(Note this one has also failed and been repaired)
On an F1 Gearbox chassis, the front engine mounting should look something like this:
(Note this one has also failed and been repaired)
The photo below is of the same assembly from a different chassis where its been forcibly disassembled. The crack isn't healthy and was the reason for the disassembly:
When originally manufactured, only the centre bolt would be present holding the assembly to the rail. A known weakness is that over time it would crack straight through the chassis rail around the centre hole, why didn't it in this case? Since this is a known weakness, at some point someone has welded the assembly onto the chassis rail (hence the hole in the top of the photo which had to be made to get one half of the rail out). The presence of the weld explains the diagonal shape of the crack which no doubt originated from the weld. An attempt was made to repair the chassis with two further bolts either side of the center one. The repair was made without knowledge of the weld or the difference in shape of the crack. Now the presence of the weld is known, its no surprise the repair failed as the small length of tube inside the assembly collapsed after a couple of track outings.
A photo from the other side of the assembly:
This shows how close the extra bolt was to the crack and why it was never going to work:
Note the shape of the removed rail and the force required to do so!
For reference the assembly in question is the one to the left of the steering wheel in this photo:
