and outgoing tides, producing useable power up to 18 hours a day.
Only five 2024 dates remain for touring the Van Wyck-Lefferts tide mill in Huntington, Long Island, N.Y. [Location on Google Maps.] The next available tour is Monday, August 19, and the last tour of the season will be October 18.
The Van Wyck-Lefferts mill is the best preserved 18th century U.S. tide-powered grist mill known to remain in its original location. It is also one of only two remaining U.S. tide mills with machinery and millstones intact. The site is maintained by the Lefferts Tide Mill & Preserve, who is continuing its multi-year fundraising and restoration campaign for the mill building and dam.
The mill site is accessible only by water, making it necessary to take visitors to the mill by boat. The tours are being offered by the Huntington Historical Society in partnership with the Lefferts Tide Mill & Preserve.
Advance registration is required. The tour cost is $20 ($15 for Huntington Historical Society members) and lasts 90 minutes. Since access to the mill is by boat, some climbing up and down steps and into and out of the boat is required. (Please note that neither the boat nor the mill is handicapped accessible and there are no bathrooms on site. This trip is not available to children under age 12.)
Mersey Tidal Power Project concept image illustrates the barrage system. (Image courtesy of Liverpool City Region Combined Authority.)
Two tidal energy projects that have been featured in the news recently nicely illustrate the two primary types of tidal hydropower generation systems: tidal barrage and tidal stream.
Tidal barrage systems are analogous to historical tide mills: seawater is impounded behind a dam at high tide; when the tide has partially ebbed outside the dam, water is released through sluices to drive turbines that generate electricity. Modern tidal barrage plants are typically able to generate power on both ebbing and flooding tides. Currently, there are only two large-scale commercial tidal power plants in the world. One is in La Rance, France, and the other is in Sihwa Lake, South Korea. Each generates approximately 250 MW, enough to power 250,000 homes.
Kittery Community Center. (Photo courtesy of OurKittery.com and Charles Denault.)
Last October’s Annual Tide Mill Conference was postponed because of a local emergency, but it has now been rescheduled for Saturday, May 4. The conference theme, “Harnessing Tides for Energy and Agriculture,” remains the same.
The May 4 conference will convene at the Kittery Community Center in Kittery, Maine, at 8:30 a.m. Eastern Daylight Time (12:30 UTC) for in-person and for online participants via Zoom conferencing.
Our friends at De Hollandsche Molen (The Dutch Mill, Molens.nl) informed us that Het Gilde van Molenaars (The Guild of Millers) in the Netherlands has made its English translation of Handboek Watermolenaar (Manual for Water Millers) available as a free PDF file on its website, GildevanMolenaars.nl.
The 350-page handbook (49MB as a PDF) is intended as a training manual for those seeking to work as millers. In the Netherlands, miller certification requires completing a water miller course and passing a national examination administered by Vereniging De Hollandsche Molen (The Dutch Mill Society), a process that typically takes two years. Learning what the craft of the miller entails, says the manual’s foreword, also gives the craft “a cultural and historical value.”
The manual covers history, technology, and operation of virtually all types of water-driven mills, but much of its content applies to tide mills. This makes it a worthwhile addition to the tide mill enthusiast’s digital library. The content is well illustrated with color photographs and clear diagrams throughout.
Italian Mariano di Jacopo (1382 – c. 1453) may have drawn the world’s first tide mill images. He was a versatile engineer and artist of the early Renaissance, whose style was later copied by Leonardo da Vinci and others. Known as Taccola (the Italian word for jackdaw, a relative of the crow) probably because of the shape of his nose, he created two volumes of drawings, notes and descriptions of many devices for hydraulic, milling and military purposes. These volumes were titled De ingeneis (1433, 1449) and De machini (1449).
These drawings do not show specific tide mills; they represent a good conceptual understanding the essentials of how water is controlled by sluice gates. The following Taccola sketch shows an open lift gate allowing water to flow into a mill pond and a simple vertical wheel (which looks very much like a horizontal wheel). No exit gate is shown.
