[GreenKeys] TTY Tape vulcanization query

[James A. Reeds]

Dear Greenkeyers,

I am a long-time lurker, and at last have a question to put to
this group.

I am editing for publication a 1944 report about a British radio 
intercept site, written by a visiting American, now in the National 
Archives.  He describes the teletype equipment used to send the 
intercept back to Bletchley Park.  One term he uses puzzles me; 
maybe someone on this list can explain what it refers to.

The relevant passage is:

   The equipment in this section consists of:
      1. Teletype perforating machines.
      2. Perforator duplicators.
      3. Perforator tape counting machine.
      4. 2. Perf. transmitting channels to Station X.
      5. Tape vulcanizing equipment.

The mystery (to me) is item 5.  What is "tape vulcanizing equipment" ?
(The "Station X" in item 4 is Bletchley Park, where the intercepts were
processed.)

Anybody have any ideas?  Many thanks in advance.

Jim Reeds
reedsj at dtc.umn.edu