The Holocaust deniers claim: “The engineering of the alleged gas chambers is implausible. The doors, the ventilation, the introduction holes, the supposed Sonderkommando handling of bodies: every aspect of the system as described would have been a hazardous and impractical operation. Real gas chambers do not work this way.”
The deniers point to features of the Birkenau and Reinhard gas chamber operations and claim that as engineering propositions they are unworkable. The features cited typically include: the introduction of Zyklon B through holes in the roof of Crematoria II and III at Birkenau; the use of regular wooden doors rather than gas-tight engineering doors; the absence of separate ventilation systems for some of the chambers; the practice of having Sonderkommando prisoners enter the chambers immediately after the gassing to remove the bodies, supposedly without protective equipment; and the carbon monoxide source at the Reinhard camps (the engines of armoured vehicles or stationary diesel engines, which the deniers claim could not have produced lethal CO concentrations). Each of these objections has been examined in the proper engineering literature and addressed; the actual operations were workable, were conducted as the historical record describes, and have left engineering and physical evidence consistent with that record. Knowing the specifics of the design is what allows the denier objections to be evaluated.
The Birkenau gas chambers
The four large gas chambers at Birkenau (Crematoria II, III, IV and V) were each engineered for the SS by Topf and Sons (for the crematoria portion) and by the SS Central Construction Office (for the gas chamber portions and the integration). The design specifications are documented in the surviving Auschwitz Construction Office files, in the Topf and Sons correspondence with the Bauleitung, and in Pressac’s reproduction of the documents in his 1989 and 1993 monographs.
Crematoria II and III were paired underground installations with an above-ground crematorium hall. The gas chamber proper (the Leichenkeller 1, originally designed as a corpse cellar in the standard crematorium plan) was a 30-metre by 7-metre underground concrete room with a 2.4-metre ceiling, accessible from above ground via a stairway and from the crematorium hall via a corpse-lift. The Zyklon B was introduced through four wire-mesh column structures (Drahtsäulen, “wire columns”) that ran from above-ground introduction openings in the roof down to floor level inside the chamber, with the wire-mesh allowing the gas pellets to release HCN inside the chamber while keeping the pellets retrievable. The roof openings were closed with concrete-and-wood Zyklon-B introduction caps. The remains of the wire columns are physically present in the ruins of Crematorium II at Birkenau and have been examined by Pressac, van Pelt and others; the four roof openings are visible in the partially-collapsed roof slab. The introduction-cap remains are preserved at the Auschwitz museum.
The doors of the gas chambers were heavy steel-and-wood doors with peep-holes for the SS to observe the gassing; the Crematorium III door survived intact and is in the collection of the Auschwitz-Birkenau State Museum. The peep-holes had heavy glass and were protected on the inside by metal grids to prevent the victims breaking the glass. The doors had heavy gaskets to provide a sufficient seal during the gassing.
The ventilation system for Crematoria II and III consisted of mechanical extraction fans installed in the wall between the gas chamber and the corridor, drawing the gas-air mixture out and exhausting it through ventilation ducts to the chimney area. The Topf and Sons documents specify the ventilation throughput; the German firm Topf was experienced in industrial ventilation systems and the specifications are technically credible. The Sonderkommando entered the chambers approximately twenty minutes after the gassing was complete, after the ventilation had cleared the chamber to a level at which the surviving HCN was tolerable for limited exposure. The Sonderkommando did experience HCN-related health effects (the standard accounts include reports of dizziness, nosebleeds, and longer-term symptoms among Sonderkommando members), and the SS replaced Sonderkommando work units periodically to limit the cumulative exposure.
Crematoria IV and V were above-ground installations with smaller gas chambers configured differently, with the Zyklon B introduced through wall-level openings rather than roof columns. The smaller scale of these installations was reflected in their lower throughput.
The engineering specifications, the surviving physical evidence at the sites, the perpetrator testimony (Pery Broad, Hans Stark, Oswald Kaduk, Rudolf Höss), the Sonderkommando testimony (Filip Müller, Henryk Tauber, Daniel Behnamias, Shlomo Venezia), and the architectural-historical analysis (Pressac, van Pelt) are all consistent with each other.
The Reinhard chambers
The Operation Reinhard camps used carbon monoxide rather than HCN. The CO was produced by stationary engines: at Bełżec, an automotive engine repurposed as a stationary unit, with the exhaust ducted into the gas chambers; at Sobibór and Treblinka, similar arrangements. The engines were started, ran for the duration of the gassing (typically 15 to 30 minutes), and the chambers were then ventilated and the bodies removed by the prisoner Sonderkommando. The deniers have argued that diesel engines (which they claim were used) cannot produce lethal CO concentrations; the historical record actually records petrol engines at the Reinhard camps, which produce CO at much higher concentrations than diesel engines. The deniers’ confusion on engine type is the foundation of their objection. Petrol-engine exhaust at Bełżec and Treblinka, in the volume produced by the units actually installed, would have produced lethal CO concentrations within the gas chamber volumes within the time frames described; the engineering is straightforward.
The Reinhard camps’ engineering is documented in the perpetrator testimony (Stangl as Treblinka commandant, Pfannenstiel as the SS hygiene officer who witnessed gassings at Bełżec, Gerstein as the SS officer whose post-war report described what he had seen, the SS men prosecuted at the Düsseldorf Treblinka Trial, the Hagen Sobibór Trial, the Bełżec defendants), in the survivor testimony from each site, in the Polish post-war Commission investigations of 1945 to 1946 (with the surviving installations and the recovered material remains), and in the recent archaeological investigations referenced in the previous leaf.
The Sonderkommando handling
The Sonderkommando work was as the testimony describes: prisoners entered the chambers after partial ventilation, removed the bodies (which were typically piled near the doors, the strongest victims having attempted to escape the gas at the centre of the chamber), conducted dental work to remove gold teeth, separated valuables, and transferred the bodies to the crematorium muffles or to the burning pits. The work was traumatic, hazardous, and conducted under SS armed guard. The Sonderkommando prisoners were forced into the work and were periodically liquidated themselves; the surviving Sonderkommando members are the small number who happened to be on a current work team when the camp was liquidated, or who managed to escape. Their testimony is detailed, technical, and consistent across many independent witnesses who did not coordinate their accounts; the Müller, Tauber, Venezia, Gabai, Behnamias and other accounts agree on the operational features and disagree only on details of the kind that independent testimony characteristically disagrees on.
Why the claim is harmful
The claim is harmful because it presents engineering scepticism that does not engage the actual engineering record. The engineering record exists in the Topf-SS documents, the Pressac and van Pelt monographs, the surviving physical evidence at the Birkenau site, and the perpetrator and Sonderkommando testimony. The denier engineering objections (the wooden doors, the introduction methods, the ventilation, the Sonderkommando handling, the CO source) all dissolve on contact with the engineering record. The claim that the system was implausible relies on the listener not having access to the engineering record; with the record, the system is documented, examined and understood.
What were the actual specifications of the Birkenau gas chambers? What CO source did the Reinhard camps use? What does the surviving physical evidence show?
See also
Sources
- Jean-Claude Pressac, Auschwitz: Technique and Operation of the Gas Chambers, Beate Klarsfeld Foundation, 1989
- Jean-Claude Pressac, Les Crématoires d’Auschwitz: La machinerie du meurtre de masse, CNRS Editions, 1993
- Robert Jan van Pelt, The Case for Auschwitz: Evidence from the Irving Trial, Indiana University Press, 2002
- Auschwitz Construction Office archive (Zentralbauleitung der Waffen-SS und Polizei Auschwitz), Auschwitz-Birkenau State Museum
- Henryk Tauber, testimony to the Polish Commission for the Investigation of Hitlerite Crimes, 24 May 1945, in Auschwitz Inmates’ Manuscripts, Auschwitz-Birkenau State Museum, 1973
- Filip Müller, Eyewitness Auschwitz: Three Years in the Gas Chambers, Stein and Day, 1979
- Shlomo Venezia, Inside the Gas Chambers: Eight Months in the Sonderkommando of Auschwitz, Polity, 2009
- Rudolf Höss, Commandant of Auschwitz: The Autobiography of Rudolf Höss, World Publishing, 1959
- Yitzhak Arad, Belzec, Sobibor, Treblinka: The Operation Reinhard Death Camps, Indiana University Press, 1987
- Kurt Gerstein, “The Gerstein Report” (Tübingen, 1945), in The Pohl Case: Trials of War Criminals before the Nuremberg Military Tribunals, Vol. V, USGPO, 1950
- Wilhelm Pfannenstiel, post-war testimony, in the Bełżec investigations, Hessisches Hauptstaatsarchiv Wiesbaden
- Charles Gray (Mr Justice Gray), Judgment in Irving v. Penguin Books Ltd and Deborah Lipstadt, 11 April 2000
- USHMM Holocaust Encyclopedia, “Gas Chambers” and “Killing Centers”, https://encyclopedia.ushmm.org