line break in unequal bars

[Hans Roels]

Hello,

Does anyone know how to force a line break in the attached example 
with two simultaneous staffs in a different tempo? The problem is 
that there is no exact simultaneous point (between the unrelated 
tempi). A invisible barline with a break just before a split point 
(within the bar) doesn't work. I also tried adding an extra empty 
staff with spacing but also without any result...

Hans R

line-break-in-unequal-bars.ly
Description: Text document