Holocaust deniers have been disputing this detail for a long time. The main critic of the "diesel story" is an American denier Friedrich Berg (his site is http://www.nazigassings.com/).
Berg strives to prove, through detailed technical discussion, that diesel engines cannot used for mass gassings efficiently. Therefore, there were no diesel gas chambers. Therefore, there was no Holocaust.
I'm not qualified to dissect Berg's technical arguments. Roberto may wish to post some details, as he has been dealing with Berg's arguments for years. Apparently, diesel engines can be used for gassings in stationary chambers with some tweaking, though it seems the same does not apply to gas vans. It also seems to me that it is simply not feasible to use diesel engines for gassings, even if they can kill, when one has access to petrol engines.
The point of this posting is that if Berg is correct about technical infeasibility of using diesel engines for mass gassings, this in no way constitutes an argument against the historicity of the gas chambers in which these engines were supposed to be used.
First of all, one must explore the source of the identification of homicidal engines as diesels.
The most prominent source is, of course, Kurt Gerstein's testimony. Or, rather, testimonies. His testimonies certainly contain the core of truth. Yet, they contain many implausible details and internal contradictions as well. One simply cannot take any detail of Gerstein's testimony and use it without corroboration - as has been done (unfortunately) by some historians. Christopher Browning characterizes Gerstein thus:
Many aspects of Gerstein's testimony are unquestionably problematic. Several statements he attributes to Globocnik are clearly exagerrated or false, and it is not clear whether Gerstein or Globocnik was the faulty source. In other statements, such as the height of the piles of shoes and clothing at Belzec and Treblinka, Gerstein himself is clearly the source of exaggeration. Gerstein also added grossly exaggerated claims about matters to which he was not an eyewitness, such as that a total of 25 million Jews and others were gassed. But in the essential issue, namely that he was in Belzec and witnessed the gassing of a transport of Jews from Lwow, his testimony is fully corroborated by Pfannenstiel. It is also corroborated by other categories of witnesses from Belzec.It is not even clear if Gerstein ever saw the engine himself. So Gerstein's testimony alone cannot be used to establish the type of the engine.
But what about Prof. Pfannenstiel's testimony? He traveled with Gerstein to Belzec, and later testified about the gassing he had witnessed. He told about the diesel engine which was used for gassings, and which he saw with his own eyes. Interestingly, he told about it without any imaginable coercion involved, to no less that a patriarch of Holocaust denial, Paul Rassinier, who described their meeting in one of his books. Here's how Rassinier relates the part about the engine:
My interlocutor told me that, upon being informed of the expected train, he decided to stay. Accompanied by Wirth and his S.S. aide, he again visited the little house that had been fixed up for exterminations, and he described it to me. It had a raised ground floor, and a hallway with three small rooms on each side, which he did not measure, but which he thought had an area of surely less than 5 x 5 meters, perhaps 4 x 5 maximum, and all of them were rectangular, not square. At the end of the hall was the room where the Diesel motor was located in the center on a cement base and a little below floor level. I asked about this motor and how it was connected up to exhaust outlets in each of the six rooms. It was a truck motor, about 1.50 meters long, a little less than 1 meter wide, and a good meter in height, including the concrete base. Its power he did not know; perhaps it had 200 horsepower, he said. I pointed out to him that it was said to have been a marine engine, and, therefore, it must have been much bigger if it had been built for a ship. "Surely not," he said. "it was a truck motor, at least its dimensions led me to visualize it on a truck." He remembered the number of cylinders, six in one row. As for the connection with the exhaust pipes, in order to proceed faster, he made a drawing for me, which showed that the motor exhaust was introduced into each room by means of a pipe that was connected to an outlet in the floor.Given that this testimony was given voluntarily, by an unsympathetic witness (just read his other comments to Rassinier; Pfannenstiel also wrote to Rassinier that fiction in Gerstein's report prevails over reality), we can be certain that it corroborates Gerstein's basic description about the Belzec gassing. It does not corroborate many details of this description, but it also mentions the diesel engine used for gassings. But, considering that Pfannenstiel was an outsider, and a hygienist, not a technician, one may suppose that he could have gotten the type of the engine wrong.
Yet another witness who testified about the diesel engine in Belzec was Karl Alfred Schluch. Carlo Mattogno quotes him in his Belzec book as follows (p. 68):
For the gassings an engine was started up. I cannot give a more detailed description of the engine, because I never saw it. I am not a specialist, but I would say that, judging from the sound, it was a medium-size diesel engine.This description speaks for itself.
So, the above testimonies for the type of engine at Belzec are not iron-clad evidence on this specific issue. There is also a testimony of Rudolf Reder, who described the Belzec gassing engine as running on petrol. Mattogno cites an early testimony of Reder, which is quite problematic in its description of the homicidal apparatus (if the translation is correct, that is), so Reder might not qualify as a good witness on this issue. But in any case, at worst we don't have any hard data about the type of engine. It could be either petrol or diesel engine. So Berg's technical arguments don't affect this camp in any way. That the witnesses might have gotten the type of engine wrong does not necessarily discredit the rest of their testimonies (this is decided on a case-by-case basis).
(I don't discuss Eichmann's submarine engine claim here, since Christopher Browning plausibly argues that it was not Belzec that Eichmann visited, as is usually assumed, but rather an experimental gassing site nearby. Eichmann's claim about the type of engine is only a hearsay, and is not worth much either way.)
Now let's move to Sobibor. Luckily, we have a testimony of the person who had personally installed a gassing engine there. It was SS-Scharfuehrer Erich Fuchs, who testified on April 8, 1963:
We unloaded the motor. It was a heavy Russian benzine engine, at least 200 horsepower. We installed the engine on a concrete foundation and set up the connection between the exhaust and the tube.
So, in case of Sobibor we have unequivocal evidence that the engine ran on petrol.
Now Treblinka. Jewish inmate Eli Rosenberg told in 1947 affidavit about "exhaust fumes of a single diesel engine". At least two Ukrainian guards - Leleko and Malagon - also said that diesels were used.
It is important to remember that, just as in case of Belzec, none of these people testifying about diesels were directly involved with them. So, in principle, they could have been easily mistaken. Especially when one considers that there was a diesel engine for generation of electricity, which could have been mistaken for the homicidal engine.
There are also testimonies about Soviet tank engine being used. Yankel Wiernik writes in A Year in Treblinka:
A motor taken from a dismantled Soviet tank stood in the power plant. This motor was used to pump the gas, which was let into the chambers by connecting the motor with the inflow pipes.Note that he did not say "diesel engine". Erich Fuchs claimed that his engine was also from a Soviet tank (though this was disputed by Erich Bauer, who said it was a Renault engine), and yet it was a petrol engine. In fact, quite a lot of Soviet tanks had petrol engines.
I have also seen claims that T-34 tank's engine was used. I have seen this claim ascribed to Kurt Franz, though I can't tell if the reference is true. I've seen deniers argue that since T-34 tanks had diesel engines, the Treblinka engine had to be diesel too. For the sake of the argument, let us assume that Treblinka engine was indeed from T-34 tank. Now, it is simply not true that all T-34s were diesels. Because of shortage of V-2 diesels in the autumn of 1941 it was ordered to implement the ways to install old carburetor engines M17-T in T-34 tanks (I. Shmelyov, "Tank T-34", Tekhnika i vooruzhenije, no. 11-12, 1998). Another author confirms that some T-34s had M-17, a powerful aviation motor, installed (E. Zubov, Dvigateli tankov (iz istorii tankostrojenija), 1991).
Now, if you visually compare petrol M-17 and diesel V-2, both used in T-34s (though the latter used in the majority of them), you will see why some people might confuse the two. Further source of confusion might stem from that incorrect belief that T-34s had only diesel engines.
As a general rule, the people who did not operate or install the engine could have been mistaken about the type of engine.
If the people who installed/operated the engines were to testify about them being diesels and Berg's technical arguments are true, that would present a problem. But we have already seen Fuchs testifying about a petrol engine. More information comes from German historian Peter Witte:
In this case even three former Gasmeister (“Gasmasters” / Erich Bauer, Erich Fuchs, and Franz Hödl), who must have really have known the facts, since they all killed with the same motor, confirmed in court that it was definitely a petrol motor. Bauer and Fuchs, having been professional motor mechanics, simply quarrelled during the trial about whether it was a Renault motor or a heavy Russian tank motor (probably a tank motor or a tractor motor) having at least 200 PS. They also disputed whether the method of ignition was a starter or an impact magnet, which diesel motors obviously do not have, being self-igniting...He adds:
Hödl reported that they once tried a Diesel motor for the the gas chambers, but it did not work!Witte's claims should be checked, of course, but in any case Berg's diesel arguments simply don't work for Aktion Reinhard(t) camps - the people that really mattered apparently testified only about petrol engines. All the witnesses who mentioned diesels would be simply mistaken, and there's nothing surprising or sinister about that.
Deniers also like to point to the two 1943 Soviet gas vans trials in Krasnodar and Kharkov. It was claimed by the Soviets that the gas van engines were diesels. Nick checked out the published English translations of trial transcripts (The People's Verdict), and found only one place where a witness mentions specifically diesel engine (p. 17, interrogation of accused Tishchenko). Given the Soviet propensity for tampering with the published transcripts, one should check the unedited version to see if it mentions "diesel" in this place. Anyway, one swallow does not make a summer, and Tishchenko wasn't even a gas van driver. The rest of the mentions were prosecution's statements, etc. - not the relevant kind of evidence.
Now let's see what other evidence we have, to establish the types of engines used in gas vans. Roberto supplies us with the following information: Zalman Levinbuck testified about the petrol engine ("The people are poisoned during the drive by gases and exhaust fumes that are created by the combustion of gasoline in the motor.", Kogon/Langbein/Rückerl et al., Nationalsozialistische Massentötungen durch Giftgas, p. 91); Friedrich Jeckeln "mentioned too high gasoline consumption" as one of the problems with gas vans (Christian Gerlach, Kalkulierte Morde, p. 767); Chelmno gas van driver Walter Burmeister testified about "Renault trucks with Otto engines" (i.e. petrol motors; Kogon et al.); SS-Oberscharfuehrer Walter Piller who served in Chelmno mentioned "gases that had been created by the gasoline motor" (Kogon et al., p. 138).
And it seems that most witnesses simply don't mention the engine type. But the preponderance of evidence is clearly on the side of petrol engines.
Finally, we know that some gas vans were Saurers. Denier Ingrid Weckert states:
What the writer claims with regard to the problems encountered during 'gassing' must be read in conjunction with Friedrich Berg's chapter in this volume. For as long as there is no proof that the RSHA's Saurer vehicles were not equipped with Diesel engines, as was normally the case, the gassing tales cannot be given any credence.Well, it's easy, then. Since we do know from extensive documentation and eyewitness statements that there were gas vans, and if we assume that Berg is correct, then Saurer gas vans were Saurers with petrol engines.
Also, Nick pointed out that old, 1920s models had petrol motors, so maybe old RSHA vehicles were converted. Otherwise, it is also possible that only Saurer chassis were ordered, and petrol engines were installed afterwards.
Be that as it may, it is clear that until deniers will dig up eyewitness statements of the people who were "in the know", who simply had to be informed about the type of engine (such as those who ran the engines in the camps, or gas vans and gas chambers inventors), and who mention the alleged successful use of diesel motors, they have no case whatsoever. They still haven't found any such statements. Thus, the "diesel issue" is moot.
Update: Nick provided me with the following document:
'Motor Wkw Pol. 51140 ausbauen und nach Lublin schaffen. Reparatur wird von hier veranlasst'I'm quoting it only to show that engines for the camps did not have to come from Poland proper - they could have come from any of the occupied territories.
SSPF Lublin an Aussenstelle Minsk, Stubaf Dolp, 1.11.41, GPD 438 (10.11.41), item 21, PRO HW 16/32
Update 2: Previous version of this article (including one of the updates) relied on two unreliable sources from a usually reliable site. Authenticity of these sources is in question, so I have removed references to them. The sources insisted on diesel engines in Treblinka, so their initial inclusion would not help my thesis in any way, so don't complain. Maybe I will tell a more detailed story about these sources some time...