John Cadman

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John Cadman is an engineer and inventor. Since 1999 he has researched one part of the Great Pyramid: the subterranean section beneath it. That section includes the descending passage, the well shaft, the grotto, the subterranean chamber, and the "dead end" shaft. In May 1999 he read excerpts from Edward Kunkel's Pharaoh's Pump and decided to build the lower passages at 1:48 scale. In April 2000 that model worked. He has kept building, running and filming models ever since. He describes the main one as a hydraulic pulse generator that also pumps water. As of 2026 he is still filming the original "Y2K" model.

John stresses that his theory and model are not the same as Kunkel's. He credits a line of researchers who shaped his work, including Edward Kunkel, Christopher Dunn (The Giza Power Plant), Stephen Mehler and Joe Parr. He appeared on the Den of Lore podcast with Danny Kerr and Doug Keenan in 2017. He was a guest again in 2018 and 2023.

• A modified hydraulic ram pump under the pyramid. John argues that the passages and chambers below the Great Pyramid form a hydraulic ram (water-hammer) pump. Water from a surrounding moat runs down the descending passage. The subterranean chamber turns that flow into strong, regular pressure pulses and lifts water. In his view the pyramid above isn't needed for the pump to run.
   
• Two forces, two models.
   
• Acoustic model: his "pulse generator." It is fiberglass and epoxy cased in reinforced concrete, weighs about 500 lb, and sits beside a creek with a pond as its reservoir. Its pulses can be felt through the ground at 20 ft and heard at 100 ft. It pumps water to several heights.
   
• Fluid-dynamics model: a chamber with a glass top and a glass east wall, fitted with 25 ink-injection ports so the flow inside can be seen. He uses it to show that the carved floor pattern in the chamber is deliberate.
   
• Every feature has a job. John assigns a role to each feature:
   
• The well shaft acts like a ram pump's standpipe and return line.
   
• The grotto works as an expansion chamber that limits the reverse pulse.
   
• The antechamber is an acoustic filter.
   
• The "dead end" shaft carries output and has a gate valve for tuning.
   
• The pit connects to a wastegate tunnel that runs toward the Sphinx area.
   
• Three functions. According to his write-up, the subterranean chamber supplies water, and possibly hydrogen, to the Queen's Chamber. It provides a pulse (he proposes 440 Hz) for the King's Chamber. It also supplies water, and possibly the pulse, to other structures on the plateau.
   
• "Heartbeat of the Sphinx." His original model beats in a double "heartbeat" rhythm rather than the steady rhythm of a normal ram pump. The loudest point on the wastegate line falls near the Sphinx area, which is where the name comes from.
   

In his words (short quotes)

• "It seems possible that the subterranean chamber can shake the whole pyramid and can elevate water to any part of the Giza plateau - pyramid peaks included." (Cadman, The Great Pyramid's Subterranean Chamber Hydraulic Pulse Generator and Water Pump)
   
• "The loudest node in wastegate line is around the Sphinx area. Hence, 'Heartbeat of the Sphinx'." (YouTube description, 2023)
   

John's working model is the experimental base under Danny's TRP model. The TRP paper says the water-hammer cycle in the lower assembly "builds on the demonstrated hydraulic pulse-generator function of the descending passage and subterranean chamber developed by John Cadman." It adds Doug Keenan's mathematical treatment from Cycles of the Pyramids. TRP takes the lower water-filled section John demonstrated and couples it to resonant water columns near 1 Hz and to a steam-flash thermoacoustic cycle in the upper chambers. The shared idea is a pyramid that moves water. John, Doug and Danny called themselves "The Power Trio."

Write-ups and articles

• The Great Pyramid's Subterranean Chamber Hydraulic Pulse Generator and Water Pump (part 1): His full illustrated paper, mirrored by Biblioteca Pleyades. It covers the ram pump, the models, the well shaft, the wastegate, gassing and his conclusions.
   
• Same paper, part 2: Covers the forces and models, the well shaft and grotto, and the compression wave diagrams.
   

YouTube: his channel @zostedguy ("John Cadman")

The channel also has many Black Russian Terrier puppy videos. Link to the pyramid videos below rather than to the channel front page.

• John Cadman's Great Pyramid "Hydraulic Pulse Generator" / water pump functioning model (since 2000): The best single overview. Recommended as the main embed.
   
• Great Pyramid subterranean chamber model (Y2K model) running (Aug 2026): The original April 2000 model with a new wastegate flow-through valve, shown starting remotely.
   
• Giza hydraulic pulse generator remote start (Aug 2026): Proof of concept for the pass-through wastegate.
   
• Great Pyramid - Heartbeat of the Sphinx (Apr 2026): The heartbeat-rhythm anomaly in the original model.
   
• Great Pyramid sound analysis Grand Gallery (Aug 2025): An analysis of the Grand Gallery's resonant frequencies.
   
• Compilation of Nikola Tesla, John Cadman and Chris Dunn (Aug 2023): A 30-minute compilation focused on the pulse generator.
   
• June 29, 2023 - Circulating and running Great Pyramid model
   
• Great Pyramid hydraulic pulse generator update and HPG running again with new reservoir
   
• Great Pyramid hydraulic pulse generator - March 2022: An 11-minute demonstration of pulse creation.
   
• Great Pyramid's hydraulic pulse generator model running - Dec 2019
   
• Great Pyramid's subterranean chamber model collecting gasses: Gas collecting in the chamber, which relates to his idea of an air/gas removal line.
   
• Pulse generator's waste gate valve (Oct 13, 2018)
   
• Great Pyramid full flow (Jun 2018): Kevan Balmer's CGI of the water flows in John's sub-chamber.
   
• January 23, 2018 Pyramid pump build
   
• Chris Dunn & Dr. Jack Kolle at pyramid pump: Visitors at the working model.
   
• Descending passage shock wave (Sept 6, 2016), Best audio clip of heartbeat pulse and Sub chamber sound sample (Aug 17, 2016): Audio recordings of the model.
   
• The Pyramid Boulder Build begins (2016), Pyramid pump vs ice and Great Pyramid subterranean chamber 2012-Feb-20
   
• Cadman's Hydraulic Pulse Generator and Great Pyramid sub chamber model - camera on top original model
   
• John Cadman interviewed by Rob Arnold
   
• Playlist: John Cadman - Great Pyramid - Subterranean Chamber: Compiled by Bruce Schwartz.
   

Podcasts and interviews

• Den of Lore EP. 034: Hard Pyramid Science w/ John Cadman (Apr 2017): With Danny Kerr and Doug Keenan, on the science behind the pyramid water pump.
   
• Den of Lore EP. 082: The Giza Power Plant & Pyramid Pulse Generator Demonstration (Mar 2018): Includes a live demonstration. Audio is on archive.org, and John also uploaded a copy to his own channel (4Bf_2i8Onzg).
   
• Den of Lore podcast #003: John Cadman: Great Pyramid's "Hydraulic Pulse Generator" (Mar 10, 2023): A two-hour interview that shows the ink-jet model. John also uploaded a copy to his own channel (L_PIU_msrq0).
   

X, Facebook, Instagram

• A post about John's work by @CTiberia_ (Oct 18, 2026): A third-party summary.