Stasi / Facebook / Big Data DAAD Day 25 – Automation in Stasi postal surveillance: Opening letters with sensitive materials using hot air

Heißluftgebläse. Credit: Museum in der Runde Ecke

The next artifact in my list is the “Heißluftgebläse”—a hot air blower constructed by the Stasi for opening envelopes and packages sealed with rubberized self-adhesive tape. Unlike the various steam methods the Stasi employed, which only worked on water-based glues and could potentially damage the contents of letters, this machine was used to focus hot, dry air directly to the flap in order to soften and release the adhesive.

Like other “hacked” machines constructed for postal surveillance the Stasi Operative-Technical Sector fashioned this blower using off the shelf, reused, and hand-made parts. In this case, they adopted a commercially-available vacuum cleaner to force air through a heating cartridge and down a steel tube towards a platform where workers laid envelopes. At the end of the tube there is a metal apparatus that could be used to focus the hot air and gently pry the envelope flap open. Impressively, the Runde Ecke index states this method be used to open up to 150 letters per hour.

Heißluftgebläse. April and July Credit: Wikepedia user Appaloosa

I’m particularly interested in the different representations of this machine. In these two photographs, both posted by the same Wikipedia user in 2008 just months apart, it appears there were two separate machines on exhibit. This is suggested by comparing the scratches on the base and stand. Yet, while they are clearly different, they are strangely positioned in exactly the same location—an exhibition at the Museum in der Runde Ecke which contains objects found in the Leipziger district administration for state security (BVfS)—with other obvious differences. In the 22 April photo (left) the vacuum cleaner is still attached, showing how the machine was originally used. But in the 27 July image the vacuum and tape have been removed. Was it needed for cleaning in the museum? Where could it have gone? There are additional small differences that point to these being distinct machines, the most noticeable of which is that a different bracket is holding the heating apparatus.

It’s thanks to deviations like this that the telling of the story of Stasi postal surveillance continues to evolve. Aesthetic decisions that seem inconsequential—like a museum staff member replacing the device with the yellowing tape with the one that doesn’t look as disheveled—change how we are able to perceive the past. Here, those moments which make the economic and material constraints the Stasi OTS experienced while hacking and iterating across their analog surveillance devices become less clear. While, thanks to the BTsU we are fortunate to be able to dissect and interpret the methods of the Stasi, it is not possible to collect everything. This unfortunately obscures the parallels with our 21st century hacker culture that, like the Stasi, have grown into immense organizations intent on perfecting and perpetuating their power through surveillance.

  1. Heißluftgebläse zum öffnen von gummierten selbstklebenden Briefen (Inventory no. 00020). Objekt- und Fotodatenbank Online im Museum in der Runden Ecke. Accessed June 13, 2017.
  2. BStU. Die Stasi und das Postgeheimnis. Accessed June 10, 2017.