II D 3 a (9) NI. 214/42 G. RS.
Berlin, 5 June 1942
Conc: Technical adjustments to special vans at present in service and to those that are in production.
Since December 1941, ninety-seven thousand have been processed, using three vans, without any defects showing up in the vehicles. The explosion that we know took place at Kulmhof is to be considered an isolated case. The cause can be attributed to improper operation. In order to avoid such incidents, special instructions have been addressed to the services concerned. Safety has been increased considerably as a result of these instructions.
Previous experience has shown that the following adjustments would be useful:
(1) In order to facilitate the rapid distribution of CO, as well as to avoid a buildup of pressure, two slots, ten centimeters, will be bored at the top of the rear wall. The excess pressure would be controlled by an easily adjustable metal valve on the outside of the vents.
(2) The normal capacity of the vans is nine to ten square meter, The capacity of the larger Saurer vans is not so great. The problem is not one of overloading but of off-road maneuverability on all terrains, which is severely diminished in this van. It would appear that a reduction in the cargo area is necessary. This can be achieved by shortening the compartment by about one meter. The problem cannot be solved by merely reducing the number of subjects treated, as has been done so far. For in this case a longer running time is required, as the empty space also needs to be filled with CO. On the contrary, were the cargo area smaller, but fully occupied, the operation would take considerably less time, because there would be no empty space.
The manufacturer pointed out during discussions that a reduction in the volume of the cargo compartment would result in an inconvenient displacement of the cargo towards the front. There would then be the risk of overloading the axle. In fact, there is a natural compensation in the distribution of the weight. When [ the van is ] in operation, the load, in its effort to reach the rear doors. places itself for the most part on the rear. For this reason the front axle is not overloaded.
(3) The pipe that connects the exhaust to the van tends to rust, because it is eaten away from the inside by liquids that flow into it. To avoid this the nozzle should be so arranged as to point downward. The liquids will thus be prevented from flowing into [ the pipe ].
(4) To facilitate the cleaning of the vehicle, an opening will be made in the floor to allow for drainage. It will be closed by a watertight cover about twenty to thirty centimeters in diameter, fitted with an elbow siphon that will allow for the drainage of thin liquids. The upper part of the elbow pipe will be fitted with a sieve to avoid obstruction. Thicker dirt can be removed through the large drainage hole when the vehicle is cleaned. The floor of the vehicle can be tipped slightly. In this way all the liquids can be made to flow toward the center and be prevented from entering the pipes.
(5) The observation windows that have been installed up to now could be eliminated, as they are hardly ever used. Considerable time will be saved in the production of the new vans by avoiding the difficult fitting of the window and its airtight lock.
(6) Greater protection is needed for the lighting system. The grill should cover the lamps high enough up to make it impossible to break the bulbs. It seems that these lamps are hardly ever turned on, so the users have suggested that they could be done away with. Experience shows, however, that when the back door is closed and it gets dark inside, the load pushes hard against the door. The reason for this is that when it becomes dark inside the load rushes toward what little light remains. This hampers the locking of the door. It has also been noticed that the noise provoked by the locking of the door is linked to the fear aroused by the darkness. It is therefore expedient to keep the lights on before the operation and during the first few minutes of its duration. Lighting is also useful for night work and for cleaning of the interior of the van.
(7) To facilitate the rapid unloading of the vehicles, a removable grid is to be placed on the floor. It will slide on rollers on a U-shaped rail. It will be removed and put in position by means of a small winch placed under the vehicle. The firm charged with the alterations has stated that it is not able to continue for the moment, due to a lack of staff and materials. Another firm will have to be found.
The technical changes planned for the vehicles already in operation will be carried out when and as major repairs to these vehicles prove necessary. The alterations to the ten Saurer vehicles already ordered will be carried out as far as possible. The manufacturer made it clear in a meeting that structural alterations, with the exception of minor ones, cannot be carried out for the moment. An attempt must therefore be made to find another firm that can carry out, on at least one of these ten vehicles, the alterations and adjustments that experience has proved to be necessary. I suggest that the firm in Hohenmauth be charged with the execution.
Due to the present circumstances, we shall have to expect a later date of completion for this vehicle. It will then not only be kept available as a model but also be used as a reserve vehicle. Once it has been tested, the other vans will be withdrawn from service and will undergo the same alterations.
II. To Gruppenleiter II D
for examination and decision.