Today we made the test of "forcing" the ladder in a new position that would not touch the SPRB flange.

• First we placed a small bluetooth shaker into PR rack, where we have our witness accelerometer (ENV_SNIFFING_ACC).
• Then Maria went near the ladder trying to move it.

The test is quite inconclusive: we did not had any 63 Hz bump variations in the accelerometers (ENV_EPRB_ACC_Y and ENV_SPR_ACC_Z) during the test (red square in the attached figure).
At the same time we noticed that there are bunches of cables that create a shortcut between the "ceiling" and SPRB vacuum chamber. We think these are also a shortcut.