The Holocaust Historiography Project
Auschwitz, by J.-C. Pressac
Document 39:

Recapitulatory table of motor powers

[The figures are expressed in kW/HP and those underlined are those of the original documents]
DESIGNATION OF ROOMS Requirements as per correspondence of 3-12 February 194 Distribution I Distribution 2
Krema II Krema III Krema II Krema III
7.3/10 2 × [5.6/7-] =
7.3/10 11.2/15,3
Gas chamber
No 450
3.3/4.5 2.5/3.4 2.6/3.5 2.6/3.5
Undressing room
No. 550
2.6/3.5 2.6/3.5 2.6/3.5 2.5/3.4
RÄUME / Dissection, washing and laying out rooms
assumed to be
about IHP

N° 375
1.1/1.5 1.1/1.5 1.1/1.5 1.1/1.5
Furnace room
No. 550
2.6/3.5 2.6/3.5 3.3/4.5 2.6/3.5
Total ventilator
motor power
14.3kW/19.5HP 16.9kW/23.0HP 20.0kW/27.2HP 16.9kW/23.0 HP 20.0kW/27.2HP

(Reply to the argument in a letter from a revisionist)

Following the exchange of letters and telephone calls with a correspondent who doubts the reality of the gas chambers, I have extracted two of his arguments that appear to me valid.

Describing the ventilation system of Leichenkeller I [of the future Krematorium II as per the cross-section on drawing 933], he pointed out to me that the air entered through the upper orifices, then was extracted through the lower ones, and concluded:
"This arrangement is perfectly suitable if the room is used as a morgue: the air entering cools, becomes denser, and is extracted from the lower part.”
He then asked me to imagine:
"the situation in the LK 1 after the gassing of a large number of people: the corpses are heaped on top of one another; they block most of the air extraction orifices; the room is full of warm toxic gas; how can there be rapid and efficient mechanical ventilation? I would say that it is nor possible...”
These remarks mean that Leichenkeller I used as a gas chamber had a poorly designed ventilation system and in the case of large-scale gassings [3000 people in 210 m² according to Nyiszli, or 13.3 per square meter], the lower orifices being blocked ventilation would become impossible [a model visible at the Museum illustrates this “maximum” case, though there are probably no more than one thousand victims depicted].

The figure of 3000 is theoretical and exaggerated, but if we take it as correct, then so is my correspondent's hypothesis and the ventilation is blocked and cannot work.

What would the SS have done in the case of such an “incident"?

They would have proceeded in two stages:
1. Open wide the doors giving basement access through the north yard and those of the undressing room, whose ventilation system working at full power would prevent the basement being contaminated:

Before putting on their gas masks, the SS would have then ordered two to four members of the Sonderkommando to put on masks, open the gas chamber door and drag bodies out into the vestibule until several of the air extraction orifices had been cleared. Then the gas-tight door would have been closed again, the ventilation restarted, and to improve its efficiency all that was required was to open the Zyklon-B introduction covers, but not until that moment. After verifying by means of a gas detector that there was no longer any danger of hydrocyanic acid intoxication outside the gas chamber, operations would have resumed their “normal” course.
2. Once the gas chamber had been emptied, a squad of fitters or bricklayers would have fixed at the end of the chamber, in the southeast corner a steel duct of about 20 cm diameter and 2 meters high or built a brick chimney of about the same dimensions connecting with or protecting one of the lower air extraction orifices and enabling it to take in warm contaminated air from above. The time taken for the “repair” would not have been longer than an afternoon. Such an incident would not have interrupted the “operation” of the Krematorium. As the documents we possess at present make no mention of such work we can assume for the moment that the case of the “3000” never occurred, the number of victims from a convoy always being less than this.
The initial ventilation system of Leichenkeller I, which was designed for a basement morgue, is not a “definitive” obstacle to using the room as a gas chamber.