[FPSPACE] Function of the three 'cradle arms' holding Soyuz DM

[James Oberg]

Re: Soyuz hardware

Does anyone have any details of the function
of the three 'cradle arms' (at 120 deg separation)
that run from the neck of the OM/DM to the base
of the DM? 

Apparently they are support structure needed
during the SAS escape tower firing to hold the
DM in place under the 20G thrust of the SAS.

Among other questions -- how are they safely
separated in a normal ascent? Are they bolted to 
the launch shroud? Are they bolted to the DM or
merely held in place by 'hooks'?

During SAS firing, how are their latches
released at the base of the DM (simo with the
OM/DM separation, which presumably uses
the norminal pyrobolts used to jettison the OM
during normal descent.

These three arms are not the umbilical tray,
which is an entirely different structure.

The general Soyuz launch prep photos at
http://www.energia.ru/eng/iss/iss21/photo_09-24.html
clearly show the three 'cradle' arms', which have been 
installed late in the launch preparation

especially these:
http://www.energia.ru/rus/iss/iss21/im/photo_09-24-12.jpg
and
http://www.energia.ru/rus/iss/iss21/im/photo_09-24-13.jpg
and
http://www.energia.ru/rus/iss/iss21/im/photo_09-24-16.jpg
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