monitoring and maintaining the tubes

While pneumatic tubes are celebrated for their efficient transportation of solid objects, sometimes the system blocks, clogs, and stops. In hospitals this can require urgent repair. The Otago Times reported on one incident of emergency surgery that was needed on a pneumatic system in Dunedin, where the piping was cut in several places to retrieve samples that had become blocked.

At the Hospital of the University of Pennsylvania, a pneumatic tube work committee meets biweekly to review problems and concerns. Their troubleshooting guide is laminated and blu-tacked near each sending/receiving station.

Pneumatic tube company Pevco have recently released an automated mobile email alert system for hospital engineers, while their Houston branch offers three day training for hospital engineers including hands-on maintenance scenarios.

Pneumatic tube engineers need to be creative. In her Cabinet article, Molly Wright Steenson writes how in Paris, in the times of the Poste Pneumatique, a tubiste would relieve blockages in the system by reversing air pressure and drawing the carrier back to the station. When this didn't work, the tubiste would try another tactic - fire a pistol into the tube which created a sound wave that allowed calculation of the location of the blocked item. Surgery of this system required sloshing through Paris' sewers to the area of blockage.

For those interested in clogging tubes and engineering creativity more generally, you will want to see Gregory Whitmore's wonderful video about blockages and all other kinds of monitoring, maintenance and mayhem associated with pneumatic tube systems on Roosevelt Island, New York. The video was made as part of the Fast Trash exhibition in New York in 2010 (read the pneumatic post about the exhibition here and for more about maintenance here). Here is a sneak peak:

Nature Abhors a Vacuum :: EXCERPT - "JAMS." from gregory whitmore on Vimeo.

All images in this post are stills from this video. See here for the longer version.