The Natural Philosopher wrote:
S Viemeister wrote:

It certainly sounds like that. I was amazed when I saw the photos - I had
assumed that the beams would be held by more than just their tapered shape,
and glue, but there was no sign of a bolt.

All the joints are in compression, so no need to cope with any shear
force at all.

Don't you mean "All the joints *should* be in compression". If it had
been in compression it's hard to see how it could have come undone.

I think if the metal tie bars that run across beneath the joints have
stretched or are insufficiently tensioned, then the joint could
potentially be in tension.

Probably don;t even need teh glue.

A reasonable flexible polyurethane glue should be entirely adequate.

But demonstrably not in this case.

Tim