The Second Leuchter Report

Published: 1990-10-01

This document is part of the Journal of Historical Review periodical.
Use this menu to find more documents that are part of this periodical.


In March of this year (1989), I was asked by Mr. Ernst Zündel of Toronto, Canada, to investigate three (3) alleged execution gas chambers and crematoria in Germany and Austria. These locations, allegedly operated by the Germans in World War II, were Dachau, in Germany, and Mauthausen and Hartheim Castle, both near Linz, Austria.

The findings of these investigations and forensic analyses at Dachau, Mauthausen and Hartheim were to result in an engineering report and forensic study on the efficacy of these aforementioned facilities to function as execution gas chambers. Although these facilities seem now accepted by many established historians to have never functioned as execution gas chambers, Mr. Zündel wanted to dispel any future doubts and scientifically prove beyond any question whether these facilities were or were not used, and if they could ever have been utilized, as gas execution facilities. Resultant to Mr. Zündel's direction, I undertook this scientific investigation and evaluation. On Sunday, April 9th of this year, I arrived at Dachau with the following team: Carolyn Leuchter as secretary/technician; Dr. Robert Faurisson, advisor and consultant; Mark Weber, historian and author of contemporary European history; Tijuda Rudolf, interpreter; Steven Devine, technician; Eugen Ernst, cinematographer, and Kenneth Ernst, assistant cinematographer. The following day, Monday, April 10th, we inspected Mauthausen and Hartheim Castle, near Linz, Austria. This report and my findings are resultant to these investigations conducted at Dachau, Mauthausen and Hartheim.


The purpose of this report, and the investigations antecedent to it, is to determine whether the alleged gas chambers at three (3) specific locations, one (1) in Germany and two (2) in Austria, specifically, Dachau, Mauthausen and Hartheim Castle, respectively, could have operated in any manner resulting in single or multiple gas executions. Although cognizant of the fact that many established historians presently seem to concur that none of these installations ever functioned as a gas execution facility, the author is also aware that immediately after American capture of these locations during World War II a mass gas execution function was ascribed to these facilities, an assertion which was widely published in the international mass media at the time. It is to eliminate any further doubt or question that this investigation was undertaken and this report written.

The purpose includes the investigation and on-site inspection of physical facilities, design of these facilities and a description of the alleged gassing procedures utilized at the alleged executions. The purpose also includes estimates of the maximum number of inclusions (persons) who could possibly have fit into these alleged gas chambers and estimated venting times. This purpose does not include a determination of any numbers of persons who died or were killed by means other than gassing, or as to whether an actual "Holocaust" occurred. It, further, is not the intent of this author to redefine "Holocaust" in historical terms, but simply to supply scientific evidence and information obtained at the actual sites and to render an opinion based on all available scientific, engineering and quantitative data as to the purpose and usages of the alleged execution gas chambers and crematory facilities at the investigated locations.


The principal investigator and author of this report is an engineer and a specialist on design and fabrication of execution hardware and specifically has worked on and designed hardware in the United States used in the execution of condemned persons and by means of hydrogen cyanide gas ("Zyklon B" gas).

The investigator has inspected the alleged execution gas chambers in Poland and is the author of the resort on these facilities: An Engineering Report on the Alleged Execution Gas Chambers at Auschwitz, Birkenau and Majdanek, Poland (1988), Samisdat Publishers Ltd. The author has been recognized by a Canadian court as an expert on gas chamber technology, and has testified as to the non-existence of execution gas chamber facilities at these sites.

The investigator has inspected the facilities at Dachau, in Germany, and Mauthausen and Hartheim Castle, in Austria, made measurements and taken forensic samples. Further, he purchased official printed brochures published and offered publicly for sale at the three (3) museum sites and reviewed this literature. He also reviewed the procedural literature on delousing with hydrogen cyanide ("Zyklon B") gas.


The scope of this report includes a physical inspection and quantitative data obtained at Dachau, Mauthausen and Hartheim, literature obtained at the three (3) museum sites, and a consideration of forensic samples taken at Mauthausen. For reasons explained below, no samples were removed from Dachau or Hartheim. Further, data on the design of U.S. gas chambers and the operational protocol utilized in gas executions in the United States coming from the investigator's own personal knowledge and experience in the field, as well as knowledge gained in the investigation of the alleged Polish gas chambers, were utilized in the production of this report. Additionally, operational procedure and equipment utilized at delousing facilities were considered. Utilizing all of the above data, the investigator has limited the focus of this study to a determination of the capability of the alleged gas chambers in question at Dachau, Mauthausen and Hartheim Castle to accomplish the mass murder (extermination) of human beings by the use of "Zyklon B" (hydrogen cyanide) gas.

Synopsis and Findings

After a study of available literature, examination and evaluation of the existing facilities at Dachau, Mauthausen and Hartheim Castle, with expert knowledge of the essential design criteria for gas chamber operation and the expert knowledge gained in the production of the previous study on the alleged gas chambers in Poland, the author finds no evidence that any of these installations, i.e., Dachau, Mauthausen or Hartheim Castle, frequently alleged to have been gas execution facilities, was ever utilized as such, and further finds, that because of the design and fabrication of these installations, they could not ever have been utilized as execution gas chambers.


The procedures involved in the study and forensic analysis which resulted in this report were as follows:

  1. A general background study of available material.
  2. An on-site inspection and forensic examination of the facilities in question, which included the taking of physical data (measurements and construction information), and a considered removal of physical samples (tile and mortar) which were returned to the United States for chemical analysis.
  3. A consideration of recorded and visual (on-site) logistic data.
  4. Data acquired on the previous study of the alleged gas chambers in Auschwitz I, Birkenau and Majdanek, Poland.
  5. A compilation of the acquired data.
  6. An analysis of the acquired information and comparison of this information with recognized and proven design, procedural and logistic information and the requirements for the design, fabrication and operation of actual gas chambers currently in use in the United States.
  7. A consideration of the chemical analysis of the materials acquired on-site.
  8. Conclusions based on the acquired evidence.


The Leuchter Report, which formed the basis of the author's expert testimony at the trial of Ernst Zündel, Toronto, Ontario, given on April 20, 1988, is a study of the existing alleged gassing facilities in Auschwitz, Birkenau and Majdanek, Poland. This report contains the definitive data for gas chamber application purposes for hydrogen cyanide, "Zyklon B." fumigation design and procedures, execution gas chamber design and protocol, U.S. gas chambers, medical and toxic effects of hydrogen cyanide, a brief history of the alleged German gas chambers with an emphasis on design characteristics, and a consideration of crematory technology, including a discussion of maximum cremation rates. Additionally, there is a discussion of forensic considerations of cyano-compounds and crematories.

The materials contained in the above paragraphs of the Leuchter Report (1988) are a necessary complement to this report.

The Sites: Dachau, Mauthausen and Hartheim Castle

These sites are considered separately and together, in that Dachau and Mauthausen have been at times described as camps which supplied prisoners to the Hartheim Castle site where they were allegedly executed.


The alleged execution facility at Dachau is located in a building called "Baracke X." This installation was erected in 1942 and contained a crematory consisting of four (4) retorts. It was constructed primarily as a replacement for the older and smaller two (2) retort crematory located nearby. The facility also housed a morgue, fumigation cubicles (delousing chambers), related work areas and a room identified by a sign over the door as a "Brausebad" (shower room). It is this shower room which has been alleged to be the gas chamber and which tourists today are informed was the "gas chamber."

The alleged gas chamber has an area of some 427 square feet and a volume of some 3,246.7 cubic feet It originally was a shower room but appears to have been modified sometime after Dachau's capture by the Americans. The present ceiling is some 7.6 feet in height and contains some seventeen (17) pseudo-shower heads, fabricated out of what appears to be soldered sheet zinc. Additionally, it contains some eight (8) recessed lighting fixtures which were/are not explosion proof. It also contains two (2) alleged gas inlet ports (dumps) with internal grates measuring 15.75 inches x 27.25 inches which are welded open to the outside. This alleged gas chamber also contains a ventilation port clearly added after construction. The walls are of tile and the ceiling of concrete painted white. There are two (2) 20.5 inch x 26 inch floor drains connected to the other floor drains throughout the building and the camp. It has two (2) doors with provision for gasketing, as do many European doors.

It appears from construction that the alleged gas chamber was originally a shower room, as found in all the other investigated camps. The pseudo-shower heads are fabricated from sheet metal of a cylinder and a cone with a sprinkler type head as found on a garden type watering can. The end is sealed and not threaded. They are not connected, nor are they capable of being connected to any piping system. They are designed to appear as functional shower heads when observed from below. The ceiling with the phoney shower heads seems to have been added at a time later than original construction. The ceiling is fabricated of poured concrete, cast around the pseudo shower heads. It is typical suspended-slab concrete construction. Document No. 47 of the 79th Congress, 1st Session, of the United States, includes an investigation of Dachau. In this document, the gas chamber is described as having a 10 foot ceiling containing brass fixtures for introducing gas into the chamber. The present ceiling, as noted, is only 7.6 feet high and has none of the gas inlet fixtures described in Document No. 47.

Directly over the shower room are the steam and heating pipes, which is consistent with good and standard design for supplying hot water to the shower area. These pipes cannot be seen in the shower room today. Their existence, however, can be confirmed by observing the pipes entering into the shower room area from an off-limits corridor behind the shower room and visible only from a rear window of the building. It is an inept and extemely dangerous design to put hot, high pressure steam pipes over a chamber containing potentially explosive gas. At one end of the chamber the ventilation port was clearly added. The ports allege to have been "Zyklon B" introduction ports, no different from apartment incinerator garbage chutes, were obviously added after the original tiling. Both these modifications are clearly discernable from the uneven replacement of the interior tiles and the exterior brick. At one end of the room there are two (2) recessed electrical boxes with grates, something which should not be in a room containing potentially explosive gas. There is no means for sealing the room to prevent gas leakage and there is no system for exhausting the gas after use or any suitable (40 foot minimum is standard) vent stack. The doors are not gas proof, or even water proof. They are only water resistant There is no system for evaporating (heating) or distributing a gas into or within the chamber. The use of the improperly designed '"Zyklon B" introduction port would prevent proper evaporation of the gas from the "Zyklon B" pellets because of insufficient surface area exposure. Most, if not all, of the "Zyklon B" pellets would remain in the dumping mechanism due to insufficient angular motion of the gas pellet dump.

On a sign posted witnin the alleged gas chamber, Dachau Museum officials state:

"GAS CHAMBER – disguised as a 'shower room'
– never used as a gas chamber."

An examination of the alleged gas chamber clearly shows, however, that this facility was constructed as a shower room, used only for this purpose. The modifications to the room, which include the addition of the ceiling, pseudo-shower heads, air intake and gas inlet ports, were made at a time much later than the original construction of "Baracke X" and the shower room, and for reasons and by persons unknown to this author. No samples were taken at this location due to excessively heavy tourist traffic inside the alleged gas chamber.

For the record, this alleged gas chamber would have held only forty-seven (47) persons utilizing the nine (9) square foot inclusion rule as accepted by standard engineering practice for air-handling systems. Without an exhaust system or windows, it would require at least one week to vent by convection. This estimate is based on American gas chambers requiring twenty (20) minutes to vent with two complete air changes per minute, and a minimum of forty-eight (48) hours to vent a fumigated building with an abundance of windows.

An inspection of the four (4) new crematory retorts at "Baracke X" revealed that, although fired, none of these ever experienced much use, if any. These retorts were coal fired.

After an in-depth investigation of the alleged gas chamber at "Baracke X," Dachau, this investigator, in his best engineering opinion, categorically states that this installation could not have ever been utilized as an execution gas chamber. It was in fact a shower room (Brausebad) as originally labelled by the Germans.


The alleged gas chamber at Mauthausen Concentration Camp was located between the hospital, the crematory and the jail. Like Dachau, it is generally considered by some established historians and the Revisionists to have never been utilized for executions.

The alleged gas chamber has an area of some 150 square feet and a volume of 1,164 cubic feet. It has a ceiling height of some 7.8 feet containing piping and working shower heads. It has a floor drain of some eight (8) inches by eight (8) inches and steam pipes on the north-west wall for heating. The walls are finished in ceramic tile. It has two doors and provision for gasketing, as do many European doors. It has an alleged gas vent in the ceiling of the west end of the northwest wall but the purpose of this alleged gas vent cannot be verified since the ground above has been repaved. Additionally, an adjacent room is alleged to have been a control room for inletting gas (apparently not solid "Zyklon B" but actual hydrogen cyanide gas). There is no hardware in place for this function nor is there any evidence of its removal. The museum officials are very confused and incoherent about the operating function, and offered a succession of varying explanations on how the gas was introduced into the chamber. It has been successively stated by museum officials that the gas was introduced: (1) through overhead shower heads; (2) through a shaft in a remote corner of the room; and (3) through a perforated pipe, which does not exist today. The lighting is not explosion proof but merely water resistant. There is nothing to indicate the alleged control room ever existed. The facility is entirely underground, as is the morgue, the hospital and the jaiL The facility also housed the area for the condemned prisoners where they were executed by shooting.

It appears from the construction that this facility was constructed as, and further was utilized only as, a shower room. The installation has no provision to prevent gas leakage, the lighting is not explosion proof, the floor drain would allow leakage into the sewer system and there is no provision for inletting gas or for exhausting the air gas mixture after an execution. Further, there are steam heating pipes (radiator) on the northwest wall of the chamber, which would most likely result in an explosion if hydrogen cyanide gas were deposited in the room. Additionally, all shower heads are working and the overall design is unquestionably that of a shower room.

Forensic Considerations at Mauthausen

Four (4) forensic samples were selectively removed from the alleged gas chamber at Mauthausen and returned to the United States for chemical testing. Detailed analysis was completed on each sample for both iron and cyanide in accordance with the standard procedures utilized in the prior testing of samples from Auschwitz I and Birkenau. Resultant to this testing and comparison with known test results for insoluable iron cyanide compounds, it is demonstrated that this alleged gas chamber facility has never been exposed to repetitive concentrations of cyanide necessary for execution: referencing the delousing chamber control sample No. 32 (from Birkenau) as having 1050 mg/kg, the greatest concentration found at Mauthausen was 32 mg/kg, indicating fumigation of the building at some point in its history. This clearly indicates that this facility was not a gas chamber.

Resultant to an in-depth investigation of this installation, this investigator has determined that this facility was not capable of conducting executions by gas. In the best engineering opinion of this investigator this facility could never have supported gas executions and was never utilized as a gas execution chamber.

Adjacent to this facility is the morgue area, which contains a refrigeration unit for cooling the cadavers. This morgue also contains a dissection room and a crematory, all adjacent and connected to the hospital. The existing crematory contains a furnace with one (1) retort. In an adjacent room, there are indications of another crematory furnace of one (1) retort which has been removed. This existing retort shows signs of considerable use, which is expected in a camp of this size with only two (2) retorts. Both units were coal fired.

For the record the alleged gas chamber would have held only seventeen (17) persons, utilizing the nine (9) square foot rule. Without an exhaust system, this investigator estimated that it would require at least a week to vent for the same reasons as explained for Dachau.

Hartheim Castle

This facility consists of a masonry room adjacent to a tower of a centuries old castle. This castle was donated by the monarchy to the mental health service of Austria and was also placed under the control of the German Government when it acquired control of the Austrian Government and the mental health service. The facilty had been utilized as a mental hospital and under German control it continued as such. Allegedly, mass gas executions were conducted at this location on prisoners transferred from Dachau and Mauthausen for this purpose.

The alleged gas chamber was a lower level room adjacent to one of the castle towers. This room has an area of 192 square feet and a volume of 1,728 cubic feet. It has a vaulted ceiling of some 8.9 feet at the highest point. The installation had one (1) door and one (1) window, although a rectangular aperture has now been made into an adjacent room. There are no facilities to inlet "Zyklon B" or evacuate the gas after use. The room now has been completely remodeled. It has recently plastered walls and ceiling. There are three (3) new floor surfaces, one on top of the other. Even the door has been changed to a modern conventional mental institution cell door with a shuttered view port. The window is alleged to have been original, but would leak gas if used for this purpose. Neither the door nor the window has any provision for gasketing. Allegedly, all gassing apparatus was removed by January, 1945. In truth, there was no gassing equipment in that the walls are very thick, as characteristic of castle architecture and construction, and not easily cut to accommodate the installation of gas vents or gas inlet ports. It and the adjacent room contain memorial plaques to those who allegedly died in gassings here. The castle is presently used as an apartment building.

It appears by construction that this facility would not lend itself for use as a gas execution installation, the walls being too thick for the installation of gassing equipment. Certainly, because of the construction, any changes would be visible, and not easy to conceal. There is no provision for a gas stack for evacuation of the gas-air mixture and no way to install one. The window would certainly leak, allowing large volumes of deadly gas to escape. No samples were taken at this location because of the extensive remodelling to the facility which decidedly would obscure any test results.

For the record, the alleged gas chamber would have held only some 24 persons, utilizing the nine (9) square foot rule. Without an exhaust system this room would require at least one week to vent (refer to Dachau).

Resultant to an in-depth investigation of this installation, this investigator categorically states that in his best engineering opinion this facility was not ever utilized for, and could never have supported, gas executions. The actual use of this room in unknown to the investigator. Based on a comparison with its mirror image on the other side of the facility, it could have been a store room.

There are no crematoria extant at this locaiton.

It is perplexing to note that the official museum literature states that Dachau and Mauthausen, both having facilities equal to, or better than those at Hartheim Castle, sent inmates to Hartheim for.gassing. It is unclear why this should occur since Hartheim's alleged facility would have been so difficult to construct, was so small and so distant from Dachau (200km). Based on all the available evidence it becomes abundantly clear that no gassing facilities ever existed at any of these locations.

Specialized Hardware: Non-existence

In all the author's investigations in Poland, Germany and Austria, hardware or constuction remarkable to gas chambers has never been found. There are no stacks of the necessary height, no ventilators, no gas generators, no intake air preheaters, no special paint or sealants on walls, floors or ceilings, no safety devices for the operators, and no coherent design consistently utilized throughout the alleged gas chambers. It is inconceivable that the Germans, having the highly developed technology utilized on the delousing chambers, would never have applied this technology to the alleged execution gas chambers.

Barracks X, Dachau

Figure 1: Barracks X, Dachau

Shower Room (Alleged Gas Chamber), Dachau

Figure 2: Shower Room (Alleged Gas Chamber), Dachau

Shower Room (Alleged Gas Chamber), Mauthausen

Figure 3: Shower Room (Alleged Gas Chamber), Mauthausen

Barracks X, Dachau

Figure 4: Alleged Gas Chamber, Hartheim Castle


After reviewing all the material and inspecting all of the sites at Dachau, Mauthausen and Hartheim Castle, this investigator has determined that there were no gas execution chambers at any of these locations. It is the best engineering opinion of this investigator that the alleged gas chambers at the above inspected sites could not have then been, or now be, utilized or seriously considered to function as execution gas chambers.

Prepared this 15th day of June, 1989, at Malden, Massachusetts.

– Fred A. Leuchter Associates, Inc.
Fred A. Leuchter, Jr.
Chief Engineer

Additional information about this document
Property Value
Author(s): Fred A. Leuchter , Robert Faurisson
Title: The Second Leuchter Report
Sources: The Journal of Historical Review, vol. 10, no. 3 (fall 1990), pp. 261-322
Published: 1990-10-01
First posted on CODOH: Nov. 14, 2012, 6 p.m.
Last revision:
Appears In: